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From | Ronan Conroy <rconroy@rcsi.ie> |
To | "statalist@hsphsun2.harvard.edu" <statalist@hsphsun2.harvard.edu> |
Subject | Re: st: Repeated measured analysis |
Date | Wed, 10 Aug 2011 17:14:39 +0100 |
On 2011 Lún 10, at 16:44, Marlis Gonzalez Fernandez wrote: > Hello- > > Trying to help a colleague who has an interesting study. > > He has distance of movement (hyoid bone) measures in mm on 13 subjects with no less than 20 measures (some have many more than that) during swallowing 3 different foods (so lots of repeats!). He wants to determine if there are significant distance differences between normal and disease states (while taking into account food type). I was concerned about having so many repeated measures and appropriately accounting for that to discern where is the true variability (ie. disease state? Subject?). Any ideas welcome.maybe I am over-thinking this? Should he just analyze food types separately? Why not -svyset- with participant as the PSU? The interesting question was whether food type interacted with disease status. In achalasia, difficulty swallowing varies considerably by food type, and this may be true for other disorders of swallowing too – it's not my area – but I'd have a look at the interaction term. Ronán Conroy rconroy@rcsi.ie Associate Professor Division of Population Health Sciences Royal College of Surgeons in Ireland Beaux Lane House Dublin 2 * * 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/