The Validity of the Short UK Health and Safety Executive Stress Indicator Tool For the Assessment of the Psychosocial Work Environment in Italy

The Health and Safety Executive Stress Indicator Tool (SIT) is a 35-item questionnaire to assess exposure to seven common psychosocial factors involved in the genesis of work-related stress. Recent work conducted in the UK has provided evidence that the SIT may be reduced to a 25-item questionnaire (the SIT-25) showing the same seven-factor model and criterion-related validity of the SIT. The SIT is the most widely used tool to assess work-related stress factors in Italy, with benchmark (normative) data managed by the Italian Workers' Compensation Authority. Thus, we conducted two studies to further test whether in Italy the SIT may be reduced to the SIT-25. In Study 1 a heterogeneous sample of workers (N = 588, 39.5% females) was used to further test the seven-factor model of the SIT-25 and its criterion-related validity with mental well-being. In Study 2 two new samples of workers (N = 625, 69.8% females; and N = 344, 3.2% females) from health and metal-mechanical sectors were used to assess the degree of measurement invariance of the SIT-25 and further test its criterion-related validity. Overall the results showed that the SIT-25 data fit the postulated seven-factor solution and that the reduced subscales (i.e., Demands, Control, Relationships, and Role) have the same criterion-related validity as their longer version. Additionally, the SIT-25 showed strong measurement invariance in the two different samples of workers of Study 2. These results provide further encouraging evidence that the SIT-25 may be effectively used in place of its longer version.