Descriptions of randomised, controlled clinical studies (the scientific “gold standard”) published in peer-reviewed journals in the period 2017-2022 collated by Dr Ann Baldwin, University of Arizona.

2017

• Effects of Reiki energy therapy on saphenous vein incision pain: A randomised clinical trial study. Shaybak, E., Abdollahimohammad, A., Rahnama, M., Masinaeinezhad, N., Azadi-Ahmadabadi, C., & Firouzkohi, M. Der Pharmacia Lettre, 2017 9(1): 100-109. Reiki, compared to sham Reiki, significantly reduced the sensory quality of pain in the leg after catheterization for heart surgery. Only 20 patients per group.
• Self-Efficacy for coping with cancer enhances the effect of Reiki treatments during the pre-surgery phase of breast cancer patients. Chirico A, D’Aiuto G, Penon A, Mallia L, De Laurentiis M, Lucidi F, Botti G, Giordano A. Anticancer Res. 2017 Jul;37(7): 3657-3665. The effectiveness of Reiki in reducing anxiety in cancer patients was amplified in those who also had good self-coping skills. 55 patients per group, no sham Reiki.
• Effects of Reiki on pain, anxiety, and blood pressure in patients undergoing knee replacement: A pilot study. Baldwin AL, Vitale A, Brownell E, Kryak E, Rand W. Holist Nurs Pract. 2017 Mar/Apr; 31(2):80-89. Reiki, compared to sham Reiki or standard care, significantly reduced pain, need for pain medication, blood pressure, anxiety and length of hospital stay in patients after knee replacement surgery. Only 15 patients per group.

2020

• Buyukbayram, Z., & Saritas, S. C. The effect of Reiki and guided imagery intervention on pain and fatigue in oncology patients: A non-randomised controlled study. Explore, 2020 17(1): 22-26. In a large-scale study, 180 oncology patients were given Reiki, guided imagery or no treatment control. After the Reiki, and guided imagery, but not no treatment control, the mean pain and fatigue scores significantly decreased.
• The effect of acupressure and Reiki application on patient’s pain and comfort level after laparoscopic cholecystectomy: A randomised controlled trial. Topdemir EA, Saritas S. Complement Ther Clin Pract. 2021 May 43: 101385. Patients (210) for surgery were assessed for anxiety. Half the patients received one 30-min. Reiki session prior to surgery and the others did not. Anxiety was reassessed immediately after Reiki or no Reiki. The anxiety level of the patients in the Reiki group did not change whereas the anxiety of the control group significantly increased. No sham Reiki group.

2021

• Yüce, U. Ö., & Taşcı, S. Effect of Reiki on the stress level of caregivers of patients with cancer: Qualitative and single-blind randomised controlled trial. Complementary Therapies in Medicine, 2021  58, 102708. 42 primary caregivers of cancer patients were randomised to Reiki and sham Reiki groups who were given 45 min treatments once a week for 6 weeks. Post-intervention Caregiver Strain Index scores significantly fell in the Reiki group compared with the sham Reiki group. All caregivers stated that they found the caring process less stressful after the Reiki sessions. Only 21 patients per group.
• The effects of Reiki and back massage on women’s pain and vital signs post-abdominal hysterectomy: A randomised controlled trial. Utli H, Yağmur Y.  Journal of Hospice and Palliative Nursing, 2021 23(1): 52-58. To determine the effects of Reiki and back massage on pain, analgesic use, and vital signs among women who had undergone an open abdominal hysterectomy. 34 patients per group (Reiki, Back Massage, Control). Treatment 20 min per day for first and second days after surgery. Reiki group had significantly less pain, lower heart rate, respiration rate and blood pressure and less analgesic use than other two groups.
• Karaman, S. & Tan, M. Effect of Reiki therapy on quality of life and fatigue levels of breast cancer patients receiving chemotherapy. A randomised controlled trial. Cancer Nursing, 2021 Nov-Dec 01;44(6): E652-E658. To determine the effect of Reiki therapy on the quality of life and fatigue levels in breast cancer patients receiving chemotherapy. 35 patients per group (Reiki, no treatment control). Reiki group received six 40-min sessions of Reiki, one during each of 3 chemotherapy sessions and 3 after the first chemotherapy session. There was statistically significant less fatigue for Reiki treated patients in the post treatment, though both groups were the same pre-treatment.
• The Effect of Reiki on Pain, Fatigue, and Quality of Life in Adolescents with Dysmenorrhea. Koçoğlu, F. & Zincir, H. Holist Nurs Pract. 2021 Nov-Dec. 35(6): 306-314. This randomised, single-blind, placebo-controlled study was conducted to evaluate the effect of Reiki applications on pain, fatigue, and quality of life in adolescents with dysmenorrhea. There were 38 patients in the Reiki group and 37 in the placebo-controlled group (sham Reiki). There were 7 sessions in total, with 4 consecutive daily sessions in the first 4 days and then 3 weekly sessions. The Reiki group had significantly reduced pain compared to the placebo group. The Reiki practitioner was the researcher, which could introduce bias. The sample size was small.

2022

• Utli, H. & Dogru, B.V. Stress and comfort levels before gastrointestinal endoscopy: a randomised sham-controlled trial. Journal of PeriAnesthesia Nursing, 2022.
  https://doi.org/10.1016/j.jopan.2022.08.010
  This single-blind, pre-test and post-test design, randomised, sham-controlled study was conducted to determine the effect of Reiki when applied before upper gastrointestinal endoscopy (GI) on levels of anxiety, stress, and comfort. There were 53 patients in the Reiki group, 53 patients in the sham Reiki group, and 53 in the control (no treatment) group. Reiki and sham Reiki were applied once for 20 to 25 minutes before GI. When the Reiki group was compared to the sham Reiki and control groups following the intervention, the decrease in the levels of patient stress (P < .001) and anxiety (P < .001) and the increase in patient comfort (P < .001) were statistically significant.

2023

• Utli, H., Dinc, M., & Utli, M.D.A. The Effect of Acupressure or Reiki Interventions on the Levels of Pain and Fatigue of Cancer Patients Receiving Palliative Care: A Randomised Controlled Study. Explore, 19(1), 91-99, 2023. https://doi.org/10.1016/j.explore.2022.11.007
  This single blinded, randomised, controlled study was conducted to determine whether a twice weekly 20-minute Reiki or acupressure session reduced levels of fatigue, pain, and use of analgesia over a month in 156 patients with stage III or stage IV cancer undergoing palliative care compared to a no treatment control group (52 in each group). There was a statistically significant reduction in the use of analgesia (p < 0.001), fatigue (p < 0.001), and pain level (p < 0.001) in both the Reiki and acupressure groups when compared to the control group. The lead author applied the Reiki introducing the possibility of bias.