Operating characteristics of ICD code U07.1 (laboratory-confirmed COVID-19) within hospital diagnostic codes (PCR test as reference) stratified by timing of first PCR test
| Parameter | Estimate (95% CI), % |
|---|---|
| Timing of first PCR test | |
| Before admission | |
| Sensitivity | 98.7 (96.2–99.7) |
| Specificity | 99.9 (99.7–100) |
| Positive predictive value | 97.8 (95.0–99.3) |
| Negative predictive value | 99.9 (99.8–100) |
| Within 0–24 h of admission | |
| Sensitivity | 95.8 (90.4–98.6) |
| Specificity | 99.7 (99.6–99.9) |
| Positive predictive value | 88.3 (81.4–93.3) |
| Negative predictive value | 99.9 (99.8–100) |
| Within 24–48 h of admission | |
| Sensitivity | 100 (63.1–100) |
| Specificity | 99.0 (96.5–99.9) |
| Positive predictive value | 80.0 (44.4–97.5) |
| Negative predictive value | 100 (98.2–100) |
| Beyond 48 h of admission | |
| Sensitivity | 97.8 (92.4–99.7) |
| Specificity | 94.2 (92.1–95.9) |
| Positive predictive value | 71.4 (62.7–79.1) |
| Negative predictive value | 99.7 (98.8–100) |
| Calendar period of admission | |
| January–April 2020 | |
| Sensitivity | 99.4 (97.0–100) |
| Specificity | 98.6 (97.9–99.2) |
| Positive predictive value | 90.5 (85.5–94.2) |
| Negative predictive value | 99.9 (99.6–100) |
| May–Aug 2020 | |
| Sensitivity | 96.2 (90.5–99.0) |
| Specificity | 99.5 (99.2–99.7) |
| Positive predictive value | 79.5 (71.5–86.2) |
| Negative predictive value | 99.9 (99.8–100) |
| September–December 2020 | |
| Sensitivity | 96.8 (92.8–99.0) |
| Specificity | 99.7 (99.6–99.9) |
| Positive predictive value | 92.2 (87.0–95.8) |
| Negative predictive value | 99.9 (99.8–100) |
Note: CI = confidence interval, ICD = International Statistical Classification of Diseases and Related Health Problems, PCR = polymerase chain reaction.