Validity and reliability of an instrument to measure barriers to bike use in adults

Abstract

The purpose of this study was to analyze the validity and reliability of an instru­ment to assess the perception of barriers related to bicycling for leisure and transportation in adults. The items composing the instrument were selected from the literature review on the subject. Content validity was analyzed by consulting experts in physical activity field. The reliability was assessed through internal consistency (Cronbach’s alpha) and agreement (intraclass correlation coefficient (ICC), kappa coefficient and relative agreement in a sample of 66 adults (18-79 years old) selected from three census tracts in Curitiba-PR. Data were analyzed using SPSS 17.0, with a significance level of 5%. Most of the sample consisted of women (60%), aged 40 years (47%) and intermediate socioeconomic level (68%). The fre­quency of bicycling in leisure time was higher than for transportation means (15.2 vs 7.6%). The internal consistency (Cronbach’s alpha) was significant, both in leisure time (?=0.77) and transportation (?=0.82). The agreement was higher for leisure (80.3 to 93.9%) than compared to commuting (76.9 to 90.8%). Kappa values were moderate to high (leisure: 0.41 to 0.82: commuting: 0.53 to 0.82). The ICC sub-scores were 0.93 (CI95%: 0.88 to 0.96) and 0.89 (CI95%: 0.82 to 0.94) for leisure and transport, respectively. It follows that the instru­ment has psychometric quality suitable for measuring the barriers to bicycle use in adults.