Type I error of 3-cycles N-of-1 trials (n = 1, 3, 5, 10, 20, 30).

Note: M1, M2, M3 and M4 denoted paired t-test (Model 1), mixed effects model of difference (Model 2), mixed effects model (Model 3) and meta-analysis (Model 4) respectively. CS1, CS2 and CS3 represented compound symmetry variance-covariance matrices with covariance of 0, 0.5 and 0.8 respectively. AR1, AR2 denoted first-order autoregressive structure with autoregressive coefficient 0.5 and 0.8 respectively. 0% and 20% meant carryover rate. N/A: Meta-analysis was not available for n = 1 subject.