Fig 1.
These simulated data represent N-of-1 trials with m crossovers of treatments A and B, randomized within block (left panels). The differences between A and B within a block (right panels) may be suitably analyzed with paired serial t-tests for level-change (top panels) and for rate-change (bottom panels). The true means are represented with lines, and serially correlated observations with points.
Fig 2.
These simulated data represent N-of-1 trials where a series of observations from treatment A are observed first, followed by a series of observations from treatment B. These data may be suitably analyzed with 2-sample serial t-tests for level-change (a) and for rate-change (b). The true means are represented with lines, and serially correlated observations with points.
Table 1.
Expected margins of error for 90% confidence intervals (95% one-sided confidence limit) for μA−B from the paired serial t-test for level change in Eq 8; assumes σ2 = 1.
Table 2.
Effect sizes of μA−B (in σ units) detectable with 0.80 power on a 0.10 (one-sided 0.) level test, using the paired serial t-test for level change in Eq 8.
Fig 3.
Paired t-test for level-change.
Type I error (top) and theoretical effect size, δ, computed using Eq 8 for 80% power with a one-sided 5% significance level test for a given m (middle). Ratios (bottom) of serial and usual δ (estimated from simulation) to the theoretical δ under same conditions as the theoretical δ.
Fig 4.
Paired t-test for rate-change.
Type I error (top) and theoretical effect size, δ, computed using Eq 13 for 80% power with a one-sided 5% significance level test for a given m (middle). Ratios (bottom) of serial and usual δ (estimated from simulation) to the theoretical δ under same conditions as the theoretical δ.
Table 3.
Factors by which the expected margin of error for a 90% confidence interval (95% one-sided confidence limit) is overestimated or underestimated for select sample sizes (m).
Table 4.
N-of-1 randomized control trial data from [23].
Table 5.
Example of indifference points from discounting tasks completed pre- and post-treatment for opioid dependence by Patient 1390.
Table 6.
Number (percent) of 119† patients discounting differently between pre- and post-treatment.