I am hoping somebody can help me. I am currently writing my protocol for my research module, however the data analysis section is baffling me!
My study is an RCT with two treatment arms, and I am wondering which is the best method for accounting for/controlling potential confounding covariates. I have visited the idea of performing within-group ANCOVA, and then further statistical analysis based on the F-test significance (e.g. if significant- create subsets and analyse with ANOVA or multiple student t-tests for continuous endpoints) and if F-test finds no significant difference between covariates, just to analyse as originally intended (e.g. student t-test for continuous and chi square for categorical). I have also considered Bonferroni correction but I am unsure if this would be suitable.
Apologies for rambling- my mind is swimming! Many thanks for any advice to be offered!
It is not clear to me what you have going on here. If it is an RCT, then why would you have confounding? That suggests to me that your randomization failed. And the only way to get a sense of that is by reviewing your table of baseline characteristics. So can I assume that you have completed your RCT and found that you have very significant differences between your treatment groups in their baseline characteristics?
Until you clarify that for me, I don't think it makes much sense for me to elaborate on an analysis plan.
Ariel
Hi Ariel. Yes I realised this not long after I had posted my question. No I have not undertaken the study, I am just writing the proposal for an undergraduate project.
Thank you very much for taking the time to reply.
Best wishes, Meg
OK! So you haven't performed the RCT. If you do the randomization properly, you should NOT have any confounding. If you need to write something about the potential adjustment for confounding, just say that you'll include potential confounders into the outcome model (with the potential confounders being baseline covarates that are not balanced between groups).
I am attaching the CONSORT statement about conducting and reporting RCTs. Read this, as it is as good it gets!
Ariel
- Badges
- Science method
- Similar topics
- Mathematics
- Statistics
- Statistical Modeling
- Analyses of Variance
- ANOVA