The Independent Review of Gender Identity Services for Children and Young People (commonly, the Cass Review) was commissioned in 2020 by NHS England and NHS Improvement[1] and led by Hilary Cass, a retired consultant paediatrician and the former president of the Royal College of Paediatrics and Child Health.[2] It dealt with gender services for children and young people, including those with gender dysphoria and those identifying as transgender in England.
The final report was published on 10 April 2024,[3] and it was endorsed by both the Conservative and Labour parties. The review led to a UK ban on prescribing puberty blockers to those under 18 experiencing gender dysphoria (with the exception of existing patients or those in a clinical trial).[4] The Gender Identity Development Service (GIDS) at the Tavistock and Portman NHS Foundation Trust closed in March 2024 and was replaced in April with two new services, which are intended to be the first of eight regional centres.[5] In August, the pathway by which patients are referred to gender clinics was revised and a review of adult services commissioned.[6] In September, the Scottish government accepted the findings of a multidisciplinary team that NHS Scotland had setup to consider how the Cass Review's recommendations could best apply there.[7] In England a clinical trial into puberty blockers is planned for early 2025.[8]
The review's recommendations have been widely welcomed by UK medical organizations.[9][10][11][12][13] However, it has been criticised by a number of international medical organisations and academic groups regarding its methodology and findings.[14][15][16][17]
The interim report[18] of the Cass Review was published in March 2022. It said that the rise in referrals had led to the staff being overwhelmed, and recommended the creation of a network of regional hubs to provide care and support to young people. The report said that the clinical approach used by the Gender Identity Development Service (GIDS) "has not been subjected to some of the usual control measures"[19] typically applied with new treatments, and raised concerns about the lack of data collection by GIDS.[20][21] While GIDS initially followed the Dutch protocol, the interim review said there were "significant differences" in the current NHS approach.[22] The report stated that children with comorbidities did not receive adequate psychological support, endocrinologists administering puberty blockers did not attend multidisciplinary meetings, and the frequency of those meetings did not increase when adolescents received puberty blockers, all of which the Dutch Approach recommends.[22]
The interim report further said that GPs and other non-GIDS staff felt "under pressure to adopt an unquestioning affirmative approach"[23] to children unsure of their gender, "overshadowing" other issues such as poor mental health. The Tavistock and Portman NHS Foundation Trust said "being respectful of someone's identity does not preclude exploration", and "We agree that support should be holistic, based on the best available evidence and that no assumptions should be made about the right outcome for any given young person."[24]
The final report of the Cass Review was published on 10 April 2024. It included several systematic reviews of scientific literature carried out by University of York, encompassing the patient cohort, service pathways, international guidelines, social transitioning, puberty blockers and hormone treatments.[25]
The Cass Review commissioned several independent, peer-reviewed systematic reviews into different areas of healthcare for children and young people with gender identity issues, including gender dysphoria.[26][27] The reviews were carried out by academics at the University of York's Centre for Reviews and Dissemination, one of three bodies funded by the National Institute for Health and Care Research (NIHR) to provide a systematic review service to the NHS.[28] The topics covered by the systematic reviews were:[25]
In the systematic reviews the report commissioned, tools such as the Mixed Methods Appraisal Tool and modified versions of the Newcastle–Ottawa scale were used to assess the quality of the studies available[37][38] because no blinded controlled studies – those usually thought of as having the highest quality – were available.[39] The systematic reviews performed meta-analyses to ascertain the best evidence-based knowledge on their respective subjects to inform the report's findings and recommendations.[40][41]
In its collection of evidence, the report also carried out qualitative and quantitative research into young people with gender dysphoria and their health outcomes,[42] carried out listening sessions and focus groups with service users and parents, held meetings with advocacy groups, and gathered existing documented insights into the lived experiences of patients.[43]
The report states on page 20 that, "When the Review started, the evidence base, particularly in relation to the use of puberty blockers and masculinising or feminising hormones, had already been shown to be weak"; and that after the examination of over 100 pieces of potential evidence, that "there continues to be a lack of high-quality evidence in this area".[44]
