Introduction: The aim of this systematic review is to summarise and critically evaluate the evidence for the effectiveness of reiki.
Methods: We searched the literature using 23 databases from their respective inceptions through to November 2007 (search again 23 January 2008) without language restrictions. Methodological quality was assessed using the Jadad score.
Results: The searches identified 205 potentially relevant studies. Nine randomised clinical trials (RCTs) met our inclusion criteria. Two RCTs suggested beneficial effects of reiki compared with sham control on depression, while one RCT did not report intergroup differences. For pain and anxiety, one RCT showed intergroup differences compared with sham control. For stress and hopelessness a further RCT reported effects of reiki and distant reiki compared with distant sham control. For functional recovery after ischaemic stroke there were no intergroup differences compared with sham. There was also no difference for anxiety between groups of pregnant women undergoing amniocentesis. For diabetic neuropathy there were no effects of reiki on pain. A further RCT failed to show the effects of reiki for anxiety and depression in women undergoing breast biopsy compared with conventional care.
Discussion: In total, the trial data for any one condition are scarce and independent replications are not available for each condition. Most trials suffered from methodological flaws such as small sample size, inadequate study design and poor reporting.
Conclusion: In conclusion, the evidence is insufficient to suggest that reiki is an effective treatment for any condition. Therefore the value of reiki remains unproven.