COMPARING ESTIMATES OF THE EFFECTS OF AIR-POLLUTION ON HUMAN MORTALITY OBTAINED USING DIFFERENT REGRESSION METHODOLOGIES

Studies using regression techniques report their results using a varie ty of statistics. Evaluation of the consistency of findings, such as i n a metaanalysis, requires calculating the statistical estimates of th e effect reported in each study in a comparable manner. In this paper, we consider multiple linear regression, multiple Poisson regression, and logistic regression estimates. We present results that are needed to calculate, on a common basis, the slope of the regression function at a specified value, the elasticity function of the regression functi on at a specified value, the relative risk at a specified value, and t he odds ratio at a specified value. We apply these results to studies of the association of daily mortality in an area to the daily air poll ution level of ozone and PM10. We calculate the estimated slope of the number of deaths per billion population associated with an increase o f 1 ppb of ozone level in studies of daily mortality in three urban ar eas. These studies, in Los Angeles, New York, and St. Louis, produced very comparable results on a common basis, especially when compared to the coefficients as reported. We also calculated the estimated elasti city function of the daily mortality and daily PM10 level for eight ar eas and found that the elasticities varied within a factor of roughly two, much less than the variability in the coefficients as reported.