Definition and research guide
This page combines a MeSH definition, publication statistics and selected research abstracts. It is a starting point for reading the literature, not a medical textbook or a systematic evidence review.
Content available: 4 complete abstracts (1,096 words), 10 references. Full article text is not stored or reproduced here; follow the PMID, DOI or PMC links to read the original sources and their access terms.
Definition
Study subjects in cohort studies whose outcomes are unknown e.g., because they could not or did not wish to attend follow-up visits.(from Dictionary of Epidemiology, 5th ed.)
Definition: NLM Medical Subject Headings (MeSH) scope note (Public domain (U.S. National Library of Medicine); attribution requested). View the MeSH record.
Also known as: Follow-Up, Lost to; Lost to Follow Up; Lost to Follow-Ups.
Where it fits in the MeSH classification
- Broader topics
- Epidemiologic Research Design
Related concepts
Research landscape
PubMed indexes 1,758 records tagged with the MeSH heading “Lost to Follow-Up” (counts retrieved 2026-10-29). 496 of them (28.2%) were published from 2020 onward, and the busiest period so far is 2010-2019 with 1,267 records.
Reviews account for 110 records (6.3%) and meta-analyses for 29. Randomized controlled trials number 157 (8.9%) as a share of all records on the topic. Randomized trials make up a comparatively large share of this literature, which means many treatment questions have been tested directly.
Show the data
| Period | Records |
|---|---|
| through 1999 | 0 |
| 2000-2009 | 8 |
| 2010-2019 | 1,267 |
| 2020 onward | 496 |
Publication-type chart data
| Type | Records | Share |
|---|---|---|
| Reviews | 110 | 6.3% |
| Meta-analyses | 29 | 1.6% |
| Randomized controlled trials | 157 | 8.9% |
Method: PubMed query "Lost to Follow-Up"[MeSH Terms] with publication-type and date filters, retrieved 2026-10-29.
Reading the evidence in clinical research
Research methods determine how much a result can be trusted. Randomized trials guard against confounding, systematic reviews and meta-analyses combine many studies, and observational designs are valuable but can show only association. Reporting standards, trial registration and pre-specified outcomes reduce bias. When reading about a method, ask what problem it is designed to solve and which problems it does not solve.
Evidence from open-access studies
These open-access studies come from PubMed’s best-match results for this heading (papers whose main topic it is), ranked here by citation count, with one recent addition. Each abstract is reproduced in full under its recorded open licence so that you can read the authors’ own words. They illustrate the literature; they are not a systematic summary of it. Citation counts measure attention, not reliability or clinical benefit.
Understanding preferences for HIV care and treatment in Zambia: Evidence from a discrete choice experiment among patients who have been lost to follow-up [1]
Abstract reading summary — source excerpts
- Opening excerpt
- BackgroundIn public health HIV treatment programs in Africa, long-term retention remains a challenge.
