LAUSR

We examined whether job security improvements were associated with improvements in mental health in a large Australian nationally representative panel study. We used both within-person fixed effects (FE) and random effects (RE) regression to analyse data from 14 annual waves covering calendar years 2002—2015 (19,169 persons, 106,942 observations). Mental Health Inventory-5 scores were modeled in relation to self-reported job security (categorical, quintiles), adjusting for age, year, education, and job change in the past year. Both FE and RE models showed stepwise improvements in MHI-5 scores with improving job security, with stronger exposure-outcome relationships in the RE models and for men compared to women. The RE coefficients for improvements in job security in males were 2.06 [1.67, 2.46] for one quintile, steadily increasing for two- (3.94 [3.54, 4.34]), three- (5.82 [5.40, 6.24]), and four- (7.18 [6.71, 7.64]) quintile improvements. The FE model for males produced slightly smaller coefficients, reaching a maximum of 5.55 [5.06, 6.05]. Supplementary analyses investigated whether six waves of cumulative exposure to job security (higher value = higher security) predicted MHI-5 score (improvement in mental health) in the seventh wave: results showed a strong dose-response (beta cumulative security was 0.60 [0.53-0.68]), with the difference between lowest and highest values of exposure corresponding to a 14-point increase in MHI-5 score. These analyses, with improved causal inference over previous observational research, showed that improving job security is strongly associated with decreasing depression and anxiety symptoms. Policy and practice intervention to improve job security could benefit population mental health.