The sex factor: epidemiology and management of chronic obstructive pulmonary disease in British Columbia.

BACKGROUND: The prevalence and mortality of chronic obstructive pulmonary disease (COPD) in women have been predicted to overtake that of men within the next decade. These predictions are based in part on data from surveys using self-reports of a COPD diagnosis. Whether these predictions have been realized is unknown. METHODS: The prevalence and mortality of men and women in British Columbia were compared from fiscal years 1992/1993 to 2003/2004 using administrative health services data. Case definitions for COPD were developed using International Classification of Diseases ninth and 10th revision (ICD-9/10) codes applied to medical and hospital data. Individuals 45 years and older, who had at least two physician visits or one hospitalization for specified COPD ICD-9/10 codes within a 365-day window, were considered to be cases. Cases were ascertained from 1992 to 2004. RESULTS: In 2003/2004, men had a greater prevalence (4.7% versus 4.0% in women) and a higher all-cause mortality rate (5.4% versus 4.1% in women) than women. Both men and women with COPD had low COPD medication use (45%) and low referral for lung function testing (55%). Including the ICD-9 code for 'bronchitis, not specified as acute or chronic' (ICD-9 490) in the case definition resulted in a greater prevalence of COPD in women than in men overall, and in the 45 to 64 year age group. CONCLUSION: Prevalence and mortality measured with administrative health data do not show evidence of relative increase in the prevalence of COPD for women in British Columbia. However, further analysis of ICD-9 490 may identify an early 'at-risk' group, specifically in women.