- Closing excerpt
- , differentiated service delivery models), current improvement strategies should also prioritize improving provider attitude and promoting patient centeredness-an area of limited policy attention to date.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (313 words)
BackgroundIn public health HIV treatment programs in Africa, long-term retention remains a challenge. A number of improvement strategies exist (e.g., bring services closer to home, reduce visit frequency, expand hours of clinic operation, improve provider attitude), but implementers lack data about which to prioritize when resource constraints preclude implementing all. We used a discrete choice experiment (DCE) to quantify preferences for a number of potential clinic improvements to enhance retention.Methods and findingsWe sought a random sample of HIV patients who were lost to follow-up (defined as >90 days late for their last scheduled appointment) from treatment facilities in Lusaka Province, Zambia. Among those contacted, we asked patients to choose between 2 hypothetical clinics in which the following 5 attributes of those facilities were varied: waiting time at the clinic (1, 3, or 5 hours), distance from residence to clinic (5, 10, or 20 km), ART supply given at each refill (1, 3, or 5 months), hours of operation (morning only, morning and afternoon, or morning and Saturday), and staff attitude ("rude" or "nice"). We used mixed-effects logistic regression to estimate relative utility (i.e., preference) for each attribute level. We calculated how much additional waiting time or travel distance patients were willing to accept in order to obtain other desired features of care. Between December 9, 2015 and May 31, 2016, we offered the survey to 385 patients, and 280 participated (average age 35; 60% female). Patients exhibited a strong preference for nice as opposed to rude providers (relative utility of 2.66; 95% CI 1.9-3.42; p ConclusionsIn this study, patients were willing to expend considerable time and effort as well as accept substantial inconvenience in order to access providers with a nice attitude. In addition to service delivery redesign (e.g., differentiated service delivery models), current improvement strategies should also prioritize improving provider attitude and promoting patient centeredness-an area of limited policy attention to date.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 30102693 · DOI · PMC6089406
Outcomes of Patients Lost to Follow-up in African Antiretroviral Therapy Programs: Individual Patient Data Meta-analysis [2]
Abstract reading summary — source excerpts
- Opening excerpt
- BackgroundLow retention on combination antiretroviral therapy (cART) has emerged as a threat to the Joint United Nations Programme on human immunodeficiency virus (HIV)/AIDS (UNAIDS) 90-90-90 targets.
- Closing excerpt
- Immediate start of cART and early tracing of patients LTFU should be priorities.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (242 words)
BackgroundLow retention on combination antiretroviral therapy (cART) has emerged as a threat to the Joint United Nations Programme on human immunodeficiency virus (HIV)/AIDS (UNAIDS) 90-90-90 targets. We examined outcomes of patients who started cART but were subsequently lost to follow-up (LTFU) in African treatment programs.MethodsThis was a systematic review and individual patient data meta-analysis of studies that traced patients who were LTFU. Outcomes were analyzed using cumulative incidence functions and proportional hazards models for the competing risks of (i) death, (ii) alive but stopped cART, (iii) silent transfer to other clinics, and (iv) retention on cART.ResultsNine studies contributed data on 7377 patients who started cART and were subsequently LTFU in sub-Saharan Africa. The median CD4 count at the start of cART was 129 cells/μL. At 4 years after the last clinic visit, 21.8% (95% confidence interval [CI], 20.8%-22.7%) were known to have died, 22.6% (95% CI, 21.6%-23.6%) were alive but had stopped cART, 14.8% (95% CI, 14.0%-15.6%) had transferred to another clinic, 9.2% (95% CI, 8.5%-9.8%) were retained on cART, and 31.6% (95% CI, 30.6%-32.7%) could not been found. Mortality was associated with male sex, more advanced disease, and shorter cART duration; stopping cART with less advanced disease andlonger cART duration; and silent transfer with female sex and less advanced disease.ConclusionsMortality in patients LTFU must be considered for unbiased assessments of program outcomes and UNAIDS targets in sub-Saharan Africa. Immediate start of cART and early tracing of patients LTFU should be priorities.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 29889240 · DOI · PMC6233676
Determinants of loss to follow-up in patients on antiretroviral treatment, South Africa, 2004-2012: a cohort study [3]
Abstract reading summary — source excerpts
- Opening excerpt
- BackgroundThe number of Human Immunodeficiency Virus (HIV) infected people eligible for initiation on antiretroviral Therapy (ART) is increasing.
