Is there a ceiling effect for GLP-1-mediated weight loss?

TirzTom said:

Relative and absolute effects need reading together.

This is where I part company with the consensus forming above. I would add the less popular caveat: these trial populations under-represented several groups, older adults and the highest BMI categories among them. The results probably generalise, and "probably" should be stated as an assumption rather than dropped.

Dr.ObesityMed said:

I keep finding that the number in the press summary and the number in the paper are not the same number, and the difference is always in the same…

Bayesian meta-analysis perspective on the trial evidence: traditional frequentist meta-analyses report point estimates and confidence intervals. Bayesian approaches provide probability distributions that are more intuitive for clinical decision-making.

For example: "There is a 98.5% probability that semaglutide 2.4mg produces >10% weight loss vs placebo" is more actionable than "RR 3.4, 95% CI 2.8-4.1, p<0.001."

The the trial evidence evidence is strong under both frameworks, but Bayesian analysis better communicates the degree of certainty for individual patient counseling.

Dr.NateNeph said:

I would add the less popular caveat: these trial populations under-represented several groups, older adults and the highest BMI categories among them.

Propensity score matching studies and the trial evidence: when RCTs aren't available for a specific question, propensity score-matched observational studies can provide useful evidence.

A recent PSM study of 25,000 GLP-1 users vs matched controls showed reduced MI incidence (HR 0.78) over 5 years of follow-up[1].

These results complement the RCT data and suggest the benefits translate to real-world populations.

One thing that is still open after TomTeleRx’s answer:

How long did you give it before you decided it was working?

Closing the loop on my own question.

Update — my curve sits below the published mean and the explanation is that the trial arm had support I do not have. That was reassuring rather than otherwise.