Hilary Cass’s review was commissioned in 2020, two years after a group of clinicians at the Tavistock Gender Identity Development Service (Gids) complained that some patients were being referred for transition too quickly.
It came amid a significant rise in the number of young people referred to Gids, the only such service in England and Wales, from 250 in 2011-12 to more than 5,000 in 2021-22, a change partly driven by an increase in patients raised as girls. That increase led to waiting times for services of more than two years.
Cass published her interim report in 2022. It concluded that Gids was under unsustainable pressure, and that differing views on the right approach among its staff were causing a “clinician lottery” for patients. That led to the NHS closing the service and beginning the rollout of new regional care hubs. And in March, NHS England stopped the use of puberty blockers, except for participants in clinical research, on Cass’s advice.
The final report draws larger conclusions: for a detailed summary, see this piece by Denis Campbell and Sally Weale. Here’s what else you need to know.
Evidence for puberty blockers and hormones
A key aspect of the review was its examination of the evidence base for the use of puberty blockers and gender-affirming hormones. Cass said that a systematic review she commissioned found a continuing lack of “high-quality evidence”. She concluded that there was a limited case for puberty blockers for some trans girls and no proven case for their use for trans boys – because while they did successfully suppress puberty, they were not proven to create a “pause” for decision-making over transition, and not proven to improve psychological health.
She also said that gender-affirming hormones should only be used after the age of 16 and with “extreme caution”, but noted limited evidence that they could help with depression, anxiety, and other mental health problems.
In assessing the impact of Cass’s conclusions, it’s worth noting the numbers involved: while you might conclude from some of the coverage that Gids patients were usually given these treatments, that is not the case. Up to 2021, the Tavistock reported (pdf) that 15-20% of children and young people it saw were assessed for those treatments, with about 160 children being prescribed puberty blockers each year.
Moving away from puberty blockers and hormones follows a model used in Sweden and Finland, with concerns that most other comparable health systems are following an approach set by a single Dutch study of puberty blockers in the 1990s.
Highly influential international guidance relied on elsewhere is said by Cass to “lack developmental rigour”. Many countries continue to prescribe both, and last year the American Academy of Pediatrics said that it had commissioned its own systematic review but had “confidence that the existing evidence is such that the current policy is appropriate”.
Why some evidence was excluded
While the review Cass commissioned found dozens of studies on puberty blockers and hormones which reported a positive impact, the majority were discarded as being of insufficient rigour. “Partly it is that they’re difficult studies to design because you can’t blind people,” Cass said in an interview with the BMJ – a reference to the difficulty of ensuring that patients, doctors and researchers do not know which patients have received a new treatment.
Those exclusions have been criticised by trans advocates who say that it is an impossible standard for treatments which may have very visible impacts, and when such studies are difficult to run ethically among a child population. “The report does not appear to suggest how the ethical problems in the approach it calls for can be solved,” discrimination barrister Robin Moira White wrote for the Independent, arguing that it suggested that Cass was “content to set an impossible-to-satisfy test for trans healthcare”.
But Cass also said: “In part the biggest weakness is the length of follow-up” – that is, that there is not enough long-term evidence available. The picture could yet change, she noted in the report: “I am very aware that this is a point in time and as new evidence is gathered different insights might emerge.“
The need for better care
Cass recommends that instead of being offered mainly medical treatment, young people exploring their gender identity should “receive a holistic assessment of their needs” – with mental health and other issues addressed at the same time.
“This group of young people have been exceptionalised compared to other young people with similarly complex presentations,” she said. “They deserve very much better.” And she said there was a need to “expand capacity at all levels of the system”, with patients too quickly referred to Gids.
Part of that recommendation is the proposal for new regional centres. But only one of the eight planned is up and running, despite the closure of Gids last year and a promise that there would be at least two by now. This piece by Amelia Gentleman from last October documents some of the consequences of that shortfall.
This piece by Robyn Vinter sets out some of the anxieties felt by young trans people and their families, with one 18-year-old suggesting that the length of waiting lists should be a bigger concern than the use of puberty blockers. Meanwhile, as Tobi Thomas explains here, wider NHS pressures mean that hopes of swift access to mental health services appear remote.
Although they disagree with some parts of the review, trans advocates support the call for improved provision of care. Stephen Whittle, professor of Equalities Law at Manchester Metropolitan University, wrote on Twitter: “There are problems with Cass, but it has, at least, acknowledged a need for a properly funded service – something we have called for, for 25 years.”
Criticisms and a ‘toxic’ debate
Although Cass says that her conclusions over healthcare should be viewed separately to the constantly roiling coverage of such issues as trans access to sport and public toilets, she does note that that climate has had an impact on both patients and on her work.
“The toxicity of the debate is exceptional,” she wrote. “Polarisation and stifling of debate do nothing to help the young people caught in the middle.”
But some have read her warning as appearing to apply only to one side of the argument: she refers to healthcare professionals being afraid to discuss their views for fear of being labelled “transphobic”, but has nothing to say about whether a sharp increase in media coverage hostile to trans people might cut the other way, for example. Cass might respond that such concerns fall outside her remit.
Others have complained that she gives undue prominence to detransitioners, who are discussed at some length in the report. Cass writes that while there is a “lack of clear data on how frequently detransition or regret occurs in young adults”, there is a “suggestion” numbers are increasing. But a 2021 review of 27 international studies involving 8,000 trans teens and adults found about 1% expressed regret – a lower rate than that for many medical procedures.
Despite all this, there is at least a fragile consensus that Cass’s review is a seriously intended and robust piece of work. In this piece, as well as noting significant objections, the journalist Freddy McConnell lists a range of points on which he agrees with Cass, drawing partly on his own experiences as a trans man.
But he also predicts that Cass’s review will be used to “perpetuate a broader hostile environment towards trans people in the UK” – and that if this happens, “the young people she has tried to help will, understandably, feel betrayed.”
