Table 4.
Predictive performance of the physical activity and sedentary behaviour composite score 1 for mortality risk in CoLaus accelerometer sub-study (N cases/N total = 105/1329, mean [standard deviation] follow-up = 3.8 [0.7] years).
| HR (95% CI) PA and SB composite score 1 | Royston's R2 (95% CI) | AIC (95% CI) | ΔAIC (95% CI) | Sensitivity % (95% CI)a | Specificity % (95% CI)b | C-index (95% CI) | ΔC-index (95% CI) | |
|---|---|---|---|---|---|---|---|---|
| Model 1 c | NA | 0.392 (0.349, 0.556) | 1121.4 (876.0, 1308.8) | Ref. | 56.1 (49.5, 90.3) | 84.2 (50.8, 90.3) | 0.757 (0.716, 0.830) | Ref. |
| Model 2 b | 1.18 (1.10, 1.26), p < 0.001 | 0.430 (0.394, 0.593) | 1103.6 (856.7, 1287.9) | −17.8 (−41.8, −4.3)d | 74.2 (55.4, 88.8) | 75.4 (56.4, 90.4) | 0.785 (0.737, 0.856) | 0.029 (0.002, 0.055)d |
CI: confidence interval; AIC: Akaike information criterion; C-index: Harrell's C-index; PA, physical activity; SB, sedentary behaviour.
Youden index cutoff points for the calculation of the sensitivity and specificity: 0.403 (95% CI: [0.345, 0.578]) for Model 1 and 0.496 (95% CI: [0.391, 0.628]) for Model 2.
Model 2: Model 1 additionally adjusted for the physical activity and sedentary behaviour composite score 1.
Model 1: Model includes socio-demographic, behavioural, and health-related factors.
Confidence intervals (calculated based on 1000 bootstrap samples) not containing zero indicate significant differences in predictive performance between Model 1 and Model 2.