Effect of the full moon on mortality among patients admitted to the intensive care unit.

OBJECTIVE To determine the lunar effect on mortality among patients admitted to the intensive care unit. METHODS The retrospective study conducted at Rosalind Franklin University of Medicine and Science, North Chicago, and comprised data of 4387 patients in intensive care unit from December 2002 to November 2004. The subjects were divided into two groups: patients who died on full moon days (the 14th, 15th, and 16th days of the lunar month); and patients who died on the other days of the month. The mortality rates were calculated for patients in both groups. Parameters including patients' age, gender, acute physiology and chronic health evaluation scores, predicted mortality rates, type of intensive care unit, and actual mortality were compared, and non-parametric tests were performed to determine whether there were any differences between the groups. RESULTS Of the 4387 patients who were followed for 23 months, 297 patients died, including 31 on full moon days and 266 patients on the other days of the month. Both groups were similar in terms of mean age (73.6 +/- 14.59 vs. 71.07 +/- 16.13 years; p = 0.599), acute physiology and chronic health evalutation scores (82.06 +/- 24.19 vs. 76.52 +/- 27.42; p = 0.258), and predicted mortality (0.405 +/- 0.249 vs. 0.370 +/- 0.268; p = 0.305). There was no difference in the frequency of death between the full moon days and the other days (10.33 +/- 0.58 vs. 9.8 +/- 3.46; p = 0.845). CONCLUSIONS The full moon does not affect the mortality of the patients in intensive care unit.