This article has Open Peer Review reports available.
Are patient falls in the hospital associated with lunar cycles? A retrospective observational study
© Schwendimann et al; licensee BioMed Central Ltd. 2005
Received: 25 July 2005
Accepted: 17 October 2005
Published: 17 October 2005
Falls and associated negative outcomes in hospitalized patients are of significant concerns. The etiology of hospital inpatient falls is multifactorial, including both intrinsic and extrinsic factors. Anecdotes from clinical practice exist in which health care professionals express the idea that the number of patient falls increases during times of full moon. The aim of this study was to examine in-hospital patient fall rates and their associations with days of the week, months, seasons and lunar cycles.
3,842 fall incident reports of adult in-patients who fell while hospitalized in a 300-bed urban public hospital in Zurich, Switzerland were included. Adjusted fall rates per 1'000 patient days were compared with days of the week, months, and 62 complete lunar cycles from 1999 to 2003.
The fall rate per 1000 patient days fluctuated slightly over the entire observation time, ranging from 8.4 falls to 9.7 falls per month (P = 0.757), and from 8.3 falls on Mondays to 9.3 falls on Saturdays (P = 0.587). The fall rate per 1000 patient days within the lunar days ranged from 7.2 falls on lunar day 17 to 10.6 falls on lunar day 20 (P = 0.575).
The inpatient fall rates in this hospital were neither associated with days of the week, months, or seasons nor with lunar cycles such as full moon or new moon. Preventive strategies should be focused on patients' modifiable fall risk factors and the provision of organizational conditions which support a safe hospital environment.
Falls occur frequently in hospitalized patients. Patient fall rates in hospital settings vary from 2.2 to 9.1 falls per 1000 patient days depending on patient populations and disease groups [1–7]. The etiology of falls in hospitalized patients is multifactorial consisting of both intrinsic and extrinsic risk factors [8–10]. Studies on hospital falls that focus on occurrences over time are limited to the frequencies of falls during the hours of the day [1, 5–7, 11, 12], and to specific time spans e.g. number of falls within the first week of hospitalization [2, 4, 7, 13].
Reasons for the fluctuation in fall-rates over time have been debated, but never scientifically researched. There exist anecdotes from health care professionals in our clinical practice that express the idea that the number of patient falls increasing during times of full moon. One survey indicated that specifically mental health professionals including psychologists, nurses and others held the personal belief that lunar phases affect patient's behavior . However, only one study could be found which reports an increased frequency in patient accidents in a hospital, of which 90% were patient falls, during times of full moon and new moon .
Associations between lunar cycles and health conditions, however, such as increased phone call rates by females to a crisis-call centre, higher frequency in misbehaviors in institutionalized patients, greater behavioral deterioration in patients with schizophrenia, increased occurrence in gout attacks, and higher frequencies in the number of appointment requests in thyroid outpatients; rates of gastrointestinal bleeding; multiparae delivery rates; and numbers of births, have been reported [16–23].
Several beliefs, theories and hypotheses regarding lunar impact on the human body have been generated throughout the history of human kind. Assumptions such as the "Gravitational pull hypothesis" or the "Tidal force hypothesis" were extensively analyzed but their impact on the human organism could not be empirically substantiated . A series of studies have rejected the hypothesis of a lunar influence on human health in view of the following: suicide rates [25, 26]; violent behavior and aggression [27, 28]; agitation in nursing home residents ; use of psychiatric community services ; psychiatric hospital admissions ; frequency of admissions toemergency care ; volume of patients admitted to emergency departments ; cardiopulmonary arrests in emergency departments ; incidence of myocardial infarction and sudden cardiac death ; onset of spontaneous pneumothorax ; survival time for breast cancer patients ; number of surgical complications ; postoperative nausea and vomiting ; workload on labor and delivery wards ; and number of deliveries .
There is evidence stating that professionals believe there are correlations between falls and times of the full moon, although an association between patient falls during hospitalization and lunar cycles, especially the influence of the full moon, has not yet been scientifically explored. We hypothesized that no relationship exists between falls in hospitalized patients and lunar cycles. The aim of this study was therefore to examine in-hospital patient fall rates and their associations with days of the week, months, seasons and lunar cycles.
Study sample and setting
We conducted a retrospective analysis of all registered in-patient falls amongst the adult patients hospitalized on the general internal medicine, surgery and geriatric rehabilitation wards of a 300-bed public hospital, which provides medical services for the inhabitants of the Northern part of the city of Zurich, Switzerland. The observation period was from January 1, 1999 to December 31, 2003. Ethical approval was granted by the Ethics Committee of the City hospitals of the City of Zurich.
Variables and measurements
Patient falls were defined as "an incident in which a patient suddenly and involuntary came to rest upon the ground or surface" and were registered regularly by the nurses discovering the fall. We retrieved the number of registered patient falls occurring during hospital stay from the incident report data system of the quality management department, and screened administrative patient data to determine daily number of hospitalized patients, individual length of patient stay, and daily bed occupancy rates. We identified the dates of the synodic lunar months within the study period, based on the European Southern Observatory Munich Image Data Analysis System (ESO-MIDAS). One synodic lunar month counts 29.53 days (29 d. 12 h. 44 m.) which is the period of time required for the moon to travel from one position relative to the sun as seen from the Earth (e.g. full moon) and return to the same position. The day counts started with the new moon at day 0 until the full moon between day 14 and 15 and ended before the next new moon on day 28 or day 29.
