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Updated: Jan 29, 2026
Diagnosing Pulmonary Tuberculosis with the Xpert MTB/RIF Test
Published on: April 9, 2012
Risk factors for sputum smear-positive in COPD patients first diagnosed with active tuberculosis
Daoyan Tang1, Jing Yang2, Yongxian Zhang2
1Department of Respiratory and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan, China; State Key Laboratory of Respiratory Health and Multimorbidity, China.
Objectives:
The purpose of this study was to determine significant clinical risk factors for sputum smear-positivity in Chronic Obstructive Pulmonary Disease (COPD) patients who were also diagnosed with active tuberculosis.
Methods:
A total of 776 patients diagnosed with COPD combined with active tuberculosis at West China Hospital of Sichuan University were retrospectively included. Of these, 527 were sputum smear-negative and 249 were sputum smear-positive at first diagnosis. Baseline data, routine blood and biochemical indices were compared between the two groups. Logistic regression was used to investigate the risk factors for sputum smear-positivity in COPD patients with active tuberculosis.
Results:
Compared with those in the sputum smear-negative group, patients in the sputum smear-positive group had lower Body Mass Index (BMI), and were more likely to have a history of significant alcohol consumption (p < 0.05). Patients with chronic kidney disease and cardiovascular disease had lower risk of sputum smear positivity (p < 0.05). The hemoglobin concentration, lymphocyte count and albumin levels were significantly lower and the neutrophil, monocyte and platelet counts, blood glucose levels and erythrocyte sedimentation rate were higher in the sputum smear-positive group than those in the sputum smear-negative group (p < 0.05). Multivariate logistic regression analysis showed that low BMI (OR:0.86; 95 %CI:0.79, 0.94;p = 0.001), alcohol consumption (OR:2.13; 95 %CI:1.15,3.93;p = 0.016), low albumin (OR:0.91; 95 %CI:0.85, 0.97;p = 0.003), and elevated neutrophils (OR:3.44; 95 %CI:1.23, 9.28;p = 0.019) were significant risk factors for sputum smear positivity in patients with COPD combined with active tuberculosis.
Conclusion:
In patients with COPD and active tuberculosis, alcohol consumption history, increased neutrophil count, low BMI and low serum albumin concentration are significant risk factors for sputum smear positivity at initial diagnosis. These risk factors should prompt clinicians to consider sputum examination. Respiratory isolation may be needed based on individual assessment.
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