Dental hygiene therapy oral care bundles and ventilator-associated pneumonia incidence in Ghanaian intensive care units: a stepped-wedge cluster evaluation of nurse-delivered decontamination

Ventilator-associated pneumonia remains a leading cause of intensive-care-acquired infection in low- and middle-income countries, yet the oral-care bundle that reduces its incidence is typically designed for nurse delivery without dental hygiene therapy involvement. The design was a before-after-control-impact (BACI) estimator evaluated across 8, 16, 24 and 32 clusters, with effect sizes of 3, 5 and 8 percentage points and 2000 replications per design cell. Under a declared variance structure with between-cluster SD of 6.0, residual SD of 4.5 and intraclass correlation of 0.640, the analysis characterised the operating characteristics of the estimator. Power to detect a 5 percentage-point reduction reached 80% at 54 clusters. The minimum detectable effect at 80% power declined as cluster count rose from 8 to 32. The results indicate that the BACI estimator is viable for evaluating oral-care bundles in Ghanaian intensive care units only when cluster counts exceed those typically available in single-region studies, and that dental hygiene therapy supervision of nurse-delivered decontamination should be evaluated with designs powered for effects no smaller than 5 percentage points.