- Closing excerpt
- Intensified measures to improve patient retention on ART must be prioritised with increasing patient time on ART and in patients that are at increased risk of becoming lost to follow-up.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (287 words)
BackgroundThe number of Human Immunodeficiency Virus (HIV) infected people eligible for initiation on antiretroviral Therapy (ART) is increasing. ART programmatic success requires that patients who are taking ART remain on treatment and are followed up regularly. This study investigated factors associated with being lost to follow-up, in a cohort of patients enrolled in a pharmacovigilance study in South Africa.MethodsThis was a retrospective observational cohort study performed at one of the Medunsa National Pharmacovigilance Centre's (MNPC) ART sentinel surveillance sites. Loss to Follow-up (LTFU) was defined as "a patient who had been followed up at the sentinel site, who had not had contact with the health facility for 180 days or more since their last recorded expected date of return or if there were 180 days or more between the expected date of return and the next clinic visit".ResultsOut of 595 patients, 65.5% (n = 390) were female and 23.4% (n = 139) were LTFU. The median time on ART before LTFU was 21.5 months (interquartile range: 12.9 - 34.7 months). The incidence rate of LTFU was 103 per 1000 person-years in the first year on ART and increased to 405 per 1000 person-years in the eighth year of taking ART. Factors associated with becoming LTFU included not having a committed partner (Adjusted Hazard Ratio (aHR): 2.9, 95% Confidence Interval (CI):1.19-6.97, p = 0.019), being self-employed (aHR: 13.9, 95% CI:2.81 - 69.06, p = 0.001), baseline CD4 count > 200 cells/ml (aHR: 3.8, 95% CI: 1.85-7.85, p ConclusionThe incidence rate of LTFU increases with additional years on ART. Intensified measures to improve patient retention on ART must be prioritised with increasing patient time on ART and in patients that are at increased risk of becoming lost to follow-up.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 26141729 · DOI · PMC4491264
Factors related to loss to follow-up and low compliance in Helicobacter pylori-infected children: The EuroPedHp Registry [4]
Abstract reading summary — source excerpts
- Opening excerpt
- ObjectivesMonitoring for Helicobacter pylori (H.
- Closing excerpt
- Improving information to patient/caregiver may increase adherence, care and treatment success.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (254 words)
ObjectivesMonitoring for Helicobacter pylori (H. pylori)-eradication is important, since symptom improvement does not indicate treatment success. Using EuroPedHp Registry data, we investigated characteristics of children missing monitoring visits after prescribed therapy, compliance effect on eradication, and factors associated with loss to follow-up and low compliance.MethodsBetween 2017 and 2020, 30 paediatric hospitals from 17 European countries reported 1605 children with biopsy-proven H. pylori-infection. Children with prescribed therapy were analysed. Risk factors for loss to follow-up or low compliance (taking ≤90% of prescribed medications) were identified applying multivariable logistic regression.ResultsOf 1263 infected children with prescribed therapy, 390 (31%) were lost to follow-up. Risk factors for loss to follow-up included nausea/dyspepsia (p = 0.004) or gastrointestinal bleeding (p = 0.03) as indication for endoscopy, living in Israel or Türkiye (p = 0.0002), and having no antibiotic susceptibility result (p = 0.004). Risk decreased with living in Southern Europe (p = 0.002), migration background (p = 0.052), and probiotic use during therapy (p = 0.02). Low compliance, reported in 69/831 (8%) children with follow-up data, was associated with vomiting (p = 0.003), peptic ulcers or erosions (p = 0.03), living in EasternEurope (p = 0.009), Israel or Türkiye (p = 0.0008), and any adverse event during therapy (p = 0.0009). First-line tailored triple therapy (TTT) for 14 days (N = 480) was successful in 92% with excellent versus 61% with low compliance (p ConclusionThe registry data identified several factors associated with non-adherence to medication and monitoring visits. Improving information to patient/caregiver may increase adherence, care and treatment success.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 41735805 · DOI · PMC13150790
Key reviews and meta-analyses
The most cited review-type papers among PubMed’s best-match results for this heading, listed with bibliographic details only. Follow the links for the full text and access terms.
