Outcomes reported in randomized controlled trials of traditional Chinese medicine for acute pharyngitis: a scoping review

Abstract

Purpose

Considerable variability exists in the outcomes reported in trials of traditional Chinese medicine (TCM) for acute pharyngitis, limiting the comparability and applicability of findings. This review aimed to systematically examine outcome selection, measurement, and reporting in these studies to inform the development of a core outcome set (COS).

Methods

A systematic search was conducted to identify randomized controlled trials evaluating TCM interventions for acute pharyngitis. Data on study characteristics, outcome domains, specific outcomes, measurement instruments, and assessment time points were extracted. Outcomes were categorized using an established outcome taxonomy, and a narrative synthesis was performed to evaluate patterns of outcome reporting.

Results

A total of 182 studies were included. Six broad outcome domains comprising 817 individual outcomes were identified. Substantial heterogeneity was observed in outcome selection, definitions, and measurement approaches, with most outcomes reported in only a small proportion of studies. Symptom- and sign-based outcomes were universally reported, whereas domains such as quality of life, economic evaluation, and long-term prognosis were rarely addressed. Standardized patient-reported measures and validated instruments were infrequently used. In addition, outcome reporting was often limited to short-term clinical effects, with minimal integration of safety, patient-centered, or health system–level outcomes.

Conclusion

Substantial heterogeneity in outcome reporting across TCM trials for acute pharyngitis hinders cross-study comparison and evidence synthesis. This review provides an evidence base for developing a Core Outcome Set (COS) to standardize future outcome assessments and improve trial transparency.

Keywords: acute pharyngitis, core outcome set, outcomes, scoping review, traditional Chinese medicine

Introduction

Acute pharyngitis is one of the most frequently encountered disorders of the upper respiratory tract and represents a common cause of outpatient visits among both pediatric and adult populations (Pellegrino et al., 2023a). In etiological terms, viral infection is responsible for the majority of cases, and the illness is generally self-limited, while bacterial infection contributes to a smaller proportion (Pellegrino et al., 2023a). Patients with acute pharyngitis usually present with throat pain and discomfort on swallowing, often accompanied by fever, erythema of the pharynx, enlargement or exudation of the tonsils, and cervical lymph node swelling (Vincent et al., 2004). Despite its usually short clinical course, which commonly resolves within approximately 1 week, acute pharyngitis can still adversely affect patients’ short-term wellbeing and has been associated with substantial antibiotic prescribing in outpatient settings (Malmberg et al., 2026; Catic et al., 2018). According to a recent review, acute pharyngitis contributes to approximately 2%–5% of ambulatory visits in children and remains a major indication for antibiotic use in pediatric practice (Malmberg et al., 2026; Pellegrino et al., 2023b). Although the overall prognosis is favorable, a small subset of patients may subsequently develop suppurative complications, including peritonsillar abscess, otitis media, and sinusitis, underscoring the need for prompt assessment and appropriate management (Hedin et al., 2023).

Given the substantial clinical burden of acute pharyngitis and the ongoing need to reduce unnecessary antibiotic exposure, traditional Chinese medicine (TCM)-based therapeutic strategies have attracted increasing clinical and research attention in China (Yan-ning et al., 2025; Lin et al., 2024a). Modern TCM management of acute pharyngitis is usually guided by syndrome differentiation; in both clinical practice and research, Chinese patent medicines are commonly employed, while compound herbal prescriptions also remain widely used (Yan-ning et al., 2025; Lin et al., 2024a; Rong et al., 2024). Accordingly, outcome assessment in this field has become increasingly multidimensional and can be organized into domains such as Symptoms/Signs, Physical and laboratory examination, Economic evaluation, Quality of life, TCM Syndrome, and Safety outcomes (Jianxin et al., 2021), rather than relying solely on a single composite overall response measure (Bossuyt et al., 2026). Recent consensus work in China has further emphasized standardized syndrome classification, scoring rules, and efficacy evaluation methods for adult acute pharyngitis, which may improve comparability across future TCM studies (Yan-ning et al., 2025). In the present study, the TCM interventions under evaluation include marketed Chinese patent medicines, hospital-prepared formulations, individualized herbal prescriptions, and related therapeutic approaches (Liu et al., 2025; Fan et al., 2025; Lin et al., 2024b).

An increasing number of clinical studies and evidence reviews have examined traditional Chinese medicine (TCM) interventions for acute pharyngitis, including Chinese patent medicines, hospital-prepared formulations, compound herbal therapies, and individualized prescriptions (Fang et al., 2024; Ma et al., 2021). However, evidence synthesis remains limited by heterogeneity in outcome reporting, definition, and measurement, as well as by variation in syndrome differentiation, intervention strategies, comparator selection, and efficacy criteria across studies (Shi et al., 2007). This heterogeneity may be reflective of differences in the focus, scope, purpose, and setting of TCM interventions for acute pharyngitis, together with the tensions investigators face between comprehensive outcome assessment, study feasibility, and statistical power. Clinical recommendations are derived largely from evaluation of the medical literature, with randomized controlled trials (RCTs), particularly the synthesis of data from multiple RCTs, generally considered to provide the highest level of evidence (Braga et al., 2025). Such synthesis can, however, be difficult when similar therapeutic effects are assessed using non-uniform definitions, instruments, or reporting approaches, which in turn reduces comparability across studies and limits the interpretability of the available evidence (Zhang et al., 2023). In addition, outcome selection and evidence interpretation should not rely solely on the perspectives of clinicians and researchers, as patients, caregivers, and healthcare professionals may prioritize different outcomes and forms of evidence (Devane et al., 2025).

A Core Outcome Set (COS) represents an agreed minimum collection of outcomes to be measured and reported across all clinical trials in a defined healthcare area (Williamson et al., 2012). Beyond the minimum required outcomes, researchers may additionally measure and report other outcomes that are particularly pertinent to the scope of specific studies. Developing and applying COS within a particular clinical domain can reduce heterogeneity and bias in outcome reporting while also improving research efficiency (Williamson et al., 2017; Chalmers et al., 2014). The development of COS can enhance consistency and comparability among clinical trials, thereby increasing the value of trial findings for systematic reviews and meta-analyses, while also helping to reduce selective outcome reporting (Kirkham et al., 2017). The development of a COS generally follows a multistep process, beginning with a systematic or scoping review to identify outcomes reported in randomized controlled trials (RCTs), which provides an important basis for subsequent COS development (Williamson et al., 2017).