We calculated fall rates per 1000 patient days to adjust for number of falls per day and number of hospitalized patients per day. To examine the pattern of fall rates over time, we calculated mean (including standard deviations (SD), and 95% confidence intervals (CI)) fall rates per day of the week, month and season throughout the study period. To model the rate of falls per 1000 patient days with lunar days, days of the week, and months as predictor variables, we used a general linear model. Statistical tests and confidence intervals were calculated two sided, and p-values <0.05 were considered statistically significant. All analyses were performed using SPSS (12.0).
The 5 year study period included 1,826 observation days. During this time a total of 34,970 patients were hospitalized (mean age: 67.3 (SD 19.3) years, female: 53.6%), accounting for 431,149 patient days. Mean length of stay was 12.3 (SD 14.4) days. The hospital bed occupancy rate was 86.2% (Median: 86.6%). Overall, a total of 3,843 falls were registered, affecting 2,512 (7.2%) patients.
Number of hospitalized patients
The number of hospitalized patients per day ranged over the entire study period from 182 to 279 with a mean of 236 patients (SD 17, median 237). The mean number of hospitalized patients per day of the week varied significantly from 221 (SD 14) on Sundays to 244 (SD 16) on Thursdays (p < 0.001). The mean number of hospitalized patients per month varied significantly from 220 (SD 17) per day in August to 247 (SD 16) per day in February (p < 0.001).
Incidence of patient falls over time
Falls, lunar cycle, and variation in time
Associations between falls/1000 patient days, lunar cycle, days of the week & month
Days of the week
Day of the week & month
Lunar day & days of the week
Lunar day & month
Lunar day, days of the week & month
Throughout the 5 year study period, no significant association was found in the incidence rate of hospital in-patient falls occurring during the time period of the full or new moon, neither was periodicity demonstrated for days of the week, months or seasons of the year. Despite significant fluctuations of the hospital's patient occupancy per day of the week and month, the patient fall rates remained relatively stable during the entire study period.
Our results contrast with the one other study that addressed the relationship between patient falls and lunar cycles . Sutton et al reported significant findings in view of increased accident rates during the seven days prior to a full moon and the seven days prior to the new moon. In contrast, we examined whether there were associations between fall rates per day during the lunar cycle, throughout 62 lunar cycles.
In general, our findings are concordant with all other studies that, as with our study, did not show an association between lunar days and patient related events such as hospital admissions, emergency department visits, accessing psychiatric services, and violent behavior [28, 30–33].
We assume that the belief of some health care professionals that frequency of in-hospital fall accidents increases with the time of the full moon rely on non-specific, non systematic observations within the realm of everyday practice. Such beliefs are probably influenced by lay press reports that highlight bizarre unusual activities when the moon is full . Empirical evidence shows that the etiology of falls during hospitalization is multifactorial. Clinically identifiable risk factors such as impaired mobility, impaired mental status, special toileting needs, psychotropic medications, and a past history of falling have been consistently found to be relevant for predicting future falls [8, 10, 43]. Of note is that it has recently been shown that hospital system related factors such as nurse staffing and nurse skill mix also influence the frequency of patient falls [44–46].
The challenge for healthcare professionals will be to support patient safety and quality of care by early identification of patients at risk for falling, and implement interventions to prevent falls and related injuries.
The in-patient fall rates were neither associated with days of the week, months, or seasons, nor with lunar cycles such as the full moon or new moon. Preventive strategies should be focused on assessment of patients' modifiable fall risk factors, and the provision of organizational conditions which support a safe hospital environment.
We thankfully recognize the work of the staff nurses from the clinical departments in filling in the incident fall reports. We also thank the executive management of the Stadtspital Waid in Zurich, namely Hugo Bühler, MD, and Lukas Furler, RN, for their support conducting this study, and we are grateful to Richard Klaghofer, PhD, for his statistical advice.
