Receiving Preferred Treatment not Associated with Positive Outcome in a Randomized Trial

Abstract

Background: In a randomized trial of treatments for chronic widespread pain (CWP), participants were asked their treatment preference just prior to randomisation (baseline). This analysis examined whether treatment preference was associated with baseline factors and whether receiving a preferred treatment affected outcomes.

Methods: The MUSICIAN trial was a 2 × 2 randomized trial of cognitive behavioural therapy (CBT) or exercise for people with CWP. Participants were randomly allocated to one of three active treatments [CBT (n = 112), exercise (n = 109), both exercise and CBT (n = 112)] or usual care (n = 109). Before allocation participants were asked, if they had a choice, which active treatment they would choose. A positive outcome was self-reported improvement in health of much or very much better 6, 9 and 30 months after entering the study. Associations between preference and baseline characteristics were examined, including age, gender, chronic pain grade (CPG), passive and active coping, fatigue, psychological distress, sleep problems and kinesiophobia. Differences in gender and CPG between preferences were tested by chi-square tests. For continuous variables, comparison was by analysis of variance and, where a difference was observed, Tukey’s honest significant difference was used to identify which preferences differed and then the standardized mean difference (d) with 95% CIs were calculated. Among those allocated to active treatments, logistic regression was used to calculate odds ratios, adjusted for factors associated with preference, with 95% CIs of positive outcome in those receiving their preferred treatment and not receiving preferred treatment as the referent group.

Results: Of 442 participants, 144 (33%) expressed preference for exercise, 20 (5%) for CBT, 199 (45%) for combined exercise and CBT and 79 (18%) expressed no preference. Compared with females, males were more likely to prefer exercise only (44 vs 28%) and less likely to prefer combined treatment (35 vs 50%). Those preferring CBT, compared with those preferring exercise, were higher in passive coping [d = 0.9 (95% CI 0.41, 1.37)], fatigue [0.8 (0.34, 1.31)], psychological distress [0.7 (0.26, 1.21)], sleep problems [0.7 (0.18, 1.12)] and kinesiophobia [0.6 (0.17, 1.12)]. Those preferring CBT also had greater scores on passive coping than those preferring combined treatment [0.6 (95% CI 0.11, 1.03)] or no preference [0.5 (−0.01, 0.98)] and greater kinesiophobia than those with no preference [0.5 (−0.05, 0.95)]. Of participants allocated to CBT, exercise or combined treatment, 7, 39 and 50%, respectively, had a preference for their allocated treatment. There was no clear association between achieving a positive outcome and whether or not someone received their preferred treatment (see Table 1).

Conclusion: Exercise and exercise combined with CBT were the most preferred treatments. Participants with specific preferences differed from each other with respect to factors which might influence outcome. However, receiving preferred treatment did not appear to influence treatment response.

Disclosure statement: M.B. has received funding for the MUSICIAN Study from Arthritis Research UK. G.J.M. has received funding for the MUSICIAN Study from Arthritis Research UK. All other authors have declared no conflicts of interest.