Thermal Therapy is Associated With Decreased Pain Treatment Use: A Retrospective Cohort Study.

BACKGROUND: Body surface heat and cold (eg, thermal) therapies are nonpharmacologic pain treatments purported to have pain-reducing benefits, but there is limited research on their use for chronic pain. The purpose of this study was to examine the potential clinical and health system benefits of thermal therapy. METHODS: Participants included 2182 Veterans Health Administration patients who received a thermal therapy device and 2182 propensity score-matched control patients. Clinical encounters, pain pharmacy data, and pain self-ratings were extracted from the electronic health record in the year prior to and following receipt of a device, or the corresponding dates for matched control patients. Mixed-effects regression and random-effects growth modeling were used to compare changes in pain treatment utilization and pain intensity, between thermal therapy recipients and matched controls. RESULTS: Patients who received thermal therapy had greater reductions in days of high-dose opioid therapy use (Time × Treatment interaction, B = 3.24; 99% CI, 0.34 to 6.14; P < .01) and concurrent use of opioids and benzodiazepines (Time × Treatment interaction, incidence rate ratio [IRR], 0.76; 99% CI, 0.67 to 0.86; P < .01) in the year following device receipt when compared with matched control patients. In addition, patients who received thermal therapy had fewer encounters with pain specialty care, including physical therapy (Time × Treatment interaction, IRR, 1.16; 99% CI, 1.00 to 1.33; P = .01) and pain clinics (Time × Treatment interaction, IRR, 1.49; 99% CI, 1.22 to 1.76; P < .01). Mean pain intensity remained relatively stable for both groups (B = -0.02; 99% CI, -0.06 to 0.02; P = .15). CONCLUSIONS: While associations identified in this observational study do not establish causality, thermal therapy may confer health system benefits through decreased use of costly specialty pain care and high-risk opioid use.