NICE review (UK, 2020)
In October 2020, the UK’s National Institute for Health and Care Excellence (NICE) conducted an evidence review of puberty blockers (GnRH analogues) for children and young people up to and including the age of 18 with gender dysphoria. NHS England commissioned the review to support Hilary Cass’s independent investigation. It is an assessment of existing research, not a treatment guideline.
The main article on this subject is Gender care in the United Kingdom.
What it says
The review assesses clinical effectiveness, safety and cost-effectiveness. For the key outcomes, such as gender dysphoria, mental health, body image and psychosocial functioning, NICE considers the certainty of the evidence to be very low. The studies show little change between the start of treatment and follow-up. Because there are no control groups, it is not possible to determine what would have happened without treatment. The studies indicate that the increase in bone density during puberty may decrease. No evidence on cost-effectiveness was found.
Design and methodology
The literature search was conducted on 23 July 2020, and the content was updated through 14 October 2020. NICE included nine observational studies: five retrospective studies, three prospective studies and one cross-sectional study. Two studies compared groups; the other seven compared the same participants before and after treatment. The certainty of the evidence was assessed for each outcome using a modified version of the GRADE method. The question was how puberty blockers compared with psychological support, social transition or no treatment. The document notes that triptorelin, the medication used in England, is not licensed for this use.
The Dutch studies
Some of the evidence comes from the Netherlands. The 2011 study by de Vries and colleagues of 70 young people found no change in gender dysphoria scores. Depression scores decreased, while anxiety and anger scores remained unchanged, and overall functioning improved. NICE notes that all studies come from a small number of mainly European centres, which may bias the results. The de Vries study is part of the evidence base for the Dutch Protocol.
NICE’s own caveats
NICE considers it possible that the absence of change is itself an effect of treatment, because symptoms might otherwise have increased during puberty. At the same time, in the absence of a control group, observed improvements could also be due to chance or bias. NICE found no evidence on quality of life.
Why it is included in this archive
During the same period, NICE also conducted a review of gender-affirming hormones; the timeline lists both under NICE assesses the evidence for blockers and hormones. Both assessments helped inform the Cass Review and are frequently cited, including in questions raised in the Dutch Parliament.