Magnusson Hanson Linda L, Madsen Ida Eh, Rugulies Reiner, Peristera Paraskevi, Westerlund Hugo, Descatha Alexis
Linda L Magnusson Hanson, Stress Research Institute, Stockholm University, 106 91 Stockholm, Sweden.
Scand J Work Environ Health. 2017 Sep 1;43(5):396-404. doi: 10.5271/sjweh.3654. Epub 2017 Jun 21.
Objectives Psychosocial working conditions are suggested risk factors for low-back pain, but it is unclear whether these associations are causal. The present study examined whether there are lagged and bidirectional associations between job strain and low-back pain and further controlled for unmeasured time-invariant confounding. Methods The study was based on four biennial waves of data from the Swedish Longitudinal Occupational Survey of Health (SLOSH), including 3084 men and women. Cross-lagged analyses using structural equation modeling (SEM) were conducted on job strain, a combination of high job demands and low control, and any as well as low-back pain severity (how much any problems affected the respondents life). Analogous SEM (dynamic panel) models with fixed effects were also fitted to remove confounding from time-invariant factors (such as non-observed individual and environmental factors, eg, genetics, childhood conditions, personality). Results The SEM models indicated bidirectional associations between job strain and any back pain over a 2-year time lag (β=0.21 and 0.19, P<0.05), when adjusting for a range of covariates. Job strain was also associated with an increase in low-back pain severity and vice versa. However, the SEM models with fixed-effects showed no statistically significant lagged relationships between job strain and any or low-back pain severity (β=-0.05 and β=0.00, respectively). Conclusions This study suggests that associations between job strain and low-back pain with a lag of years may be due to residual confounding by time invariant characteristics. Further studies are, however, needed to elucidate short-term relationships.
目标 心理社会工作条件被认为是腰痛的风险因素，但这些关联是否具有因果关系尚不清楚。本研究调查了工作压力与腰痛之间是否存在滞后和双向关联，并进一步控制了未测量的时间不变性混杂因素。方法 该研究基于瑞典健康纵向职业调查（SLOSH）的四轮两年期数据，包括3084名男性和女性。使用结构方程模型（SEM）对工作压力（高工作要求与低控制的组合）以及任何腰痛和腰痛严重程度（任何问题对受访者生活的影响程度）进行交叉滞后分析。还拟合了具有固定效应的类似SEM（动态面板）模型，以消除时间不变因素（如未观察到的个体和环境因素，如遗传、童年条件、个性）的混杂影响。结果 SEM模型表明，在调整一系列协变量后，工作压力与任何背痛之间在2年的时间滞后存在双向关联（β=0.21和0.19，P<0.05）。工作压力也与腰痛严重程度的增加相关，反之亦然。然而，具有固定效应的SEM模型显示，工作压力与任何背痛或腰痛严重程度之间没有统计学上显著的滞后关系（分别为β=-0.05和β=0.00）。结论 本研究表明，数年滞后的工作压力与腰痛之间的关联可能是由于时间不变特征的残余混杂。然而，需要进一步的研究来阐明短期关系。
