Medical Sociology of Bedside Rationing Discretion and Catastrophic Out-of-Pocket Spending in Ugandan Private Not-for-Profit Hospitals: A Vignette-Experiment Estimation of Informal User-Fee Exposure

Bedside rationing discretion in Ugandan private not-for-profit hospitals is widely theorised to generate informal user-fee exposure that pushes households into catastrophic out-of-pocket spending, yet the vignette experiments used to estimate such effects are typically underpowered and their operating characteristics are rarely characterised before fieldwork. Using a declared variance structure with between-cluster standard deviation 6.0, residual standard deviation 4.5 and intraclass correlation 0.64, 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.52 clusters are required to detect a 5 percentage point reduction in informal fee exposure at 80 per cent power, that power falls steeply below this threshold, and that the minimum detectable effect at 80 per cent power declines non-linearly with cluster count. The results imply that single-site or small-cluster vignette studies of bedside rationing cannot credibly distinguish modest discretion effects from sampling noise, and that the field should treat cluster counts as a design parameter to be justified rather than a convenience of access.