Stock-outs of essential medicines among community health workers (CHWs) in low- and middle-income countries (LMICs): a systematic literature review of the extent, reasons, and consequences

BACKGROUND: This paper explores the extent of community-level stock-out of essential medicines among community health workers (CHWs) in low- and middle-income countries (LMICs) and identifies the reasons for and consequences of essential medicine stock-outs. METHODS: A systematic review was conducted and reported in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Five electronic databases were searched with a prespecified strategy and the grey literature examined, January 2006–March 2021. Papers containing information on (1) the percentage of CHWs stocked out or (2) reasons for stock-outs along the supply chain and consequences of stock-out were included and appraised for risk of bias. Outcomes were quantitative data on the extent of stock-out, summarized using descriptive statistics, and qualitative data regarding reasons for and consequences of stock-outs, analyzed using thematic content analysis and narrative synthesis. RESULTS: Two reviewers screened 1083 records; 78 evaluations were included. Over the last 15 years, CHWs experienced stock-outs of essential medicines nearly one third of the time and at a significantly (p < 0.01) higher rate than the health centers to which they are affiliated (28.93% [CI 95%: 28.79–29.07] vs 9.17% [CI 95%: 8.64–9.70], respectively). A comparison of the period 2006–2015 and 2016–2021 showed a significant (p < 0.01) increase in CHW stock-out level from 26.36% [CI 95%: 26.22–26.50] to 48.65% [CI 95%: 48.02–49.28] while that of health centers increased from 7.79% [95% CI 7.16–8.42] to 14.28% [95% CI 11.22–17.34]. Distribution barriers were the most cited reasons for stock-outs. Ultimately, patients were the most affected: stock-outs resulted in out-of-pocket expenses to buy unavailable medicines, poor adherence to medicine regimes, dissatisfaction, and low service utilization. CONCLUSIONS: Community-level stock-out of essential medicines constitutes a serious threat to achieving universal health coverage and equitable improvement of health outcomes. This paper suggests stock-outs are getting worse, and that there are particular barriers at the last mile. There is an urgent need to address the health and non-health system constraints that prevent the essential medicines procured for LMICs by international and national stakeholders from reaching the people who need them the most. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12960-022-00755-8.