The inclusion criteria of the pilot RCT were intentionally broad, in order to prevent any selection of participants according to their protected characteristics (age, sex, disability, gender reassignment, marriage or civil partnership, pregnancy and maternity, race, religion/belief, or sexual orientation). We produced information leaflets for adults, children and parents/guardians of children in order to offer the opportunity to take part regardless of age. We used non-sex-specific terminology when referring to people with brain cavernoma. Participant information leaflets were written in plain English with PCPI input, and translation was offered into Welsh, but not any other languages. We collected data on age, sex, disability and ethnicity for participants who were randomised, but not any other protected characteristics.
Ultimately, we included 4 children and 68 adults. Symptomatic brain cavernoma is a rare disease, and in clinical practice, it is relatively more frequent in adults, although incidence and prevalence studies have not been done on entire populations, including children.4,47 We had hoped to include more children, but the extent to which the age distribution of participants is unrepresentative remains uncertain. The sex distribution in the RCT (41 females, 31 males) reflected the female preponderance seen in hospital- and population-based studies.4,5,47 Epidemiological data about the ethnicity of people with brain cavernoma in the UK are not available, but participants’ ethnicities were less diverse than in England (www.ons.gov.uk/peoplepopulationandcommunity/culturalidentity/ethnicity/bulletins/ethnicgroupenglandandwales/census2021), but similar to ethnicity in Scotland (www.scotlandscensus.gov.uk/census-results/at-a-glance/ethnicity/). The overall sample size was too small to disaggregate data to determine differences in findings by protected characteristics.
Ultimately, the generalisability of the evidence is uncertain for age, good for sex and uncertain for ethnicity. The generalisability of the evidence outside the UK remains to be determined. In future, we would implement recommendations from the INCLUDE ethnicity framework in the design, oversight and conduct of the research to maximise diversity and inclusiveness.