Do Japanese workers who experience an acute myocardial infarction believe their prolonged working hours are a cause? Yoshimi Fukuoka a, * , Kathleen Dracup a , Erika Sivarajan Froelicher b , Miyoshi Ohno c , Haruo Hirayama d , Hiromi Shiina e , Fumio Kobayashi f a School of Nursing, University of California San Francisco, 2 Koret Way, Room N611E, San Francisco, California 94143-0604, United States b School of Nursing and Medicine, UCSF, United States c Department of Cardiology, Japanese Red Cross, Nagoya First Hospital, Japan d Department of Cardiology, Nagoya Dai-ni, Red Cross Hospital, Japan e Nursing Department, Nihon University Surugadai Hospital, Japan f Department of Health and Psychosocial Medicine, Aichi Medical University, Japan Received 3 October 2003; received in revised form 7 March 2004; accepted 25 April 2004 Available online 7 August 2004 Abstract Background: Cardiovascular disease related to excessive work/job stress has been a significant social concern for the Japanese public. Therefore, we conducted a cross-sectional study to (1) compare job stress levels between patients with acute myocardial infarction (AMI) patients and healthy workers, and (2) examine the types of stresses associated with patients’ causal belief of AMI among patients with AMI. Methods: Forty-seven patients admitted to the hospital with AMI and 47 healthy workers visiting a hospital for their annual physical examination were recruited in Japan. Both groups were employed full time and matched on age and gender. Job stress was assessed by the Brief Job Stress Questionnaire, which consists of four subscales: job demand, job control, support from supervisors, and support from coworkers. Causal belief was assessed by a semi-structured interview. Results: Compared with healthy workers (50.7F8.6 h), AMI patients worked significantly longer hours per week (58.3F15.0 h) prior to their AMI. Among AMI patients, 38% reported that job stress might have contributed to their AMI. AMI patients who reported acute stressful events at work during the month prior to AMI were 6.88 times (95% CI: 1.84, 25.75) more likely to believe that job stress/overwork caused their AMI after controlling for working hours per week and age. Conclusions: Like other known cardiac risk factors, it is important for clinicians to assess patient’s excessive working hours. The education and counseling of patients following AMI must take into consideration long working hours, acute stressful events at work, and the patient’s perceived view of job stress. D 2004 Elsevier Ireland Ltd. All rights reserved. Keywords: Acute myocardial infarction; Japan; Job stress; Karoshi; Overtime 1. Introduction Health problems related to excessive work and occupa- tional stress are a worldwide phenomena [1]. However, Japanese is the only language that contains a word for sudden death due to cardiovascular disease resulting from overwork, Karoshi. The term reflects the special issues of work patterns in Japan over the last two decades. Although the Japanese Ministry of Health, Welfare and Labor has aimed to reduce the total number of working hours accrued by workers [2], Japanese employees still worked an average of 1889 h annually in 1996, far more than most other industrialized countries [3]. This average does not include unpaid overtime that Japanese workers frequently accrue, especially in times of economic recession. 0167-5273/$ - see front matter D 2004 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ijcard.2004.04.003 * Corresponding author. Tel.: +1 415 514 1794; fax: +1 415 476 8899. E-mail address: hina@itsa.ucsf.edu (Y. Fukuoka). International Journal of Cardiology 100 (2005) 29 – 35 www.elsevier.com/locate/ijcard