Hola! I have a problem which is not strictly R, although R will be used for the analysis. We have data from a large investigation of drug abuse, initially analyzed by logistic regression. But the pupils are selected by first sampling schools, and as it happens the prevalence of use varies sharply from school to school, so there is over-dispersion. Now we are interested in comparing the prevalences estimated from this study with prevalences from 3 earlier studies (93, 96, 99), which were analysed assuming no overdispersion, withouyt investigating that issue. For various reasons we can not get hold of the original databases from those studies, only the published summary statistics. But we know the structure of sampling were the same as in the 2002 study, so probaby the overdispersion were the same (at least assuming that is the best I can do). So assuming equal overdispersion I can get four confidence interval s of "binomial" p's, but people will want an hypothesis test of the overall null: p_1=p_2=p_3=p_4. Is there some way I can construct an hypothesis test for that null, from the four confidence intervals? Hoping this is enough information of the background, as the mail is already to long! Thanks, Kjetil Halvorsen
Non-R question.
1 message · kjetilh@jupiter.umsanet.edu.bo