Validity and reliability of the effort-reward imbalance questionnaire in a sample of 673 Italian teachers

This study explores the explicative potential of effort-reward imbalance Model to unveil the dimensions involved in teacher stress process and analyses the psychometric characteristics of the Italian version of the ERI Questionnaire (Siegrist, J Occup Health Psychol 1:27-43, 1996) with respect to a homogeneous occupational group: Italian school teachers. The Italian version of the ERI Questionnaire was submitted to 673 teachers randomly drawn from a cross-section of school types. Internal consistency, reliability, discriminative validity, and factorial structure were evaluated. Predictive validity was explored with respect to a measure of perceived strain, the Crown-Crisp Experiential Index. Discriminative validity was explored with respect to age, gender, education, type of school, the presence/absence of physical pains in the last 12 months before the survey, and teachers' intention to leave the profession. Item-total correlations are for all items included between 0.30 and 0.80 (p < 0.01). Mean inter-item correlation is 0.26. Cronbach's alpha for the whole questionnaire reaches the value of 0.89. The factor analysis identified four reliable factors that accounted for 44.8 per cent of the total variance and which confirmed the basic structure emerged from previous studies yet highlighting two instead of three different components for reward. Higher efforts (T = -3.82, p < 0.001) and both lower material (T = 3.23, p < 0.001) and immaterial rewards (T = 3.17, p < 0.005) characterised the group of teachers, which reported to suffer for physical pains. Higher efforts (T = -5.26, p < 0.001), higher overcommitment (T = -3.15, p < 0.005), and both lower material (T = 4.63, p < 0.001) and immaterial rewards (T = 4.00, p < 0.001) were observed in the group of teachers inclined to give up the job. Multiple regression analyses have highlighted that higher efforts, higher overcommitment, and lower rewards are significantly predictive of higher levels of free-floating and somatic anxiety as well as depression and global psychological strain. This preliminary analysis of the reliability and validity of the Italian version of the ERI Questionnaire reveals that it constitutes a useful and reliable measure to analyse work-related stress with respect to the school setting. The validity of the ERI model to describe the dimensions involved in teacher's stress and to highlight those associated to leaving intentions and to several physical and psychological strain outcomes in Italian school teachers has been confirmed.