Table 2.
Determinants of comprehensive sample size planning
| α level | n (%) |
|---|---|
| 5% | 36 (46.2) |
| <5% | 4 (5.1) |
| no information | 38 (48.7) |
| β level | |
| 80% | 33 (42.3) |
| >80% | 10 (12.8) |
| no information | 35 (44.9) |
| N conditions | |
| 2 (%) | 61 (78.2) |
| 3 (%) | 14 (17.9) |
| ≥4 (%) | 3 (3.9) |
| Number of repeated measurementsa | |
| 2 (%) | 62 (79.5) |
| 3–4 (%) | 8 (10.2) |
| 5–12 (%) | 8 (10.2) |
| Correlation among repeated measures (s.d. of r) | 0.25 (0.26) |
| Expected treatment effect (Cohen's d; s.d. of d) | 0.52 (0.17) |
| Subgroup analysis conducted | 31 (53.4) |
| Actual study dropout | |
| Face-to-face (% of N) | 29 (21) |
| Internet intervention (% of N) | 51 (19.9) |
a
Between pre- and post-assessment.