Getting the grip on nonspecific treatment effects: emesis in patients randomized to acupuncture or sham compared to patients receiving standard care

Abstract

Background: It is not known whether or not delivering acupuncture triggers mechanisms cited as placebo and if acupuncture or sham reduces radiotherapy-induced emesis more than standard care.

Methodology/principal findings: Cancer patients receiving radiotherapy over abdominal/pelvic regions were randomized to verum (penetrating) acupuncture (n = 109; 99 provided data) in the alleged antiemetic acupuncture point PC6 or sham acupuncture (n = 106; 101 provided data) performed with a telescopic non-penetrating needle at a sham point 2-3 times/week during the whole radiotherapy period. The acupuncture cohort was compared to a reference cohort receiving standard care (n = 62; 62 provided data). The occurrence of emesis in each group was compared after a mean dose of 27 Gray. Nausea and vomiting were experienced during the preceding week by 37 and 8% in the verum acupuncture group, 38 and 7% in the sham acupuncture group and 63 and 15% in the standard care group, respectively. The lower occurrence of nausea in the acupuncture cohort (verum and sham) compared to patients receiving standard care (37% versus 63%, relative risk (RR) 0.6, 95 % confidence interval (CI) 0.5-0.8) was also true after adjustment for potential confounding factors for nausea (RR 0.8, CI 0.6 to 0.9). Nausea intensity was lower in the acupuncture cohort (78% no nausea, 13% a little, 8% moderate, 1% much) compared to the standard care cohort (52% no nausea, 32% a little, 15% moderate, 2% much) (p = 0.002). The acupuncture cohort expected antiemetic effects from their treatment (95%). Patients who expected nausea had increased risk for nausea compared to patients who expected low risk for nausea (RR 1.6; Cl 1.2-2.4).

Conclusions/significance: Patients treated with verum or sham acupuncture experienced less nausea and vomiting compared to patients receiving standard care, possibly through a general care effect or due to the high level of patient expectancy.

Trial registration: ClinicalTrials.gov NCT00621660.

Figure 1. Selection of the patients in the standard care and the acupuncture cohort.

Figure 2. Nausea and vomiting within the past 24 hours and the past week.

Emesis was measured at that time the radiotherapy dose was 27 Gray (mean) in the verum, sham and standard care groups. Measured in all patients and in patients not receiving potent antiemetics in the verum (n = 88 and n = 77), sham (n = 95 and n = 78) and standard care group (n = 62 and n = 55).

Figure 3. Trust in the effect of the received treatment for preventing and reducing nausea.

The trust was stated at the sixth and the last verum or sham treatment in patients free from nausea and patients experiencing nausea after the sixth verum or sham treatment. Number of patients rating trust in antiemetic effects of received treatment at both the sixth and the last session was 183.