Nausea remains a significant clinical problem despite the use of the best available antiemetic medications. Several studies have shown that expectations of developing nausea are a significant determinant of whether patients actually develop treatment-induced nausea. For example, we found that breast cancer patients (N = 194) about to begin their first chemotherapy regimen containing doxorubicin who believed that they were very likely to experience severe nausea were five times more likely to experience severe nausea than those who believed that they were very unlikely to do so. In addition, studies have shown that expectations of efficacy are largely responsible for the placebo effect and for many of the benefits derived from some CAM therapies. For example, in a multicenter study (N = 465) examining acupressure wristbands for control of chemotherapy-induced nausea, we found that patients who expected the bands to be effective in nausea control experienced significantly less nausea than patients who did not expect them to be effective. As a test of whether the effectiveness of acupressure bands in reducing nausea could be enhanced by boosting patients' expectations of the bands' efficacy, we conducted a double-blind, randomized R21 pilot study examining the efficacy of acupressure bands with and without expectancy-enhancing supplementary materials in breast cancer patients beginning chemotherapy. Patients were stratified by expected nausea (high, low). Patients in the active condition received a handout with expectancy-enhancing materials and a 12-minute relaxation CD that included a 30-second suggestion concerning the acupressure bands' effectiveness. Patients in the control group received a handout that had only neutral materials concerning the bands' likely effectiveness and a relaxation CD that was identical to the active one except additional music was substituted for the 30-second suggestion concerning the bands' effectiveness. For the 26 patients expecting nausea, peak nausea on the 1-7 scale was an average of 1.2 points less in the patients randomized to the active condition of expectancy enhancing supplementary materials compared to the control condition with neutral supplementary materials; this represents a large effect size of 0.78 (Cohen's D). The present study seeks to confirm and extend these findings in a multi-site, 3-arm, randomized, controlled study of 216 breast cancer patients beginning chemotherapy who expect to have nausea. All patients will receive a standardized antiemetic regimen. Arm 1: Neutral handout; Arm 2: Neutral handout + control relaxation MP3 + acupressure bands; Arm 3: Active handout + active relaxation MP3 + acupressure bands. We hypothesize that acupressure bands provided with efficacy-enhancing materials will be more effective in controlling chemotherapy-induced nausea than acupressure bands provided with neutral materials. We build upon a successful R21 study that was designed to refine methods and provide an effect size estimate for this application.
Treatment-induced nausea is a pervasive and often severe problem among cancer patients undergoing chemotherapy, despite the best available antiemetic regimens. Acupressure bands with expectancy-enhancing materials have been shown to have great patient acceptance and may be a low-cost, non-intrusive, safe, and helpful adjunct to standard antiemetic.
