How service delivery implementation strategies can contribute to attaining universal health coverage: lessons from polio eradication using an implementation science approach

BACKGROUND: Improving service delivery is a key strategy for achieving service coverage, one of the two components of universal health coverage (UHC). As one of the largest global public health initiatives, individuals involved with the Global Polio Eradication Initiative (GPEI) have learned many important lessons about service delivery. We identified contributors and challenges to delivering health services at national and subnational levels using experiences from the GPEI. We described strategies used to strengthen service delivery and draw lessons that could be applicable to achieving UHC. METHODS: Online cross-sectional surveys based on the Consolidated Framework for Implementation Research (CFIR) domains and socioecological model were conducted from 2018–2019. Data were analyzed using an embedded mixed methods approach. Frequencies of the contributors and challenges to service delivery by levels of involvement were estimated. Chi-square tests of independence were used to assess unadjusted associations among categorical outcome variables. Logistic regressions were used to examine the association between respondent characteristics and contributors to successful implementation or implementation challenges. Horizontal analysis of free text responses by CFIR domain was done to contextualize the quantitative results. RESULTS: Three thousand nine hundred fifty-five people responded to the online survey which generated 3,659 valid responses. Among these, 887 (24.2%) reported involvement in service delivery at the global, national, or subnational level with more than 90% involved at subnational levels. The main internal contributor of strengthened service delivery was the process of conducting activities (48%); working in frontline role had higher odds of identifying the process of conducting activities as the main internal contributor (AOR: 1.22, p = 0.687). The main external contributor was the social environment (42.5%); having 10–14 years of polio program implementation was significantly associated with identifying the social environment as the main external contributor to strengthened service delivery (AOR: 1.61, p = 0.038). The most frequent implementation challenge was the external environment (56%); working in Eastern Mediterranean region was almost 4 times more likely to identify the external environment as the major challenge in service delivery strengthening (AOR:3.59, p < 0.001). CONCLUSION: Priority actions to improve service delivery include: adopt strategies to systematically reach hard-to-reach populations, expand disease-focused programs to support broader primary healthcare priorities, maximize community outreach strategies to reach broader age groups, build community trust in health workers and develop multisectoral leadership for collaboration. Achieving UHC is contingent on strengthened subnational service delivery. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12889-022-13681-0.