Reliability and Validity of the SmartDiet Canadian Version Questionnaire

Abstract

Measuring the outcomes of nutrition interventions in health promotion settings can be a challenge. Nutrition screening tools are often used to measure dietary patterns and nutrition intervention outcomes, but these tools may lack quantitative scoring methods. Using the SmartDiet questionnaire from Oslo, Norway, as a model, the SmartDiet Canadian Version questionnaire was developed to assess fiber and fat intake. The purpose of this study was to assess the reliability and validity of this new questionnaire. In 2007, 54 volunteer subjects (63% men, mean age 68.3±9.7 years) were recruited from the Cardiac Rehabilitation Program at Vancouver General Hospital, Vancouver, BC, Canada. Test–retest reliability was assessed by having subjects complete the questionnaire at recruitment and 1 month later. Intraclass correlation coefficients of reliability (ICC) for both fiber and fat intake were calculated. For fiber scores the ICC was 0.66 (95% confidence interval 0.48, 0.79) and for fat scores the intraclass correlation coefficient was 0.74 (95% confidence interval 0.59, 0.84). Validity was assessed by correlating the completed questionnaire at recruitment with a 3-day food diary. The daily fat and fiber scores from the questionnaire were correlated with the corresponding average daily fat and fiber scores from the 3-day food diary by means of the Spearman correlation coefficient. For fiber scores, Spearman rho was 0.53 ( P<0.001), and for fat scores it was 0.48 ( P<0.001). The SmartDiet Canadian Version questionnaire is a reliable and valid tool for assessing the daily fiber and fat intake of cardiac rehabilitation clients.