Medical Pluralism Consultation Sequences and Delayed Tuberculosis Diagnosis in Mozambican Health Districts: A Sequence-Analysis Estimation of Healer-First Pathways and Diagnostic Interval

Delayed tuberculosis diagnosis in Mozambique is frequently attributed to patients consulting traditional healers before biomedical services, yet the evidence for this healer-first pathway rests largely on cross-sectional recall and does not establish how consultation order shapes the diagnostic interval. The framework formalises consultation sequences as ordered states, defines the diagnostic interval as the elapsed time from symptom onset to first smear-positive diagnosis, and specifies a before-after-control-impact estimator with district-level clustering. Under a declared variance structure with an intraclass correlation of 0.64, a between-cluster standard deviation of 6.0 and a residual standard deviation of 4.5, power was estimated across 2000 replications per design cell for cluster counts of 8, 16, 24 and 32 and effect sizes of 3, 5 and 8 percentage points. Fifty-two clusters are required to detect a 5 percentage point reduction at 80% power. The framework reframes healer-first consultation as a modifiable sequence property rather than a fixed cultural trait, and the design analysis indicates that district-level evaluations of healer-referral interventions are feasible only at cluster counts well above those typical of current pilot programmes.