Brief relaxation training is associated with long-term endocrine therapy adherence among women with breast cancer: post hoc analysis of a randomized controlled trial.

Abstract

Despite life-saving potential, many women struggle to adhere to adjuvant endocrine therapy (AET) for their breast cancer (BCa). Prior research has demonstrated that emotional distress is a barrier to AET adherence. We followed women from a trial to test the long-term effects of two 5-week post-surgical group-based stress management interventions, cognitive behavioral therapy (CBT), and relaxation training versus an attention-matched health education control, on AET adherence. We conducted a long-term follow-up (median = 8years) of women randomized to CBT, relaxation training, or health education after surgery for stage 0-3 BCa. We measured adherence with the Endocrine Therapy Medication Usage Questionnaire (ETMUQ). First, we established factors on the ETMUQ via confirmatory factor analysis. We then used Bayesian structural equation modeling to regress these factors on study arm, controlling for age and treatments received. Of those who completed long-term follow-up (n = 59, 44.7%), over half (n = 33; 55.9%) reported problems with adherence generally. Women receiving relaxation training (n = 15) had better adherence than those receiving health education (n = 24) on the Forgetfulness/Inconsistency [B(SE) = 0.25(0.14), p = 0.049] and Intentional Nonadherence [B(SE) = 0.31(0.14), p = 0.018] factors of the ETMUQ. Similar results were observed for those receiving relaxation training compared to CBT (n = 20): Forgetfulness/Inconsistency [B(SE) = - 0.47(0.25), p = 0.031]; Intentional Nonadherence [B(SE) = - 0.31(0.15), p = 0.027]. Women receiving relaxation training were less likely to (1) forget to take their AET and (2) intentionally miss doses of AET in the long term compared to women receiving health education or CBT. This is evidence for the need of randomized trials that aim to improve adherence by incorporating theoretically based behavioral change techniques. Trial 2R01-CA-064710 was registered March 26, 2006.