Methodological issues and problems in shift work research.
Haider-M; Kundi-M; Koller-M
The twenty-four hour workday: proceedings of a symposium on variations in work-sleep schedules. Johnson LC, Texas DI, Colquhoun WP, Colligan MJ, eds. Cincinnati, OH: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 81-127, 1981 Jul; :197-220
Methodological constraints in shiftwork (SW) research and ways to overcome them were discussed. Available data indicated that SW was increasing. Comparison of SW studies in different countries was confounded by legislative, ethnic, cultural, or political differences. Selection bias could be partially controlled by including dropouts as an extra group. Laboratory studies afforded more opportunities to control variables and test specific hypotheses. The state of the organism, defined by physiological variables, was in many cases characterized by level of activation. Hierarchical models were helpful in solving problems such as choice of physiological variables in SW research. In performance measurements, it was informative to examine cost to an individual in maintaining a certain performance level and to examine relationship between performance and expectations of work demands. The authors developed a set of questions to assess personality differences. A problem with questionnaires and subjective scales was that scores might represent stereotyped responses, since answers were influenced by many personal, situational, and social factors. No sound epidemiological methods were available to perform well controlled studies of health status and well being. Complex interaction structure of shiftwork effects on health and well being were discussed using two models. The Kundi model was represented by a network of relations between nine variable groups in shiftworkers. It showed that groups of variables existed which seemed not so much directly related to eventual reduction in health, but acted by making the shiftworker more susceptible to primary disease risk factors. The authors state that one should not look simply for causal chains between shiftwork and health and well being, but rather try to establish the network of significant relations between different parts of the process and evaluate conditions and possibilities for stabilization and destabilization of the interactional structure.
Shift-work; Health-surveys; Psychophysiological-testing; Health-hazards; Occupational-health; Mathematical-models; Physiological-measurements; Psychological-effects
Johnson-LC; Texas-DI; Colquhoun-WP; Colligan-MJ
DHHS (NIOSH) Publication No. 81-127
The twenty-four hour workday: proceedings of a symposium on variations in work-sleep schedules