Table 2 Diagnostic test properties of marginal food security status based on the 1-item NutriSTEP® question compared with the 2-item Hunger Vital Sign™
From: Screening for marginal food security in young children in primary care
1-item NutriSTEP® | 2-item hunger vital sign™ | ||
|---|---|---|---|
Yes | No | Total | |
Yes | 45 | 99 | 144 |
No | 8 | 1022 | 1030 |
Total | 53 | 1121 | 1174 |
Sensitivity: 45 / (45 + 8) * 100 = 84.9% (95% CI: 72.4, 93.3) | |||
Specificity: 1022 / (1022 + 99) * 100 = 91.2% (95% CI: 89.4, 92.8) | |||
PPV: 45 / (45 + 99) * 100 = 31.3% (95% CI: 26.7, 36.2) | |||
NPV: 1022 / (1022 + 8) * 100 = 99.2% (95% CI: 98.5, 99.6) | |||
Likelihood Ratio (for a positive test): sensitivity / (1-specificity) = 9.6 (95% CI: 7.7, 12.0) | |||
Likelihood Ratio (for a negative test): (1 – sensitivity / specificity) = 0.2 (95% CI: 0.1, 0.3) | |||
Accuracy: sensitivity x prevalence + specificity x (1 – prevalence) = 90.9% (95% CI: 89.1, 92.5) | |||