Participants and sample size
The sampling procedure for the initial study, from which the participants in the follow-on study were recruited, has been described elsewhere [The survey sample size for the follow-on study was based on comparisons of proportions in one sample. Assuming sample estimates were 20% at baseline and would increase 10 percentage points to 30% by endline, a sample of N = 137 at 80% power and alpha = 0.05 was required. We added 10% to the sample size to account for attrition, giving a total sample size of N = 151.At endline, we conducted separate focus group discussions (FGDs) with fathers (four FGDs, total of 24 fathers) and mothers (four FGDs, total of 24 mothers) and in-depth interviews (IDIs) with CEHOs (N = 6) and model fathers (N = 6). We chose these methods to gather perspectives from a variety of participants and implementers and to ensure that we could achieve data saturation [