In 2023, a network meta-analysis coupled with data mining synthesized the published evidence on Chinese patent medicines used for acute pharyngitis (Keyan et al., 2023). Moreover, a Chinese-language systematic review published in 2017 evaluated traditional Chinese medicine interventions for acute pharyngitis (Mingsan et al., 2017). As COS development generally starts with identifying candidate outcomes for measurement, this review offers an important empirical starting point for future COS development in this area (Young et al., 2019). However, to our knowledge, no published review has systematically examined the broader spectrum of outcomes measured and reported in randomized controlled trials of traditional Chinese medicine for acute pharyngitis, nor the frequency with which these outcomes are reported; rather, existing reviews have primarily evaluated the efficacy and safety of particular interventions (Lin et al., 2024b; Ma et al., 2021). Therefore, the present scoping review was conducted as the first step toward developing a core outcome set for randomized controlled trials of traditional Chinese medicine for acute pharyngitis, with the aim of summarizing the outcomes reported in these trials (Williamson et al., 2017).

Materials and methods

Methodological framework

This scoping review was structured according to the foundational methodological framework proposed by Arksey and O’Malley (2005) and further informed by the Joanna Briggs Institute (JBI) guidelines. The process comprises five stages: (1) identifying the research question; (2) identifying relevant studies; (3) selecting eligible studies; (4) charting the data; and (5) collating, summarizing, and reporting the results. The optional sixth stage (consultation) was not undertaken in this review, as stakeholder engagement will be conducted during the subsequent Delphi survey and consensus process for core outcome set development. Finally, this review is reported in accordance with the PRISMA extension for Scoping Reviews (PRISMA-ScR).

Registration

A systematic scoping review methodology was employed because it is particularly useful for systematically identifying and mapping the available evidence and for summarizing how research has been conducted in a given area (Munn et al., 2018). In addition, the Core Outcome Measures in Effectiveness Trials (COMET) Handbook recognizes scoping reviews as a valid approach for identifying existing outcome knowledge during COS development (Williamson et al., 2017).

This scoping review was registered with the COMET Initiative (registration number: 2,601). Established guidance for the conduct of scoping reviews was followed (Alexander et al., 2024), and reporting was undertaken in accordance with the PRISMA extension for Scoping Reviews (PRISMA-ScR) (Tricco et al., 2018). As this study involved the identification and synthesis of outcomes reported in published randomized controlled trials, rather than the collection of individual patient data, trial registry records, or other human participant data, institutional review board approval was not required.

Search strategy

We systematically searched four English-language databases (PubMed, Web of Science, Embase, and the Cochrane Library) and four Chinese databases (CNKI, Wanfang Data, VIP, and SinoMed) from database inception to 30 September 2025. The search strategy combined controlled vocabulary terms, including MeSH and Emtree terms where applicable, with free-text terms for acute pharyngitis, traditional Chinese medicine, and randomized controlled trials (RCTs), using Boolean operators. The full PubMed search strategy is provided in Table 3 and was adapted for the other databases.

To identify prespecified outcomes, we additionally searched ChiCTR, ClinicalTrials.gov, and the WHO International Clinical Trials Registry Platform (ICTRP) for relevant trial registration records. Prespecified outcomes were extracted from eligible registration records and compared with the outcomes reported in the corresponding published articles.

Study selection

All retrieved records were exported to Microsoft Excel for management and screening. Title and abstract screening and subsequent full-text assessment were independently conducted by two reviewers (Pang and Li) according to the predefined eligibility criteria. Disagreements were resolved through discussion and, when necessary, consultation with a third reviewer (Zhang). Records were retained for full-text assessment when eligibility could not be determined based on the title and abstract alone.

Inclusion and exclusion criteria

The inclusion criteria for studies were:

• Any randomized controlled trial conducted in any country.
• Participants diagnosed with acute pharyngitis, regardless of age, sex, ethnicity, or care setting.
• Studies evaluating traditional Chinese medicine (TCM) interventions for acute pharyngitis, including Chinese patent medicines, hospital-prepared formulations, compound herbal medicines, individualized herbal prescriptions, and other oral or drug-based TCM therapies.
• Interventions delivered alone or in combination with conventional treatment, provided that the TCM component could be clearly identified.
• Studies comparing TCM interventions with placebo, no treatment, usual care, conventional medicine, or other active treatments.
• Trials reporting at least one clinical, symptomatic, laboratory, safety, or other outcome related to acute pharyngitis.
• Any duration of treatment or follow-up.
• For studies with duplicate or overlapping data, only the latest publication or the report providing the most complete information was retained.
• English language and Chinese language

The exclusion criteria for studies included:

• Non-randomized or quasi-randomized studies, observational studies, case series, case reports, reviews, editorials, letters, commentaries, study protocols, and conference abstracts without full-text data.
• Studies not specifically involving acute pharyngitis, or those including mixed upper respiratory conditions when data for acute pharyngitis could not be extracted separately.
• Studies focused on non-pharmacological traditional Chinese medicine interventions, such as acupuncture, moxibustion, cupping, massage, or acupoint stimulation.
• Studies in which Chinese medicine was combined with other treatments and the independent effect of the herbal intervention could not be determined.
• Studies evaluating prevention, rehabilitation, mechanistic exploration, pharmacology, animal experiments, or in vitro research rather than clinical treatment effects.
• Studies enrolling patients with other major throat-related diseases or specific infectious conditions that could confound the assessment of acute pharyngitis outcomes.
• Studies with unavailable, incomplete, or non-extractable outcome data.
• Articles published in languages other than Chinese or English.

Data extraction

Following the recommendations of the COMET Initiative (Williamson et al., 2017), a Microsoft Excel–based data extraction form was developed. The first four included studies were used for pilot testing by two independent reviewers (Li and Pang), and discrepancies were checked through comparison. Once the extraction form was finalized, the same two reviewers independently recorded outcomes exactly as reported in the original articles in order to preserve transparency (Williamson et al., 2017). The extracted information comprised the study title, study start date, study completion date, recruitment status, study objectives and/or hypotheses, type of randomized controlled trial, country of recruitment, study setting, summary of the intervention, summary of the comparator, participant eligibility criteria, sample size, participant age, reported primary and secondary outcomes, outcome measurement instruments, outcome definitions, assessment time points, publication links, and details of the principal investigator and sponsor. When no link to a related publication was available, we searched for peer-reviewed articles using trial titles and keywords related to the lead author across the eight bibliographic databases described above. To ensure transparency, two independent reviewers additionally extracted verbatim any further relevant data from both linked and non-linked publications (Williamson et al., 2017).

Data standardization

During outcome standardization, internationally and nationally recognized authoritative medical terminology standards were consulted, including SNOMED CT, MeSH, relevant clinical practice guidelines, the Chinese Traditional Medicine Subject Headings, and the National Standard of the People’s Republic of China—Clinical Terminology of Traditional Chinese Medicine Diagnosis and Treatment. For TCM-related outcomes, relevant national or industry standards were preferentially used to avoid ambiguity caused by non-standard terminology. Based on the expression and content of each outcome term, standardization was performed while preserving the original meaning. This process included correcting typographical errors, harmonizing synonyms and alternative names, standardizing English abbreviations, splitting or merging outcome terms where appropriate, clarifying specific referents, and combining identical outcomes under standardized labels (Table 4).

