Table 3. Prevalence, positive and negative predictive value, false positive and false negative by different cut‐offs of fasting plasma glucose to screen diabetes.
| Rule out | Rule in | |||||
|---|---|---|---|---|---|---|
| Prevalence (<cut‐off) | NPV | False negative† | Prevalence (≥cut‐off) | PPV | False positive‡ | |
| 5.0 | 51.0% | 99.0% | 6.93% | 49.1% | 14.1% | 45.52% |
| 5.1 | 60.2% | 98.8% | 9.90% | 39.8% | 16.8% | 35.77% |
| 5.2 | 68.0% | 98.7% | 11.88% | 32.0% | 20.4% | 27.52% |
| 5.3 | 75.0% | 98.8% | 11.88% | 25.0% | 26.1% | 19.98% |
| 5.4 | 80.0% | 98.6% | 14.85% | 20.0% | 31.5% | 14.83% |
| 5.5 | 81.6% | 98.6% | 15.84% | 18.4% | 33.9% | 13.16% |
| 5.56 | 83.3% | 98.3% | 18.8% | 16.7% | 36.1% | 11.5% |
| 5.6 | 85.1% | 98.3% | 19.80% | 14.9% | 39.9% | 9.67% |
| 5.7 | 87.7% | 98.1% | 22.77% | 12.3% | 46.4% | 7.14% |
| 5.8 | 90.2% | 97.9% | 25.74% | 9.8% | 56.0% | 4.68% |
| 5.9 | 91.5% | 97.7% | 28.71% | 8.5% | 62.1% | 3.49% |
| 6.0 | 92.0% | 97.6% | 29.70% | 8.0% | 65.1% | 3.01% |
| 6.1 | 93.2% | 97.3% | 33.66% | 6.8% | 72.0% | 2.06% |
| 6.2 | 94.4% | 97.1% | 37.62% | 5.6% | 82.9% | 1.03% |
| 6.3 | 95.0% | 96.8% | 40.59% | 5.0% | 88.2% | 0.63% |
| 6.4 | 95.2% | 96.6% | 43.56% | 4.8% | 87.7% | 0.63% |
| 6.5 | 95.3% | 96.5% | 44.55% | 4.7% | 87.5% | 0.63% |
| 6.6 | 95.6% | 96.5% | 45.54% | 4.4% | 91.7% | 0.40% |
| 6.7 | 96.0% | 96.2% | 49.50% | 4.0% | 94.4% | 0.24% |
| 6.8 | 96.2% | 96.1% | 50.50% | 3.8% | 96.2% | 0.16% |
| 6.9 | 96.7% | 95.7% | 56.44% | 3.3% | 97.8% | 0.08% |
| 7.0 | 96.8% | 95.6% | 57.43% | 3.2% | 100.0% | 0.00% |
†False negative values among patients with diabetes by oral glucose tolerance test are shown. ‡False positive values among patients without diabetes by oral glucose tolerance test are shown. NPV, negative predictive value; PPV, positive predictive value.