An odds ratio (OR) is a measure of association between an exposure and an outcome. The OR represents the odds that an outcome will occur given a particular exposure, compared to the odds of the outcome occurring in the absence of that exposure. OR equal 1 indicated that exposure does not affect odds of outcome. OR more than 1 that means exposure associated with higher odds of outcome. OR less than 1 indicated that exposure associated with lower odds of outcome. The OR was used to explain a relationship between health effect and pesticide exposure.