.- help for ^confsvy^ .-Assessing confounding effects in survey studies ----------------------------------------------------------------

^confsvy^ yvar xvar, [^con^(covlist) ^cat^(covlist) ^nog^raph ^b^ackward ^det^ail ^l^evel(#) ^co^ef graph_options] ^confsvy^ calculates the change in effect estimates such as odds ratio, after adjusting for a potential confounder using either "forward selection" or "backward deletion" strategies.

^confsvy^ also calculates and graphs adjusted effect measures and their confidence intervals. The order of variables being selected is based on the "importance" (magnitude) of "change in estimate". Variables required -------------------

^yvar^ -- dependent variable, binary variable for logistic or poisson regression; survival time variable for Cox proportional hazards model.

^xvar^ -- exposure of interest Options -------- ^con^ -- list of potential continuous confounding variables. ^cat^ -- list of potential categorical confouding variables. ^nog^graph -- suppresses graphs. By default, a graph is given. ^b^ackward -- specifies selection strategy as "back deletion method", otherwise, "forward selection" method is default. ^co^ef -- graphs regression coefficients instead of effect estimates for graphs. ^det^ail -- gives details at each step. Default only gives a summary. ^l^evel(#) -- specifies the confidence level, in percent, for calculation of confidence intervals (default=95%) ^graph_options^ -- some options with ^graph^ are allowed; see help @graph@.

Examples ---------

. ^confsvy dead ab_uria, con(sbp weight) cat(sex agegroup)^ Calculates and graphs crude and adjusted odds ratios using ^svylogit^ with a forward selection approach. . ^confsvy dead ab_uria, con(weight sbp) cat(sex agegroup) detail^ Calculates and graphs crude and adjusted odds ratios using ^svylogit^. Details in each step are given.

Author ------- Zhiqiang Wang Menzies School of Health Research, Darwin, Australia wang@@menzies.su.edu.au