TABLE 3.
Sensitivity, specificity, positive and negative predictive values of tuberculosis screening symptoms and diagnostic tests in pregnant and postpartum women attending antenatal and postnatal care clinics in Eswatini between April and November 2015.
| Test | HIV positive |
HIV negative |
||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| n | SN |
SP |
PPV |
NPV |
n | SN |
SP |
PPV |
NPV |
|||||||||
| % | 95% CI | % | 95% CI | % | 95% CI | % | 95% CI | % | 95% CI | % | 95% CI | % | 95% CI | % | 95% CI | |||
| ‘Standard NTBSS tool’- WHO screening Option #1 | 350 | 0 | 0–29 | 94 | 91–97 | 0 | 0–18 | 97 | 94–98 | 354 | 0 | 0–60 | 94 | 91–97 | 0 | 0–17 | 99 | 97–100 |
| ‘At least one TB symptom’- WHO screening Option #2 | 350 | 9 | 0.2–47 | 84 | 79–87 | 2 | 0.0–9 | 97 | 94–98 | 354 | 0 | 0–60 | 77 | 72–81 | 1 | 0–4 | 99 | 96–100 |
| Household TB symptoms | 350 | 9 | 0.2–41 | 95 | 92–97 | 6 | 0.1–29 | 97 | 95–99 | 354 | 0 | 0–60 | 90 | 86–93 | 0 | 0–10 | 99 | 97–100 |
| Enhanced: ‘NTBSS tool’ + household TB symptoms | 350 | 9 | 0.2–41 | 90 | 86–93 | 3 | 0.1–15 | 97 | 94–99 | 354 | 0 | 0–60 | 86 | 82–89 | 0 | 0–7 | 99 | 98–100 |
| Enhanced: ‘NTBSS tool’ + household TB symptoms+ TB contact | 350 | 18 | 2–52 | 62 | 57–64 | 2 | 0.2–5 | 96 | 92–98 | 354 | 0 | 0–60 | 57 | 52–62 | 0 | 0–2 | 98 | 95–100 |
| Enhanced: At least one symptom plus TB contact history | 350 | 18 | 2–52 | 64 | 59–69 | 2 | 0.2–6 | 96 | 93–98 | 354 | 0 | 0–60 | 59 | 53–64 | 0 | 0–3 | 98 | 95–100 |
| Chest X-Ray† | 143 | 50 | 1–99 | 88 | 81–93 | 6 | 0.1–27 | 99 | 96–100 | 140 | ‡ | ‡ | ‡ | ‡ | ‡ | ‡ | ‡ | ‡ |
| Xpert® MTB/RIF | 175 | 0 | 0–60 | 99 | 96–100 | 0 | 0–84 | 98 | 94–99 | - | § | § | § | § | § | § | § | § |
| LF-LAM | 327 | 11 | 0–48 | 94 | 91–96 | 5 | 0–25 | 97 | 95–99 | - | - | - | - | - | - | - | - | - |
| LF-LAM (if CD4 count ≤ 100) | 28 | All 6 participants with CD4 count ≤ 100 tested negative with LF-LAM. | - | - | - | - | - | - | - | - | - | |||||||
| TST | 255 | 20 | 3–56 | 67 | 61–73 | 2 | 0.3–8 | 95 | - | 294 | 0 | 0–84 | 59 | 53–65 | 0 | 0–3 | 99 | 96-100 |
| IGRA | 319 | 22 | 3–60 | 63 | 57–68 | 2 | 0.2–6 | 97 | - | - | - | - | - | - | - | - | - | - |
CD4, cluster of differentiation 4; NPV, negative predictive value; CI, confidence interval; NTBSS, National TB symptom screening tool; PPV, positive predictive value; IGRA, interferon gamma release assay; SN, sensitivity; IQR, interquartile range; SP, specificity; LF-LAM, lateral flow urine lipoarabinomannan; TB, tuberculosis; TST, tuberculin skin test; WHO, World Health Organization.
, among postpartum women only.
, All cultures were negative in this group.
, All Xpert® tests were negative in this group.