Use of decision aid to improve informed decision-making and communication with physicians on the use of oral complementary and alternative medicine (CAM) among cancer patients on chemotherapy treatment: a randomised controlled trial

Purpose Complementary and alternative medicine (CAM) is often used by cancer patients and is concerning as concomitant oral CAM and chemotherapy use may result in adverse interactions and toxicities. We hypothesise that a decision aid (DA) may promote informed and rational use of oral CAM during chemotherapy, and increase patients’ discussion with their oncologists on CAM use. Methods We randomised 240 patients initiating chemotherapy to receive DA or none. Questionnaires were administered at randomisation (visit 1), 1 month (visit 2) and 3 months (visit 3). The primary endpoint was the decisional conflict score (DCS) for decision made on CAM use during chemotherapy. Secondary endpoints include patients’ decision regret score (DRS) on CAM use, CAM uptake, discussion with oncologists on CAM usage, and difference in quality of life (QoL) score between CAM and non-CAM users at visit 3. Results There was no difference in the mean DCS (mean difference 2.7 [95 CI − 2.9 to 8.3, p = 0.345]) and DRS (mean difference − 0.3 [95% CI − 6.3 to 5.8, p = 0.926]) between the two arms. There was a reduction in odds of CAM usage in the intervention arm compared to control arm (OR = 0.36, 95% CI 0.17 to 0.78, p = 0.009), but there was no difference in discussion with oncologists on CAM usage (OR = 0.46, 95% CI 0.07 to 3.01, p = 0.419), or in the QoL between CAM and non-CAM users. Conclusion Our DA did not reduce DCS among cancer patients on chemotherapy. DA that provides more evidence-based information on CAM, and non-judgemental discussion initiated by oncologists to discuss CAM, may improve its effectiveness.