Introduction: The European directives concerning the evaluation of work-related stress were absorbed into Italian law by means of Legislative Decree No. 81 of 9 April 2008.
Aims: To develop a new questionnaire to assess the impact of work-related psychological distress and to validate it by testing its factorial structure, its content, its construct and discriminant validity.
Methods: After critically reviewing the literature, we generated an initial item set to identify the items to be used in a preliminary version of the questionnaire, and then used a focus group to test the comprehensibility of the items. The questionnaire was administered to 329 subjects working in state and private organisation and a small sample of 29 subjects complaining of vexation at work.
Results: The Maugeri Stress Index (MSI) is reliable (Cronbach alpha: 0.93). Factorial analysis indicated five factors: Well-being, Adaptation, Support, Irritability and Avoidance. The total and subscale scores were significantly different when comparing subjects with and without vexation at work.
Conclusion: The MSI has a multi-factorial structure, good internal reliability and sufficient discriminant power.