Comparison of self-reported use and observed presence of pesticides and their relationship to the odds ratio.
Sieber WK; Williams LA; Catlett LR; Wilkins JR III
Proceedings of the 2002 American Statistical Association, Section on Statistics and the Environment. Alexandria, VA: American Statistical Association, 2003 Mar; :1-3
Obtaining accurate information about the types of agents to which an individual may be exposed is important in studying the association between disease and exposure. The agreement between two methods of obtaining exposure data and its relationship to the odds ratio was investigated. Information on the number and type of pesticides used on crops was collected using a questionnaire and compared to the presence of pesticides noted during site visits to 71 farms. Mean value of the kappa statistic for agreement between self-reports and observation of 30 pesticides was 0.2, indicating poor to fair agreement between self-reported use of individual pesticides and their observed presence on farms. Odds ratios for the use of pesticide and presence of headache were negatively associated with the percent of farms reporting a potential for exposure to the pesticide. Such results could be due to factors such as recall bias, misclassification in completing questionnaires, or differing pesticide application and storage practices on farms, and indicate the difficulty often met obtaining valid exposure data from a self-reported questionnaire.
Questionnaires; Pesticides; Pesticides-and-agricultural-chemicals; Insecticides; Epidemiology; Information-processing
Proceedings of the 2002 American Statistical Association, Section on Statistics and the Environment