Table 1.
Characteristics of included stepped-wedge cluster randomized trials (SW-CRTs)(N = 160)
| Characteristic | Frequency (%) |
|---|---|
|
| |
| Publication Year | |
| 2016 | 12 (7.5) |
| 2017 | 9 (5.6) |
| 2018 | 23 (14.4) |
| 2019 | 30 (18.8) |
| 2020 | 34 (21.3) |
| 2021 | 40 (25.0) |
| 2022 | 12 (7.5) |
| Country or region of study recruitmenta | |
| North America | 40 (25.0) |
| South or Central America | 5 (3.1) |
| Europe | 51 (31.9) |
| Asia | 15 (9.4) |
| Australia or New Zealand | 23 (14.4) |
| Middle East | 3 (1.9) |
| Africa | 26 (16.3) |
| Type of cluster randomized | |
| Hospitals (38) or hospital wards (23) | 61 (38.1) |
| Primary care practices or clinics | 42 (26.3) |
| Nursing homes | 5 (3.1) |
| Communities or geographical areas | 20 (12.5) |
| Schools or classrooms | 3 (1.9) |
| Other (e.g., specialty clinics, groups of the above, families, etc.) | 29 (18.1) |
| Type of design | |
| Cross-sectional | 122 (76.3) |
| Open cohort | 15 (9.4) |
| Closed cohort | 23 (14.4) |
| Number of clusters randomized | |
| Median (Q1, Q3) | 11 (8, 18) |
| Min, Max | 5, 291 |
| Not reported | 1 |
| Number of sequences | |
| Median (Q1, Q3) | 5 (4, 7) |
| Min, Max | 2, 81 |
| Not reported | 2 |
| Allocation ratio | |
| Equal number of clusters per sequence | 112 (70.0) |
| Unequal number of clusters per sequence | 44 (27.5) |
| Unclear | 4 (2.5) |
| Number of clusters per sequence (N = 112 with equal allocation of clusters per sequence) | |
| 1 | 58 (51.8) |
| 2 | 20 (17.9) |
| 3 | 12 (10.7) |
| 4 or more | 22 (19.6) |
| Sample sizeb | |
| Median (Q1, Q3) | 2724 (643, 14,733.5) |
| Min, Max | 44, 4,801,573 |
| Not reported | 5 |
a
Multiple selections possible.
b
Defined as number of participants or participant-visits in a cross-sectional design, number of participants in an open or closed cohort design, or the off-set or person-time in a design with a rate or time-to-event outcome.