The de Vries study had no control group and cannot credit blockers
Tom Swarbrick said:
“That particular study, again, was not a randomised trial. It had no control group. 100 percent of the adolescents who were on puberty blockers moved on to cross sex hormones. The benefits attributed to blockers were actually measured after the hormones and surgery. So the blockers can't really be credited for any improvements.”
The methodological critique sounds technically informed: randomised controlled trials are the gold standard in medicine, and pointing out that outcomes were measured after additional interventions is a legitimate question about attribution. A listener with any science background will find this persuasive.
The methodological bar being applied here is not the one medicine actually uses. Randomised controlled trials, in which you give some children an unwanted puberty and others a paused one, are not ethically possible in this population, and that is why prospective cohort studies are the recognised design for this kind of research. The de Vries studies followed participants over time, measured outcomes carefully, and found sustained improvements in wellbeing: that is meaningful evidence, not a gap in the record. The point about outcomes being measured after hormones and surgery is a legitimate question about attribution, and researchers have acknowledged it, but it does not erase the longitudinal picture or justify dismissing the findings altogether. What concerns me is that this standard, ruling out evidence because it is not an RCT, is never applied to other areas of paediatric medicine, only here, and the young people who pay for that selective scepticism are the ones left waiting.
Trans young people whose access to care is undermined when the best available evidence is dismissed on methodological grounds that would not be applied to other areas of paediatric medicine.