tag:blogger.com,1999:blog-8285737581949527996.post3389974383446849371..comments2023-10-11T09:14:08.345+01:00Comments on Pyjamas in Bananas: Regression in depressionpjhttp://www.blogger.com/profile/06832177812057826894noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-8285737581949527996.post-81312791134490194072008-06-21T09:24:00.000+01:002008-06-21T09:24:00.000+01:00This comment has been removed by a blog administrator.Unknownhttps://www.blogger.com/profile/02322501703293001810noreply@blogger.comtag:blogger.com,1999:blog-8285737581949527996.post-38454276436265596132008-03-19T10:35:00.000+00:002008-03-19T10:35:00.000+00:00[Reposting robert's comment without his email addr...[Reposting robert's comment without his email address]<BR/><BR/>What happens when you drop the single study with baseline HRSD 17 (protocol 62 mild IIRC). Your scatter looks like an illustration of how one leverage point can take over a regression.<BR/><BR/>Hmmmm I'll ask STATA. I will get different results as I use change/d as the standard deviation within a trial. for SSRI including all trials I regress average change on baseline wighted by the inverse of the variance of the average change.<BR/>Coeff 0.53 (or in other words end of trial HRSD score 0.47 points higher if initial HRSD score 1 point higher) reported se 0.038. R squared of 0.66.<BR/><BR/>Now I redo the data for sSSRI patients dropping the study with baseline 17 and get a coefficient of 0.48. Much higher standard error of course, but almost no change in the point estimate.<BR/><BR/>Oh wow you're right !<BR/><BR/>Also I get similar results weighting by sample size which, as I as I explain at length at my blog, in my opinion, trades a tiny loss of precision for a large gain in robustness.<BR/><BR/>in contrast there is no hint of a slope in the Placebo regressions<BR/>For placebo slope = 0.023 se 0.162.pjhttps://www.blogger.com/profile/06832177812057826894noreply@blogger.comtag:blogger.com,1999:blog-8285737581949527996.post-11586400544954193292008-03-11T16:01:00.000+00:002008-03-11T16:01:00.000+00:00This comment has been removed by a blog administrator.Roberthttps://www.blogger.com/profile/14455788499385673507noreply@blogger.com