Table 2 Reproducibility of the test-retest measurements of the ACP Engagement Survey (34 items) and its subscales
Intraclass correlation coefficient (95% CIa) | Mean change (SDb) | Limits of agreementc | Bland Altman’s: t-test; linear regressiond | |
|---|---|---|---|---|
Total ACP Engagement (mean of all items) | 0.88 (0.84–0.91) | 0.019 (0.593) | −1.14 to 1.18 | p = 0.6; p = 0.7 |
Subscale: Knowledge | 0.64 (0.53–0.72) | −0.103 (1.318) | − 2.69 to 2.48 | p = 0.2; p = 0.2 |
Subscale: Contemplation | 0.84 (0.79–0.88) | −0.167 (0.923) | −1.98 to 1.64 | p = 0.006; p = 0.7 |
Subscale: Self-efficacy | 0.82 (0.76–0.86) | 0.052 (0.724) | −1.37 to 1.47 | p = 0.3; p = 0.6 |
Subscale: Readiness | 0.87 (0.83–0.90) | −0.055 (0.725) | −1.48 to 1.37 | p = 0.3; p = 0.5 |