Table 3.
Model performance in the pooled dataset and after internal-external cross-validation
| Development of model | Internal-external cross-validation | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Apparent performance (in 4 pooled cohorts) | Optimism-corrected performancea (in 4 pooled cohorts) | Development in ELSA, InCHIANTI, LASA | External validation in ActiFE-ULM | Development in ActiFE-ULM, InCHIANTI, LASA | External validation in ELSA | Development in ActiFE-ULM, ELSA, LASA | External validation in InCHIANTI | Development in ActiFE-ULM, ELSA, InCHIANTI | External validation in LASA | |
| n = 2560 | n = 2560 | n = 2110 | n = 450 | n = 1424 | n = 1136 | n = 2090 | n = 470 | n = 2056 | n = 504 | |
| Discrimination | ||||||||||
| C statisticb | 0.719 (0.717–0.721) | 0.719 (0.716–0.720) | 0.721 (0.719–0.723) | 0.698 (0.695–0.700) | 0.738 (0.736–0.740) | 0.691 (0.687–0.694) | 0.713 (0.712–0.716) | 0.720 (0.718–0.723) | 0.711 (0.709–0.713) | 0.740 (0.738–0.742) |
| Calibration | ||||||||||
| Interceptc | 0.000 (0.000–0.000) | 0.059 (0.047–0.073) | 0.000 (0.000–0.000) | 0.135 (0.113--0.159) | 0.000 (0.000–0.000) | − 0.271 (− 0.293- -0.263) | 0.000 (0.000–0.000) | − 0.116 (− 0.144- -0.103) | 0.000 (0.000–0.000) | − 0.096 (− 0.112- -0.976) |
| Slopec | 1.000 (1.000–1.000) | 1.053 (1.042–1.065) | 1.000 (1.000–1.000) | 0.949 (0.931–0.958) | 1.000 (1.000–1.000) | 0.757 (0.739–0.769) | 1.000 (1.000–1.000) | 0.966 (0.949–0.981) | 1.000 (1.000–1.000) | 1.215 (1.191–1.228) |
Values are median (IQR)
aOptimism 0.049–0.054, determined by internal validation in bootstrap samples (250 samples with replacement)
bC statistic of 0.50 represents no discrimination and 1.00 represents perfect discrimination
cIntercept of 0 and slope of 1 represent perfect calibration