Are long working hours risk factors for workplace accidents and cardiovascular diseases?

Non-standard working hours are becoming an increasingly prominent aspect of modern society. Shift and night work are well established risk factors for several health outcomes, including workplace accidents and cardiovascular diseases. However, there is still an important lack of knowledge related to the potential health effects of long, daily working hours. This project will examine if a single extended shift may produce increased risk of accidents or changes in an early indicator of adverse cardiovascular effects, or if such effects mainly are related to compressed working weeks, with sleep deprivation and disturbance of diurnal rhythms. The study participants are nursing staff recruited from a nursing home where all the day workers work compressed weeks, 3 or 4 consecutive days of 13 hours per day.

We will use advanced, recently developed methods to identify fatigue-related indicators relevant to human error and accidents, together with measurements of subclinical effects on the cardiovascular system. Continuous measurements of heart rate variability (HRV) during working time, leisure time and night, will be used as an intermediate outcome variable representing a proxy for risk of cardiovascular disease.
The cognitive tests, the fitting of the HRV-monitor, and the completion of questionnaires will be performed at the work site. Participants will also write a daily log of work.

The project will be organized by, and performed within the NIOH, in cooperation with the University of Eastern Finland for analyses of the HRV, and in cooperation with the Institute of Aviation medicine and Dr Kazuma form the Jikei Institute, Osaka Japan, regarding the use and analyses of the cognitive tests.

Project page in Norwegian