Duloxetine and cognitive behavioral therapy with phone-based support for the treatment of chronic musculoskeletal pain: a randomized controlled trial

Chronic musculoskeletal pain (CMP) is the most common and disabling of all pain conditions. Combination treatment that includes duloxetine and web-based cognitive behavioral therapy (CBT) has not been rigorously evaluated. We investigated the effectiveness of the combination treatment against duloxetine monotherapy and also examined the effects of adding motivational interviewing (MI) to enhance participant's motivation to engage in web-based CBT. Participants with CMP (n = 281) were randomized to 1 of 3 treatment arms: (1) duloxetine monotherapy, (2) combination treatment (duloxetine + web-based CBT) without phone-based MI, and (3) combination treatment with 6 sessions of phone-based MI. The primary outcome was the Brief Pain Inventory total pain score (BPI TPS) at week 24. Overall, mean (SD) baseline BPI TPS in arms 1, 2 and 3 were 5.8 (1.8), 5.7 (2.1), and 6.1 (1.6), respectively. Compared with baseline, participants in all 3 arms had significant improvement in their BPI TPS during the 24-week trial. However, BPI TPS were not significantly different among the 3 arms, neither were the BPI pain interference and severity, and global ratings of change. The proportion of participants who completed ≥ 6 web-based modules were about the same in arms 2 and 3: 46.3% vs 45.8%, respectively. Web-based CBT did not demonstrate additional benefits beyond those observed with duloxetine monotherapy, which may, in part, be due to low participant completion of the web-based modules. Unexpectedly, the addition of phone-based MI did not significantly improve module completion rates. These findings support the utility of duloxetine over the 24-week study period.