Data analysis

In the present study, narrative synthesis was first applied to organise the included studies according to their design characteristics, reported outcome indicators, and measurement methods, while the COMET taxonomy served as the overarching framework for classification (Williamson et al., 2017). This approach was adopted to provide a transparent overview of outcome reporting and to reduce the influence of inconsistent or selective outcome reporting on subsequent evidence synthesis (Kirkham et al., 2010). Considering the distinctive features of traditional Chinese medicine, the outcome indicators were further refined and assigned to corresponding domains according to the seven-domain TCM classification framework developed by Professor Zhang Junhua and colleagues (Jianxin et al., 2021). In the classification stage, indicators specific to TCM were initially mapped onto the 12 COMET-recommended outcome categories and were subsequently organised by functional characteristics into seven domains: TCM disease and syndrome, symptoms/signs, physical and chemical examinations, quality of life, long-term prognosis, economic evaluation, and safety events (Jianxin et al., 2021; Williamson et al., 2017).

During the conceptualisation stage, two researchers worked collaboratively: Pang conducted the initial extraction and provisional classification of the indicators, while Li reviewed and merged indicators with similar definitions or conceptual overlap. The indicator domains and their definitions were then further revised by a multidisciplinary steering group, which included experts in COS development and senior scholars from relevant disciplines, through several rounds of consensus-based discussion until a final consensus was established (Kirkham et al., 2017). Statistically, the reporting frequency of each indicator was summarised using descriptive statistics, and phi coefficients combined with hierarchical clustering heatmaps were employed to further investigate the relationships among indicators and their distributional patterns.

Regarding the assessment of measurement properties, no quantitative appraisal of the measurement characteristics reported in the included studies was conducted at this review stage, as the objective of this review was to identify and classify outcomes rather than to select outcome measurement instruments (Gorst et al., 2020; Prinsen et al., 2016). Moreover, although COSMIN offers methodological guidance for evaluating PROMs (Mokkink et al., 2018), no universally accepted appraisal framework is currently available for all TCM-specific outcome measures, particularly syndrome-related indicators (Zonghai et al., 2022).

Results

Search results and study selection

A total of 6,235 records were identified through database searching. After the removal of 2,240 duplicate records, 3,995 records were retained for title and abstract screening. Of these, 2,248 records were excluded because they did not meet the eligibility criteria. The remaining 1,747 full-text articles were assessed for eligibility. During the full-text review, 1,565 articles were excluded for the following reasons: ineligible population (n = 1,204), ineligible intervention (n = 168), ineligible study design (n = 178), non-extractable outcome data (n = 5), duplicate or overlapping data (n = 7), and unavailable full text (n = 3).

Specifically, excluded populations mainly involved patients with other respiratory or throat conditions that could not be clearly separated from pharyngitis. Ineligible interventions primarily consisted of external TCM therapies outside our predefined scope of oral TCM treatments. Additionally, studies with ineligible designs were largely non-randomized trials or animal experiments. Through this rigorous screening process, a highly relevant subset of 182 studies strictly meeting the inclusion criteria was finally identified and included in the review. Details of the study selection process are presented in the PRISMA flow diagram (Figure 1).

FIGURE 1 PRISMA diagram of study selection for inclusion into the review. (Figure not reproduced here; see the original article.)

Study characteristics

The 182 included studies enrolled a total of 25,230 participants. Across studies, the sample size varied from 40 to 756 participants, and the median sample size was 105 participants (IQR, 78–160). Based on the intervention forms described in the included studies, we grouped the TCM interventions into six categories for descriptive analysis. Marketed Chinese patent medicines (standardized, commercially manufactured herbal formulations approved for clinical use by regulatory authorities) were the most frequently investigated intervention type, accounting for 133 studies (73.1%), followed by individualized prescriptions (herbal formulas tailored to individual patients based on traditional syndrome differentiation principles) in 26 studies (14.3%) and hospital preparations (in-house herbal formulations prepared and dispensed within specific medical institutions for internal clinical use) in 15 studies (8.2%). Empirical formulas (fixed herbal prescriptions developed based on clinicians’ experience rather than individualized modification) were evaluated in four studies (2.2%), whereas investigational new Chinese medicines (novel herbal products under clinical investigation that have not yet received regulatory approval for routine clinical use) and combined regimens were each reported in two studies (1.1%).

To provide a clearer overview of the distribution of interventions, Figure 2 presents a hierarchical treemap of the five most frequently reported specific interventions within each category. Among marketed Chinese patent medicines, the most commonly reported were Shufeng Jiedu capsules (7, 3.8%), Ertong Qingyan Jiere oral liquid (6, 3.3%), Lanqin oral liquid (6, 3.3%), Ganjie Bingmei tablets (5, 2.7%), and Qingyan dropping pills (5, 2.7%). Within the category of individualized prescriptions, Qingrun decoction (3, 1.6%) was the most frequently reported, followed by modified Gancao-Jiegeng-Shegan decoction (2, 1.1%), modified Shufeng Qingre decoction (2, 1.1%), modified Qingyan Chubi decoction (2, 1.1%), and Qingyan Lige formula granules (2, 1.1%). For hospital preparations, Yanhouqing lozenges (2, 1.1%) represented the leading intervention. Empirical formulas included Chuihou powder (1, 0.5%), Huanglian Qing Drink Soup (1, 0.5%), Yinshe lozenges (1, 0.5%), and Zizheng Dihuang decoction (1, 0.5%). Combined regimens comprised Kangfuxin combined with Dual-material Houfeng Powder (1, 0.5%) and Yinqiao Powder combined with Qingkailing injection (1, 0.5%). Investigational new Chinese medicines included artificial bear bile powder capsules (1, 0.5%) and Banzhilian total flavonoids capsules (1, 0.5%). The detailed compositions of these multi-component preparations are provided in Supplementary Data Sheet 1.

FIGURE 2 Hierarchical treemap of the five most frequently reported specific interventions within each category. (Figure not reproduced here; see the original article.)

As shown in Figure 3, treatment duration was generally short among the included studies. The most frequently reported treatment course was 3–5 days, which was used in 119 studies (63.0%), followed by 6–7 days in 56 studies (29.6%). Longer treatment durations were relatively uncommon, with 8–14 days reported in six studies (3.2%) and 15–30 days in three studies (1.6%). Five studies (2.6%) did not provide information on treatment duration. Overall, the majority of TCM interventions were administered within 1 week.

FIGURE 3 Distribution of treatment duration among the included studies. (Figure not reproduced here; see the original article.)

