Table 5.
Pooled estimates of Medical Research Council (MRC) Dyspnoea score.a
| Population | Outcome | Number of study populations | Proportion of participants (n/N) | Pooled estimate (95% CI) | Prediction interval | I2 |
|---|---|---|---|---|---|---|
| All TB patients | MRC 1–2b | 13 | 2439/3179 | 72.6% (64.4%–79.6%) | 35.8%–92.7% | 92.8% |
| MRC 3–5b | 13 | 706/3179 | 24.7% (18.8%–31.7%) | 7.6%–56.8% | 92.2% | |
| MDR-TB | MRC 1–2 | 1 | 24/32 | 75.0% (57.4%–87.0%) | – | – |
| MRC 3–5 | 1 | 8/32 | 25.0% (13.0%–42.6%) | – | – | |
| DS-TB | MRC 1–2 | 1 | 119/144 | 82.6% (75.6%–88.0%) | – | – |
| MRC 3–5 | 1 | 25/144 | 17.4% (12.0%–24.4%) | – | – | |
| HIV positive | MRC 1–2 | 2 | 336/443 | 75.8% (71.6%–79.6%) | – | 21.5% |
| MRC 3–5 | 2 | 107/443 | 24.2% (20.4%–28.4%) | – | 21.5% | |
| HIV negative | MRC 1–2 | 2 | 266/358 | 74.3% (69.5%–78.6%) | – | 1.3% |
| MRC 3–5 | 2 | 92/358 | 25.7% (21.4%–30.5%) | – | 1.3% | |
| Obstructionc | MRC 1–2 | 2 | 185/227 | 81.5% (75.9%–86.0%) | – | 63.1% |
| MRC 3–5 | 2 | 42/227 | 18.5% (14.0%–24.1%) | – | 63.1% | |
| Restrictionc | MRC 1–2 | 2 | 129/196 | 69.6% (52.1%–82.8%) | – | 88.7% |
| MRC 3–5 | 2 | 67/196 | 30.4% (17.2%–47.9%) | – | 88.7% | |
| Mixed patternc | MRC 1–2 | 2 | 98/170 | 56.6% (38.4%–73.3%) | – | 90.8% |
| MRC 3–5 | 2 | 72/170 | 43.4% (26.7%–61.6%) | – | 90.8% |
Pooled estimates included all persons at risk for disability (I.e., the denominator in these estimates was all persons post-TB in the studies reporting on post-TB MRC scores).
MRC Scale: 1 = no dyspnoea except with strenuous exercise, 2 = dyspnoea when hurrying on the level or walking up a slight hill, 3 = walks slower than people of the same age on the level because of dyspnoea or has to stop for breath when walking at own pace on the level, 4 = stops for breath after walking 100 m or after a few minutes on the level, 5 = too dyspneic to leave the house or breathless when dressing.
“-“ 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; CI, confidence interval.
Due to pooling, estimates (%) do not always add up to 100%. MRC was measured at the end of treatment or after treatment completion.
Or an equivalent score on the Modified Medical Research Council (mMRC) scale. An MRC score of 1–2 is equivalent to an mMRC score of 0–1. An MRC score of 3–5 is equivalent to an mMRC score of 2–4.
As measured by spirometry after 6 months of treatment. Manji [70], performed spirometry after 5 months of treatment. Only measures at end of treatment were used for this table. 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).