Table 4.

Conduct and reporting of sample size or power calculations (N=62)

Characteristic	Frequency (%)
Sample size / power calculations presented?
Yesa	50 (80.6%)
No	12 (19.4%)
Did sample size / power calculation account for clustering?
Cluster randomized trial (N=38)
Yes: Participant-level accounting for clustering	20 (52.6%)
Yes: Cluster-level	2 (5.3%)
No: Participant -level without accounting for clustering	5 (13.2%)
Unclear whether accounted for clustering	1 (2.6%)
No sample size calculation presented	10 (26.3%)
Individually randomized group treatment trial (N=9)
Yes: Participant-level accounting for clustering	3 (33.3%)
No: Participant -level without accounting for clustering	6 (66.7%)
No sample size calculation presented	0
Did sample size/ power calculation account for repeated measures? (N=54)
Yes	9 (16.7%)
No	33 (61.1%)
No sample size calculation presented	12 (22.2%)
Was correlation in dyadic or multivariate outcome accounted for in sample size calculation? (N=17)
Yes	0
No	12 (70.6%)
No sample size calculation presented	5 (29.4%)

^aIncludes one trial presenting a sample size calculation based on an unspecified outcome