The report found no clear explanation for the rise in the number of children and adolescents with gender dysphoria, but said there was broad agreement for attribution to a mix of biological and psychosocial factors. The report's suggested influences included a lower threshold for medical treatment, social media-related mental health consequences, abuse, access to information regarding gender dysphoria, struggles with emerging sexual orientation, and early exposure to online pornography. The report considered a rise in acceptance of transgender identities to be insufficient to explain the increase.[45][29][46][47]
A systematic review evaluated 11 studies assessing the outcomes of social transition in minors using a modified version of the Newcastle-Ottawa scale and considered nine to be low quality and two to be moderate quality.[37][30] The report said that insufficient evidence was available to assess whether social transition in childhood has positive or negative effects on mental health, and that there was weak evidence for efficacy in adolescence. It also said that sex of rearing seems to influence gender identity, and hypothesised that early social transition may change the way a child's gender identity develops.[48]
The report classified social transition as an "active intervention". It also advised caution in approaching social transition, and stressed the need for clinical involvement in determining risks and benefits, saying that it is not a role that can be undertaken without appropriate clinical training.[47][49]
The report said that the evidence base and rationale for early puberty suppression remains unclear, with unknown effects on cognitive and psychosexual development. A systematic review[32] examined 50 studies on the use of puberty blockers using a modified version of the Newcastle–Ottawa scale and considered only one to be of high quality, along with a further 25 being of moderate quality, and the remaining 24 being of low quality. The review concluded that the lack of evidence means no conclusions can be made regarding the impact on gender dysphoria and mental health, but did find evidence of bone health being compromised during treatment. The review disagreed with the idea of puberty blockers providing youth patients with "time to think", due to its finding that nearly all patients who went on blockers later decided to proceed on to hormone therapy.[50][32][51][47][52][53] For youth assigned male at birth the report states that blockers taken too early can make a later penile inversion vaginoplasty more difficult due to insufficient penile growth.[54] The report states one of the benefits of puberty blockers is the prevention the irreversible changes of a lower voice and facial hair.[55]
The report said that many unknowns remained for the use of hormone treatment among under-18s, despite longstanding use among transgender adults, with poor long-term follow-up data and outcome information on those starting younger. A systematic review[33] evaluated 53 studies on transgender hormone therapy using a modified version of the Newcastle-Ottawa scale, and considered only one study to be of high quality, 33 moderate and 19 low quality. Overall, the review found some evidence that hormone treatment improves psychological outcomes after 12 months, but found insufficient and inconsistent evidence regarding physical risks and benefits. The review advised that there should be a 'clear clinical rationale' for the prescription of hormone therapy under 18 years of age.[50][33][51][49]
A systematic review assessed ten studies on the efficacy of psychosocial support interventions in transgender minors using the Mixed Methods Appraisal Tool and considered only one to be of medium quality, with the remaining nine being of low quality. The review concluded that no robust conclusions can be made and more research is needed.[31][56]
The report said that the evidence for psychosocial intervention as opposed to hormonal was "as weak as research on endocrine treatment", but that the result of psychological treatment was "either benefit or no change".[57][58]
The report said that clinicians cannot be certain which children and young people will have an enduring trans identity in adulthood, and that for most, a medical pathway will not be the most appropriate. When a medical pathway is clinically indicated, wider mental health or psychosocial issues should also be addressed. Due to a lack of follow-up, the number of individuals who detransitioned after hormone treatment was unknown.[50]
The Cass Review attempted to work with the Gender Identity Development Service and the NHS adult gender services to "fill some of the gaps in follow-up data for the approximately 9,000 young people who have been through GIDS to develop a stronger evidence base." However, despite encouragement from NHS England, "the necessary cooperation was not forthcoming."[59][60]
A systematic review[35][36] assessed 23 regional, national and international guidelines covering key areas of practice, such as care principles, assessment methods and medical interventions. Most guidelines were said to lack editorial independence and developmental rigour, and were nearly all influenced by the 2009 Endocrine Society guideline and the 2012 WPATH guideline, which were themselves closely linked. The Cass review questioned the guidelines' reliability, and concluded that no single international guideline regarding transgender care could be applied in its entirety to NHS England.[50]
