Prevalence of chronic obstructive pulmonary disease among residents aged 40 years and above in Tibet in 2015: a cross-sectional survey

  Objective  To examine the prevalence and influencing factors of chronic obstructive pulmonary disease (COPD) among residents aged≥40 years in Tibet Autonomous Region (Tibet) and to provide evidences for formulating COPD prevention and treatment strategies.

  Methods  We conducted a questionnaire survey, physical examination, and lung function test among 1 120 Tibet residents aged≥40 years selected with multistage stratified cluster random sampling in 2015. Prevalence and associated factors of COPD among the participants were analyzed.

  Results  The COPD prevalence rate was 6.16% and the rate increased significantly with the increment of age for all the participants (χ²_trend = 10.631, P = 0.001). The prevalence rate of COPD was significantly higher in the male participants than in the female participants (8.55% vs. 3.86%) (χ² = 10.631, P = 0.001) and in the smoking participants than in non-smoking participants (8.50% vs. 5.13%) (χ² = 4.658, P = 0.031). Significantly higher COPD prevalence rate was observed among the participants with frequent cough (χ² = 5.886, P = 0.015) and phlegm (χ² = 4.785, P = 0.029). The results of Chronic Obstructive Pulmonary Disease Assessment Test (CAT) revealed that 58.06%, 33.87%, and 8.06% of the COPD sufferers reporting mildly, moderately, and severely impacted quality of life, respectively.

  Conclusion  Among the Tibet residents 40 years old and elder, the prevalence rate of COPD is lower than that among the national population and mainly influenced by gender, age, smoking, frequent cough and phlegm; the results suggest that health education on COPD prevention in general population and lung function test in people at high COPD risk should be promoted for early diagnosis and treatment of the disease.