Intervention codes: No.1, Shufeng Jiedu capsules; No.2, Ertong Qingyan Jiere oral liquid; No.3, Lanqin oral liquid; No.4, Ganjie Bingmei tablets; No.5, Qingyan dropping pills; No.6, Qingrun decoction; No.7, modified Gancao-Jiegeng-Shegan decoction; No.8, modified Shufeng Qingre decoction; No.9, modified Qingyan Chubi decoction; No.10, Qingyan Lige formula granules; No.11, Yanhouqing lozenges; No.12, Chuihou powder; No.13, Huanglian Qing Drink Soup; No.14, Yinshe lozenges; No.15, Zizheng Dihuang Decoction; No.16, Kangfuxin + Dual material Houfeng Powder; No.17, Yinqiao Powder + Qingkailing Injection; No.18, Artificial bear bile powder capsules; No.19, Banzhilian Total Flavonoids Capsules.

Outcome domains

Based on the seven-domain TCM classification framework (Jianxin et al., 2021), 817 individual outcomes were extracted from the 182 studies included in this review and classified into six broad domains, as summarized in Table 1. No eligible outcomes could be mapped to the long-term prognosis domain; this domain was retained in the framework to preserve its completeness and to highlight this evidence gap. Ten eligible trial registration records were identified. All prespecified outcomes in these records were reported in the corresponding published articles; therefore, extracting outcomes from trial registries did not change the candidate outcome list, which remained at 817 individual outcomes. Some published articles also reported additional outcomes beyond those prespecified in the corresponding registration records.

The most frequently reported outcome domain was Symptoms/Signs (n = 182, 100%), reflecting the central role of symptom assessment in acute pharyngitis trials. All included studies reported at least one outcome within this domain. Physical and chemical examination was the second most commonly reported domain (n = 47, 25.8%), followed by TCM Syndrome (n = 34, 18.7%). Security event outcomes were reported in 15 studies (8.2%), while Economic evaluation was addressed in nine studies (4.9%). Quality of life was the least frequently reported domain, identified in only two studies (1.1%), despite multiple related measures being reported within individual trials (Table 1). The mean number of outcome domains per study was 1.62 (range 1–4; median = 1, IQR = 1). The study reporting the widest range of outcome domains included four domains.

Figure 4 presents the distribution of outcomes across the six predefined domains using a Sankey diagram. Overall, outcomes were predominantly concentrated in the Symptoms/Signs domain, indicating that clinical studies mainly focused on symptom relief and overall therapeutic response. Within this domain, clinical efficacy was the most frequently reported outcome (168,20.6%), followed by sore throat (77,9.4%), fever (44,5.4%), pharyngeal congestion (35,4.3%), dry and burning throat (26,3.2%), cough (23,2.8%), pharyngeal redness and swelling (17,2.1%), dry throat (16,2.0%), thirst (15,1.8%), VAS (10,1.2%), time to recovery (10,1.2%) and foreign body sensation in the throat (10,1.2%). Outcomes classified as others within this domain also accounted for a substantial proportion (137,16.8%), reflecting considerable heterogeneity in symptom-related outcome selection. The second largest domain was Physical and chemical examination, in which inflammatory and immune-related indicators were commonly used, including TNF-α (20,2.4%), IL-6 (17,2.1%), WBC (11,1.3%), CRP (10,1.2%), IL-1β (9,1.1%), CD4⁺ (8,1.0%), hs-CRP (7,0.9%), CD3⁺ (6,0.8%), CD8⁺ (6,0.8%), and SIgA (6,0.8%), with an additional 73 (8.9%) outcomes grouped as others. In the TCM Syndrome domain, TCM syndrome efficacy (16,2.0%) and TCM syndrome score (13,1.6%) were reported most often, whereas specific syndrome types, such as wind-heat syndrome (3,0.3%), lung-stomach heat syndrome (2,0.2%), and spleen-stomach damp-heat syndrome (1,0.1%), were reported less frequently. Outcomes related to Economic evaluation, Quality of life, and Security event were relatively scarce. The Economic evaluation domain contained only a small number of cost- or cost-effectiveness-related outcomes, all of which were reported once. Quality-of-life outcomes, all derived from the Brief Pain Inventory (BPI), included the BPI rating and interference-related items such as mood, daily work, daily life, life interests, slumber, walking ability, and relationship with others; each item was reported once. Only one outcome, adverse event, was identified in the Security event domain. This distribution pattern revealed a clear imbalance in outcome selection in current pharyngitis trials, with a strong emphasis on acute and subjective symptom assessments rather than multidimensional or long-term evaluations. Although objective inflammatory and immune biomarkers were also reported, their reporting frequencies were substantially lower than those of symptom-related outcomes. Moreover, these domains were generally assessed separately rather than being systematically integrated, reflecting a fragmented approach to clinical evaluation.

FIGURE 4 Sankey diagram illustrating the distribution of outcomes across the six predefined domains. (Figure not reproduced here; see the original article.)

Temporal analysis demonstrated a clear shift in the distribution of outcome domains across publication periods (Figure 5). Symptoms/Signs consistently represented the predominant domain throughout all time intervals, with proportions remaining above 60% and peaking at over 90% during 2010–2014. In contrast, Physical and chemical examination outcomes showed a gradual increase over time, rising markedly after 2015 and reaching their highest level in 2020–2025. TCM Syndrome-related outcomes were more frequently reported in earlier periods, particularly before 2000, but their relative contribution declined in subsequent years despite a transient increase between 2015 and 2019. Economic evaluation outcomes were sporadically reported, with a modest presence in earlier and mid-period studies, followed by an absence in the most recent period. Security event outcomes emerged only in later years, with a slight increase after 2015. Notably, Quality of life outcomes were absent in studies published before 2020 but appeared in the most recent period, indicating a growing emphasis on patient-centered measures. No studies across any time period reported outcomes related to long-term prognosis. Overall, these findings suggest a transition from a symptom-dominated evaluation framework toward a more diversified outcome structure incorporating laboratory indicators, safety, and patient-reported outcomes.

FIGURE 5 Temporal trends in the distribution of outcome domains across included studies. (Figure not reproduced here; see the original article.)

Outcomes

Among the 182 included studies, clinical efficacy emerged as the primary outcome (84.6%, n = 154). Symptom-based assessments predominantly focused on sore throat (n = 120, 65.9%), fever (n = 68, 37.4%), and pharyngeal congestion (n = 62, 34.1%). Assessments of cough and pharyngeal irritation (dryness/burning) were moderately represented, occurring in 30.2% and 26.4% of trials, respectively. Less common outcomes included dysphagia, pharyngeal paresthesia, and hoarseness, all reported in distal proportions (<12%). Notably, the adoption of standardized patient-reported measures (e.g., VAS) remained limited (8.2%), with most other specific outcomes falling below a 5% reporting threshold. This pattern suggests that existing trials have primarily evaluated TCM interventions for pharyngitis through short-term symptomatic relief and overall treatment response.