The report identified conflicting views among clinicians regarding appropriate treatment, with expectations of care sometimes deviating from clinical norms. It said that disputes over language such as "exploratory" and "affirmative" approaches meant it was difficult to establish neutral terminology. Some clinicians feared working with gender-questioning young people.[61] The report said that some professionals were concerned about being accused of conversion practices, and were likewise concerned about legislation to ban conversion therapy. The report went on to say that many professionals were "overshadowed by an unhelpfully polarised debate around conversion practices".[62][63]
The report made 32 recommendations covering areas including assessment of children and young people, diagnosis, psychological interventions, social transition, improving the evidence base underpinning medical and non-medical interventions, puberty blockers and hormone treatments, service improvements, education and training, clinical pathways, detransition and private provision.[64]
Recommendations included:
NHS England responded positively to the interim and final reports. As of April 2024[update] they have implemented a number of measures.[5] The Gender Identity Development Service (GIDS) at the Tavistock and Portman NHS Foundation Trust closed in March 2024.[5] Two new services, located in the north west of England and in London, opened in April 2024, which are intended to be the first of up to eight regional services.[5] These will follow a new service specification for the "assessment, diagnosis and treatment of children and young people presenting with gender incongruence".[5] Puberty suppressing hormones are no longer routinely available in NHS youth gender services.[5] New patients that have been assessed as possibly benefiting from them will be required to participate in a clinical trial that is being set up by the National Institute for Health and Care Research.[26][81] A new board, chaired by Simon Wessely will encourage further research in the areas highlighted in the review as having a weak evidence base.[5]
On August 7, 2024, NHS England announced a status update,[82] including the publication of a new pathway specification[82] for young people being considered for referral to specialist gender services. One recommendation is that those considering social transition be seen quickly by a clinical professional with relevant experience.
The clinical trial to study the "potential benefits and harms of puberty suppressing hormones for children and young people" was due to start late 2024 but is now delayed to early 2025.[8]
A new service for patients wishing to detransition, i.e., to return to their birth gender, has been announced by NHS England in the wake of the Cass Review, and will be the first of its kind in the UK.[83]
In May 2024, then Health Secretary Victoria Atkins implemented an emergency three-month ban on the prescription of puberty blockers by medical providers outside of the NHS. It went into effect on 3 June 2024 and was set to expire on 3 September 2024. The ban restricted their use to only those already taking them, or within a clinical trial. In July, this ban was challenged by campaign groups TransActual and Good Law Project who instigated a legal case arguing the ban was unlawful.[84] On 29 July 2024 the High Court of Justice ruled that the ban was lawful.[85][86][87]
The Health Secretary, Wes Streeting welcomed the "evidence led" decision and said efforts were being made to set up a clinical trial to "establish the evidence on puberty blockers".[4][88] Following the ruling, TransActual announced that they would not appeal the decision due to limited funds and the unlikelihood of an appeal being heard before the ban expires.[89]
On 22 August 2024, the government extended the emergency ban an additional three months and is now set to expire on 26 November 2024. The ban was also extended to cover Northern Ireland, following agreement from the Northern Ireland Executive and came into effect on 27 August 2024.[90][91][92]
In April 2024, in response to Cass, NHS England said it would also initiate a review of all its adult gender clinics.[93]
The Cass Review did not cover Adult Care. In May 2024, Cass wrote to NHS England, to pass on the feedback regards Adult Care from clinicians who had approached her during the Review process. Clinicians across the country in adult gender services had expressed concern about both the clinical practice and model of care. Some clinicians in other settings, especially general practice, had raised concerns about the treatment of patients under their care.[94]
On 7 August, NHS England included a response to the adult care letter, in a status report for the under-18s services.[95]
On 8 August, they stated that the review of adult services would be led by Dr. David Levy, medical director for Lancashire and South Cumbria integrated care board, to assess "the quality (i.e. effectiveness, safety, and patient experience) and stability of each service, but also whether the existing service model is still appropriate for the patients it is caring for"; and that Dr. Levy would work with a group of "expert clinicians, patients and other key stakeholders, including representatives from the CQC, Royal Colleges and other professional bodies and will carefully consider experiences, feedback and outcomes from clinicians and patients, past and present". The first onsite visits are planned to start in September 2024. The findings will be used to support an updated adult gender service specification which will then be liable to engagement and public consultation. Unlike the Cass Review, the review of adult gender services is expected to be completed within months, rather than years.[6][96][97]
