Absence of nonresponse bias in a study of sport-caught Great Lakes fish consumption and conception failure

Introduction: We have reported that men's lifetime sport-caught Great Lakes fish consumption was associated with lifetime prevalence of conception del ay or failure. Those cross-sectional data were based on responses to a post al questionnaire, The present study was conducted to evaluate whether nonre sponse bias could explain the cross-sectional findings. Methods: We conduct ed telephone interviews with 230 men and 38 women who did not respond to th e original survey, and compared these individuals to the original responder s with respect to key demographic, behavioral, and reproductive characteris tics. Results: Nonresponders were approximately 1.5 years older at intervie w, were more likely to be Caucasian, and reported higher incomes than respo nders. Among men, nonresponders had fished fewer days in the past year (12% reported no fishing, compared to 4.3% of responders), Almost one half of n onresponders reported no fish consumption in the past year, compared to one quarter of responders. Nonresponders were more likely than responders to h ave ever conceived a live-born child, had more children, and were less like ly to intend to have additional children in the next 5 years, Among both re sponders and nonresponders there was an increased prevalence of a period of conception failure among men who reported consuming greater quantities of sport-caught Great Lakes fish. Discussion: Our study provides support for t he cross-sectional analyses presented previously, insofar as nonresponse bi as is unlikely to have a major role in the observed association. (C) 1999 A cademic Press.