Risk factors for asthma deaths: a population-based, case-control study

Objectives: To investigate risk factors for death from asthma using a case- control study design with two control groups. Methods: Cases (n=42) comprised subjects aged 10-59 years who died from ast hma. Two control groups were selected: a random sample of asthmatics from t he community (n=132) and age and sex matched patients recently admitted to hospital for asthma (n=89). We obtained information from proxies of cases a nd controls, and their general practitioners, by a structured telephone sur vey. Matched and unmatched logistic regression analyses were used to determ ine odds ratios for risk factors for asthma deaths. Results: Compared to community controls, important risk factors for asthma deaths included indicators of asthma severity, use of three or more groups of asthma medications, more extensive use of health services for asthma, po or compliance with asthma medications and regularly missing hospital and ge neral practitioner appointments for asthma. Compared to hospital controls, risk factors for asthma deaths were previous visits to emergency department for asthma, knowledge about asthma medications and regularly missing gener al practitioner appointments. Conclusions: In this study, severity of asthma, increased health service ut ilisation and suboptimal asthma selfmanagement were associated with increas ed risks for asthma death. Implications: People with severe asthma or poorly controlled asthma have a greater risk of dying from their asthma. Both clinicians and non-clinicians managing asthma should regularly assess the appropriateness of management to prevent deaths.