Step 2: Assessment of Content Validity
2A. Expert Panel Review
To assess the content validity of the survey items, a panel of 32 local, national, and international asthma experts was identified. This panel included clinicians who were members of the National Asthma Education and Prevention Program’s expert panel or participated in the Global Initiative on Asthma.
Local experts included faculty members, asthma case managers, and members of asthma-related quality improvement teams. This panel was instructed to review each item and rate it using a scale from 0 to 2, where 0 indicated that the item did not target an issue of importance, and 2 indicated that the item was very important to retain. The panel members were also asked to make qualitative comments regarding content or construction. Finally, the panel members were asked to indicate any issues that they thought were missing from the item pool. other
For each item, the ratings from all panel members were combined to produce an average. Using these averages, the survey items in the pool were then rank-ordered. Those items with the lowest ratings became candidates for exclusion. The mean rating for the deleted items was 1.19; the mean for the retained items was 1.77. Examples of items added based on recommendations from the panel include “Some people have asthma and don’t know it (T/F [true/false])” and “There is little a person can do to control their asthma (T/F).” Examples of deleted items include “Children with asthma have a hard time achieving their life goals (T/F)” (mean rating, 1.38), and “Children with asthma are less adventuresome than other children (T/F)” (mean rating, 1.07).
Step 2B: Cognitive Interviews
In order to gauge clarity and comprehensibility of the items, cognitive interviews were conducted with individuals from the Chicago community. A convenience sample of 83 individuals was recruited from diverse sites, including church groups, community colleges, local businesses, a long-term care facility, and a homeless shelter. Many of the persons (62.5%) in the sample had a high-school education or less. The interviewees were asked to complete a written, self-administered version of the 58-item survey, to flag any items that they found unclear or confusing, and to write comments about these items.