Together these findings demonstrate the benefit of

Together these findings demonstrate the benefit of simultaneous analysis in elucidating potential pathways between the environment and activity, by ensuring that significant relationships are not obscured by unaccounted for aspects of the environment. However, few studies used interaction or mediation analyses to explore hypotheses arising from ecological models positing that social and physical environmental variables work together to affect physical activity. This review supplies evidence of the current lack of research exploring interactive environmental effects on physical activity in adults and therefore provides support to previous calls by researchers in the field to make this a future research priority (Gubbels, Van Kann, de Vries, Thijs, & Kremers, 2014).
Conflicts of interest
Acknowledgements This work was supported by a studentship funded by University College London and the Glasgow Centre for Population Health.
Introduction Scandinavian GSK1120212 have been characterised as welfare states, with high levels of labour union membership, effective collective wage bargaining, and strong employment protection legislation, all contributing to relatively high job security (Muffels & Luijkx, 2008), and in turn with positive effects on mental health (Kim et al., 2012). Sweden has also been described as a ‘low-flexibility’ country (McAllister et al., 2015), among other reasons due to its previously strict application of the employment policy ‘last-in – first out’ at a specific workplace (von Below & Skogman Thoursie, 2010). Theoretically, this might lead to job immobility, due to an increased threshold for being able to get new employment with a different employer. This highlights the ‘employability’ aspect of job security, which is the conviction, based on one’s individual situation, that one can easily find a new job if necessary (Sverke, Hellgren & Naswall, 2002). However, the notion of personal employability is necessarily influenced by the objective status of the general labour market. Already in 1995, labour force surveys showed that the proportion of persons holding the view that they can ‘obtain a similar job without moving’ had fallen from 55% to 17% between 1989 and 1993 (Aronsson & Göransson, 1999). With low self-perceived employability, an individual who finds her- or himself in an undesired, yet relatively secure employment, may choose not to leave the job, but remain in place, however dissatisfied. Such a position can be experienced as a type of ‘locked-in’ situation, which can be expected to cause psychological strain. Indeed, in a study by Aronsson & Göransson, published almost two decades ago, restriction fragment length polymorphism (RFLP) was found that people holding a non-desired job reported considerably higher levels of fatigue, slight depression, and headaches than those in comparison groups (Aronsson & Göransson, 1999). In a later study by Aronsson, Dallner, and Gustafsson (2000) examining various types of non-desired work situations, no specific differences between those not preferring their workplace and those not preferring to continue in their occupation were found. However, those preferring neither workplace nor occupation reported more work- and health-related problems than those with only one type of non-preference. Since the original work by Aronsson and colleagues, there have only been a few studies focusing on the mental health consequences of remaining in non-desired work positions. Being ‘doubly locked-in’ (i.e. being both in a non-preferred occupation and a non-preferred workplace) was associated with poor mental health in one cross-sectional study (Muhonen, 2010). In another study, higher rates of long-term sick-leave were found in persons who were in a ‘locked-in’ position in either their occupation, their place of work, or both (Fahlen et al., 2009). Since there is a likelihood of bidirectional causality between labour market factors on the one hand and mental health on the other (Cornwell, Forbes, Inder & Meadows, 2009), longitudinal studies are preferable in order to disentangle causal directions. In a recent follow-up study of almost 4000 gainfully employed persons from the Swedish Longitudinal Occupational Survey of Health (SLOSH), it was found that persons described as ‘locked-in at the workplace’ had poorer well-being in terms of subjective health and depressive symptoms at follow-up after two years (Stengård, Bernhard-Oettel, Berntson, Leineweber & Aronsson, 2016).