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. The final report was published on 10 April 2024,[3] and its recommendations were endorsed by NHS England and both the Conservative and Labour parties. The review has been criticised by some international medical organisations.[4][5][6]
The interim report[7] 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 noted that the clinical approach used by the Gender Identity Development Service (GIDS) "has not been subjected to some of the usual control measures"[8] typically applied with new treatments, and raised concerns about the lack of data collection by GIDS.[9][10] While GIDS initially followed the Dutch protocol, the interim review said there were "significant differences" in the current NHS approach.[11] Children with comorbidities did not receive adequate psychological support, endocrinologists administering puberty blockers did not attend multidisciplinary meetings nor did the frequency of meetings increase when adolescents received puberty blockers, all of which the Dutch Approach recommends.[11]
The interim report further stated that GPs and other non-GIDS staff felt "under pressure to adopt an unquestioning affirmative approach"[12] 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."[13]
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.[14]
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.[15][16] 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.[17] The topics covered by the systematic reviews were:[14]
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[26][27] because no blind control studies - those usually thought of as having the highest quality - were available.[28] 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.[29][30]
In its collection of evidence, the report also carried out qualitative and quantitative research into young people with gender dysphoria and their health outcomes,[31] 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.[32]
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 / 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".[33]
The report found no clear explanation for the rise in the number of children and adolescents with gender dysphoria, but stated there was broad agreement for attribution to a mix of biological and psychosocial factors. 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.[34][18][35][36]
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 9 to be low quality and two to be moderate quality.[26][19] The report stated 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 stated 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.[37]
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.[36][38]
The report stated that the evidence base and rationale for early puberty suppression remains unclear, with unknown effects on cognitive and psychosexual development. A systematic review[21] 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 the finding that nearly all patients who went on blockers later decided to proceed on to hormone therapy.[39][21][40][36][41][42] For prepubescent children assigned male at birth the report states uncontroversially that blockers taken too early can make a later vaginoplasty more difficult, although blockers do prevent lower voice and facial hair [43]
The report stated 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[22] 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/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.[39][22][40][38]
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.[20][44] 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".[45][46]
The report stated 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.[39]
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."[47][48]
A systematic review[24][25] assessed 23 regional, national and international guidelines covering key areas of practice, such as care principles, assessment methods and medical interventions. Most guidelines were stated 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.[39]
The report identified conflicting views among clinicians regarding appropriate treatment, with expectations of care sometimes deviating from clinical norms. It noted 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.[49] The report stated 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".[50][51]
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.[52]
The report recommended the development of a regional network of centres, and continuity of care for 17-25-year-olds.[53][54]
The report recommended using standard psychological and pharmacological treatments for co-occurring conditions like anxiety and depression.[55]
The report recommended patients receiving individualised care plans, including mental health assessments and screening for neurodivergent conditions such as autism.[56]
The report recommended there being a medical practitioner who takes personal responsibility for the safety of children receiving care.[16]
The report recommended that children and families considering social transition should be seen as soon as possible by a relevant clinical professional.[57]
NHS England responded positively to the interim and final reports. As of April 2024[update] they have implemented a number of measures.[58] The Gender Identity Development Service (GIDS) at the Tavistock and Portman NHS Foundation Trust closed in March 2024.[58] 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.[58] These will follow a new service specification for the "assessment, diagnosis and treatment of children and young people presenting with gender incongruence".[58] Puberty suppressing hormones are no longer routinely available in NHS youth gender services.[58] 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.[15][59] A new board, chaired by Simon Wessely will encourage further research in the areas highlighted in the review as having a weak evidence base[58]
The interim report, published in February 2022, stated 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 stated 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.[60][61][62]
In April 2022, Health Secretary Sajid Javid told MPs that services in this area were too affirmative and narrow, and "bordering on ideological".[63]
In November 2022, the World Professional Association for Transgender Health (WPATH), along with ASIAPATH, EPATH, PATHA, and USPATH issued a statement criticising the NHS England interim service specifications based on the interim report. It stated several points of contention with the report, including the pathologizing of gender diversity, the making of "outdated" assumptions regarding the nature of transgender individuals, "ignoring" of 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 noted that "the denial of gender-affirming treatment under the guise of 'exploratory therapy' is tantamount to 'conversion' or 'reparative' therapy under another name".[4]
Prime Minister Rishi Sunak said that the findings "shine a spotlight" on the need for a cautious approach to child and adolescent gender care.[64][65] 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.[66][67][68] Speaking to Sky News, Shadow Home Secretary Yvette Cooper stated that Labour welcomed the Cass Review and committed to implementing all of its recommendations.[69]
The Scottish Government said it would "take the time to consider the findings".[70][71] SNP politician Joanna Cherry called for an overhaul to services in Scotland for gender-questioning children, including screening out neurodivergent patients, and an end to the use of puberty blockers.[71] In contrast, Humza Yousaf, First Minister of Scotland and SNP leader, stated that the Cass Review did not validate closing the Sandyford gender identity clinic.[72]
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.[73][74][75]
On 18 April 2024, NHS Scotland announced that it had paused prescribing puberty blockers to children referred by its specialist gender clinic.[76]
The British Psychological Society commended the review as "thorough and sensitive", in light of the complex and controversial nature of the subject.[77]
The American Academy of Pediatrics and the Endocrine Society 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".[78] The Cass Review graded the developmental rigour of the most recent guidelines from the American Academy of Pediatrics at 12%, and the Endocrine Society at 42%.[79]
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."[80]
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.[81]
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".[82][83]
The Professional Association for Transgender Health Aotearoa (PATHA), a New Zealand professional organisation, stated 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 stated 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."[6][84] A joint statement by Equality Australia signed by the Australian Professional Association for Trans Health (AusPATH) and PATHA among others stated 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".[85][6][86]
Gender-critical organisations including Sex Matters and Genspect welcomed the report. Stella O'Malley of Genspect cited the review as reason not to institute a ban on conversion therapy, saying that it "would ban the very therapy that Cass is saying should be prioritised".[87]
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."[88][89] 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.[84]
The 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.[90] The report was praised by some academics in the UK, who agreed with its findings stating a lack of evidence;[67][47][91] while others both in the UK[92] and internationally[80][93][94] disagreed with the report's methodology and findings. It was praised by author J.K. Rowling and United Nations Special Rapporteur Reem Alsalem. [95][96][97][98]
In the week after the release of the final report, Cass described receiving abusive emails and was given security advice to avoid public transport.[99] She also said that "disinformation" had frequently been spread online about the report. Cass stated "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."[99] There were widespread, false claims from critics of the report that it had dismissed 98% of the studies it collected and all studies which weren't 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.[30][100][101] She criticised Dawn Butler MP for repeating, during a debate in the House of Commons, incorrect claims that the review had dismissed more than 100 studies.[102][103][104] After talking with Cass, Butler subsequently used a point of order to admit her mistake and correct the record in Parliament.[105][106]
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."[107]
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.