Principal findings
This study found that among previously mentally healthy young adults in southern Sweden, labour market trajectories including a precarious employment situation in 1999/2000 or in 2005 was a predictor for poor mental health in 2010. The IRR was 1.4 (95 % CI: 1.1–2.0) after adjustment for age, gender, emotional and instrumental support, social participation and neighbourhood anchorage, and economic difficulties in childhood. The calculated population attributable fraction for a precarious employment situation regarding poor mental health in this group was 18 %.
Findings in relation to other studies and possible mechanisms
Mental health problems have become increasingly common among young people during the last decades, and particularly so in Sweden. In 2011, seven percent of men and 10 % of women aged 16–24 years old had been in touch with a psychiatric clinic or used psychotropic drugs [
31]. It has been suggested that recent changes in the labour market, increasing the risk of experiencing precariousness, have contributed to the rapidly deteriorating trend in mental health among young people [
32].
In a meta-analysis from 2002, covering international studies on job insecurity and its consequences, a relatively strong effect size for mental health was found (mean correlation: −0.237) [
33]. Several recent cross-sectional [
23,
34] and longitudinal [
35‐
37] studies also support the relationship found between job insecurity and mental health problems. Benach et al. suggest that one pathway from job insecurity to adverse health outcome may consist of stress response to sustained uncertainty, unpredictability, and lack of control over the future [
4].
The current study primarily focuses on aspects of employment insecurity in the definition of PE used here. Another link between PE and poor mental health may consist of poorer working conditions for persons with PE. These may include poorer supervision, inadequate training, exposure to higher risk tasks, lack of workplace voice, economic and reward pressures, disorganisation at the workplace, and regulatory failure [
38].
In one study, insecure employment negatively affected the likelihood of getting married and having children, which could be a mediating factor for poorer mental health in young people [
39].
Fear of the stigmatisation connected to a precarious labour market may also play a part. In a recent qualitative study, indications of negative stereotyping about ‘unemployed persons’ were found among nurses working in a healthcare program for job seekers [
40]. On the other hand, it could be argued that since precarious employment is steadily increasing, and in particular among young people, the potential stigmatisation of not having a stable employment may become less pronounced with time.
This study was performed in Sweden. The degree of health impairment of individuals with precarious employment was least in Scandinavian settings in one comparative study [
15]. Scandinavian societies have been characterised as egalitarian welfare states, with effective collective bargaining institutions, lifelong job training, and generous unemployment schemes, all of which may contribute to a buffering effect. Therefore, it could be hypothesised that a similar study performed elsewhere might have shown even stronger associations between precarious employment and poor mental health.
However, a study performed in Sweden today might yield greater associations compared with previous decades, since ‘Scandinavian welfare’ is not a constant. A recent Swedish study showed that mental distress among women increased between 2006 and 2010, and more so among groups outside the labour market [
41]. The authors suggested that one of the reasons might be the considerable modifications, e.g. stricter eligibility criteria and lower benefit levels, which have been implemented by the Swedish social insurance system during the last decade.
Moreover, the global trend towards precarious labour market relations seems different than previous cyclic unemployment situations. Not only have the past decades of neoliberal politics, with general deregulation and privatisations, led to a shift in power relations characterised by a markedly increased influence of employers vis-à-vis workers [
42,
43], but also, a broad range of changes have occurred regarding the individual’s relation to society and the capacity of the welfare state to buffer the negative impacts among those exposed to this situation. The British sociologist Guy Standing has developed the concept of precarity, and he states:
‘This is not just a matter of having insecure employment, of being in jobs of limited duration and with minimal labour protection, although all this is widespread. It is being in a status that offers no sense of career, no sense of secure occupational identity and few, if any, entitlements to the state and enterprise benefits that several generations of those who saw themselves as belonging to the industrial proletariat or the salariat (non-manual employees with secure employment)
had come to expect as their due.’ [
44] p. 24. Standing also suggests that it is of major public health interest to assess the potential negative health impacts of such living conditions for the increasing numbers of persons living in this
‘class-in-the-making’ [
44].
