RESUMO
Long-term trials are key to understanding chronic symptoms such as pain and itch. However, challenges such as high attrition rates and poor recruitment are common when conducting research. The aim of this work was to explore these issues within a long-term randomized control trial using transcranial direct current stimulation to treat pain and itch. This parallel double blinded, placebo-controlled randomized trial was comprised of 15 transcranial direct current stimulation visits and 7 follow-up visits. Participants were over the age of 18, had a burn injury that occurred at least 3 weeks before enrollment, and reported having pain and/or itch that was moderate to severe in intensity. A total of 31 subjects were randomized into either an active or sham transcranial direct current stimulation groups. There were no significant differences between the groups in terms of age, race, education, baseline depression, or anxiety. The median dropout time was at visit 19 (visit 16 [SE = 1.98] for the sham group and visit 19 [SE = 1.98] for the active group). Analysis showed no differences in the dropout rate between groups [χ2(1) = 0.003, P = .954]. The dropout rate was 46.7% for the sham group and 43.8% for the active group. Overall, 45.2% of the subjects dropped out of the trial. Long-term clinical trials are an essential part of evaluating interventions for symptoms such as chronic pain and itch. However, as seen in this trial, long-term studies in the burn population often face recruitment and adherence challenges.