Background: Exacerbations requiring hospital admission for chronic obstructive pulmonary disease (COPD) contribute to a decline in health status and are costly to the community. Long-term trends in admissions and associated outcomes are difficult to establish because of frequent readmissions, high case fatality and potential diagnostic transfer between COPD and asthma. The Western Australian Data Linkage System provides a unique opportunity to examine admissions for patients with COPD over the long term.
Method: Nineteen years of hospital morbidity data, based on International Classification of Diseases-9 criteria were extracted from the Western Australian Data Linkage System (1980-1998) and merged with mortality records to examine trends in hospital admissions for COPD.
Results: The rate of hospital admissions for COPD has declined overall and the rate of first presentation declined in men and remained constant in women. The risk of readmission increased throughout the period (P < 0.0001) and more than half of all admissions were followed by readmission within a year. Median survival following first admission was 6 years (men 5 years; women 8 years). Age, sex and International Classification of Diseases subcategory each showed an independent effect on the risk of mortality (P < 0.0001). The poorest survival was in patients subcategorized as emphysema. For patients with multiple admissions, the likelihood of cross-over between COPD and asthma was high and increased with the total number of admissions.
Conclusion: The rate of admission for COPD has declined in Western Australia; however, the resource burden will continue to increase because of the ageing population. This has policy implications for the development of acute care treatment programmes for COPD.