Table 3.

Distribution of analytic methods in 123 articles reporting on group-randomized trials in cancer research published in peer-reviewed journals during the period 2011–2015, inclusive.

Criteria	N	%	N	%
Articles reporting only appropriate methods	63	51.2
Mixed-model ANOVA or ANCOVA with 1 time point			39	56.5
Mixed-model repeated measures with 2 time points			7	10.1
Random coefficients model with >2 time points			2	2.9
Generalized estimating equations with ≥38 degrees of freedom			9	13.0
Cox regression with adjustment for the unit of assignment			4	5.8
Two-stage analysis			6	8.7
Other			2	2.9
Articles reporting both appropriate and inappropriate methods	17	13.8
Appropriate Methods
Mixed-model ANOVA or ANCOVA with 1 time point			11	64.7
Mixed-model repeated measures with 2 time points			1	5.9
Random coefficients model with >2 time points			0	0.0
Generalized estimating equations with ≥38 degrees of freedom			2	11.8
Cox regression with shared frailty for the unit of assignment			3	17.6
Two-stage analysis			0	0.0
Other			0	0.0
Inappropriate Methods
Analysis at an individual level, ignoring groups			16	94.1
Analysis at a subgroup level, ignoring groups			0	0.0
Analysis with group as a fixed effect			0	0.0
Mixed-model repeated measures, > 2 time points			0	0.0
GEE with ≤38 df and no small sample correction			1	5.9
Individual-level analysis with post-hoc correction			0	0.0
Other			0	0.0
Articles reporting only inappropriate methods	37	30.1
Analysis at an individual level, ignoring groups			18	45.0
Analysis at a subgroup level, ignoring groups			7	17.5
Analysis with group as a fixed effect			2	5.0
Mixed-model repeated measures, > 2 time points			3	7.5
GEE with ≤38 df and no small sample correction			8	20.0
Individual-level analysis with post-hoc correction			1	2.5
Other			1	2.5
Not enough information provided	6	4.9

This work was performed in Bethesda Maryland during 2016–17.