Procedure
BPD
Consecutive referrals to HYPE were considered for an invitation to participate in the RCT. Written informed consent was obtained from all participants (and from a parent/legal guardian for individuals under 18 years of age). Upon completion of baseline questionnaires, carers were randomly and consecutively assigned as a ‘unit’ (defined by their relationship to the young person with BPD features) in a 1:1 ratio, using randomised permuted blocking, and stratified by client’s sex and age (<18 years cut-point). The interventions were delivered in seven rounds, approximately 12 weeks apart, between March 2016 and September 2017. Follow-up questionnaires were issued to all carers at week 7, i.e., 4 weeks post-intervention (including those who had discontinued the intervention), and carers had up to 4 weeks to complete these. Data regarding the young person were extracted from their medical records.