The feasibility and acceptability of short-term, individual existential behavioural therapy for informal caregivers of patients recruited in a specialist palliative care unit

Helena S Stöckle, Sigrid Haarmann-Doetkotte, Claudia Bausewein, Martin J Fegg

Existential behavioural therapy (EBT) is a recently developed intervention to support informal caregivers of patients in a specialist palliative care unit and was initially established as a six-session group programme. This pilot study aimed to test the feasibility and acceptability of an adapted short-term, individual approach of EBT in preparation for a randomized controlled trial (RCT). The study was conducted in a prospective, mixed methods design including four quantitiative assessments with embedded qualitative interviews at one assessment. The intervention offered two one-hour therapeutic sessions focusing on (1) mindfulness and (2) existential meaning-in-life as a source of strength provided by a trained psychotherapist. To test the feasibility of the intervention, doubling of the participation rate, compared to the previous group study (13,6 %) as well as an attrition rate of less than 30 % were set as thresholds. To test the acceptability of the intervention, self-rated usefulness of individual aspects of the intervention and the frequency of implementing therapeutic elements by the carers were set as criteria. Acceptability testing also included the number of participants who completed both sessions, where we expected more than 75 % as a criterion for acceptability. Return rates of quantitative questionnaires were set as criteria for the feasibility of data collection (<33 % loss expected within the study period). Qualitative interviews were used to collect additional data on feasibililty and acceptability and to explore potential harms and benefits of the intervention. 44/102 (43,1 %) of eligible informal caregivers agreed to participate in the study. Due to attrition of 13 caregivers (attrition rate: 29,5 %), 31 caregivers were included in the trial. Self-rated usefulness showed sufficiant results for all but one individual aspect. Frequency of implementing therapeutic elements showed wide inter-item as well as inter-participant ranges and decreased over the study period. All participants completed both sessions. Return rates of the questionnaires were within the expected range. According to the interviews, the intervention was associated with several participant-identified benefits. No severe adverse effects were observed. Findings suggest that the short-term, individual EBT proved feasible and mostly acceptable.