Table 7. The predictive ability of the obesity risk score for childhood obesity derived from a model comprising sex, birthweight z-score, weight change z-score between birth and 6 (equation 1), 9 (equation 2) or 12 (equation 3)months, and maternal BMI.
| Proportion of the populationabove risk score threshold (%) | Risk scorethreshold | Sensitivity %(95% CI) | Specificity %(95% CI) | PPV %(95% CI) | NPV %(95% CI) |
| Equation 1 | |||||
| 30 | 0.0696 | 81.9 (72.0, 89.5) | 74.5 (71.6, 77.3) | 22.1 (17.6, 27.2) | 97.9 (96.6, 98.8) |
| 20 | 0.1156 | 71.1 (60.1, 80.5) | 84.5 (82.0, 86.7) | 28.8 (22.7, 35.5) | 97.1 (95.7, 98.1) |
| 10 | 0.2183 | 50.6 (39.4, 61.8) | 93.5 (91.7, 95.0) | 40.8 (31.2, 50.9) | 95.5 (94.0, 96.8) |
| Equation 2 | |||||
| 30 | 0.0646 | 76.9 (68.3, 84.0) | 74.0 (71.6, 76.3) | 20.3 (16.7, 24.2) | 97.4 (96.2, 98.3) |
| 20 | 0.1076 | 69.4 (60.4, 77.5) | 84.2 (82.2, 86.1) | 27.5 (22.5, 32.8) | 97.0 (95.9, 97.9) |
| 10 | 0.2042 | 52.1 (42.8, 61.2) | 93.7 (92.3, 94.9) | 41.4 (33.5, 49.7) | 95.8 (94.6, 96.8) |
| Equation 3 | |||||
| 30 | 0.0612 | 88.5 (77.8, 95.3) | 75.2 (71.8, 78.5) | 24.5 (19.0, 30.8) | 98.6 (97.2, 99.4) |
| 20 | 0.1051 | 77.0 (64.5, 86.8) | 85.2 (82.3, 87.8) | 32.2 (24.7, 40.4) | 97.6 (96.0, 98.7) |
| 10 | 0.2404 | 67.2 (54.0, 78.7) | 95.1 (93.2, 96.6) | 55.4 (43.4, 67.0) | 97.0 (95.3, 98.1) |
PPV = positive predictive value; NPV = negative predictive value.