Analysis of outcome frequency revealed that clinical efficacy was the most frequently reported indicator (Figure 6), accounting for 20.6% of all outcome occurrences (n = 168). This was followed by several symptom-related outcomes, including sore throat (n = 77, 9.4%), fever (n = 44, 5.4%), and pharyngeal congestion (n = 35, 4.3%). Other commonly reported symptoms comprised dry and burning throat (n = 26, 3.2%) and cough (n = 23, 2.8%). In addition, a number of inflammatory and laboratory markers were among the top-ranked outcomes, such as TNF-α (n = 20, 2.4%), interleukin-6 (IL-6) (n = 17, 2.1%), white blood cell count (WBC) (n = 11, 1.3%), and C-reactive protein (CRP) (n = 10, 1.2%). TCM-related measures, including TCM syndrome efficacy (n = 16, 2.0%) and TCM syndrome score (n = 13, 1.6%), were also frequently reported. Other outcomes, such as pharyngeal redness and swelling (n = 17, 2.1%), dry throat (n = 16, 2.0%), thirst (n = 15, 1.8%), adverse events (n = 11, 1.3%), visual analogue scale (VAS) scores (n = 10, 1.2%), foreign body sensation in the throat (n = 10, 1.2%), time to recovery (n = 10, 1.2%), and interleukin-1β (IL-1β) (n = 9, 1.1%) were reported with moderate to low frequency. Several additional outcomes, including dry stool, difficulty swallowing, and yellow urine (each n = 9, 1.1%), were among the least frequently reported within the top-ranked indicators. Overall, the distribution of the most commonly reported outcomes highlights a predominance of symptom-based measures, supplemented by selected laboratory, TCM-specific, and safety-related indicators.These estimates are derived from outcome-level frequencies and therefore differ from study-level reporting proportions presented above.

FIGURE 6 Bar chart of the 20 most frequently reported outcome measures across included studies. (Figure not reproduced here; see the original article.)

The Phi coefficient matrix combined with hierarchical clustering revealed distinct patterns of co-occurrence among outcome measures (Figure 7). Strong positive associations were observed among inflammatory biomarkers, particularly between IL-6 and TNF-α (φ = 0.80), as well as between IL-6 and IL-1β (φ = 0.65), indicating that these markers were frequently assessed together within the same studies. Similarly, immune-related indicators formed a tightly connected cluster, with high correlations between CD3⁺ and CD4⁺ (φ = 0.86), CD4⁺ and CD8⁺ (φ = 0.86), and CD4⁺/CD8⁺ ratio with CD4⁺ (φ = 0.78), suggesting a consistent pattern of combined immunological evaluation.Symptom-related outcomes also demonstrated moderate clustering. For example, sore throat showed notable associations with fever (φ = 0.56) and pharyngeal congestion (φ = 0.53), while cough was moderately correlated with both fever and throat-related discomfort (φ ≈ 0.44–0.45). In addition, TCM-related manifestations, such as thirst, yellow urine, and dry stool, exhibited relatively strong internal correlations (φ up to 0.77), reflecting their tendency to be reported collectively within syndrome-based assessments.In contrast, clinical efficacy and time-to-event outcomes (e.g., time to recovery, onset time) showed weak or negligible correlations with most other indicators, suggesting that these measures were often reported independently rather than as part of a structured outcome set. Adverse events and patient-reported outcomes (e.g., VAS) also displayed generally low correlation coefficients, indicating limited integration with other outcome domains.Overall, the clustering structure highlights a fragmented outcome reporting pattern, characterized by tightly grouped biomarker and immunological measures alongside more loosely connected symptom and clinical endpoints.

FIGURE 7 Phi coefficient matrix with hierarchical clustering of outcome measures. (Figure not reproduced here; see the original article.)

Heterogeneity of outcome reporting

Marked heterogeneity was identified in the measurement approaches applied to frequently reported outcomes (Table 2). In this analysis, measurement methods and judgment criteria were examined for outcomes with a reporting frequency greater than 10. Among these outcomes, the majority were assessed using two or more measurement tools or evaluation standards. For instance, clinical efficacy—the most frequently reported endpoint—was evaluated using 20 distinct criteria, primarily derived from national-level guidelines (e.g., Guiding Principles for Clinical Research of New Chinese Medicines), professional society standards, specialty textbooks, and, in some cases, study-specific definitions. A similar pattern was observed for symptom-based outcomes, including sore throat, fever, and pharyngeal congestion, which were measured using a wide array of sources, ranging from formal diagnostic criteria to narrative clinical descriptions, with only limited use of standardized instruments such as the visual analogue scale (VAS).In contrast, laboratory-based outcomes, such as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), demonstrated substantially greater consistency, with measurements predominantly conducted using enzyme-linked immunosorbent assay (ELISA). This contrast underscores a clear distinction between subjective symptom-based assessments and objective biochemical indicators, with the latter benefiting from more standardized and reproducible measurement techniques.Notably, incomplete reporting of measurement methods remained a concern. For clinical efficacy, 52 out of 207 studies (25.1%) did not specify the criteria used, while similar issues were observed for outcomes such as white blood cell count (WBC) and adverse events, where reporting of measurement details was frequently absent or insufficient.

Considerable variability was also identified in the timing of outcome assessment among outcomes with a reporting frequency greater than 10 (Figure 8). Although most evaluations were conducted at the end of the treatment course, the specific time points varied markedly across studies, ranging from early assessments (e.g., day 1–3) to later follow-up points extending beyond 7 days or even longer durations. In addition, some trials adopted multiple assessment time points within the same study, further increasing heterogeneity. Notably, a subset of studies did not clearly specify the timing of outcome measurement (reported as “NK”), which limits interpretability and comparability. Overall, the lack of standardized assessment time points introduces an additional layer of inconsistency, potentially undermining the synthesis of evidence and highlighting the need for harmonized timing frameworks in future research.

FIGURE 8 Stacked bar chart illustrating the distribution of measurement time points for outcomes with a reporting frequency greater than 10. (Figure not reproduced here; see the original article.)

Discussion

The findings of this review indicate substantial heterogeneity in outcome selection and reporting across randomized controlled trials of traditional Chinese medicine (TCM) for acute pharyngitis, largely driven by the limited overlap in outcomes measured between studies. Although six overarching outcome domains and a large number of individual outcomes were identified, no single study captured all domains, and most trials reported outcomes within only one or two domains. This pattern suggests not merely incomplete coverage, but a lack of consistency in outcome prioritization across the evidence base. Symptom- and sign-based outcomes were universally reported and clearly dominated the evaluation framework, whereas other domains—including physical and chemical examinations, TCM syndrome measures, safety outcomes, economic evaluation, and particularly quality of life—were reported far less frequently. In addition, even within commonly assessed domains, only a small subset of outcomes (e.g., clinical efficacy and key symptom indicators) were repeatedly measured across studies, while the majority of outcomes were reported sporadically and with low frequency. Taken together, this imbalance between highly concentrated core outcomes and a long tail of infrequently reported measures highlights a fragmented outcome landscape in this field. Such variability limits comparability across studies and complicates evidence synthesis, underscoring the need for greater standardization in outcome definition, selection, and reporting in future TCM trials for acute pharyngitis.

