Lunar Phases and Emergency Department Visits for Renal Colic Due to Ureteral Calculus.
BACKGROUND
Urolithiasis affects an estimated 5% of the population and the lifetime risk of passing a stone in the urinary tract is estimated to be 8-10%. Urinary calculus formation is highly variable and while certain risk factors such as age, gender, seasonality, anatomic abnormality, and metabolic diseases have been identified, not much is known regarding the association of environmental factors such as lunar phases on renal colic. We conducted a retrospective study to test the hypothesis that full moon phase is an environmental factor associated for increased emergency department (ED) visits for renal colic due to ureteral calculus.


METHODS
We analyzed 559 renal colic diagnoses by the ED at the University of Nebraska Medical Center in a 24-month period and compared them with corresponding lunar phases as well as supermoon events. The lunar phases were defined as full moon ± two days, new moon ± two days, and the days in-between as normal days according to the lunar calendar. Supermoon event dates were obtained from NASA.


RESULTS
90 cases (16.1%) were diagnosed during full moon phase, 89 cases (15.9%) were diagnosed during new moon phase, and 380 cases (68.0%) were diagnosed during normal days. The incidence of renal colic showed no statistically significant association with lunar phases or supermoon events.


CONCLUSIONS
In this retrospective longitudinal study with adequate power, neither full moon phase nor supermoon event exhibited an association with increased renal colic diagnoses due to ureteral calculus by the ED at the University of Nebraska Medical Center.
Department of Surgery, Division of Urologic Surgery, University of Nebraska Medical Center, Omaha, Nebraska, United States of America.
Andy W
AW
Yang
Department of Surgery, Division of Urologic Surgery, University of Nebraska Medical Center, Omaha, Nebraska, United States of America.
Justin D
JD
Johnson
Department of Surgery, Division of Urologic Surgery, University of Nebraska Medical Center, Omaha, Nebraska, United States of America.
Carolyn M
CM
Fronczak
Department of Surgery, Division of Urologic Surgery, University of Nebraska Medical Center, Omaha, Nebraska, United States of America.
Chad A
CA
LaGrange
D005260:Female; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D016081:Moon; D056844:Renal Colic / Q000175:diagnosis / Q000453:epidemiology*; D012189:Retrospective Studies; D012307:Risk Factors; D014514:Ureteral Calculi / Q000150:complications*