Implementing essential diagnostics-learning from essential medicines: A scoping review

Abstract Background The World Health Organization (WHO) model list of Essential In vitro Diagnostic (EDL) introduced in 2018 complements the established Essential Medicines List (EML) and improves its impact on advancing universal health coverage and better health outcomes. We conducted a scoping review of the literature on the implementation of the WHO essential lists in Africa to inform the implementation of the recently introduced EDL. Methods We searched eight electronic databases for studies reporting on the implementation of the WHO EDL and EML in Africa. Two authors independently conducted study selection and data extraction, with disagreements resolved through discussion. We used the Supporting the Use of Research Evidence (SURE) framework to extract themes and synthesized findings using thematic content analysis. We used the Mixed Method Appraisal Tool (MMAT) version 2018 to assess the quality of included studies where applicable. Results We included 172 studies reporting on EDL and EML after screening 3,813 articles titles and abstracts and 1,545 full-text papers. Most (75%, n=129) included studies were purely quantitative in design comprising descriptive cross-sectional designs (60%, n=104), 15% (n=26) were purely qualitative, and 10% (n=17) had mixed-methods approaches. There were no qualitative or randomised experimental studies about the EDL. The main barrier facing the EML and EDL was poorly equipped health facilities - including unavailability or stock-outs of essential in vitro diagnostics and medicines and inadequate infrastructure to enable health service delivery. Financial and non-financial incentives to health facilities and workers were a key enabler to the implementation of the EML however, their impact differed from one context to another. Fifty-six (33%) of the included studies were of high quality. Conclusions The EDL implementation at the national level can learn from health system interventions to improve the availability and supply of essential medicines such as financial and non-financial incentives in different contexts. Plain language summary The World Health Organization (WHO) periodically publishes the Model lists of essential medicines (EML) and essential in vitro diagnostics (EDL) to offer guidance to member states. The model lists help countries prioritise the critical health products that should be widely available and affordable throughout health systems. Countries frequently use these model lists to help develop their local lists of essential medicines and diagnostics. The model list of essential diagnostics was introduced in 2018, while the essential medicines were introduced 45 years ago. This work evaluates current evidence on the implementation of the more established model list of essential medicines to inform the development and implementation of the national list of essential in vitro diagnostics in Africa. We reviewed results from all available studies that looked at the provision of treatment and/or diagnostic services in Africa and assessed the barriers and enablers for their implementation. We found 172 articles assessing the provision of treatment and diagnostics in Africa. We looked in detail at the barriers and enablers to implementing the model lists of essential medicines and essential in vitro diagnostics. We also assessed the quality of the included research studies. We combined the results of the studies and established that the health system barriers were the most dominant constraints to implementing the model lists. Our review found the implementation of the established EML, the new EDL was mainly due to poorly equipped health facilities, including limited availability, and stock outs of essential medicines and tests. It is important to consider these constraints when developing and implementing the EDL at various national levels. EDL Implementation at the national level can learn from interventions to improve the availability and supply of essential medicines. Financial and non-financial incentives may be enabling interventions, but their effect varies in different countries and contexts.