Reducing lost to follow-up in a large clinical trial of prevention of mother-to-child transmission of HIV: the Breastfeeding, Antiretrovirals and Nutrition study experience

Participant retention in paediatric randomised controlled trials published in six major journals 2015-2019: systematic review and meta-analysis

BACKGROUND

The factors which influence participant retention in paediatric randomised controlled trials are under-researched. Retention may be more challenging due to child developmental stages, involving additional participants, and proxy-reporting of outcomes. This systematic review and meta-analysis explores the factors which may influence retention in paediatric trials.

METHODS

Using the MEDLINE database, paediatric randomised controlled trials published between 2015 and 2019 were identified from six general and specialist high-impact factor medical journals. The review outcome was participant retention for each reviewed trial's primary outcome. Context (e.g. population, disease) and design (e.g. length of trial) factors were extracted. Retention was examined for each context and design factor in turn, with evidence for an association being determined by a univariate random-effects meta-regression analysis.

RESULTS

Ninety-four trials were included, and the median total retention was 0.92 (inter-quartile range 0.83 to 0.98). Higher estimates of retention were seen for trials with five or more follow-up assessments before the primary outcome, those less than 6 months between randomisation and primary outcome, and those that used an inactive data collection method. Trials involving children aged 11 and over had the higher estimated retention compared with those involving younger children. Those trials which did not involve other participants also had higher retention, than those where they were involved. There was also evidence that a trial which used an active or placebo control treatment had higher estimated retention, than treatment-as-usual. Retention increased if at least one engagement method was used. Unlike reviews of trials including all ages of participants, we did not find any association between retention and the number of treatment groups, size of trial, or type of treatment.

CONCLUSIONS

Published paediatric RCTs rarely report the use of specific modifiable factors that improve retention. Including multiple, regular follow-ups with participants before the primary outcome may reduce attrition. Retention may be highest when the primary outcome is collected up to 6 months after a participant is recruited. Our findings suggest that qualitative research into improving retention when trials involve multiple participants such as young people, and their caregivers or teachers would be worthwhile. Those designing paediatric trials also need to consider the use of appropriate engagement methods. RESEARCH ON RESEARCH (ROR) REGISTRY: https://ror-hub.org/study/2561.

Community-based follow-up of participants of a mother-friendly clinical trial: A patient-centric methodology for pregnant women

Repeated visits to clinical trial sites inflict hardships on study participants, especially pregnant women. A newer trend is community-based follow-up for measurements, dosage, or monitoring, through technology or physical visits. We conducted a methodological experiment of performing "community-based physical follow-up" of participants of a trial, receiving facility-based diagnosis and pathogen-specific antibiotics for asymptomatic bacteriuria, guided by an optical-sensor-based rapid point-of-care test. We were able to retain 95.8% participants in the study. Here we describe challenges faced and socio-economic and gender issues encountered in this approach in a low-resource Indian scenario, to guide researchers world-wide for designing mother-friendly clinical trials.

Discontinuation and loss to follow-up rates in clinical trials of intravitreal anti-vascular endothelial growth factor injections

PURPOSE

Clinical trials are often designed to include homogenous, highly specific patient populations with many resources to reduce patient dropout. Results may not translate to real-world settings. We evaluated discontinuation and loss to follow-up (LTFU) rates in clinical trials of anti-vascular endothelial growth factor (anti-VEGF) injections for diabetic macular edema (DME), age-related macular degeneration (AMD), and retinal vein occlusion (RVO).

METHODS

Retrospective meta-epidemiological study. The authors queried ClinicalTrials.gov for all completed trials of anti-VEGF injections for DME, AMD, or RVO. Of 658 trials identified, 582 were excluded for being non-interventional, <100 patients, terminating early, or missing study results. The remaining 76 trials of 27,823 patients were analyzed for discontinuation and LTFU rates.

RESULTS

Mean discontinuation rate was 12.44% (SD 8.12%, range 0-54.12%), with higher rates among control (18.87%) than treatment arms (10.78%, p = .006). Mean LTFU rate was 1.84% (SD 1.78%, range 0-7.76%), with no differences by disease, treatment type, or treatment frequency.

CONCLUSION

Discontinuation rates of major intravitreal anti-VEGF clinical trials were highly variable, suggesting even trials struggle with overall patient retention. Though trial LTFU rates were low, real-world outcomes may differ due to higher reported LTFU rates, which should be considered when extrapolating trial results to clinical practice.

