Relationship of negative affect and outcome of an opioid therapy trial among low back pain patients
Pain Practice, 06/13/2012
Jamison RN et al. – Negative affect is associated with diminished benefit during a trial of opioid therapy and is predictive of dropout in a controlled clinical trial.Methods
- Four hundred fifty–nine (N = 459) patients participated in the titration/conversion phase of a multicenter study, of which 268 were randomized to receive once–daily hydromorphone or placebo.
- All patients completed the Hospital Anxiety and Depression Scale (HADS) at baseline and were divided evenly into Low (N = 157), Moderate (N = 155), and High (N = 147) negative affect groups based on their scores.
- Group differences in numerical pain intensity measures at home and in the clinic, Roland–Morris Disability ratings, and measures of symptoms from the Subjective Opiate Withdrawal Scale (SOWS) throughout the trial were analyzed.
- Two hundred sixty–eight of the initial 459 subjects who entered the 2 to 4–week titration/conversion phase (pretreatment) were successfully randomized to either placebo or ER hydromorphone; a total of 110 patients then completed this double–bflind phase of the study.
- Those in the Moderate and High negative affect groups tended to drop out more often during the titration/conversion phase because of the adverse effects or lack of efficacy of their prescribed opioid than those in the Low negative mood group (P < 0.05).
- Overall, those patients in the Moderate and High groups reported significantly higher pain intensity scores in at–home and in–clinic pain intensity ratings (P < 0.05), greater disability on the Roland–Morris Scale (P < 0.01), and more withdrawal symptoms on the SOWS (P < 0.05) than those in the Low group.
- Higher negative affect scores also predicted less favorable ratings of the study drug during the titration phase (P < 0.05).
- Interestingly, the High negative affect group showed the most improvement in pain in the placebo condition (P < 0.05).