TABLE 1.

Simulation results of a stratified SWT across 2000 datasets simulated via model (7) as described in Section 3.2.1 with cluster sizes m_ij ∼ U{20, 30}

		Type I error (%)			CI coverage (%)			Average CI width
		N
Method	γ*	6	10	14	6	10	14	6	10	14
Randomization	0-ns	5	6	4	94	95	95	1.42	0.71	0.50
	0	3	5	4	94	95	96	1.67	0.72	0.50
	0.2	3	5	5	96	95	95	1.69	0.71	0.49
	0.7	3	5	5	95	95	94	1.58	0.67	0.46
	1.5	3	5	4	95	95	96	1.46	0.61	0.43
	1.5-ns	0	0	0	100	100	100	4.73	2.10	1.58
GLMM-C	0-ns	6	7	5	94	93	95	1.14	0.66	0.47
	0	6	7	5	94	93	95	1.12	0.65	0.47
	0.2	5	6	6	95	94	94	1.11	0.64	0.46
	0.7	6	6	6	94	94	94	1.06	0.62	0.44
	1.5	5	5	6	95	95	94	1.08	0.63	0.45
	1.5-ns	4	5	5	96	95	95	1.29	0.77	0.56
GEE-FGd5	0-ns	3	5	5	97	95	95	1.97	0.77	0.52
	0	2	6	5	98	94	95	2.11	0.77	0.51
	0.2	2	5	6	98	95	94	2.02	0.75	0.50
	0.7	2	5	6	98	95	94	2.20	0.73	0.48
	1.5	2	5	5	98	95	95	2.13	0.74	0.49
	1.5-ns	4	5	4	96	95	96	1.49	0.76	0.52

Note: Methods considered included our proposed individual-level randomization-based approach (Randomization), a logistic mixed model with random cluster effects (GLMM-C), and a marginal model fit via a small-sample adjusted generalized estimating equation (GEE-FGd5). Increasing values of γ* correspond to increasing strengths of Y-Z association. Rows designated with “-ns” correspond to a nonstratified analysis; all other rows correspond to a stratified analysis. For complete stratified SWT simulation results, see Tables S11 to S16 in the Supporting Information.

Abbreviations: CI, confidence interval; SWT, stepped wedge cluster randomized trial.