Additional predictive information after extending the traditional risk factor model with ADAMTS13 in prediction of ischemic stroke
| . | . | Model fit . | Model discrimination . | |
|---|---|---|---|---|
| Models . | Likelihood ratio test statistics (χ2) . | C-statistic (95% CI) . | ||
| Traditional risk factor model | 123.7 | 0.694 (0.665, 0.723) | ||
| Traditional risk factor model + ADAMTS13 | 136.9* | 0.707 (0.678, 0.735)* | ||
| Reclassification after addition of ADAMTS13 to the traditional risk factors, total population (N = 5941) | ||||
| Subjects with event (%)† | Subjects without event (%)† | NRI (95% CI)‡ | ||
| Up | Down | Up | Down | |
| 15.0% | 9.4% | 8.8% | 9.0% | 0.058 (–0.002, 0.119) |
| Reclassification after addition of ADAMTS13 to the traditional risk factors, among the 5%-7.5% risk category (N = 1179) | ||||
| Subjects with event (%)† | Subjects without event (%)† | NRI (95% CI)‡ | ||
| Up | Down | Up | Down | |
| 33.3% | 19.8% | 20.3% | 28.0% | 0.212 (0.048, 0.376) |
| . | . | Model fit . | Model discrimination . | |
|---|---|---|---|---|
| Models . | Likelihood ratio test statistics (χ2) . | C-statistic (95% CI) . | ||
| Traditional risk factor model | 123.7 | 0.694 (0.665, 0.723) | ||
| Traditional risk factor model + ADAMTS13 | 136.9* | 0.707 (0.678, 0.735)* | ||
| Reclassification after addition of ADAMTS13 to the traditional risk factors, total population (N = 5941) | ||||
| Subjects with event (%)† | Subjects without event (%)† | NRI (95% CI)‡ | ||
| Up | Down | Up | Down | |
| 15.0% | 9.4% | 8.8% | 9.0% | 0.058 (–0.002, 0.119) |
| Reclassification after addition of ADAMTS13 to the traditional risk factors, among the 5%-7.5% risk category (N = 1179) | ||||
| Subjects with event (%)† | Subjects without event (%)† | NRI (95% CI)‡ | ||
| Up | Down | Up | Down | |
| 33.3% | 19.8% | 20.3% | 28.0% | 0.212 (0.048, 0.376) |
The traditional risk factor model is composed of the variables included in the American Heart Association Pooled Cohort Equation: age, sex, systolic blood pressure, treatment of hypertension, total and HDL cholesterol, smoking, and diabetes.
χ2, Chi-square statistic; CI, confidence interval; NRI, net reclassification improvement index.
P < .01 for the increase in model fit and for the increase in the C-statistic after addition of ADAMTS13 to the traditional risk factors.
Percentages of subjects with or without an event who move to a higher or lower risk category after adding ADAMTS13 to the traditional risk factors. The risk categories are based on 10-year ischemic stroke risk <5%, 5%-7.5%, and >7.5%.
NRI is estimated as ([number of events reclassified higher minus number of events reclassified lower]/number of events) + ([number of nonevents reclassified lower minus number of nonevents reclassified higher]/number of nonevents).