The predominance of symptom- and sign-based outcomes was expected given the clinical nature of acute pharyngitis, where short-term relief of throat discomfort and visible inflammatory signs represents the primary therapeutic goal. Frequently reported outcomes such as sore throat, fever, and pharyngeal congestion are closely aligned with disease presentation and are readily assessable in routine practice. The widespread use of composite indicators such as overall clinical efficacy further reflects a preference for global measures that integrate multiple symptom dimensions into a single endpoint, an approach commonly adopted in clinical trials to capture overall treatment effects across related outcomes (Walker et al., 2024). However, this strong emphasis on clinician-assessed symptoms also suggests a continued reliance on a predominantly biomedical evaluation framework, with comparatively limited incorporation of patient-reported outcomes, which are considered the gold standard for capturing symptoms, quality of life, and overall wellbeing from the patient perspective (Puccini et al., 2025).

The increasing use of physical and chemical examination outcomes, particularly in more recent studies, may indicate a shift toward incorporating ostensibly objective biomarkers. Nevertheless, in the context of a largely self-limiting condition such as acute pharyngitis, the clinical relevance of routinely measuring inflammatory markers (e.g., CRP, leukocyte counts) warrants careful consideration. It remains unclear whether the inclusion of such indicators meaningfully enhances the assessment of treatment effectiveness or instead reflects a tendency to prioritize measurable laboratory endpoints over patient-important outcomes, potentially introducing unnecessary complexity and cost. By contrast, TCM syndrome-related outcomes, although more frequently reported in earlier studies, appear less prominent in recent research. This trend may not solely reflect changing methodological preferences, but also the inherent challenges associated with standardizing syndrome differentiation. The lack of universally accepted and validated measurement instruments for TCM syndrome assessment limits comparability across studies and reduces their utility in evidence synthesis, as inconsistency in diagnostic criteria and evaluation methods has been widely recognized as a major barrier to standardization and evidence-based research in this field (Zhenhan et al., 2024).

From a methodological perspective, the approach employed by Yang et al. (2026) is highly instructive. In their retrospective study of sepsis, clinical characteristics, traditional Chinese medicine (TCM) syndrome patterns, and laboratory biomarkers were systematically integrated to evaluate disease dynamics and patient responses. Although sepsis differs substantially from pharyngitis in clinical severity and endpoints, their framework highlights the value of harmonizing subjective clinical presentations with objective pathophysiological markers. Compared with this multidimensional approach, the pharyngitis trials included in our review exhibited a more fragmented outcome structure, with insufficient crosstalk between macro-level symptoms, traditional TCM syndrome characteristics, and micro-level laboratory evaluations. Therefore, future Core Outcome Set (COS) development for TCM treatment of pharyngitis should retain clinically important symptom-related outcomes while also incorporating objective inflammatory or immune indicators, safety outcomes, and health-related quality of life within a more balanced and standardized framework.

In addition, the near absence of quality-of-life measures and the limited reporting of economic outcomes highlight important gaps in the current evidence base. Despite the typically short disease course, acute pharyngitis can substantially affect swallowing, sleep, and daily activities, underscoring the importance of incorporating patient-centered outcomes. Similarly, given the widespread use of healthcare resources and concerns regarding inappropriate antibiotic prescribing, the lack of economic evaluation restricts understanding of the broader value of TCM interventions. Taken together, these patterns suggest that outcome selection in this field remains largely focused on immediate clinical manifestations, with insufficient attention to patient-centered and health system–level considerations.

Although used in the included studies, the Brief Pain Inventory (BPI) may not be the optimal tool for assessing quality-of-life outcomes in acute pharyngitis. This reflects a broader mismatch between generic pain-interference instruments and the disease-specific burden of acute pharyngitis. The BPI can capture the impact of pain on daily functioning and psychosocial wellbeing, but acute pharyngitis is characterized by a short and rapidly changing clinical course, involving localized symptoms, such as swallowing pain, throat irritation, and voice changes, as well as their immediate functional disruptions to eating, sleeping, and daily activities. These dimensions are only partially represented by BPI interference items. Therefore, reliance on BPI-derived outcomes may underestimate or incompletely characterize patient-perceived benefit in acute pharyngitis, particularly when symptom resolution, functional recovery, and short-term treatment response are central to clinical decision-making. Although several disease-specific patient-reported instruments have been developed for related conditions, such as tonsil and adenoid disease, recurrent acute tonsillitis, or tonsillectomy outcomes, validated PROMs specifically designed for acute pharyngitis appear to remain limited. This highlights an important measurement gap in the field. Future studies should not only include patient-reported outcomes, but also evaluate whether the selected instruments demonstrate adequate content validity for the symptom profile and time course of acute pharyngitis. In the context of core outcome set development, this finding supports the need to develop, validate, or adapt disease-specific PROMs that can better capture the short-term, symptom-driven, and functionally disruptive nature of acute pharyngitis.

No outcomes were identified in the long-term prognosis domain. This may partly reflect the acute and often self-limiting nature of pharyngitis, as well as trial designs that tend to prioritize rapid symptom relief, immediate clinical response, and feasibility of follow-up. However, the absence of this domain is particularly important in the evaluation of TCM interventions. From a TCM perspective, treatment is not limited to relieving acute symptoms, but may also aim to restore balance, reduce susceptibility, prevent recurrence, and avoid progression from an acute to a chronic condition. Without follow-up beyond the immediate treatment period, it is difficult to determine whether TCM interventions offer sustained benefits or advantages in reducing recurrence and downstream healthcare use. This evidence gap is also relevant to broader clinical and public health concerns, such as repeated consultations and potential antibiotic overuse in acute pharyngitis. Future studies should therefore consider incorporating outcomes such as recurrence, sustained symptom resolution, subsequent healthcare utilization, antibiotic use, long-term safety, and patient-reported recovery experience, so as to better capture the potential long-term and patient-centered value of TCM interventions.