The chief medical officer of Scotland setup a multidisciplinary clinical team to asses how the Cass Review's 32 recommendations might be applied to NHS Scotland. Their Cass Review – implications for Scotland: findings report was published in July 2024 and found that the majority of recommendations were applicable to NHS Scotland to a varying degree, with some modification dealing with differences in the Scottish health service. They recommended that the use of puberty blockers be paused until clinical trials are begun. NHS Scotland will participate in the forthcoming UK study.[98] That report was fully accepted by the Scottish government in September. Among the changes recommended are that the gender identity service for children and young people should be moved to a paediatric setting and more than one service offered across the regions. In common with other specialities, a referral to these services will now be required to have come from a clinician rather than the patient themselves.[7]
The interim report, published in February 2022, said that there were "gaps in the evidence" over the use of puberty blockers. A public consultation was held and a further review of evidence by NICE said there was "not enough evidence to support the safety or clinical effectiveness of puberty suppressing hormones to make the treatment routinely available at this time." As a result, NHS England stopped prescribing them to children.[99][100][101]
In April 2022, Health Secretary Sajid Javid told MPs that services in this area were too affirmative and narrow, and "bordering on ideological".[102]
In November 2022, the World Professional Association for Transgender Health (WPATH), along with regional groups ASIAPATH, EPATH, PATHA, and USPATH, issued a statement criticising the NHS England interim service specifications based on the interim report. It contested several points in the report, including the pathologizing of gender diversity, the making of "outdated" assumptions regarding the nature of transgender individuals, "ignoring" newer evidence regarding such matters, and making calls for an "unconscionable degree of medical and state intrusion" into everyday matters such as pronouns and clothing choice, as well as into access to gender-affirming care. It further said that "the denial of gender-affirming treatment under the guise of 'exploratory therapy' is tantamount to 'conversion' or 'reparative' therapy under another name".[14]
Prime Minister at the time Rishi Sunak said that the findings "shine a spotlight" on the need for a cautious approach to child and adolescent gender care.[103][104] Wes Streeting, the shadow Health Secretary, welcomed the final report, saying that the report "must provide a watershed moment for the NHS's gender identity services" and committing the Labour Party to implementing the report's recommendations in full.[105][106][107] Speaking to Sky News, Shadow Home Secretary Yvette Cooper said that Labour welcomed the Cass Review and committed to implementing all of its recommendations.[108]
The Scottish Government said it would "take the time to consider the findings".[109] Humza Yousaf, First Minister of Scotland and SNP leader at the time of the final report's release, said that while the Scottish government would discuss the Cass Review with health authorities, it would leave its implementation up to clinicians.[110]
Just prior to the Review, in March 2024, NHS England announced that it would no longer prescribe puberty blockers to minors outside of use in clinical research trials, citing insufficient evidence of safety or clinical effectiveness.[111][112]
Regarding transgender hormone therapy use for adults, in response to the report the NHS England National Director of Specialised Commissioning John Stewart sent a letter to Cass stating that it would review the use of gender-affirming transgender hormone therapy in adults in a similar manner as was done for puberty blockers in the Cass Review.[113][114][115]
On 18 April 2024, NHS Scotland announced that it had paused prescribing puberty blockers to children referred by its specialist gender clinic.[116]
The British Psychological Society said in April 2024 that they support "the report's primary focus of expanding service capacity across the country" and acknowledged that "while psychological therapies will continue to have an incredibly important role to play in the new services, more needs to be done to assess the effectiveness of these psychological interventions." BPS president Roman Raczka commended the review as "thorough and sensitive", in light of the complex and controversial nature of the subject. He said "it will take time to carefully review and respond to the whole report" but he was sure the field of psychology would learn lessons from it. He welcomed the recommendation for a consortium of relevant bodies to develop better trainings and upskill the workforce.[9]
The Royal College of Psychiatrists welcomed the report and strongly agreed with some of its recommendations. They supported the emphasis on a holistic and person-centred approach and research to improve the evidence basis for treatment protocols. They said that some of its trans members, and the wider trans community, had concerns about availability of treatments while awaiting research, said there was "a strong view that the report makes assumptions in areas such as social transition and possible explanations for the increase in the numbers of people who have a trans or gender diverse identity, which contrasts with the more decisive statements about treatment approaches", and called for direct and comprehensive involvement of those with lived experience.[10]
