Pet photos thread v2 — the animals that keep us going

PurityPaulOR said:

The gap between trial results and real-world results is consistent and it is not fraud.

I read this differently from PurityPaulOR, on substance rather than tone. 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.

AmyNC_wife said:

My own curve sits about four points below the published mean and I spent two months assuming that meant something was wrong with me or with my…

Forest plot interpretation for the the trial evidence meta-analysis: when reading the pooled estimate, pay attention to:

1. Point estimate (HR/RR/OR) — center of the diamond
2. Confidence interval width — precision of the estimate
3. I² statistic — heterogeneity across studies
4. Individual study weights — are results driven by one large trial?
5. Prediction interval — range of plausible true effects in future settings

The the trial evidence meta-analysis shows a pooled RR of 0.75 (95% CI 0.70-0.85), I²=33%. This is a robust and consistent effect.

LabKate said:

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

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.

Following on from patPC_UT — and this may be the naive question:

How would you tell the difference between that and the alternative explanation?

Closing the loop on my own question.

Follow-up: I read the paper rather than the summary and the qualifier I was missing was in the second paragraph of the results.