Among individual outcomes, overall clinical efficacy was the most frequently reported endpoint, being used in the vast majority of included studies. While this high prevalence underscores its central role in evaluating treatment effects, it also raises important methodological concerns. As a composite indicator, clinical efficacy typically aggregates multiple symptom changes into a single categorical judgment (Cordoba et al., 2010), which may obscure variation across individual components and limit interpretability (Ferreira-González et al., 2007). Nevertheless, its continued widespread use is likely attributable to its practicality and feasibility (Freemantle et al., 2003), as it provides a convenient summary measure that is relatively simple to implement in clinical settings without requiring complex or resource-intensive assessments. In comparison, previous reviews in other clinical fields have similarly reported a high reliance on composite or global endpoints, often driven by the need to capture overall treatment effects while maintaining feasibility in trial design. However, such approaches have also been critiqued for potentially masking clinically meaningful differences across individual outcomes and for lacking standardization in definition and measurement (Cordoba et al., 2010; Ferreira-González et al., 2007; Freemantle et al., 2003). From a conceptual perspective, the prominence of global clinical efficacy measures may also reflect an implicit alignment with holistic evaluation frameworks (Hu et al., 2025), particularly within TCM practice, where treatment effects are often interpreted in terms of overall symptom improvement rather than isolated endpoints (H et al., 2015). At the same time, the limited adoption of standardized patient-reported measures, such as visual analogue scales, suggests that this holistic orientation has not yet been translated into rigorously validated and patient-centered measurement approaches (Hu et al., 2025). Together, these findings highlight a tension between pragmatic outcome selection, traditional evaluation paradigms, and evolving expectations for methodological rigor in clinical research.

The predominance of symptom-based outcomes is both clinically justified and methodologically problematic. On the one hand, this pattern reflects a patient-centered orientation, capturing the perceived disease burden of pharyngitis (e.g., sore throat, fever, pharyngeal discomfort, dryness, and cough). Furthermore, the frequent reporting of TCM syndrome scores aligns with TCM clinical practice, where syndrome differentiation is central to therapeutic evaluation. On the other hand, over-reliance on symptom-based outcomes weakens the comparability of trial findings, especially when assessed using unstandardized or self-developed criteria. In our review, standardized tools (such as VAS) were reported far less frequently than general symptom descriptions. Moreover, objective inflammatory markers (e.g., TNF-α, IL-6, WBC, CRP) and vital safety outcomes were substantially underreported, indicating a lack of risk-benefit and mechanistic evaluation. These findings suggest that future Core Outcome Set (COS) development should retain patient-centered and TCM-specific outcomes, while mandating the inclusion of standardized symptom scales, objective biomarkers, and safety metrics.

The focus on sore throat, fever, and pharyngeal congestion is expected, as these are the primary reasons patients seek medical care for pharyngitis. Consequently, current trial designs have prioritized the relief of acute, visible symptoms over a comprehensive assessment of overall disease burden. While clinically relevant, the heavy reliance on broad “clinical efficacy” categories—often based on subjective physician judgment—limits comparability across studies. Notably, the rare use of standardized patient-reported outcome measures (PROMs), such as the Visual Analogue Scale (VAS), indicates a failure to accurately capture the patients’ subjective experience. Furthermore, the low reporting frequency of symptoms like dysphagia and hoarseness suggests that functional impairments impacting quality of life remain marginalized. This likely reflects the difficulty in standardizing these metrics, driving researchers toward more conventional inflammatory symptoms. Ultimately, these findings highlight a critical methodological gap. Future Core Outcome Set (COS) development must retain core acute symptoms but urgently incorporate validated PROMs and functional endpoints to comprehensively evaluate therapeutic efficacy.

Economic evaluation outcomes were also rarely reported, despite the high prevalence of acute pharyngitis and the associated use of healthcare resources. Given the widespread use of therapeutic interventions—including ongoing concerns regarding unnecessary antibiotic prescribing—the absence of cost-related outcomes limits understanding of the broader value and potential health system implications of these treatments. This gap suggests that current research remains largely focused on short-term clinical effects, with insufficient integration of health economic considerations that are increasingly important for informing policy and resource allocation. At a broader level, outcomes related to long-term prognosis, patient-reported wellbeing, and system-level or environmental factors were largely absent. This may partly reflect the typically short disease course of acute pharyngitis, as well as trial designs that prioritize feasibility and immediate symptom relief. However, there is growing recognition that intervention evaluation should extend beyond short-term clinical endpoints to consider wider health, behavioral, and system-level impacts, including healthcare utilization, patient experience, and downstream consequences. Overall, these findings suggest that future studies should move beyond narrowly defined clinical outcomes to incorporate patient-centered, safety, economic, and system-level measures. Importantly, outcome selection should also reflect the perspectives of multiple stakeholders. The current emphasis on researcher-driven endpoints may not fully capture outcomes that matter most to patients, caregivers, and healthcare providers, highlighting the need for more inclusive and consensus-based approaches to outcome development.

Since only a small proportion of included trials reported safety events, relying solely on published data risks yielding an incomplete candidate list for subsequent COS development. This limitation is particularly critical for TCM interventions, where safety profiles encompass not only general adverse events but also preparation-specific reactions, herb–drug interactions, and organ-function abnormalities. To address this, we will supplement our candidate list by consulting additional sources, including package inserts of the included TCM preparations, pharmacovigilance data, national or regional essential-medicines catalogues, relevant clinical guidelines, and expert/stakeholder suggestions. This strategy is expected to minimize under-ascertainment and ensure the Delphi survey includes clinically relevant and patient-important safety domains applicable to TCM for pharyngitis.

Correlation analysis revealed distinct, clinically interpretable outcome clusters. Jointly mediating inflammatory signaling, IL-6, TNF-α, and IL-1β clustered strongly as a coherent biomarker panel, reflecting their frequent co-evaluation in mechanistic TCM research. For instance, despite pathophysiological differences from pharyngitis, studies on herbal interventions in critical care (Yang et al., 2026) demonstrate the value of evaluating these related cytokines as an integrated cluster rather than isolated variables. Similarly, T-cell subsets (CD3⁺,CD4⁺, CD8⁺, and the CD4⁺/CD8⁺ ratio) closely clustered as a standardized immunological panel, consistent with the growing trend of pairing biological markers with clinical scales (Jin et al., 2026). Regarding clinical presentations, moderate clustering also emerged among symptoms like sore throat, fever, and pharyngeal congestion. Ultimately, these empirical patterns suggest that future core outcome set (COS) development for TCM treatment of pharyngitis must move away from disconnected domains. Instead, a balanced framework should integrate patient-perceived symptoms, TCM-specific responses, objective biological markers, and safety outcomes to improve trial comparability and risk-benefit interpretability.

The characterization of TCM interventions was often insufficient in the original studies. Although most trials reported the name and dosage of the Chinese patent medicine, decoction, or hospital preparation, key information needed to define the preparation itself was often incomplete. This is particularly problematic for multi-component herbal preparations, because differences in composition, source materials, processing, extraction, and manufacturing standards may alter their chemical profiles and, consequently, their pharmacological and clinical effects. As a result, preparations with the same or similar names cannot necessarily be assumed to be equivalent across studies, and the comparability of interventions should be interpreted with caution. Future clinical studies of TCM and other herbal medicinal products should follow ConPhyMP (Heinrich et al., 2022) or similar reporting guidelines and provide standardized information on taxonomically validated species names, plant families, medicinal parts, formulation composition, manufacturer, batch number, preparation and extraction procedures, quality-control methods, and chemical standardization markers where applicable. More transparent reporting would improve the reproducibility, comparability, and interpretability of clinical evidence on herbal and multi-component medicinal preparations.