The Royal College of Paediatrics and Child Health (RCPCH) said they would take the time to review the recommendations in full and said that data collected had identified a lack of confidence by paediatricians and GPs to support this patient group, which the RCPCH pledged to address by developing new training. RCPCH President's Steve Turner thanked Cass and her team for the "massive undertaking" and said they would consider the report's recommendations.[11] In August 2024, the RCPCH acknowledged there had been some academic criticism of the Cass Review and a call to pause the implementation of recommendations. They regarded this as a "backwards step", further delaying care that already has "unacceptable waiting times". While remaining mindful of "emerging criticisms of any chosen approach", their priority is "that this group of children receive timely, holistic and high-quality care".[117]
In response to the Cass Review, the Royal College of General Practitioners in July 2024 updated its position statement on the role of the GP in transgender care. They advise that, for patients under 18, no GP should prescribe puberty blockers outside of a clinical trial, and the prescription of gender-affirming hormones should be left to specialists. The GCGP affirms it will fully implement the recommendations of the Cass Review. They specifically highlight recommendations for services 17–25 year olds, noting that some other fields are moving to a 0–25 service for better continuity of care, and the need for additional services for those people considering detransition.[12]
On 31 July 2024 the British Medical Association, which is both a trade union and professional body,[118] publicly called for a pause on the review's implementation while it conducted an evaluation that it intends to complete by January 2025.[119] The BMA's council voted in favor of a motion to "publicly critique the Cass Review" due to "unsubstantiated recommendations driven by unexplained study protocol deviations, ambiguous eligibility criteria, and exclusion of trans-affirming evidence". The BMA criticised the related ban on puberty blockers, arguing this was not a decision for politicians to make, while calling for more research.[119][120] The call has prompted opposition from some doctors, 1,400 of whom signed an open letter to the BMA characterising their planned critique as a "pointless exercise".[121]
Following the BMA's announcement of their critique, the Academy of Medical Royal Colleges (AoMRC) issued at statement in support of the Cass Review, stating that "further speculative work risks greater polarisation on this matter which is not helpful and our focus should be on implementing the recommendations of the Cass Review".[13]
The American Academy of Pediatrics and the Endocrine Society both responded to the report by reaffirming their support for gender-affirming care for minors and saying that their current policies supporting such treatments are "grounded in evidence and science".[122]
The Canadian Pediatric Society responded to the report by saying "Current evidence shows puberty blockers to be safe when used appropriately, and they remain an option to be considered within a wider view of the patient's mental and psychosocial health."[123]
The Amsterdam University Medical Center put out a statement saying that while it agrees with the goals of reducing wait times and improving research, it disagrees that the research-base for puberty blockers is insufficient, asserting that puberty blockers have been used in trans care for decades.[124]
The Royal Australian and New Zealand College of Psychiatrists rejected calls for an inquiry into trans healthcare following the release of the Cass Review.[125] They characterised the Cass Review as one review among several in the field.[125] They emphasised that, "assessment and treatment should be patient centred, evidence-informed and responsive to and supportive of the child or young person's needs and that psychiatrists have a responsibility to counter stigma and discrimination directed towards trans and gender diverse people."[125]
The World Professional Association for Transgender Health released an email statement saying that the report "is rooted in the false premise that non-medical alternatives to care will result in less adolescent distress" and further criticised recommendations which "severely restrict access to physical healthcare, and focus almost exclusively on mental healthcare for a population which the World Health Organization does not regard as inherently mentally ill".[126][127] An official statement expanded on these concerns, criticising Cass's "negligible prior knowledge or clinical experience", asserting that "the (research and consensus-based) evidence is such to recommend that providing medical treatment including puberty-blocking medication and hormone therapy is helpful and often life-saving", and questioning the provision of puberty blockers only in the context of a research protocol: "The use of a randomized blinded control group, which would lead to the highest quality of evidence, is ethically not feasible."[128]
