Accuracy of the cognitive charts for identifying participants with dementia in the training sample population (Canadian Study of Health and Aging)22
| Parameter | At baseline n = 7569 | At 5-yr follow-up n = 4401 | At 10-yr follow-up n = 2528 | Combined* |
|---|---|---|---|---|
| Sensitivity (95% CI) | 80 (75 to 84) | 84 (79 to 88) | 76 (70 to 81) | 80 |
| Specificity (95% CI) | 89 (88 to 90) | 81 (80 to 82) | 88 (86 to 89) | 87 |
| PPV (95% CI) | 26 (24 to 29) | 22 (20 to 25) | 43 (38 to 47) | 29 |
| NPV (95% CI) | 99 (99 to 99) | 99 (98 to 99) | 97 (96 to 98) | 99 |
| LR+ | 7.3 | 4.4 | 6.3 | 6.2 |
| LR− | 0.22 | 0.20 | 0.27 | 0.23 |
Note: CI = confidence interval, LR+ = positive likelihood ratio, LR− = negative likelihood ratio, NPV = negative predictive value, PPV = positive predictive value.
↵* Combined values were obtained by modelling the relation between diagnoses and our classifier using repeated-measures logistic regression analyses. This takes into account the correlation between observations from a single participant; however, estimated sensitivities, specificities and predictive values are the same as if we had taken each individual observation independently. Consequently, we do not present confidence intervals for these combined values.