Full Moon and Out-of-Hospital Cardiac Arrest in Japan　― Population-Based, Double-Controlled Case Series Analysis ―

Abstract

Background: It is commonly believed that a full moon affects human behavior or the occurrence and outcome of various diseases; thus, the occurrence of out-of-hospital cardiac arrest (OHCA) might increase during full moon nights. Methods and Results: This nationwide, population-based observational study consecutively enrolled OHCA patients in Japan with attempted resuscitation between 2005 and 2016. The primary outcome measure was the occurrence of OHCA. Based on the doublecontrol method, assuming Poisson sampling, we evaluated the average number of OHCA events that occurred on full moon nights compared with that which occurred on control nights, which included events that occurred on the same calendar days 1 week before and after the full moon nights. A total of 29,552 OHCA that occurred on 148 full moon nights and 58,707 OHCA that occurred on 296 control nights were eligible for analysis. The occurrence of OHCA did not differ between full moon and control nights (199.7 vs. 198.3 per night; relative risk [RR], 1.007; 95% CI: 0.993-1.021). On subgroup analysis, compared with control nights, the RR of OHCA occurrence were 1.013 (95% CI: 0.994-1.032, P=0.166) and 0.998 (95% CI: 0.977-1.020, P=0.866) for cardiac and non-cardiac origins, respectively. Conclusions: In this population, there was no significant difference in OHCA occurrence between full moon and control nights.

Impact of lunar phase

“…However, nearly all studies on surgical and post‐surgical outcomes find no association with lunar cycles and poorer clinical outcomes . In a nationwide Japanese study examining out‐of‐hospital cardiovascular arrest, there was no variation in the incidence between full moon and control nights; this study described that if there were a relationship, emergency medical service facilities should be increased on such nights . It is possible that given the biases held by medical professionals that there are already resources allocated assuming causation of lunar phases and various pathologies.…”

Survival outcomes after traumatic brain injury during national academic meeting days in Japan

“…For analyses, we used the double-control method based on previous studies 22 , which allows near-perfect temporal symmetry for cases and controls and does not create time imbalance inside each pair to assess outcome differences during the exposure and control periods. In accordance with this method, we identified two groups: the exposure group, which included patients with TBI occurrence on meeting days, and the control group, which included patients with TBI occurrence during the same day of the week, 1 week before and after meetings.…”

G20 Summit and emergency medical services in Osaka, Japan

“…On the basis of previous studies, we used the double‐control method, 7 which allows for near‐perfect temporal symmetry between cases and controls and does not create a time imbalance inside each pair, to assess the differences in emergency transport, difficulties in obtaining hospital acceptance, and deaths among hospitalized emergency patients during the G20 and control periods. In accordance with this method, the following two periods were identified: the exposure period occurring on the event dates and the control periods occurring during the same calendar days 1 week before and 1 week after the event dates.…”

“…To assess the differences in the numbers of transports, difficulties in obtaining hospital acceptance, and deaths among hospitalized emergency patients between the G20 and control periods, we calculated relative risks (RRs) and their 95% confidence intervals (CIs) under the assumption that they followed common Poisson distribution. Details of the calculation method were described previously 7 . Differences in the time intervals between the G20 and control periods were assessed using an unpaired t ‐test.…”