Non-randomised evaluations of strategies to increase participant retention in randomised controlled trials: a systematic review

BACKGROUND

Retention of participants is essential to ensure the statistical power and internal validity of clinical trials. Poor participant retention reduces power and can bias the estimates of intervention effect. There is sparse evidence from randomised comparisons of effective strategies to retain participants in randomised trials. Currently, non-randomised evaluations of trial retention interventions embedded in host clinical trials are rejected from the Cochrane review of strategies to improve retention because it only included randomised evaluations. However, the systematic assessment of non-randomised evaluations may inform trialists' decision-making about retention methods that have been evaluated in a trial context.Therefore, we performed a systematic review to synthesise evidence from non-randomised evaluations of retention strategies in order to supplement existing randomised trial evidence.

METHODS

We searched MEDLINE, EMBASE, and Cochrane CENTRAL from 2007 to October 2017. Two reviewers independently screened abstracts and full-text articles for non-randomised studies that compared two or more strategies to increase participant retention in randomised trials. The retention trials had to be nested in real 'host' trials ( including feasibility studies) but not hypothetical trials. Two investigators independently rated the risk of bias of included studies using the ROBINS-I tool and determined the certainty of evidence using GRADE (Grading of Recommendations Assessment, Development and Evaluation) framework.

RESULTS

Fourteen non-randomised studies of retention were included in this review. Most retention strategies (in 10 studies) aimed to increase questionnaire response rate. Favourable strategies for increasing questionnaire response rate were telephone follow-up compared to postal questionnaire completion, online questionnaire follow-up compared to postal questionnaire, shortened version of questionnaires versus longer questionnaires, electronically transferred monetary incentives compared to cash incentives, cash compared with no incentive and reminders to non-responders (telephone or text messaging). However, each retention strategy was evaluated in a single observational study. This, together with risk of bias concerns, meant that the overall GRADE certainty was low or very low for all included studies.

CONCLUSIONS

This systematic review provides low or very low certainty evidence on the effectiveness of retention strategies evaluated in non-randomised studies. Some strategies need further evaluation to provide confidence around the size and direction of the underlying effect.

Proportion and predictors of loss to follow-up in a longitudinal cohort study of female entertainment and sex workers in Cambodia

We examined the proportion and correlates of loss to follow-up (LTFU) among female entertainment and sex workers (FESWs) in a longitudinal HIV prevention intervention trial in Cambodia. The Cambodia Integrated HIV and Drug Prevention Intervention trial tested a comprehensive package of interventions aimed at reducing amphetamine-type stimulant use and HIV risk among FESWs in ten provinces. The present study estimated the proportion of women LTFU and assessed factors associated with LTFU. Logistic regression analyses were used. Of a total 596 women enrolled, the cumulative proportion of LTFU was 29.5% (n = 176) between zero- and 12-month follow-up. In multivariate analyses, women with no living children (adjusted odds ratio [AOR] 1.6; 95% confidence interval [CI]: 1.1, 2.3) and those who experienced recent food insecurity (AOR 1.7; 95%CI: 1.1, 2.7) were more likely to be LTFU. Women who were members of the SMARTgirl HIV prevention programme for ≥ 6 months compared to non-members were less likely to be LTFU (AOR 0.3; 95%CI: 0.2, 0.6). LTFU was moderately high in this study and similar to other studies, indicating a need for strategies to retain this population in HIV prevention programmes and research. Interventions aimed at stabilizing women's lives, including reducing food insecurity and creating communities of engagement for FESWs, should be considered.

Development and clinical application of an evidence-based pharmaceutical care service algorithm in acute coronary syndrome

WHAT IS KNOWN AND OBJECTIVE

Drug therapies are critical for preventing secondary complications in acute coronary syndrome (ACS). The purpose of this study was to develop and apply a pharmaceutical care service (PCS) algorithm for ACS and confirm that it is applicable through a prospective clinical trial.

METHODS

The ACS-PCS algorithm was developed according to extant evidence-based treatment and pharmaceutical care guidelines. Quality assurance was conducted through two methods: literature comparison and expert panel evaluation. The literature comparison was used to compare the content of the algorithm with the referenced guidelines. Expert evaluations were conducted by nine experts for 75 questionnaire items. A trial was conducted to confirm its effectiveness. Seventy-nine patients were assigned to either the pharmacist-included multidisciplinary team care (MTC) group or the usual care (UC) group. The endpoints of the trial were the prescription rate of two important drugs, readmission, emergency room (ER) visit and mortality.

RESULTS AND DISCUSSION

The main frame of the algorithm was structured with three tasks: medication reconciliation, medication optimization and transition of care. The contents and context of the algorithm were compliant with class I recommendations and the main service items from the evidence-based guidelines. Opinions from the expert panel were mostly positive. There were significant differences in beta-blocker prescription rates in the overall period (P = .013) and ER visits (four cases, 9.76%, P = .016) in the MTC group compared to the UC group, respectively.

