The effects of interventions and shift work arrangements based on recording complex physiological changes

Research Project

Project/Area Number	08457121
Research Category	Grant-in-Aid for Scientific Research (B)
Allocation Type	Single-year Grants
Section	一般
Research Field	Hygiene
Research Institution	The Institute for Science of Labour
Principal Investigator	SAKAI Kazuhiro The Institute for Science of Labour, Vice Director, 副所長 (90072660)
Co-Investigator(Kenkyū-buntansha)	SASAKI Tsukasa The Institute of Science of Labour, Researcher, 研究部, 研究員 (10260134) ITO Akiyoshi The Institute of Science of Labour, Chief Researcher, 研究部, 主任研究員 (30151492) WATANABE Akihiko The Institute of Science of Labour, Special Researcher, 研究部, 特別研究員 (30072648)
Project Period (FY)	1996 – 1997
Project Status	Completed (Fiscal Year 1997)
Budget Amount *help	¥6,400,000 (Direct Cost: ¥6,400,000) Fiscal Year 1997: ¥2,600,000 (Direct Cost: ¥2,600,000) Fiscal Year 1996: ¥3,800,000 (Direct Cost: ¥3,800,000)
Keywords	shift work / intervention study / improvement for shift work arrangement / portable devices for recording complex physiological changes / physiological work load / time budget analysis / compressed work system / trade-off relations between the length of shifts and the frequency of days / 休日と勤務時間とのトレードオフ / 交代制、介入研究 / 覚醒及び睡眠評価法 / 4組3交代制、9組2交代制
Research Abstract	The effects of interventions in working conditions and shift work arrangements in a petroleum refinery were studied when the refinery changed its continuous shift system from a four-team three-shift system to nine-team two-shift system. 1) Portable devices developed for recording complex physiological changes were redesigned. The new devices, smaller and more stable than the original ones, were useful for analyzing the physiological changes during the work and rest periods of shift workers. 2) The circadian patterns of physiological and psychological changes during the 12-hour night shift in the 9-team two-shift system were similar to those during the 8-hour shifts. There differences between the two systems were not significant. The results of time budget records showed that the total time spent for work-related activities reduced in the new system. The mean sleeping time in the 9-team two-shift systems was 16 min shorter for daytime sleep and 31 min longer for nighttime sleep than corre … More sponding mean time in the three-shift system 3) One year after the transfer to the 9-team two-shift system, the questionnaire replies from 202 shift workers showed that they were in favor of the transfer. Fifty-eight percent replied that the shift working arrangements were better in the new system with only 11 percent replying that they were worse in the new system. This two-year intervention study confirmed the need for a comprehensive assessment of the effects of a transfer to a new shift system. First, action programs for improving work arrangements should address not only improvements in working time arrangements but also those in job content and coping behavior. The trade-off relations between the length of shifts and the frequency of days off and the detailed coping strategies including inserting napping periods were found important. Second, it was found essential to assess these effects by means of combining the evaluation of physiological and psychological changes, the time budget analysis and the questionnaire study of the views of shift workers and their families. Less