- Research article The cascade of care in diagnosis and treatment of latent tuberculosis infection: a systematic review and meta-analysis [5]
- Research article Potential impact on estimated treatment effects of information lost to follow-up in randomised controlled trials (LOST-IT): systematic review [6]
- Research article Retention in care among HIV-infected patients in resource-limited settings: emerging insights and new directions [7]
- Research article Loss to programme between HIV diagnosis and initiation of antiretroviral therapy in sub-Saharan Africa: systematic review and meta-analysis [8]
- Research article Pre-treatment loss to follow-up in tuberculosis patients in low- and lower-middle-income countries and high-burden countries: a systematic review and meta-analysis [9]
- Research article The magnitude of loss to follow-up of HIV-exposed infants along the prevention of mother-to-child HIV transmission continuum of care: a systematic review and meta-analysis [10]
References
- Zanolini A, Sikombe K, Sikazwe I, Eshun-Wilson I, Somwe P, Bolton Moore C, et al.. Understanding preferences for HIV care and treatment in Zambia: Evidence from a discrete choice experiment among patients who have been lost to follow-up. . 2018. PMID 30102693 · DOI · PMC6089406
- Chammartin F, Zürcher K, Keiser O, Weigel R, Chu K, Kiragga AN, et al.. Outcomes of Patients Lost to Follow-up in African Antiretroviral Therapy Programs: Individual Patient Data Meta-analysis. . 2018. PMID 29889240 · DOI · PMC6233676
- Mberi MN, Kuonza LR, Dube NM, Nattey C, Manda S, Summers R. Determinants of loss to follow-up in patients on antiretroviral treatment, South Africa, 2004-2012: a cohort study. . 2015. PMID 26141729 · DOI · PMC4491264
- Le Thi TG, Kotilea K, Cabral J, Kori M, Cilleruelo ML, Tavares M, et al.. Factors related to loss to follow-up and low compliance in Helicobacter pylori-infected children: The EuroPedHp Registry. . 2026. PMID 41735805 · DOI · PMC13150790
- Alsdurf H, Hill PC, Matteelli A, Getahun H, Menzies D. The cascade of care in diagnosis and treatment of latent tuberculosis infection: a systematic review and meta-analysis. Lancet Infect Dis. 2016. PMID 27522233 · DOI
- Akl EA, Briel M, You JJ, Sun X, Johnston BC, Busse JW, et al.. Potential impact on estimated treatment effects of information lost to follow-up in randomised controlled trials (LOST-IT): systematic review. BMJ. 2012. PMID 22611167 · DOI
- Geng EH, Nash D, Kambugu A, Zhang Y, Braitstein P, Christopoulos KA, et al.. Retention in care among HIV-infected patients in resource-limited settings: emerging insights and new directions. Curr HIV/AIDS Rep. 2010. PMID 20820972 · DOI · PMC3021803
- Mugglin C, Estill J, Wandeler G, Bender N, Egger M, Gsponer T, et al.. Loss to programme between HIV diagnosis and initiation of antiretroviral therapy in sub-Saharan Africa: systematic review and meta-analysis. Trop Med Int Health. 2012. PMID 22994151 · DOI · PMC3895621
- MacPherson P, Houben RM, Glynn JR, Corbett EL, Kranzer K. Pre-treatment loss to follow-up in tuberculosis patients in low- and lower-middle-income countries and high-burden countries: a systematic review and meta-analysis. Bull World Health Organ. 2014. PMID 24623906 · DOI · PMC3949536
- Sibanda EL, Weller IV, Hakim JG, Cowan FM. The magnitude of loss to follow-up of HIV-exposed infants along the prevention of mother-to-child HIV transmission continuum of care: a systematic review and meta-analysis. AIDS. 2013. PMID 24056068 · DOI · PMC3814628
About this article
- Sources
- NLM Medical Subject Headings (definition, synonyms); NCBI PubMed (counts, identifiers); Europe PMC (open-access abstracts and citation counts).
- Verification
- Every reference was resolved against PubMed on 2026-10-31; title, year and DOI matched.
- Review state
- automated source verified; no human expert review has been recorded yet.
- Version
- 1, last updated 2026-10-29.
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