Table 3.
Lung function abnormalities: Pooled proportions of TB participants with different types of spirometry abnormalities.a
| Meta-analysis | Number of study populations | Proportion of participants (n/N) | Pooled estimate (95% CI) | Prediction intervals | I2 |
|---|---|---|---|---|---|
| All TB patients | |||||
| Abnormal | 42 | 4082/9864 | 59.1% (48.8%–68.7%) | 8.4%–95.8% | 98.3% |
| Obstruction | 41 | 1882/9803 | 17.8% (13.4%–23.1%) | 2.5%–64.5% | 96.6% |
| Restriction | 35 | 1339/5822 | 21.3% (15.3%–28.9%) | 2.3%–75.7% | 95.4% |
| Mixed pattern | 30 | 861/5095 | 12.7% (8.2%–19.2%) | 1.0%–68.9% | 93.2% |
| Controls | |||||
| Abnormal | 4 | 794/21,804 | 5.4% (2.6%–10.8%) | 0.2%–67.7% | 97.4% |
| Obstruction | 4 | 794/21,804 | 5.4% (2.6%–10.8%) | 0.2%–67.7% | 97.4% |
| Restriction/Mixed | 0 | – | – | – | – |
| DS-TB | |||||
| Abnormal | 12 | 1677/2900 | 54.4% (41.8%–66.5%) | 13.7%–89.9% | 96.3% |
| Obstruction | 12 | 777/2900 | 16.8% (9.6%–27.5%) | 1.7%–70.6% | 94.2% |
| Restriction | 11 | 493/2771 | 16.1% (6.8%–33.8%) | 0.5%–89.0% | 96.9% |
| Mixed pattern | 7 | 407/2086 | 14.5% (6.5%–29.4%) | 0.7%–80.4% | 96.4% |
| MDR-TB | |||||
| Abnormal | 7 | 178/286 | 85.9% (49.5%–97.4%) | 1.1%–100.0% | 93.3% |
| Obstruction | 7 | 57/286 | 18.8% (11.3%–29.6%) | 3.5%–59.9% | 71.9% |
| Restriction | 5 | 41/161 | 24.2% (15.5%–35.9%) | 6.0%–61.7% | 27.% |
| Mixed pattern | 4 | 80/134 | 60.1% (47.3%–71.6%) | 18.0%–91.1% | 60.5% |
| HIV positive | |||||
| Abnormal | 3 | 111/398 | 27.8% (19.4%–38.0%) | 0.2%–98.8% | 79.6% |
| Obstruction | 3 | 54/398 | 13.9% (10.1%–18.8%) | 0.9%–75.1% | 44.3% |
| Restriction | 2 | 54/316 | 17.1% (13.3%–21.6%) | – | – |
| Mixed pattern | 1 | 3/85 | 3.5% (1.1%–10.4%) | – | – |
| HIV negative | |||||
| Abnormal | 7 | 739/985 | 82.6% (65%–92.4%) | 14.9%–99.2% | 95.2% |
| Obstruction | 7 | 396/985 | 30.1% (17.1%–47.3%) | 3.0%–85.5% | 94.3% |
| Restriction | 6 | 123/728 | 17.3% (14.0%–21.3%) | 10.4%–27.4% | 35.7% |
| Mixed pattern | 6 | 220/826 | 30.3% (15.2%–51.4%) | 1.7%–91.7% | 92.6% |
Pooled estimates included all persons at risk for respiratory impairment (I.e., the denominator in these estimates was all persons post-TB in the studies reporting on post-TB respiratory impairment).
“-“ Denotes prediction interval was not able to be estimated.
TB, tuberculosis; HIV, human immunodeficiency virus; DS-TB, drug susceptible tuberculosis; MDR-TB, multidrug-resistant tuberculosis; FEV1, forced vital capacity in 1 s; FVC, forced vital capacity; %pred., percentage of predicted value; L, litres; CI, confidence interval; LLN, lower limit of normal.
Definitions of spirometry abnormalities: Obstruction pattern = FEV1/FVC < LLN or <70%; Restriction pattern = FEV1/FVC ratio >70% and FVC <80% or < LLN; Mixed pattern = FEV1/FVC ratio <70% and FVC <80% pred. Exceptions to these definitions are outlined in the appendix (Table S5).