Web-based Acceptance and Commitment Therapy (ACT) for adults living with cancer: A single case experimental design (SCED)

A randomised multiple-baseline design assessed the preliminary efficacy of a low-intensity, minimally-guided, online, self-help Acceptance and Commitment Therapy (ACT) intervention for people affected by cancer on quality of life (QoL), psychological symptoms, psychological flexibility, and level of interference from pain and fatigue. Acceptability and feasibility was also assessed. Adult participants (n = 7) had either completed cancer treatment within the last 18 months or were currently receiving treatment. Participants were randomly assigned to a baseline length of 1-3 weeks prior to completing the six-week ACT intervention, followed by a one-month follow-up. At pre- and post-intervention, and one-month follow-up, cancer-specific QoL, psychological symptoms (anxiety and depression), and psychological flexibility were assessed using standardised questionnaires. Single-item daily ratings of mood, anxiety, psychological flexibility, and bother ratings of pain and fatigue were also assessed. Questionnaire data were analysed using reliable and clinically significant change. Daily measures were analysed using visual and Tau-U analysis. Participants reported less negative impact of cancer on QoL (n = 3: CancerDQoL), fewer depressive symptoms (n=5: HADS depression) and greater psychological flexibility (n=3: MPFI) at follow-up. Daily measures showed improvements in self-reported mood (n=3), anxiety (n=3) and psychological flexibility (n=5) across different phase comparisons. Most participants (n=5) were significantly less bothered by fatigue at follow-up, and two were significantly less bothered by pain. Feedback from participants supported the acceptability of the intervention. The results provide preliminary support for the efficacy of the ACT intervention in reducing the negative impact of cancer on QoL, and improving self-reported psychological outcomes and psychological flexibility. Longitudinal studies utilising a larger sample are warranted. • A low intensity online ACT intervention was acceptable to adults with cancer. • The negative impact of cancer on QoL was reduced reliably for 57% of participants. • Symptoms of depression were reduced reliably for 71% of participants. • Most participants (71%) were less bothered by fatigue. • Psychological flexibility improved reliably for 57% of participants. • A clinical trial with longer follow-up is needed to replicate the findings in a large sample.