Participant recruitment and retention in longitudinal preconception randomized trials: lessons learnt from the Calcium And Pre-eclampsia (CAP) trial

• Published in: Current controlled trials in cardiovascular medicine 2017-10, Vol.18 (1), p.500-11, Article 500
• Main Authors: Lawrie, Theresa A, Betrán, Ana Pilar, Singata-Madliki, Mandisa, Ciganda, Alvaro, Hofmeyr, G Justus, Belizán, José M, Purnat, Tina Dannemann, Manyame, Sarah, Parker, Catherine, Cormick, Gabriela
• Format: Article
• Language: English
• Subjects: Analysis; Argentina; Calcium; Calcium Carbonate - adverse effects; Calcium Carbonate - therapeutic use; Care and treatment; Clinical trials; Compensation; Dietary Supplements - adverse effects; Double-Blind Method; Female; Health aspects; Hospitals; Humans; Hypertension; Intervention; Laboratories; Low income groups; Medical records; Miscarriage; Patient Dropouts; Patient Selection; Pre-eclampsia; Pre-Eclampsia - diagnosis; Pre-Eclampsia - physiopathology; Pre-Eclampsia - prevention & control; Preconception; Preconception Care - methods; Preeclampsia; Pregnancy; Pregnant women; Questionnaires; Randomized; Recruitment; Recurrence; Retention; Risk Factors; Sample Size; Software; South Africa; Surveys and Questionnaires; Time Factors; Treatment Outcome; Womens health; Zimbabwe
• ISSN: 1745-6215; 1745-6215
• DOI: 10.1186/s13063-017-2220-0

The preconception period has the potential to influence pregnancy outcomes and randomized controlled trials (RCTs) are needed to evaluate a variety of potentially beneficial preconception interventions. However, RCTs commencing before pregnancy have significant participant recruitment and retention challenges. The Calcium And Pre-eclampsia trial (CAP trial) is a World Health Organization multi-country RCT of calcium supplementation commenced before pregnancy to prevent recurrent pre-eclampsia in which non-pregnant participants are recruited and followed up until childbirth. This sub-study explores recruitment methods and preconception retention of participants of the CAP trial to inform future trials. Recruiters at the study sites in Argentina, South Africa and Zimbabwe completed post-recruitment phase questionnaires on recruitment methods used. Qualitative data from these questionnaires and quantitative data on pre-pregnancy trial visit attendance and pregnancy rates up to September 2016 are reported in this paper. RStudio (Version 0.99.903 https://www.rstudio.org ) statistical software was used for summary statistics. Between July 2011 and 8 September 2016, 1354 women with previous pre-eclampsia were recruited. Recruitment took 2 years longer than expected and was facilitated mainly through medical record/register and maternity ward/clinic-based strategies. Recruiters highlighted difficulties associated with inadequate medical records, redundant patient contact details, and follow-up of temporarily ineligible women as some of the challenges faced. Whilst the attendance rates at pre-pregnancy visits were high (78% or more), visits often occurred later than scheduled. Forty-five percent of participants became pregnant (614/1354), 33.5% (454/1354) within 1 year of randomization. In preconception trials, both retrospective and prospective methods are useful for recruiting eligible women with certain conditions. However, these are time-consuming in low-resource settings with suboptimal medical records and other challenges. Trial planners should ensure that trial budgets cover sufficient on-site researchers with pre-trial training, and should consider using mobile phone and web-based electronic tools to optimize recruitment and retention. This should lead to greater efficiency and shorter trial durations. Pan-African Clinical Trials Registry, Registration Number: PACTR201105000267371 . The trial was registered on 6 December 2016.