Effectiveness of cooling therapy (cryotherapy) on leg pain and self-efficacy in patients with chronic venous disease: A randomized controlled trial.

BACKGROUND:Individuals with chronic venous disease (CVeD) frequently experience associated leg pain that may influence disease management self-efficacy. OBJECTIVE:To evaluate the influence of a cooling intervention on leg pain associated with more severe stages of CVeD and self-efficacy. This was a secondary aim of the trial. DESIGN:Randomized, blinded, comparator-controlled, multisite trial. SETTING:Three wound clinics and an academic medical research center in the United States of America. PARTICIPANTS:276 participants (54.3% female, 46.7% male) with stage 4 and 5 CVeD were randomly assigned by computer generated tables to the cooling intervention group (n = 138) or control group (n = 138). INTERVENTIONS:Participants received either a cooling (intervention) leg cuff or placebo cuff (control) to apply topically over the affected skin area. Both groups performed standard of care including wearing compression wraps and elevating legs for 30 min during the intervention. Study visits occurred at baseline, and months 1, 3, 6, and 9. METHODS:Visit measures included: Numeric Rating Scale (NRS) for short term pain; VEINES-QOL/Sym questionnaire for long-term pain; and, the Self Efficacy for Managing Chronic Disease Scale (SEMCD-6) for self-efficacy. Data were collected from September 2010 to December 2015 and analyzed using pooled t-tests, Chi-square tests, and mixed effects models. Observed 9-month patient retention rates were 94/138 (68.1%) in the intervention group and 91/138 (65.9%) in the control group. The primary analysis was based on the intention-to-treat principle. RESULTS:Both the cooling intervention and control group experienced statistically significant decreases in unadjusted and adjusted mean NRS pain scores of 1.2 (95% CI: (-1.82, -0.64); p < 0.0001) and 1.8 (95% CI: (-2.31, -1.24); p < 0.0001) respectively from baseline, however, no statistically significant differences in change scores were observed between groups. The unadjusted mean VEINES-QOL/Sym pain scores had statistically significant decreases of 0.9 ((95% CI: (-1.07, -0.62) p < 0.0001 cooling)) and 0.8 (95% CI: (-1.09, -0.55) p < 0.0001 - control) points. When adjusting the scores for demographic and clinical features, both cooling and control groups maintained statistically significant decreases (p < 0.001 for both). No statistically significant differences in change scores were observed between groups. The unadjusted and adjusted mean self-efficacy scores had no statistically significant improvements from baseline to month 9 within and between the cooling and control groups. CONCLUSIONS:Pain was reduced in both groups while self-efficacy did not change. Findings suggest that strictly implemented standard of CVeD care in each study group, with or without cooling, improved pain while there were no effects on self-efficacy.