Table 5. The predictive ability of the obesity risk score for childhood obesity derived from a model comprising baby’s sex, birthweight z-score and weight change z-score between birth and 6 (equation 1), 9 (equation 2) or 12 (equation 3) months.
| Proportion of the populationabove risk score threshold (%) | Risk scorethreshold | Sensitivity %(95% CI) | Specificity %(95% CI) | PPV %(95% CI) | NPV %(95% CI) |
| Equation 1 | |||||
| 30 | 0.0731 | 78.3 (67.9, 86.6) | 74.2 (71.3, 77.0) | 21.2 (16.7, 26.2) | 97.5 (96.1, 98.5) |
| 20 | 0.1155 | 69.9 (58.8, 79.5) | 84.3 (81.9, 86.6) | 28.3 (22.2, 35.0) | 96.9 (95.5, 98.0) |
| 10 | 0.2072 | 50.6 (39.4, 61.8) | 93.6 (91.9, 95.1) | 41.2 (31.5, 51.4) | 95.5 (94.0, 96.8) |
| Equation 2 | |||||
| 30 | 0.0662 | 77.7 (69.2, 84.8) | 73.9 (71.5, 76.2) | 20.4 (16.8, 24.4) | 97.5 (96.3, 98.3) |
| 20 | 0.1104 | 68.6 (59.5, 76.7) | 84.1 (82.1, 86.0) | 27.0 (22.1, 32.4) | 96.9 (95.8, 97.8) |
| 10 | 0.2082 | 53.7 (44.4, 62.8) | 93.5 (92.1, 94.8) | 41.7 (33.8, 49.8) | 95.9 (94.7, 96.9) |
| Equation 3 | |||||
| 30 | 0.0609 | 86.9 (75.8, 94.2) | 75.1 (71.6, 78.3) | 24.1 (18.6, 30.3) | 98.4 (96.9, 99.3) |
| 20 | 0.1065 | 77.0 (64.5, 86.8) | 85.1 (82.1, 87.7) | 32.0 (24.5, 40.2) | 97.6 (96.0, 98.7) |
| 10 | 0.2391 | 65.6 (52.3, 77.3) | 94.9 (93.0, 96.5) | 54.1 (42.1, 65.7) | 96.8 (95.2, 98.0) |
PPV = positive predictive value; NPV = negative predictive value.