The Employment Precariousness Scale (EPRES): psychometric properties of a new tool for epidemiological studies among waged and salaried workers

TLDR: Evidence is provided in support of the psychometric properties of EPRES, which appears to be a promising tool for the measurement of employment precariousness in public health research.

Abstract: Background: Despite the fact that labour market flexibility has resulted in an expansion of precarious employment in industrialized countries, to date there is limited empirical evidence about its health consequences. The Employment Precariousness Scale (EPRES) is a newly developed, theory-based, multidimensional questionnaire specifically devised for epidemiological studies among waged and salaried workers. Objective: To assess acceptability, reliability and construct validity of EPRES in a sample of waged and salaried workers in Spain. Methods: Cross-sectional study, using a sub-sample of 6.968 temporary and permanent workers from a population-based survey carried out in 2004-2005. The survey questionnaire was interviewer administered and included the six EPRES subscales, measures of the psychosocial work environment (COPSOQ ISTAS21), and perceived general and mental health (SF-36). Results: A high response rate to all EPRES items indicated good acceptability; Cronbach’s alpha coefficients, over 0.70 for all subscales and the global score, demonstrated good internal consistency reliability; exploratory factor analysis using principal axis analysis and varimax rotation confirmed the six-subscale structure and the theoretical allocation of all items. Patterns across known groups and correlation coefficients with psychosocial work environment measures and perceived health demonstrated the expected relations, providing evidence of construct validity. Conclusions: Our results provide evidence in support of the psychometric properties of EPRES, which appears to be a promising tool for the measurement of employment precariousness in public health research.

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Table 2. Demographic and occupational characteristics of the study population (frequency and percentages). Spain, 2004-2005.

Figure 1. Mean EPRES scores (95% CI) in waged and salaried workers according to sex, age, country of birth, type of contract, and occupational social class. Spain, 2004- 05.

Table 4. Exploratory Factor Analysis of the Employment Precariousness Scale (EPRES). Spain, 2004-2005.

Table 1: Hypotheses concerning the expected logical relations between employment precariousness and other related constructs.

Table 5. Spearman correlation coefficients. Multitrait-multimethod matrix of the EPRES and the SF-36 and COPSOQ ISTAS21 dimensions in waged and salaried workers. Spain, 2004-2005

Table 3. Distribution and reliability of EPRES in a population sample of permanent (P) (n=5147) and temporary (T) (n=1821) workers. Spain, 2004-2005.