Methods: Two studies were conducted to validate the MIBI. Study one involved a sample of 222 students enrolled in allied mental health profession courses. Cronbach’s alpha and the standard error of measurement coefficient were calculated to determine the reliability of the measure. Factorial validity was established using a confirmatory factor analysis strategy estimated using structural equation modeling (SEM) techniques. Finally convergent and discriminant validity were tested. The second study involved a separate sample of 270 students, used to validate the factorial structure and retest the SEM model.

Results:  Findings suggest the MIBI is a reliable and valid uni-dimensional and global measure of belief in the medical model of mental illness. In both studies, the MIBI achieved acceptable thresholds of reliability (.89 and .87 respectively). Factorial validity was established in study one and replicated in study two with excellent SEM fit indices observed in both studies. The MIBI demonstrated convergent construct validity correlating highly with measures of psychosocial determinants of alcohol abuse and non-pathologizing views towards clients. Discriminant validity was obtained by examining scores on the MIBI and single item indicators of theoretical orientation, demonstrating that theoretical orientation was not related to one’s belief in the medical model of mental illness.

Implications:  This instrument shows promise for examining the extent to which individual beliefs may affect social work practice, policy, and education. For instance, the MIBI may be used to assess the role which beliefs hold in relation to the practice of referrals for psychiatric medication. Also, the MIBI holds utility as a pre/post measure in order to measure potential changes in beliefs.