LAUSR

https://doi.org/10.1177/1403494817720104 © Author(s) 2017 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/ 403 9 817 2 4 journals.sagepub.com/home/sjp Vancea and Utzet reviewed the past academic literature on the effect of unemployment or precarious employment on health among young European adults aged 18–35 years [1]. Among the articles, 28 studies focused on unemployment and 16 on precarious employment. Mental-health disorders, health-risk behaviour, poor quality of life and occupational injuries were used as the indicators of health, and the majority of studies found an association between unemployment or precarious employment and poor health. However, I have some concerns about their study. First, some other reports present no association between unemployment or precarious employment and poor health. I previously reported that the prevalence of degraded psychological well-being in permanent workers in their 30s was significantly higher than that in subjects engaged in precarious employment [2]. As workers who engaged in precarious occupations had signed contracts for three years, the healthy-worker effect would affect newly employed precarious workers [3]. Benavides et al. reported that the level of stress in precarious workers was lower than that in permanent workers [4]. Pirani et al. also found that precarious employment did not involve adverse health consequences in men, although damage to health was observed over the long term [5]. Second, about a half of the articles in the review by Vancea and Utzet were cross-sectional studies, and the causal association between the type of employment and health should be confirmed by longitudinal studies, even though there are some difficulties in the long-term follow-up of precarious workers. Health-risk appraisal of unemployment by a longitudinal study is also difficult, and workers in poor health and/or a lower level of well-being were found to be at a higher risk of engaging in precarious employment or of staying unemployed [6]. The authors summarised the previous studies, which reported contrary findings, and caution should be exercised in using cross-sectional studies to investigate a causal association. Reviews examining the effect of unemployment or precarious employment on health in young adults should only include studies applying a longitudinal design.