tag:blogger.com,1999:blog-7082878015421475244.post2586396971963599397..comments2024-01-19T13:58:02.291-08:00Comments on LawsDystopiaBlog: My Bloody Valentine: CBT for unmedicated psychosisProfessor Keith R Lawshttp://www.blogger.com/profile/11760248140027990471noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-7082878015421475244.post-15922836407625758652014-02-07T04:30:57.572-08:002014-02-07T04:30:57.572-08:00In this study there is a conflict between the kind...In this study there is a conflict between the kind of analysis typically carried out in relatively small treatment trials (ie comparison of means at key outcome points such as end of trial and end of follow-up) and the more sophisticated analysis employed by the investigators (‘Primary analysis was by intention to treat. Changes in all primary and secondary outcomes were analysed with STATA’s xtreg command to fit random effects regression models (essentially, repeated measures ANCOVAs) with summed scores as dependent variables, allowing for attrition and the variable follow-up times introduced by the trial design.’).<br /><br />Is the latter approach appropriate for a smallish trial of this type, especially given the high attrition rate? Is there scope for generating false positive or misleading results? Or is it actually a better choice, for example when you have a lot of data points? <br /><br />I don’t know the answer to these questions – my statistical expertise is limited – but I wondered if anyone out there can comment.<br />Peter McKennahttps://www.blogger.com/profile/08728369741190657853noreply@blogger.comtag:blogger.com,1999:blog-7082878015421475244.post-84054726672620552872014-02-06T22:53:26.794-08:002014-02-06T22:53:26.794-08:00In terms of 'change', the scores favour TA...In terms of 'change', the scores favour TAU for both positive and negative symptoms but CBT for overall PANSS score. <br /><br />I am clear - CBT & TAU show no significant differences at end of the intervention - but the direction goes against CBT even after 9 months of intensive treatment (compared to absolutely nothing, not even a placebo in the TAU group)Professor Keith R Lawshttps://www.blogger.com/profile/11760248140027990471noreply@blogger.comtag:blogger.com,1999:blog-7082878015421475244.post-70835327469398997622014-02-06T16:36:52.271-08:002014-02-06T16:36:52.271-08:00"No significant difference exists between TAU..."No significant difference exists between TAU reduction at 9 months and CBT reduction at 9 or 18 months". Raw numbers are slightly in favour of CBT group, what makes you conclude that this is not significant? A very similar small difference in favour of TAU at 9 months leads you to conclude "So, after 9 months of intensive CBT intervention, controls - who don't even receive a placebo - show a greater reduction in positive and negative symptoms"Anonymousnoreply@blogger.com