Methodological considerations
The study was designed to investigate a causal relation between a PE situation and mental health problems in young persons. We thus used a model excluding all persons with poor mental health at baseline and followed the trajectory over two subsequent follow-up occasions, which reduces the risk of reversed causality.
Other strengths of our study include the adjustment for a substantial number of potential confounders and the recruitment from a large random general population sample. However, a first selection took place in the very establishment of The Scania Public Health Cohort, since the response rate was 58 % for women 18–30 years old and 45 % for men in the same age range [
45]. Moreover, our study group (participating in all three surveys) differed from the original cohort regarding several characteristics (education level, country of origin, economic difficulties, and self-rated health), which makes it reasonable to assume [
2] that PE may have been more common among non-respondents. This was indeed the case for those non-respondents who supplied this information at baseline (1208 out of 1618), where 52 % reported PE. Since the baseline association between exposure and outcome was similar in both groups, we conclude that selection bias in our final study sample may have resulted in an underestimation of the association at follow-up between PE and poor mental health in the general population of young people.
Our measure of PE is based on extensive information on relevant indicators but has not been validated previously. It is highly probable that a multifaceted and continuous measure of precarity such as the comprehensive EPRES (The Employment Precariousness Scale) [
46] would have resulted in a more accurate description and conceivably a discernible dose–response association between exposure and outcome.
Moreover, the ‘forced’ dichotomisation of our instrument may have led to some misclassified cases. For instance, we chose to classify those with ‘contingent work but no previous unemployment and no self-rated risk of future unemployment’ as NP cases. However, and perhaps particularly in this population of young people, it may be argued that they are correctly classified. As stated in a recent EU-commission report on new forms of employment, aspects of the ‘flexible’ labour market may be utilised as a positive choice by some individuals who have competitive characteristics regarding the labour market, and who do not risk unemployment despite the lack of a long-term contract [
47]. This phenomenon is discussed also in Guy Standing’s seminal book ‘The precariat – the new dangerous class’ [
44].
In this context it should be noted that we chose to categorise unemployment as one form of PE. This is in contrast to the EPRES, where persons without employment contracts were excluded [
46], and also in contrast to the ‘peripheral employment score’ [
48]. In the latter study, exposure to peripheral employment was positively related to psychological distress, but adjustment for unemployment attenuated the association. Our model, in which unemployment is seen as an extreme form of precarious employment, could thus be debated. However, the fact that only 7 out of 62 unemployed persons remained so after ten years could indicate that there is a considerable mobility in and out of this category, and excluding these very persons, as was done in the EPRES study, would restrict the study findings to those concerning persons with a less precarious situation.
Changes in precarious employment status may have taken place between the measurement of exposure in 1999/2000 to 2005 and the measure of the outcome in 2010. In particular, the economic recession in 2008 may have led to a number of persons being misclassified as NP, which could have biased the results towards the null, and thus led to an underestimation of the associations. On the other hand, only 23 % of the participants were in a PE situation at follow-up, versus 42 % in 1999/2000, which partly may be explained by the fact that the participants had had 10 years to establish themselves on the labour market.
The determination of a cut-off point for the GHQ-12 test is a trade-off between sensitivity and specificity. Since the mean values in the population were below 1.85 (1.22 in 1999/2000 and 1.01 in 2010), we chose the threshold of 1/2, as advocated by the creator of the test [
22].
There were several reasons for choosing financial difficulties during childhood as a proxy for socioeconomic status in the multivariate analyses. A large proportion (N = 186) of the participants were students, i.e. thus with uncertain present and future socioeconomic position. Furthermore, since the focus of the study was on precarious employment, we firstly considered it essential to identify and categorise all unemployed persons, and secondly, we expected that being unemployed would influence and overrule any socioeconomic position to the point where a classification of socioeconomic status according to job description would become meaningless. Lastly, socioeconomic position according to job description showed no correlation with the outcome. On the other hand, it is reasonable to assume that parental social position in the form of background economic and cultural resources must have influenced these young persons’ present circumstances, both in terms of risk for a precarious employment situation and for poor mental health.