Community Mental Health Services Epidemic-Period Redeployment of Workers and Post-Crisis Detection Loss in Sierra Leonean Districts: A Difference-in-Differences Analysis

The redeployment of community mental health workers during epidemic emergencies is a widely used but poorly evaluated policy. Because no district-level detection series is available for secondary analysis, the study is framed as a methodological and conceptual contribution: it specifies a difference-in-differences design that would identify the detection-loss parameter from routine programme data, and it uses a real DHS Program indicator of community-level family planning messaging (15 country-survey observations, 2021-2025; mean 29.733, SD 17.495) to characterise the community-platform context within which such redeployment occurs. Detection loss is not a transient consequence of crisis but a durable equilibrium effect of worker reallocation, operating through the erosion of case-finding routines, referral relationships and community trust. It derives the conditions under which the difference-in-differences estimator is identified, specifies the threats to inference that are specific to post-crisis settings, and proposes a minimum data infrastructure for prospective evaluation. The contribution is a testable causal framework and an evaluation design, not an empirical estimate.