Residual respiratory disability after successful treatment of pulmonary tuberculosis: a systematic review and meta-analysis

BACKGROUND: Pulmonary tuberculosis (PTB) can result in long-term health consequences, even after successful treatment. We conducted a systematic review and meta-analysis to estimate the occurrence of respiratory impairment, other disability states, and respiratory complications following successful PTB treatment. METHODS: We identified studies from January 1, 1960, to December 6, 2022, describing populations of all ages that successfully completed treatment for active PTB and had been assessed for at least one of the following outcomes: occurrence of respiratory impairment, other disability states, or respiratory complications following PTB treatment. Studies were excluded if they reported on participants with self-reported TB, extra-pulmonary TB, inactive TB, latent TB, or if participants had been selected on the basis of having more advanced disease. Study characteristics and outcome-related data were abstracted. Meta-analysis was performed using a random effects model. We adapted the Newcastle Ottawa Scale to evaluate the methodological quality of the included studies. Heterogeneity was assessed using the I(2) statistic and prediction intervals. Publication bias was assessed using Doi plots and LFK indices. This study is registered with PROSPERO (CRD42021276327). FINDINGS: 61 studies with 41,014 participants with PTB were included. In 42 studies reporting post-treatment lung function measurements, 59.1% (I(2) = 98.3%) of participants with PTB had abnormal spirometry compared to 5.4% (I(2) = 97.4%) of controls. Specifically, 17.8% (I(2) = 96.6%) had obstruction, 21.3% (I(2) = 95.4%) restriction, and 12.7% (I(2) = 93.2%) a mixed pattern. Among 13 studies with 3179 participants with PTB, 72.6% (I(2) = 92.8%) of participants with PTB had a Medical Research Council dyspnoea score of 1–2 and 24.7% (I(2) = 92.2%) a score of 3–5. Mean 6-min walk distance in 13 studies was 440.5 m (I(2) = 99.0%) in all participants (78.9% predicted, I(2) = 98.9%) and 403.0 m (I(2) = 95.1%) among MDR-TB participants in 3 studies (70.5% predicted, I(2) = 97.6%). Four studies reported data on incidence of lung cancer, with an incidence rate ratio of 4.0 (95% CI 2.1–7.6) and incidence rate difference of 2.7 per 1000 person-years (95% CI 1.2–4.2) when compared to controls. Quality assessment indicated overall low-quality evidence in this field, heterogeneity was high for pooled estimates of nearly all outcomes of interest, and publication bias was considered likely for almost all outcomes. INTERPRETATION: The occurrence of post-PTB respiratory impairment, other disability states, and respiratory complications is high, adding to the potential benefits of disease prevention, and highlighting the need for optimised management after successful treatment. FUNDING: Canadian Institutes of 10.13039/100009007Health Research Foundation Grant.