Allocation concealment mechanism
A statistician, who was unaware of the study-group assignments, used a table of random numbers for each stratum. Fifteen clusters were randomly allocated to each intervention group and 30 to the usual care group. Either in the intervention or control arm, all children were eligible to be recruited in the control or intervention arm if they were under 15 years of age and had a viral load > 1,000 cells/mm. The allocation remained in the regional medical office until the site had completed the basic introductory training of study personnel (both in standard model and control model clinics [clusters]). After completion of the introductory training, the allocated facilities were delivered directly to the principal investigator.