Psychological intervention (ConquerFear) for treating fear of cancer recurrence: mediators and moderators of treatment efficacy

Purpose ConquerFear is an efficacious intervention for fear of cancer recurrence (FCR) that demonstrated greater improvements than an attention control (relaxation training) in a randomized controlled trial. This study aimed to determine mediators and moderators of the relative treatment efficacy of ConquerFear versus relaxation. Methods One hundred and fifty-two cancer survivors completed 5 therapy sessions and outcome measures before and after intervention and at 6 months' follow-up. We examined theoretically relevant variables as potential mediators and moderators of treatment outcome. We hypothesized that metacognitions and intrusions would moderate and mediate the relationship between treatment group and FCR level at follow-up. Results Only total FCR score at baseline moderated treatment outcome. Participants with higher levels of FCR benefited more from ConquerFear relative to relaxation on the primary outcome. Changes in metacognitions and intrusive thoughts about cancer during treatment partially mediated the relationship between treatment group and FCR. Conclusions These results show that ConquerFear is relatively more effective than relaxation for those with overall higher levels of FCR. The mediation analyses confirmed that the most likely mechanism of treatment efficacy was the reduction in unhelpful metacognitions and intrusive thoughts during treatment, consistent with the theoretical framework underpinning ConquerFear.