Measuring Co-Coverage in Global Health and Nutrition Interventions: A Scoping Review of Analytical Approaches

Multi-sectoral nutrition (MSN) approaches coordinate interventions across sectors such as health, agriculture, education, and social protection to improve nutrition outcomes, and have gained prominence in low- and middle-income countries (LMICs). Measuring co-coverage - the clustering of multiple interventions at the individual and household level - remains uncommon yet offers a viable method for tracking MSN intervention coverage. This scoping review examined existing analytic approaches and applications for assessing co-coverage of health and nutrition interventions. We searched Web of Science Core Collection, PubMed, and EBSCOhost for studies that used, described, or developed co-coverage methods to measure nutrition- and health-related intervention coverage. Titles and abstracts were screened by two independent reviewers using Covidence, followed by full-text screening based on pre-defined criteria. Screening 4,478 abstracts yielded 73 eligible studies applying 8 distinct methods to quantify co-coverage across health and nutrition interventions. Most studies were observational (90%) and conducted in LMICs, particularly Sub-Saharan Africa and South Asia, with publications increasing over the past decade. Data were primarily drawn from surveys (93%), particularly Demographic and Health Surveys (41 studies). Commonly included individual-level interventions in co-coverage indices were antenatal care (ANC, 66 studies) or ANC components, child immunizations (48 studies), and skilled birth attendance (42 studies). Evidence on measuring a range of multisectoral interventions at the household level was limited. Intervention selection was often guided by established frameworks or guidelines. Coverage indices were calculated using simple counts, weighted averages, and scoring systems. While 18 studies validated their indices through methods such as Cohen's kappa and sensitivity analyses, most relied on previously used approaches without specific validation. These findings underscore the considerable variability in co-coverage methodologies and the need for greater harmonization and validation to enable consistent monitoring of multisectoral nutrition progress.