Evaluating phone call follow-ups in Sub-Saharan Africa: A systematic review and meta-analysis

Background: Healthcare systems in Sub-Saharan Africa (SSA) face significant challenges, including limited resources, understaffing, and geographical barriers, which hinder effective healthcare delivery. Phone call follow-ups have emerged as a promising strategy to improve participant retention, enhance data accuracy, and optimize health outcomes in resource-constrained settings. Despite their growing adoption, there is limited synthesized evidence of their effectiveness across various public health contexts in SSA. Methodology: This systematic review and meta-analysis included 32 studies published between 2000 and 2024, conducted in 11 SSA countries. Studies employing phone call follow-ups in community and facility-based health interventions were evaluated. Participant retention rates, reasons for loss to follow-up, and health outcomes were analyzed. Risk of bias and quality were assessed using validated tools tailored to study designs, including the Hoy et al. checklist for observational studies and the Joanna Briggs Institute (JBI) checklist for experimental studies. Statistical analysis employed a random-effects model to calculate pooled estimates and sensitivity analysis was conducted to assess the robustness of findings. Although the primary focus was on phone call follow-up interventions, a few included studies also utilized text messaging alongside phone calls. Results: The pooled retention rate across studies was 89% (95% CI: 85–91), with substantial variability among countries. Retention rates were highest in Kenya (96%) and Nigeria (87%). In contrast, countries like Cameroon reported a high participant loss rate of 42%. Frequent and consistent follow-up calls were associated with improved retention rates; studies that contacted participants 4–5 times reported retention rates as high as 98%. Barriers to follow-up included network issues, outdated contact information, and participant relocations. Risk of bias assessments showed that 81% of observational studies were rated as low risk. Additionally, 69% of experimental studies were assessed as high quality. Funnel plots assessing publication bias indicated some asymmetry in studies reporting lost rates, suggesting potential bias. Conclusion: Phone call follow-ups have enhanced participant retention and improved SSA health outcomes in regions with robust health infrastructure. However, variability in retention rates underscores the need for tailored strategies to address barriers like network challenges and participant mobility. Integrating innovative platforms like WhatsApp and leveraging consistent follow-up methods can enhance their scalability and impact. Policymakers should consider incorporating phone call follow-ups into routine care to optimize healthcare delivery in resource-constrained settings.