Table 4.
Reclassification of Cases and Noncases Correctly Identified by the IROC Algorithm at 5 Years of Age Using Data from the ALSPAC Cohort
| Risk threshold | No. of cases correctly identified (% of total cases) | No. of noncases correctly identified (% of total noncases) | Net reclassification index (NRI)a |
|---|---|---|---|
| IOTF defined overweight | |||
| 2.5% | 151 (0.99) | 39 (0.05) | — |
| 5% | 138 (0.90) | 197 (0.24) | 11 |
| 10% | 81 (0.53) | 587 (0.71) | 21 |
| 15% | 37 (0.24) | 761 (0.92) | 13 |
| 20% | 19 (0.12) | 806 (0.98) | 6 |
| 25% | 6 (0.04) | 821 (0.99) | 0 |
| 30% | 4 (0.03) | 827 (1.00) | −11 |
| UK 1990 defined overweight | |||
| 2.5% | 114 (0.98) | 39 (0.05) | — |
| 5% | 104 (0.90) | 200 (0.23) | 10 |
| 10% | 60 (0.52) | 603 (0.70) | 19 |
| 15% | 30 (0.26) | 791 (0.92) | 15 |
| 20% | 16 (0.14) | 840 (0.97) | 8 |
| 25% | 4 (0.03) | 856 (0.99) | 0 |
| 30% | 2 (0.02) | 862 (1.00) | −1 |
*
NRI is the net change in percentage of individuals correctly classified from a baseline risk threshold of 2.5%.
IROC, Infant Risk of Overweight Checklist; ALSPAC, Avon Longitudinal Study of Parents and Children; IOTF, International Obesity Task Force.