DIFFERENCE IN THE BODE INDEX BETWEEN SMOKER AND NON-SMOKER PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD)

Abstract

Introduction: COPD is increasingly recognized as a multisystem disorder, and multidimensional indices such as the BODE score better reflect functional limitation and systemic involvement than spirometry alone.

Objective: To compare BODE index scores between smokers and non-smokers with COPD and to examine the association between pack-years and multidimensional severity.

Methods: An analytical cross-sectional study was conducted at the Department of Internal Medicine, Isra University, Hyderabad from April 2025 to August 2025. Stable outpatients aged ≥40 years with spirometry-confirmed COPD were recruited consecutively. Smoking status was classified as smoker/non-smoker, and cumulative exposure was quantified as pack-years. BODE index was calculated using BMI, FEV₁% predicted, mMRC dyspnea grade, and six-minute walk distance. Mean BODE scores were compared using an independent samples t-test, and correlation between pack-years and BODE was assessed using Pearson correlation. Pack-years were also compared across BODE severity categories.

Results: A total of 150 patients were analyzed (mean age 60.25 ± 8.91 years; 74% male). Smokers had mean BODE score numerically higher than non-smokers (3.09 ± 1.67 vs 2.70 ± 1.35), but the difference was not statistically significant (p = 0.223). Pack-years showed a weak positive correlation with BODE score (r = 0.268, p = 0.001). Patients with moderate-to-severe disease had higher pack-years than those with mild disease (16.49 ± 11.77 vs 10.64 ± 9.81; p = 0.003).

Conclusion: In stable outpatient COPD, smoking status alone did not significantly differentiate BODE severity; however, cumulative exposure (pack-years) showed a modest association with multidimensional disease burden.