Determinants of chronic obstructive pulmonary disease in Chinese patients in Hong Kong

The prevalence of chronic obstructive pulmonary disease (COPD) is rising in many parts of the world. This is a study of risk factors for COPD in Chinese patients in Hong Kong.

Case-control study matched by sex and age (+/-5 years).

A total of 289 consecutive patients with COPD were recruited from out-patient clinics while healthy controls were recruited from two sources: random population and community centres for senior citizens. All patients and controls underwent a questionnaire-based interview and spirometry.

The mean ages of COPD patients and controls were 71.1 +/- 9.4 and 67.5 +/- 9.3 years, respectively. The male to female ratio of COPD patients was 5 to 1. Smoking was found to be the most important determinant for COPD, followed by poor education and low body mass index adjusted for confounders. A dose-dependent relationship was found between the risk of COPD and pack-years smoked. Place of birth, exposure to environmental tobacco smoke and a history of asthma and tuberculosis were not associated with increased risk of COPD.

Despite a progressive reduction in prevalence, smoking remains the most important predictor of COPD in Hong Kong. Greater anti-smoking efforts are warranted.