Randomisation and masking
tuberculosis
TUBERCULOSIS
Constrained randomisation was used to randomly assign 24 clusters (1:1) to intervention or control groups, balanced for prefecture (difference by group was at most one prefecture), health setting type (hospital or dispensary; seven hospitals and five dispensaries in each group), area (urban or rural; difference in number per group was at most one), and sputum smear-positive tuberculosis notifications in 2015 (difference in average notifications by group was at most ten cases). Randomisation was done by the trial statistician using Stata (version 14). After randomisation, it was identified that two clusters in the intervention group used the same dispensary, so these were combined into one cluster.Cluster randomisation was justified to reduce contamination between groups and for logistical convenience: the intervention required changes to the delivery of care, so there were concerns that individual randomisation would lead to staff changing their behaviour towards patients in the control group and patients discussing care with one another.Only the independent endpoints review committee who assessed endpoint data for some participants were masked to study group assignment.