Re-employment had a positive effect on self-rated health and quality of life. Persons who became re-employed were almost three times more likely to improve from poor to good health and 1.76 times more likely to improve from a poor to good quality of life after entering paid employment, compared with those who continued to be unemployed. For every month in paid employment after re-employment, the likelihood of changing towards a good quality of life increased with 1.12.
The longitudinal design with up to four measurements in one and a half year gives more insight into the change of health before and after entering paid employment. Persons only participated in the study one more time after re-employment, so the maximum follow-up after the employment transition was six months. Previous studies showed the largest change in health in the first months after re-employment transition [4, 17]. Therefore, this study gives important information on the effects of re-employment on health and quality of life.
The response of the four sequential waves varied between 35% and 59%. Non-participation and loss-to follow up were more frequent among younger, low educated, non-native persons and persons on social security benefits. The current study showed that the effect of re-employment on health was not influenced by educational level or type of benefit. Re-employment resulted in less health benefits among persons with a non-Dutch origin and more health benefits among younger persons. Therefore, the effect of re-employment on health may be biased by selective loss to follow-up.
The monthly improvement of quality of life after re-employment was higher (OR 1.12, 95% CI 1.02–1.23] than the improvement of self-rated health (OR 1.06). The larger improvement of quality of life is likely to be explained by differences in scale size and precision of the two measures (10-point scale compared to 5-point Likert-scale). The proportion of persons reporting poor health might be too small to improve significantly. A more sensitive instrument measuring general health would have showed the positive health effect of the duration of re-employment more clearly. However, a trend in improvement of health and quality of life is demonstrated.
This study showed a positive association between re-employment and a change of self-rated health after controlling for several important determinants of health. Due to practical and ethical reasons, the effect of re-employment on self-rated health cannot be studied in a randomized controlled trial. Nevertheless, in this study we observed a stable proportion of persons experiencing poor health in the group of prolonged unemployed persons (61%) and this stability is in congruence with earlier studies . Repeated measurements analyses showed that among re-employed persons 60% improved in self-rated health. The improvement of health among re-employed persons compared to the stable trend of health among persons who continued to be unemployed provides evidence for a causal relation between re-employment and changes in health.
The positive change in self-rated health as a consequence of re-employment transition is in accordance with findings from previous studies. Recent studies found that re-employment had a positive effect on physical health , limiting illness  and mental health [4, 8, 16, 27]. Other studies showed the positive effect of re-employment on psychological symptoms , well-being [11, 14] and life satisfaction . Only two studies addressed physical health, a Dutch study showed that re-employment positively influenced mental health as well as physical health in a short time window  and a Norwegian longitudinal study reported a positive effect of re-employment on somatic symptoms .
The current study shows that starting with paid employment positively influences health and quality of life. However, there are differences between native and non-native Dutch person in the effect of re-employment on health and quality of life. Persons from minority ethnic groups may be disadvantaged in terms of pay, working conditions and job status, all factors explaining the relation between employment and health . The positive health effect of becoming employed may be limited to certain employment conditions, for instance the psychosocial quality of the work , the number of hours worked and the type of contract, flexible versus permanent [27, 30]. In addition, among ethnic minorities in the Netherlands, flex-work is on average about twice as high as among Dutch workers . However, although the non-native re-employed persons show a smaller increase in health compared to the native Dutch re-employed persons, they are still better of than their unemployed counterparts. This is also found by Grun et al. , who suggests that job quality only matters to some extent, since there is evidence that persons in poor quality employment are still better off, report a higher life satisfaction, than those who remain unemployed.
The current study showed that the effect of re-employment on self-rated health and quality of life decreased with an increase in age. Several studies have found that the negative effect of unemployment on health is especially large for the younger age groups . Older workers who are approaching retirement may be able to cope better with unemployment compared with the younger workers who will be staying longer in the labour force. Therefore, especially among younger persons the negative effect of unemployment on health can be reversed by re-employment.