Since its development, the OSI has been used with a growing number of occupational groups.1,2 Two scales of the OSI were selected for investigation, namely, the mental health and coping subscales. The mental health scale has been developed to provide an insight into mental well-being among employed individuals, and not as a measure of extreme clinical abnormality.1 The stress coping scales were developed to determine the ways in which respondents attempt to cope with the stresses relating to work. One aim of the study is to investigate the construct validity of the OSI mental health scale and the discriminant validity of the OSI coping measure. In order to demonstrate construct validity, the scores from a measure should converge with scores from different measurement techniques that purportedly measure the same dimension of a construct (convergent validity), and should not converge with the scores of instruments that are not supposed to measure the construct (discriminant validity).3