The Professional Association for Transgender Health Aotearoa (PATHA), a New Zealand professional organisation, said that the Cass Review made "harmful recommendations" and was not in line with international consensus, and that "Restricting access to social transition is restricting gender expression, a natural part of human diversity." They further said that several people involved in the review "previously advocated for bans on gender-affirming care in the United States, and have promoted non-affirming 'gender exploratory therapy', which is considered a conversion practice."[16][129] A joint statement by Equality Australia signed by the Australian Professional Association for Trans Health (AusPATH) and PATHA among others said the review "downplays the risk of denying treatment to young people with gender dysphoria and limits their options by placing restrictions on their access to care".[16][130][131]
Amnesty International criticised "sensationalised coverage" of the review, stating "This review is being weaponised by people who revel in spreading disinformation and myths about healthcare for trans young people."[132][133] Trans youth charity Mermaids and the LGBTQIA+ charity Stonewall endorsed some of the report's recommendations, such as expanding service provisions with the new regional hubs, but raised concerns the review's recommendations may lead to barriers for transgender youth in accessing care.[129]
Gender-critical organisations including Sex Matters and Genspect welcomed the report. Stella O'Malley of Genspect expressed concern that if a conversion therapy ban were to criminalise any exploration into why a child identifies as trans, it "would ban the very therapy that Cass is saying should be prioritised".[134]
The British Equality and Human Rights Commission described it as a "vital milestone" and called for all service providers to fully implement the recommendations of the review.[135] The report was praised by some academics in the UK, who agreed with its findings stating a lack of evidence;[106][59][136] while others both in the UK[137] and internationally[123][138][139] disagreed with the report's methodology and findings.
The Integrity Project at Yale Law School released a white paper critiquing the Cass Review, accusing it of having "serious flaws."[140][141][142] The white paper, co-authored by a group of eight legal scholars and medical researchers, argues that the Cass Review "levies unsupported assertions about gender identity, gender dysphoria, standard practices, and safety of gender-affirming medical treatments, and it repeats claims that have been disproved by sound evidence" and that "is not an authoritative guideline or standard of care, nor is it an accurate restatement of the available medical evidence on the treatment of gender dysphoria."[140][141]
In the week after the release of the final report, Cass described receiving abusive emails and was given security advice to avoid public transport.[143] She also said that "disinformation" had frequently been spread online about the report. Cass said "if you deliberately try to undermine a report that has looked at the evidence of children's healthcare, then that's unforgivable. You are putting children at risk by doing that."[143] There were widespread false claims from critics of the report that it had dismissed 98% of the studies it collected and all studies which were not double-blind experiments. Cass described these claims as being "completely incorrect". Although only 2% of the papers collected were considered to be of high quality, 60% of the papers, including those considered to be of moderate quality, were considered in the report's evidence synthesis.[41][144][145] She criticised Labour MP Dawn Butler for repeating, during a debate in the House of Commons, incorrect claims that the review had dismissed more than 100 studies.[146][147][148] After talking with Cass, Butler subsequently used a point of order to admit her mistake and correct the record in Parliament, stating the figure came from a briefing she had received from Stonewall.[145][149][150][151]
In an interview with The New York Times in May 2024, Cass expressed concern that her review was being weaponized to suggest that trans people do not exist, saying "that's really disappointing to me that that happens, because that's absolutely not what we're saying." She also clarified that her review was not about defining what trans means or rolling back health care, stating "There are young people who absolutely benefit from a medical pathway, and we need to make sure that those young people have access — under a research protocol, because we need to improve the research — but not assume that that's the right pathway for everyone."[152]
In an interview with WBUR-FM in May 2024, Cass responded to WPATH's criticism about prioritising non-medical care, saying the review did not take a position about which is best. Cass hoped that "every young person who walks through the door should be included in some kind of proper research protocol" and for those "where there is a clear, clinical view" that the medical pathway is best will still receive that, and be followed up to eliminate the "black hole of not knowing what's best". On the allegation that the review was predicated on the belief that a trans outcome for a child was the worst outcome, Cass emphasised that a medical pathway, with lifetime implications and treatment, required caution but "it's really important to say that a cis outcome and a trans outcome have equal value".[153]
Cass commissioned four systematic reviews of the evidence on key issues...
During a systematic review, researchers looking at studies on transgender healthcare found no blind control ones — so used another system altogether to determine study quality.