I recently analysed a randomised controlled trial whereby I adjusted the effect estimates to their respective baseline measures in a regression model, a practice I usually perform when analysing trial data (bunch of literature on this incl CONSORT statement).
When writing up the clinical study report I generally provide the the point and interval estimates of the effect adjusted to baseline measure (and other covariates if prespecified) and the point and interval estimates of the endpoints for each group. Furthermore, I plot the descriptive endpoint statistics per group over the various visits of the trial.
However, the investigators of the recent trial have asked me to provide, besides the effect estimate, the change-from-baseline estimates per trial arm.
I find this a little problematic as the difference between the two arm point estimates for change-from-baseline is often not the same as the point estimate of the effect adjusted to baseline (for reference see Twisk, J. et al. Different ways to estimate treatment effects in randomised controlled trials. Contemporary Clinical Trials Communications 10 , 80–85 (2018), specifically Table 5 Eq 1a vs 3a).
I’m a bit stuck on this as I think readers might be confused to what they may see as a discrepancy between the effect estimate adjusted to baseline and the difference between the two change-from-baseline group estimates. The investigators’ justification is that they would like to show the change from baseline for each arm.
I’m sympathetic to their request as the trial has an active comparator, and a side-by-side demonstration of change from baseline may be interesting. However, this is ultimately not the research question of the trial; the difference between the groups is and I think showing these changes in a graph can also be more informative.
I’d be very grateful for any advice on this and on how you would normally report these findings?