Table 2.
Reporting of study characteristics
| Component | Number of studies (%) (N total = 31) |
|---|---|
| Trial design | |
| Parallel arm | 30 (97%) |
| Stepped-wedge design | 1 (3%) |
| Types of randomized clusters | |
| Hemodialysis centers | 17 (55%) |
| Hemodialysis shifts or sessions | 12 (39%) |
| Providers or professionals | 1 (3%) |
| Nephrology units₱ | 1 (3%) |
| Method of random allocation | |
| Completely randomized design (unrestricted randomization) | 8 (26%) |
| Stratified design | 4 (13%) |
| Pair-matched design | 4 (13%) |
| Split-cluster (i.e., shifts within a hemodialysis center) | 11 (35%) |
| Covariate-constrained | 1 (3%) |
| Not reported | 3 (10%) |
| Number of clusters per trial [median (25th, 75th percentile)]¥ | 28 (12, 43) |
| Number of patients per trial [median (25th, 75th percentile)]₳ | 228 (120, 1723) |
| Number of patients per cluster [median (25th, 75th percentile)]€,Ϫ | 20 (8, 32) |
₱It is not clear how a “nephrology unit” was defined
Estimate is based on ¥32, ₳29, and €28 trials. Missing data may have been a result of not reporting or the study being a protocol with no final information on the number of clusters/patients being available
ϪFor each study, we estimated the average cluster size by dividing the total number of patients recruited by the number of clusters (e.g., 200 patients recruited in a trial/10 clusters = 20 patients per cluster). We then took the median of the calculated average of patients per clusters from each trial