Psychosocial job characteristics and insomnia: A prospective cohort study using the Demand-Control-Support (DCS) and Effort–Reward Imbalance (ERI) job stress models
Received 25 December 2008; received in revised form 4 March 2009; accepted 5 March 2009.
Abstract
Objective
To examine the prospective effects of psychosocial job characteristics evaluated with the Demand-Control-Support (DCS) and Effort–Reward Imbalance (ERI) models on insomnia.
Methods
A prospective cohort study with a two-year observation was performed. The subjects were 1022 middle-aged (⩾39 years) Japanese workers. The following associations were analyzed: high job strain, low social support, effort–reward imbalance, and overcommitment to work at the baseline with self-reported persistence and future onset of insomnia.
Results
Among those who were insomniacs at the baseline (N=292), low social support [adjusted odds ratio (95% CI): 2.00 (1.18, 3.40)] and effort–reward imbalance [2.40 (1.13, 5.10)] at the baseline had a significant relationship to insomnia at the follow-up. Among those who were not insomniacs at the baseline (N=730), overcommitment to work [1.75 (1.16, 2.66)] and high job strain [1.72 (1.06, 2.79)] at the baseline were associated with insomnia at follow-up.
Conclusions
Prospective effects of psychosocial job characteristics on insomnia differed between its persistence and future onset. Proportionate reward for work effort and sufficient support at work assist recovery from insomnia, while overcommitment to work and high job strain cause future onset of insomnia.
aDepartment of Public Health, Fujita Health University School of Medicine, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi 470-1192, Japan
bDepartment of Public Health, Kochi Medical School, Kohasu, Oko-cho, Nankoku, Kochi 783-8505, Japan
cDaito Occupational Health Center, SANYO Co. Ltd., 1-1 Sanyo-cho, Daito, Osaka 574-8534, Japan
dOccupational Health Training Center, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahata-nishi-ku, Kitakyushu 807-8555, Japan
eCollege of Social Welfare, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
Corresponding author. Address: Department of Public Health, Fujita Health University School of Medicine, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi 470-1192, Japan. Tel.: +81 562 93 2453; fax: +81 562 93 3079.
ABSTRACT