WHAT IS NEW AND CONCLUSION

We developed a PCS algorithm for ACS based on the contents of evidence-based drug therapy and the core concept of pharmacist services.

Nonparametric binary instrumental variable analysis of competing risks data

In both observational studies and randomized trials with noncompliance, unmeasured confounding may exist which may bias treatment effect estimates. Instrumental variables (IV) are a popular technique for addressing such confounding, enabling consistent estimation of causal effects. This paper proposes nonparametric IV estimators for censored time to event data that may be subject to competing risks. A simple, plug-in estimator is introduced using nonparametric estimators of the cumulative incidence function, with confidence intervals derived using asymptotic theory. To provide an overall test of the treatment effect, an integrated weighted difference statistic is suggested, which is applicable to data with and without competing risks. Simulation studies demonstrate that the methods perform well with realistic samples sizes. The methods are applied to assess the effect of infant or maternal antiretroviral therapy on transmission of HIV from mother to child via breastfeeding using data from a large, recently completed randomized trial in Malawi where noncompliance with assigned treatment may confound treatment effect estimates.

Frequent nevirapine resistance in infants infected by HIV-1 via breastfeeding while on nevirapine prophylaxis

OBJECTIVE

The objective of this study is to assess nevirapine (NVP) resistance in infants who became infected in the three arms of the Breastfeeding, Antiretrovirals and Nutrition (BAN) study: daily infant NVP prophylaxis, triple maternal antiretrovirals or no extra intervention for 28 weeks of breastfeeding.

DESIGN

A prospective cohort study.

METHODS

The latest available plasma or dried blood spot specimen was tested from infants who became HIV-positive between 3 and 48 weeks of age. Population sequencing was used to detect mutations associated with reverse transcriptase inhibitor resistance. Sequences were obtained from 22 out of 25 transmissions in the infant-NVP arm, 23 out of 30 transmissions in the maternal-antiretroviral arm and 33 out of 38 transmissions in the control arm.

RESULTS

HIV-infected infants in the infant-NVP arm were significantly more likely to have NVP resistance than infected infants in the other two arms of the trial, especially during breastfeeding through 28 weeks of age (56% in infant-NVP arm vs. 6% in maternal-antiretroviral arm and 11% in control arm, P¼0.004). There was a nonsignificant trend, suggesting that infants with NVP resistance tended to be infected earlier and exposed to NVP while infected for a greater duration than infants without resistance.

CONCLUSION

Infants on NVP prophylaxis during breastfeeding are at a reduced risk of acquiring HIV, but are at an increased risk of NVP resistance if they do become infected. These findings point to the need for frequent HIV testing of infants while on NVP prophylaxis, and for the availability of antiretroviral regimens excluding NVP for treating infants who become infected while on such a prophylactic regimen.

Outcomes of prevention of mother to child transmission of the human immunodeficiency virus-1 in rural Kenya--a cohort study

BACKGROUND

Success in prevention of mother-to-child transmission (PMTCT) raises the prospect of eliminating pediatric HIV infection. To achieve global elimination, however, strategies are needed to strengthen PMTCT interventions. This study aimed to determine PMTCT outcomes and identify challenges facing its successful implementation in a rural setting in Kenya.

METHODS

A retrospective cohort design was used. Routine demographic and clinical data for infants and mothers enrolling for PMTCT care at a rural hospital in Kenya were analysed. Cox and logistic regression were used to determine factors associated with retention and vertical transmission respectively.

RESULTS

Between 2006 and 2012, 1338 infants were enrolled and followed up for PMTCT care with earlier age of enrollment and improved retention observed over time. Mother to child transmission of HIV declined from 19.4 % in 2006 to 8.9 % in 2012 (non-parametric test for trend p = 0.024). From 2009 to 2012, enrolling for care after 6 months of age, adjusted Odds Ratio [aOR]: 23.3 [95 % confidence interval (CI): 8.3-65.4], presence of malnutrition ([aOR]: 2.3 [95 % CI: 1.1-5.2]) and lack of maternal use of highly active antiretroviral therapy (HAART) (aOR: 6.5 [95 % CI: 1.4-29.4]) was associated with increased risk of HIV infection. Infant's older age at enrollment, malnutrition and maternal HAART status, were also associated with drop out from care. Infants who were not actively followed up were more likely to drop out from care (adjusted Hazard Ratio: 6.6 [95 % CI: 2.9-14.6]).

DISCUSSION

We report a temporal increase in the proportion of infants enrolling for PMTCT care before 3 months of age, improved retention in PMTCT and a significant reduction in the proportion of infants enrolled who became HIV-infected, emphasizing the benefits of PMTCT.

CONCLUSION

A simple set of risk factors at enrollment can identify mother-infant pairs most at risk of infection or drop out for targeted intervention.