Pulmonary function impairment and associated factors among patients treated for pulmonary tuberculosis in Northwest Ethiopia: a hospital-based cross-sectional study

Post-tuberculosis lung disease (PTLD) is an increasingly recognized cause of chronic respiratory morbidity worldwide. Impaired pulmonary function is one of its most common manifestations and may persist despite successful completion of anti-tuberculosis treatment. However, evidence on the magnitude and associated factors of pulmonary function impairment among patients treated for pulmonary tuberculosis remains limited in Ethiopia. To assess pulmonary function impairment and its associated factors among patients treated for pulmonary tuberculosis at Tibebe Ghion Specialized Hospital, Northwest Ethiopia. A hospital-based cross-sectional study was conducted among adults previously treated for pulmonary tuberculosis from January to November 2023. Participants were recruited using consecutive sampling. Socio-demographic and clinical data were collected using structured questionnaires and medical records. Pulmonary function was assessed by spirometry according to American Thoracic Society/European Respiratory Society (ATS/ERS) 2019 standards, and Global Lung Function Initiative (GLI) 2012 reference equations were used for interpretation. Post-bronchodilator spirometry was performed for participants with obstructive patterns. Data were analyzed using SPSS version 27, and bivariable and multivariable logistic regression analyses were performed to identify factors associated with pulmonary function impairment. Among 216 participants, 57.4% were male, with a mean age of 42.3 ± 13.7 years. The prevalence of pulmonary function impairment was 79.2% (95% CI: 73.0–84.0). Obstructive spirometric pattern was observed in 37.5% of participants, restrictive spirometric pattern in 22.2%, and mixed spirometric pattern in 19.4%. Independent factors associated with pulmonary function impairment included rural residence (AOR 4.57; 95% CI: 1.14–18.26), respiratory symptoms (AOR 7.59; 95% CI: 1.58–36.47), and symptom duration > 1 month before TB treatment (AOR 36.45; 95% CI: 10.19–130.38). Pulmonary function impairment is common among patients treated for pulmonary tuberculosis in this setting. Delayed presentation before TB treatment and respiratory symptoms were independently associated with pulmonary function impairment. These findings highlight the potential value of incorporating pulmonary function assessment into post-tuberculosis follow-up care. Longitudinal studies are warranted to establish temporal relationships and causal pathways.