Mental Health Service User Fees and Community Follow-Up Dropout in Ghanaian Districts: A Difference-in-Differences Analysis of Fee Exemption Rollout

Ghana's National Health Insurance Scheme has progressively exempted community mental health service users from point-of-care fees, yet the causal effect of this rollout on community follow-up dropout remains unquantified. the present analysis specifies a difference-in-differences design that exploits staggered district-level fee exemption timing to identify the effect of user-fee removal on dropout from community follow-up among registered service users. The design defines treatment as the district-month in which exemption becomes operational, uses never-exempted districts as a comparison group, and conditions on district and month fixed effects to absorb time-invariant heterogeneity and common shocks. The estimand is the average treatment effect on the treated for the probability of dropout within ninety days of a scheduled community visit. Identification rests on parallel trends in pre-rollout dropout, which the design tests through event-study leads and a pre-trend placebo. It does not report empirical estimates; it reports the design, the assumptions, and the inferential boundaries that any future implementation of this analysis must respect.