Targeting asthma care in general practice using a morbidity index.

objectivesTo evaluate a morbidity index as a postal surveillance tool in defining previously diagnosed asthmatic patients needing extra education or management; to determine the accuracy of a computerised asthma register in general practice.

designPostal questionnaire survey of asthmatic patients identified from a computer register. Questionnaire comprised three morbidity questions, two questions about current asthma status, and one about treatments.

settingUrban general practice of 8400 patients linked to academic unit. SUBJECTS: 853 asthmatic patients of all ages.

main outcome measuresNumbers of patients with low, medium, and high morbidity; associations of these groups with age, asthma status, and drugs taken.

resultsTwo mailings yielded 621 replies (73%); 28 patients (5%) had moved away, leaving 593 for analysis. Attempts were subsequently made to contact 20% sample of non-respondents. 234 respondents (40%) were in the "low morbidity" group, 149 (25%) in the "medium morbidity" group, and 210 (35%) in the "high morbidity" category. 53% of patients perceiving themselves as currently asthmatic (193/362) were in the high morbidity group, but 7% (11/153) who said they were no longer asthmatic and 8% (6/78) who did not believe they had ever been asthmatic were also in that group. High morbidity was also found in 10% (18/185) of those on no treatment, 38% (59/154) of those on bronchodilators alone, and 54% (119/220) of those on inhaled corticosteroids. 25 patients (4%) were wrongly identified as asthmatic; when combined with returns marked "gone away" this gave a disease register accuracy of 91%.

conclusionsThis exercise identified subgroups of previously diagnosed asthmatic patients with high morbidity in general practice who might benefit from extra education and management and revealed some misclassification on the asthma disease register.