The results of this study indicate that workers whose mean overtime was > or =50 h have lower risks of developing definite hypertension and increasing their BMI.

Effort-Reward Imbalance and Depression in Japanese Medical Residents: Yumi SAKATA, et al. Department of Occupational Mental Health, Graduate School of Medical Sciences, Kitasato University-The effort-reward imbalance is an important psychosocial factor which is related to poor health among employees. However, there are few studies that have evaluated effort-reward imbalance among medical residents. The present study was done to determine the association between psychosocial factors at work as defined by the effort-reward imbalance model and depression among Japanese medical residents. We distributed a questionnaire to 227 medical residents at 16 teaching hospitals in Japan at the end of August 2005. We asked participants to answer questions which included demographic information, depressive symptoms, effort-reward imbalance, overcommitment and social support. Depression was evaluated using the Japanese version of the Center for Epidemiologic Studies-Depression (CES-D) scale. The effort-reward imbalance and overcommitment were assessed by the Effort-Reward Imbalance (ERI) questionnaire which Siegrist developed. Social support was determined on a visual analog scale. Logistic regression analysis was performed to determine the associations between effort-reward imbalance and depressive symptoms. Depressive symptoms were found in 35 (29.2%) 1st-year residents and 21 (27.6%) 2nd-year residents. The effort-reward ratio >1 (OR, 8.83; 95% CI, and low social support score (OR, 2.77, 95% CI, 1.36-5.64) were associated with depressive symptoms among medical residents. Effort-reward imbalance was independently related to depression among Japanese medical residents. The present study suggests that balancing between effort and reward at work is important for medical residents' mental health. (J Occup Health 2008; 50: 498-504)

. PSQI score also improved, but the inter-group difference was not statically significant. The present study provides preliminary evidence that brief sleep hygiene education may improve afternoon sleepiness at work, but not sleep at night for IT workers.

Development of Japanese Version of the Checklist Individual Strength Questionnaire in a Working Population: Yutaka Aratake, et al. Department of Occupational Mental Healthl, Graduate School of Medical Sciences, Kitasato University—The aims of the present study were to develop and validate the Japanese version of the checklist individual strength questionnaire (CIS) which is used to measure prolonged fatigue not only in the general population but also in the working population. We obtained permission to use CIS from its author and translated the questionnaire into Japanese. Then, the Japanese version of the questionnaire was translated back into English by a bilingual person. The author of the original version agreed that the back‐translated version was conceptually and linguistically equivalent to the original CIS. To validate CIS, 399 workers (66.7% were men) from different companies answered the Japanese version of the CIS (CIS‐J), Maslach burnout inventory‐general survey (MBI‐GS), Beck Depression Inventory‐II (BDI‐II), visual analogue scale (VAS) questionnaires for subjective fatigue, number of overtime hours and number of hours of sleep. Cronbach's α for the total CIS‐J score was 0.91. The test‐retest reliability assessed with an intra‐class correlation coefficient was 0.82. Although confirmatory factor analysis did not show an ideal model fit, the correlation coefficients between the total CIS score and the MBI‐GS exhaustion score, the BDI‐II score and the VAS score were 0.58 (p<0.01), 0.66 (p<0.01) and 0.63 (p<0.01), respectively. The less workers slept and the longer they worked, the higher their total CIS score became. CIS‐J showed good reliability and acceptable validity in the working population. Thus, it could be useful for studying fatigue among Japanese working populations.

These findings suggest that maternity blues is a strong predictor of postpartum depression. The higher the blues score, the higher the risk of postpartum depression.