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From | "Weichle, Thomas" <Thomas.Weichle@va.gov> |
To | <statalist@hsphsun2.harvard.edu> |
Subject | Re: st: RE: RE: joinby command and memory issues |
Date | Tue, 12 Oct 2010 12:02:48 -0500 |
Eric, I'm trying to apply the second method that you suggested because I need to keep all the receipt dates. After I reshape epo.dta, it creates a dataset of 1 record per individual. Here are my reshaped data results. 36,381 individuals with a maximum of 854 dates. Someone received the EPO drug very often! Now that I have 1 record per individual, wouldn't it be appropriate to then do a 1:m (many) merge instead of a joinby where the many represents each of the hemoglobin test dates for the individual? I believe the data are set up appropriately for this 1:many merge. reshape wide epo_dt, i(study_id) j(i) Data long -> wide ------------------------------------------------------------------------ ----- Number of obs. 278492 -> 36381 Number of variables 4 -> 856 j variable (854 values) i -> (dropped) xij variables: epo_dt -> epo_dt1 epo_dt2 ... epo_dt854 ------------------------------------------------------------------------ ----- Tom Weichle Math Statistician Center for Management of Complex Chronic Care (CMC3) Hines VA Hospital, Bldg 1, C202 708-202-8387 ext. 24261 Thomas.Weichle@va.gov * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/