a qualitative study is a limitation in validating this finding. However, the existing literature does not provide substantial contradictory evidence to refute this finding. While studies do reflect the promising role of CHWs in FP utilization, there is limited evidence of influence on other utilization indicators.<sup>37</sup> Nonetheless, this limited role is not promising, especially when compared with other countries in the South Asia region that have shown the impressive role of CHWs in driving maternal and child service uptake. The Accredited Social Health Activist (ASHA) program in India, for example, has emerged as one of the largest and most effective CHW programs globally for RMNCH-N services.<sup>38</sup> It is worth noting that the Bangladesh National Community Health Worker Strategy 2019 also calls for reinforcing the scope of CHWs in community health through multi-faceted approaches.<sup>37</sup>

# **Study Limitations**

This study has certain limitations. First, the selection of determinants and outcome indicators was limited by both data availability and compatibility for a comparative analysis across two time points. Therefore, certain crucial health outcomes (e.g., maternal and under-five mortalities) and child feeding practices could not be included when considering the nutrition outcomes. Also, data for Mymensingh was not separately included in DHS 2014 and therefore this division was excluded from division-specific analyses. Second, this study inherits the data quality issues and biases of both DHS and BHFS. Utilization and quality of care data were self-reported without verification, with a chance of recall bias, information bias and social desirability bias. BHFS did not physically verify the availability of services in facilities, as it collected information from the facility records. Validation studies in LMICs, however, have found a <mark>moderate to high sensitivity, and a m</mark> oderate validity for self-reported coverage of RMNCH-N service utilization and quality of care in household surveys.<sup>39,40</sup> For quality of care, DHS uses objective questions on standardized medical procedures and thus, the typical subjectivity concerns for psychometric assessments may not be applicable here as shown by validating studies.<sup>39,40</sup> Also, while assessing the determinants of RMNCH-N service utilization, the service seekers’ experience is more meaningful than a facility-based empirical assessment of quality.<sup>40</sup> Third, this study did not have a primary data component, and, in particular, a qualitative component to triangulate why and how certain determinants influenced each outcome in a particular way. Therefore, drawing conclusions from the findings requires a cautionary approach. Fourth, the machine learning analysis provides the top determinants that influenced the study outcomes. But a careful approach (substantiated by literature) is needed while concluding the direction of association between a specific determinant and an outcome. This study used a vast contextual literature including the DHS reports for triangulation.

Fifth, this study exclusively focused on the pre-pandemic (COVID-19) phase and used one of the most recent household and facility surveys data. Findings may not be appropriate for any decision making during the pandemic but would certainly be relevant for the post-COVID phase. The existing evidence indicates that the determinants of RMNCH-N service utilization would remain largely the same in the post-pandemic phase. Nonetheless, low service provision, poor quality and financial constraints of service seekers perhaps would be multiplied and remain as the top determinants in the post-pandemic phase.<sup>41</sup> This study, however, also shows that service availability, quality and household wealth status are the top determinants even in the pre-pandemic phase. Lastly, this study did not assess the impact of any ongoing policy interventions. Thus, findings are not robust enough to make a conclusion on the ultimate impact of any initiatives. However, findings certainly reflect the key determinants that could be addressed further, on a priority basis. Findings can also indicate the need, as well as the direction, for mainstreaming some of the current policy strategies and interventions.

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