Table 4. Performance Characteristics of Screened Symptom for Bacteriologically Positive TB, by Age Status, China, 2010.
| Screened symptoms | No. of participants with defined symptoms | No. of TB cases with defined symptoms | Sensitivity | Specificity | PPV | NPV | AUC |
|---|---|---|---|---|---|---|---|
| Cough or haemoptysis of any duration | |||||||
| Participants aged under 65 | 15409 | 95 | 51.6 | 95.5 | 0.6 | 99.9 | 0.74 |
| Participants aged 65 and above | 5272 | 67 | 51.1 | 88.8** | 1.3 | 99.8 | 0.70 |
| All participants | 20681 | 162 | 51.4 | 94.7 | 0.8 | 99.9 | 0.73 |
| Cough of any duration | |||||||
| Participants aged under 65 | 15380 | 95 | 51.6 | 95.5 | 0.6 | 99.9 | 0.74 |
| Participants aged 65 and above | 5263 | 67 | 51.1 | 88.9** | 1.3 | 99.8 | 0.70 |
| All participants | 20643 | 162 | 51.4 | 94.7 | 0.8 | 99.9 | 0.73 |
| Cough ≥2 weeks | |||||||
| Participants aged under 65 | 3439 | 77 | 41.8 | 99.0 | 2.2 | 99.9 | 0.70 |
| Participants aged 65 and above | 1853 | 58 | 44.3** | 96.1** | 3.1 | 99.8 | 0.70 |
| All participants | 5292 | 135 | 42.9 | 98.7 | 2.5 | 99.9 | 0.71 |
| Cough ≥3 weeks | |||||||
| Participants aged under 65 | 2150 | 59 | 32.1 | 99.4 | 2.7 | 99.9 | 0.66 |
| Participants aged 65 and above | 1241 | 47 | 35.9** | 97.4** | 3.7 | 99.8 | 0.67 |
| All participants | 3391 | 106 | 33.7 | 99.1 | 3.1 | 99.9 | 0.66 |
| Haemoptysis | |||||||
| Participants aged under 65 | 206 | 8 | 4.3 | 99.9 | 3.8 | 99.9 | 0.52 |
| Participants aged 65 and above | 82 | 6 | 4.6* | 99.8** | 7.1 | 99.7 | 0.52 |
| All participants | 288 | 14 | 4.4 | 99.9 | 4.8 | 99.9 | 0.52 |
| Suspected symptom defined by China NTP | |||||||
| Participants aged under 65 | 3514 | 78 | 42.4 | 99.0 | 2.2 | 99.9 | 0.71 |
| Participants aged 65 and above | 1876 | 58 | 44.3** | 96.1** | 3.0 | 99.8 | 0.70 |
| All participants | 5390 | 136 | 43.2 | 98.6 | 2.5 | 99.9 | 0.71 |
PPV, positive predictive value; NPV, negative predictive value; AUC, area under the receiver operating characteristic curve
In analysis of cough and haemoptysis, the AUC for any duration of cough were significantly larger than for haemoptysis (P<0.01 for both subpopulations)
When analysis was conducted in participants under aged 65, the sensitivities of cough of any duration/ Cough or haemoptysis of any duration were significantly higher than that of suspected symptom defined by China NTP (P<0.01).
* Compared with participants aged under 65, P<0.05
** Compared with participants aged under 65, P<0.01