[Psychometric evaluation of an instrument measuring motivation]

McEwen's Health Motivation Assessment Inventory (HMAI) (1993) tool was developed to assess the motivation of patients with coronary artery disease to initiate and sustain healthy habits. Because of its measurement difficulties, it was modified and translated into French. The purpose of this methodological study was to examine the psychometric properties (content validity, internal consistency, and test-retest reliability) of the modified HMAI on 255 normal subjects. The average proportions of the items, rated congruent by the three raters, were 0.99 for clarity and 0.95 for relevancy. The final Cronbach's alpha coefficients for the six subscales ranged from 0.08 to 0.67. Confirmatory factor analysis provided evidence that the majority of the items were moderately independent of each other. Also, temporal stability coefficients ranged from 0.49 to 0.81. Finally, the modified HMAI was found to be free of social desirability bias. Although the modified HMAI appears to be a promising tool for future research, further refinement is needed to improve its validity.