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From | Andre Siqueira <andresiqueira10@hotmail.com> |
To | <statalist@hsphsun2.harvard.edu> |
Subject | st: xtgee for skewed data |
Date | Thu, 25 Aug 2011 11:56:01 +0100 |
Dear members I?d like some opinions about how to build a model of a very skewed data (parasitemia) using GEE. My data consist of repeated measures of parasitemia of many individuals (some of them having only one measurement and others having up to five) I?d like to assess the association with a 4-level exposures adjusted for 3 covariates. Only 5% of the measurements had a value above zero. I?ve already discussed with some people who told me not to transform the data and analyse it with a normal distribution, so I?ve built the following model but I?m still in doubt if it?s the best way to do it: Xtgee parasitemia i.main_exp i.co_var1 i.co_var2 i.co_var3, i(id) vce(robust) If anyone has an opinion I?d very much appreciate. Best regards Andre Machado Siqueira Fundacao de Medicina Tropical Gerência de Malaria Av. Pedro Teixeira, 25 Manaus ? AM ? Brazil CEP 69040-000 Tel/Fax: +55 (92) 2127-3443 e-mail: amsiqueira@gmail.com * * 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/