Assessing the feasibility of retrospective cohort studies.
Steenland K; Stayner L; Greife A
Am J Ind Med 1987 Oct; 12(4):419-430
Issues involved in feasibility studies for retrospective cohort studies were discussed using as an example a study of the relationship between lymphopoietic disease and worker exposure to ethylene-oxide (75218). Goals and concerns for the study were addressed with regard to the development of the study plan. This plan, developed by NIOSH and the National Cancer Institute, ultimately involved two phases comprising a mail and telephone survey and a series of on site surveys at selected facilities. Telephone and mail surveys were conducted at 75 companies that used ethylene-oxide for sterilization purposes. The response rate for these surveys was 100 percent. A total of 39 companies with the largest determined contribution of person years were then chosen for on site review by an epidemiologist and an industrial hygienist. Criteria for inclusion in the study were a contribution of at least 400 person years, adequate records for the identification of past and current exposures to ethylene-oxide, and no confounding exposures to known or suspected leukemogens. The decision making process was discussed with regard to the adequacy of personnel records, sample size, person years estimation, industrial hygiene considerations, and power calculations. A total of 35 of the 39 facilities selected from the mail and telephone surveys were visited, and 14 were selected for inclusion in the study. The authors note that the purpose of the steps followed is not to determine whether a particular site is representative of all exposed groups but whether the level of exposure warrants further study.
NIOSH-Author; Epidemiology; Occupational-exposure; Environmental-health-monitoring; Exposure-levels; Morbidity-rates; Industrial-hygiene; Analytical-methods; Case-studies; Ethylenes; Cancer-rates;
Author Keywords: epidemiology; occupation; cohort studies
Dr. Kyle Steenland, Mailstop R-15, National Institute for Occupational Safety and Health, 4676 Columbia Pkwy., Cincinnati, Ohio 45226
American Journal of Industrial Medicine