Learning Objective #1: Describe content areas that are required for self-management of adults with asthma

Learning Objective #2: Critique the use of exploratory factor analysis in the development of a clinically relevant questionnaire

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Adults with asthma require core asthma knowledge in order to function as partners in self-management, yet available instruments to measure this knowledge do not assess knowledge related to inhaled corticosteroids that are currently recommended as first-line treatment for adults with persistent asthma. This paper presents the development and psychometrics of a brief asthma self-management questionnaire for adults that incorporates 5 content areas considered essential for asthma self-management by the National Asthma Education and Prevention Program (NIH, NHLBI, “NAEPP Expert Panel,”1997). Using a true-false format to enhance readability, initial questions were developed to reflect topics in each content area. Six asthma experts evaluated the questions using a content validity index, and questions that were not rated as both succinct and relevant were deleted or revised. After approval by the Institutional Review Board, the questionnaire was piloted with a convenience sample of 40 adults with self-identified asthma. Deleting questions that did not discriminate in a computerized item analysis, internal consistency was determined to be .723 on the resulting questionnaire using KR-20. The revised 33-item, true/false questionnaire was subsequently administered to 305 adults with asthma. Mean overall knowledge score was 83%, with standard deviation of 11%. Internal consistency was .720 using KR-20. Caucasian race (p = .04) and education (p = .001) were significantly correlated with higher knowledge scores using Pearson's Correlation. Exploratory factor analysis was undertaken to identify interrelationships among the items. Seven factors were identified, with 23 of 33 items loading at .3 or greater. However, two of the 7 identified factors were not conceptually distinct and moderate cross-loading occurred. Of the total variance, 32% was explained by the seven factors. Since the abbreviated questionnaire eliminated some content viewed as very clinically relevant, it is recommended that the full-length questionnaire be utilized to assess the educational needs of adults with asthma.