The substantial heterogeneity observed in outcome selection and reporting poses a significant challenge for the evaluation and synthesis of evidence in this field. The wide variation in both outcome domains and individual measures, together with the limited overlap across studies, restricts comparability and undermines the reliability of cross-trial interpretation. This inconsistency not only complicates meta-analysis and evidence integration, but may also contribute to research inefficiency and waste, as findings cannot be readily combined or meaningfully compared. These findings underscore the need for greater standardization in outcome selection, definition, and measurement in trials of traditional Chinese medicine for acute pharyngitis. In this context, the development of a core outcome set (COS) represents a pragmatic and internationally recognized approach to address current limitations by establishing a minimum set of outcomes that should be consistently measured and reported across studies. Importantly, beyond defining what to measure, future work should also consider how outcomes are measured, including the selection of valid, reliable, and responsive measurement instruments in line with established methodological frameworks such as COSMIN, to further reduce heterogeneity at the measurement level.

Discrepancies between registered and published outcomes may undermine the reliability of the evidence base by introducing selective outcome reporting. In this review, all prespecified outcomes in the eligible registration records were reported in the corresponding articles, but several publications also included additional non-prespecified outcomes. If such outcomes are introduced or emphasized after trial conduct, they may overstate treatment effects, inflate the apparent diversity of reported outcomes, and complicate the interpretation of intervention benefits. Our comparison of trial registrations with published reports, strengthened the methodological rigor of this review by making these reporting patterns more transparent. Future trials should prospectively register clearly defined primary and secondary outcomes and explicitly justify any post hoc additions or deviations from the registered protocol.

This review represents the first stage in the development of such a COS. The outcomes identified herein provide a comprehensive foundation for subsequent consensus-building processes, including Delphi surveys and structured consensus meetings, conducted in accordance with methodological guidance such as that recommended by the COMET Initiative. Crucially, these processes should involve a broad range of stakeholders, including clinicians, researchers, patients, and policymakers. Such inclusive engagement is essential to ensure that the resulting COS reflects not only clinical priorities but also patient-valued outcomes, such as quality of life, as well as health system considerations, including economic impact.

The establishment of a standardized and stakeholder-informed COS may also facilitate greater alignment of TCM clinical research with international reporting standards, thereby enhancing its transparency, comparability, and global relevance. In addition, the consistent use of predefined core outcomes has the potential to reduce selective outcome reporting and improve the completeness of evidence, ultimately strengthening the credibility and usability of research findings. Collectively, these efforts will support more robust evidence synthesis and contribute to the advancement of high-quality, patient-centered, and policy-relevant research in this field.

The present review has several notable strengths. First, by restricting inclusion to randomized controlled trials (RCTs), this study prioritizes evidence derived from rigorous experimental designs, thereby enhancing the internal validity of the findings and reducing the influence of confounding factors commonly encountered in observational research. Second, a comprehensive and systematic search strategy was implemented across multiple databases, with predefined eligibility criteria and standardized procedures for study selection and data extraction, which helps to minimize selection bias and improve reproducibility. Third, this review places particular emphasis on clinically relevant outcomes in patients with acute pharyngitis, allowing for a more meaningful interpretation of the therapeutic value of traditional Chinese medicine interventions in real-world practice. In addition, the structured synthesis of outcome measures across studies contributes to a clearer understanding of commonly assessed endpoints and highlights areas of consistency and divergence in the existing evidence base. Collectively, these methodological strengths enhance the reliability and interpretability of the current findings, and provide a valuable foundation for future research in this field.

Limitations

Our review has several limitations that inform the interpretation of these findings and the subsequent development of a core outcome set. First, outcome identification relied mainly on published reports and specific trial registries; therefore, outcomes that were incompletely reported, omitted, or published in non-target languages may not have been fully captured. Second, harmonizing diverse outcome terminology and assigning them to standardized domains inherently required reviewer judgment, which introduces potential subjective bias despite our consensus checks. Third, because we focused strictly on identifying and mapping reported outcomes, we did not evaluate the measurement properties (e.g., validity, reliability) of the corresponding instruments; thus, a high reporting frequency does not necessarily equate to clinical importance. Finally, the inadequate reporting of TCM intervention details—such as variations in formulation, dosage, or syndrome differentiation—limited our ability to ensure strict comparability across similarly named treatments.

Conclusions

This review demonstrates considerable inconsistency in the selection and reporting of outcomes across studies evaluating traditional Chinese medicine interventions for acute pharyngitis. Although a wide range of outcome domains and individual measures were identified, most were reported infrequently, indicating limited alignment in outcome prioritization across trials. Such variability constrains the comparability of findings and reduces the efficiency of evidence synthesis.

Given the high burden of acute pharyngitis and the extensive use of therapeutic interventions, improving the consistency and relevance of outcome reporting is essential. The findings of this review provide a foundation for the development of a core outcome set (COS) tailored to this field, with the aim of promoting more standardized, transparent, and patient-relevant outcome assessment. The implementation of a COS is expected to enhance the quality and interpretability of future research, support more robust evidence synthesis, and ultimately contribute to more informed clinical and policy decision-making.

Funding Statement

The author(s) declared that financial support was received for this work and/or its publication. This work was supported by the Traditional Chinese Medicine Innovation Team and Talent Support Program - National Natural Science Foundation of China (No. 82305437), Traditional Chinese Medicine Innovation Team and Talent Support Program - National Traditional Chinese Medicine Multidisciplinary Cross-Innovation Team Project (ZYYCXTD-D-202401), and Young Elite Scientists Sponsorship Program by China Association for Science and Technology (No. YESS20240392).

Footnotes

Data availability statement

The original contributions presented in the study are included in the article/Supplementary Material, further inquiries can be directed to the corresponding authors.

Author contributions

DL: Conceptualization, Data curation, Formal Analysis, Investigation, Methodology, Software, Validation, Writing – original draft, Writing – review and editing. CZ: Data curation, Writing – original draft. YJ: Data curation, Writing – original draft. XJ: Funding acquisition, Writing – original draft. FY: Funding acquisition, Writing – original draft. WP: Funding acquisition, Project administration, Resources, Supervision, Writing – original draft, Writing – review and editing. JZ: Funding acquisition, Project administration, Resources, Supervision, Writing – original draft, Writing – review and editing.

Conflict of interest

The author(s) declared that this work was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Generative AI statement

The author(s) declared that generative AI was not used in the creation of this manuscript.

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Supplementary material

The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fphar.2026.1872689/full#supplementary-material

References

Associated Data

Supplementary Materials

Data Availability Statement

The original contributions presented in the study are included in the article/Supplementary Material, further inquiries can be directed to the corresponding authors.

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