Computing Adjusted Risk Ratios and Risk Differences in Stata. (September 2013)

• Record Type: Journal Article
• Authors: Norton, Edward C.; Miller, Morgen M.; Kleinman, Lawrence C.
• Is Part Of: Stata journal. Volume 13:Number 3(2013)
• Page Start: 492
• Page End: 509
• Publication Date: 2013-09
• Subjects: st0306 -- adjrr -- risk ratio -- adjusted risk ratio -- risk difference -- adjusted risk difference -- odds ratio -- logistic -- logit -- probit -- multinomial -- ordered; Statistics -- Periodicals; Statistics -- Computer programs -- Periodicals; 001.422
• DOI: 10.1177/1536867X1301300304
• Languages: English
• ISSNs: 1536-867X

Abstract

In this article, we explain how to calculate adjusted risk ratios and risk differences when reporting results from logit, probit, and related nonlinear models. Building on Stata'smargins command, we create a new postestimation command, adjrr, that calculates adjusted risk ratios and adjusted risk differences after running a logit or probit model with a binary, a multinomial, or an ordered outcome.adjrr reports the point estimates, delta-method standard errors, and 95% confidence intervals and can compute these for specific values of the variable of interest. It automatically adjusts for complex survey design as in the fit model. Data from the Medical Expenditure Panel Survey and the National Health and Nutrition Examination Survey are used to illustrate multiple applications of the command.