RESUMO
AIM: To develop a valid and reliable questionnaire for measuring patients' beliefs about inhaler treatments for asthma. METHODS: In seven general practices, 335 patients prescribed both beclomethasone and salbutamol inhalers completed a 66-item questionnaire. Sub-scales were developed using factor analysis and a 29-item questionnaire sent to 90 patients in another practice to estimate test-retest reliability. RESULTS: Three factors explained 31.4% of the variance relating to beliefs about inhalers: preventing asthma symptoms, problems with and concerns about inhalers, and relieving asthma symptoms. Cronbach's alpha coefficients of the sub-scales were 0.71, 0.70 and 0.70 respectively. Intra-class correlation coefficients were 0.87 or more for all three sub-scales. The prevention and relief scale scores were significantly correlated with estimates of corticosteroid and ß2-agonist use. CONCLUSIONS: A valid and reliable questionnaire has been developed for measuring patients' beliefs about inhaler treatments for asthma. Its utility in predicting adherence and facilitating patient education needs to be tested.
