Limitations
We were not able to collect data on service readiness and quality of care at any point of time between 2016 and 2020. We, therefore, could not assess whether the observed declines had occurred earlier or later, and whether the decline followed a linear pattern or occurred at certain points in time. Because there were no major changes in policy, infrastructure, or human resource or staff attrition in the assessed intervention facilities over this period; we assume the deterioration occurred slowly.We also cannot ascertain whether any effect of the intervention may have in fact optimised after 2016, and whether any positive effects observed in 2020 reflected that subsequent optimisation rather than intervention durability. However, the 4-year gap between assessments is likely to be a long enough period to hone out only the durable post-trial effects.As this study focused on evaluating sustainability in facilities that received the intervention, we did not evaluate the former control facilities for comparison; therefore, it is possible that our findings were a result of other external influences that might have alleviated a possible decline of SAR and/or QoCE, rather than of the durability of the intervention. However, there were no major changes in health policy, health facility management or community initiatives during this period, and we are not aware of any other (e.g., NGO-related) health service efforts to strengthen health service performance, neither among the former intervention nor the former control facilities. Although all primary care centres in Uganda participate in ongoing efforts of the national NCD control programme to strengthen the response to NCDs, the effect of these efforts has been limited: for example, the proportion of health workers trained “during the last year” was 23% in 2020 and 39% in 2016, and there was little difference in having “received any NCD training” (68% in 2020 vs. 65% in 2016).Our sample size of health workers and patients in 2016 was fixed; therefore, our ability to increase the power of the study was limited. However, where possible, we increased the number of participants in the 2020 survey so that we had reasonable power (> 80%) to detect important changes in service readiness or quality of care.Both health workers and patients who participated in the MeLoHanD study represent clusters of participants: it can be assumed that individuals from the same HF were likely to be more similar with regards to the variables that we determined in this study than a random selection of independent individuals. We accounted for this clustered design in the statistical analysis.However, there were some notable differences in the study populations between the two surveys e.g., there were fewer health workers at HCIIs in 2016 than in 2020 (18% vs 28%) and more at HCIIIs (60% vs 47%) which could mean that HCIIs were over-represented or HCIIIs were under-represented in the 2020 health worker sample. This could be partly explained by the fewer number of health workers that were available for survey in 2020 due to COVID restrictions or related absenteeism. In spite of this, there was generally a more equitable spread in 2020.