Prevalence of chronic respiratory symptoms among Ohio cash grain farmers

Background The prevalence of chronic cough, chronic phlegm, dyspnea, and no n-cold wheeze was estimated from a mixed-mode survey of Ohio cash grain far mers in 1993. Methods Personal characteristics of the principal operators (POs) such as a ge find cigarette smoking, in addition to selected farm characteristics and relevant medical and work history factors potentially associated with both exposure To respiratory irritants and subsequent respiratory symptoms were considered. Results The overall design-adjusted prevalences (and the corresponding 95% confidence intervals (CIs)) were: 9.4% (7.6-11.1%) for chronic cough, 10.8% (9.0-12.6%)for chronic phlegm, 16.2% (14.1-18.3%) for dyspnea, and 8.1% (6 .4-9.8%) for non-cold wheeze. In univariate and multivariate analyses, smok ing status was found, not surprisingly, to be the strongest predictor of in creased symptom prevalence compared to all other factors. Other non-occupat ional factors found associated with increased symptom prevalence include ag e (cough, phlegm, dyspnea) and pet allergy (non-cold wheeze). Occupational factors found at least weakly associated with increased symptom prevalence include lifetime hours of cab tractor operation (cough); percent time spent farming (phlegm); having livestock other than cattle, cows, and calves (dy spnea); acres of corn for silage or green chop (cough); acres of alfalfa ha y (non-cold wheeze); and personal involvement, with pesticides (cough). Conclusions Symptom prevalences reported here are consistent with previous findings from studies of other groups of farmers. Results pertaining to fac tors found associated with symptom prevalences should be interpreted in lig ht of several sources of potential bias. Am. J. Ind. Med. 35:150-163, 1999. (C) 1999 Wiley-Liss , Inc.