Background: Restoring meaning is an important element of adaptation to disease. It could potentially be supported by enhancing psychological flexibility through an Acceptance and Commitment Therapy intervention (i.e. by building explanations of the disease and treatment burden that are personally values based and flexible). Thus, this study investigated the effectiveness of self-help online acceptance and committed therapy (ACT) intervention using a multiple-baseline single-case experimental design (MBSCED) across 7 male patients following hematopoietic cell transplantation (HCT).
Methods: Participants were randomly assigned to a baseline period lasting 7-21 days following HCT hospital discharge, followed by the ACT-based intervention (14 days), one- and three-month follow-up phases (7 days each). Primary outcome included meanings made (i.e., sense making, benefit finding, and sense of identity). Secondary outcome included meaning-making coping (automatic and deliberate), and psychological flexibility. Data were analyzed using multilevel modeling on an individual and group level.
Results: On an individual level, the intervention showed a positive, statistically significant effect on one- and three-month follow-up sense of identity among 3 patients. The effect on other variables was mixed - no, positive, or negative. On a group level, participants showed no significant changes in meanings made and meaning-making coping. Psychological flexibility significantly increased in the intervention phase, but decreased in follow-ups as compared to baseline.
Discussion: Online ACT-based intervention showed mixed meaning-related results in post-HCT patients, and its effectiveness on meaning-related outcomes varied among participants.