Reported Symptom Prevalence Rates from Comparison Populations in Community-based Environmental Studies

Abstract

National, regional, state, and county rates of mortality and morbidity are frequently used as reference values in epidemiologic studies. However, baseline information on self-reported symptom rates is currently unavailable. This information is potentially very useful as outcome measures in environmental and occupational epidemiologic studies in which symptoms may be the most sensitive measure of effects of low-level chemical exposure. Comparison populations (n = 934 adults) from three community-based studies were used to determine 1-y symptom prevalence rates. Symptoms rates varied greatly between one study, in which a self-administered questionnaire was used, and the two studies for which data were collected via a similar questionnaire administered by trained interviewers. Four symptoms were selected for detailed analysis of covariates associated with symptom reporting: (1) skin irritation, (2) eye irritation, (3) sleep disturbance, and (4) fatigue. Logistic regression analysis of symptom reporting, by demographic data, and a risk perception variable suggested that the prevalence of symptoms varied with gender, race, and degree of respondent's environmental concern. The results from two of three surveys provide rates that might be used as reference rates in a community-based survey if resources are not available to permit the study of a comparison population. These rates may also provide a quick, initial impression prior to embarking on a full-scale epidemiologic study.