Development and validation of stages-of-change questions to assess consumers' readiness to use a food thermometer when cooking small cuts of meat.

Consumers' readiness to use a food thermometer when cooking small cuts of meat was assessed using Prochaska's Transtheoretical Model of Behavior Change. Face, content, and concurrent validity were assessed by peer review, cognitive interviews, and mail surveys. The self-administered mail survey was sent to two groups of Washington and Idaho residents: 1,000 randomly selected consumers (41% return rate), and 231 employees and volunteers of Cooperative Extension involved in food and nutrition education (60% return rate). Two-stage classification questions were compared with a behavior question about thermometer use, and validated using Cronbach's if-item-deleted option for alpha. Concurrent validity was assessed using cross-tabulation chi2 test. The detailed classification question more accurately classified respondents in both Consumer and Extension groups. Cronbach's alpha of the detailed question with the behavior question showed a consistency level of alpha=.73 compared to alpha=.35 for the simple question format. As expected, Consumer and Extension groups differed significantly in their stages of change (P<0.0001), verifying concurrent validity. We recommend use of the detailed classification question when staging persons related to food thermometer use. The process used for development and testing can be used to refine instruments for use in other types of interventions.