- Goodwin MB, Westbrook JI: An analysis of patient accidents in hospital. Aust Clin Rev. 1993, 13 (3): 141-149.PubMedGoogle Scholar
- Halfon P, Eggli Y, Van_Melle G, Vagnair A: Risk of falls for hospitalized patients: a predictive model based on routinely available data. J Clin Epidemiol. 2001, 54 (12): 1258-1266. 10.1016/S0895-4356(01)00406-1.View ArticlePubMedGoogle Scholar
- Hitcho EB, Krauss MJ, Birge S, Claiborne Dunagan W, Fischer I, Johnson S, Nast PA, Costantinou E, Fraser VJ: Characteristics and circumstances of falls in a hospital setting: a prospective study. J Gen Intern Med. 2004, 19 (7): 732-739. 10.1111/j.1525-1497.2004.30387.x.View ArticlePubMedPubMed CentralGoogle Scholar
- Schwendimann R: Frequency and circumstances of falls in acute care hospitals: a pilot study. Pflege. 1998, 11 (6): 335-341.PubMedGoogle Scholar
- Tutuarima JA, van der Meulen JH, de Haan RJ, van Straten A, Limburg M: Risk factors for falls of hospitalized stroke patients. Stroke. 1997, 28 (2): 297-301.View ArticlePubMedGoogle Scholar
- Vassallo M, Azeem T, Pirwani MF, Sharma JC, Allen SC: An epidemiological study of falls on integrated general medical wards. Int J Clin Pract. 2000, 54 (10): 654-657.PubMedGoogle Scholar
- von_Renteln_Kruse WKT: Sturzereignisse stationärer geriatrischer Patienten. Z Gerontol Geriatr. 2004, 37: 9-14. 10.1007/s00391-004-0204-7.View ArticlePubMedGoogle Scholar
- Evans D, Hodgkinson B, Lambert L, Wood J: Falls risk factors in the hospital setting: a systematic review. Int J Nurs Pract. 2001, 7 (1): 38-45. 10.1046/j.1440-172x.2001.00269.x.View ArticlePubMedGoogle Scholar
- Moreland J, Richardson J, Chan DH, O_Neill J, Bellissimo A, Grum RM, Shanks L: Evidence-based guidelines for the secondary prevention of falls in older adults. Gerontology. 2003, 49 (2): 93-116. 10.1159/000067948.View ArticlePubMedGoogle Scholar
- Oliver D, Daly F, Martin FC, McMurdo ME: Risk factors and risk assessment tools for falls in hospital in-patients: a systematic review. Age Ageing. 2004, 33 (2): 122-130. 10.1093/ageing/afh017.View ArticlePubMedGoogle Scholar
- Grenier_Sennelier C, Lombard I, Jeny_Loeper C, Maillet_Gouret MC, Minvielle E: Designing adverse event prevention programs using quality management methods: the case of falls in hospital. Int J Qual Health. 2002, 14 (5): 419-426. 10.1093/intqhc/14.5.419.View ArticleGoogle Scholar
- Kerzman H, Chetrit A, Brin L, Toren O: Characteristics of falls in hospitalized patients. J Adv Nurs. 2004, 47 (2): 223-229. 10.1111/j.1365-2648.2004.03080.x.View ArticlePubMedGoogle Scholar
- Vassallo M, Sharma JC, Briggs RS, Allen SC: Characteristics of early fallers on elderly patient rehabilitation wards. Age Ageing. 2003, 32 (3): 338-342. 10.1093/ageing/32.3.338.View ArticlePubMedGoogle Scholar
- Vance DE: Belief in lunar effects on human behavior. Psychol Rep. 1995, 76 (1): 32-34.View ArticlePubMedGoogle Scholar
- Sutton J, Standen P, Wallace A: Incidence and documentation of patient accidents in hospital. Nurs Times. 1994, 90 (33): 29-35.PubMedGoogle Scholar
- Barr W: Lunacy revisited. The influence of the moon on mental health and quality of life. J Psychosoc Nurs Ment Health Serv. 2000, 38 (5): 28-35.PubMedGoogle Scholar
- Ghiandoni G, Secli R, Rocchi MB, Ugolini G: Does lunar position influence the time of delivery? A statistical analysis. Eur J Obstet Gynecol Reprod Biol. 1998, 77 (1): 47-50. 10.1016/S0301-2115(97)00226-1.View ArticlePubMedGoogle Scholar
- Guillon P, Guillon D, Pierre F, Soutoul JH: Seasonal, weekly and lunar cycles of birth. Statistical study of 12,035,680 births. Rev Fr Gynecol Obstet. 1988, 83 (11): 703-708.PubMedGoogle Scholar
- Hicks-Caskey WE, Potter DR: Effect of the full moon on a sample of developmentally delayed, institutionalized women. Percept Mot Skills. 1991, 72 (3 Pt 2): 1375-1380.View ArticlePubMedGoogle Scholar
- Kollerstrom N, Steffert B: Sex difference in response to stress by lunar month: a pilot study of four years' crisis-call frequency. BMC Psychiatry. 2003, 3 (1): 20-10.1186/1471-244X-3-20.View ArticlePubMedPubMed CentralGoogle Scholar
- Mikulecky M, Rovensky J: Gout attacks and lunar cycle. Med Hypotheses. 2000, 55 (1): 24-25. 10.1054/mehy.1999.0973.View ArticlePubMedGoogle Scholar
- Roman EM, Soriano G, Fuentes M, Galvez ML, Fernandez C: The influence of the full moon on the number of admissions related to gastrointestinal bleeding. Int J Nurs Pract. 2004, 10 (6): 292-296. 10.1111/j.1440-172x.2004.00492.x.View ArticlePubMedGoogle Scholar
- Zettinig G, Crevenna R, Pirich C, Dudczak R, Waldhoer T: Appointments at a thyroid outpatient clinic and the lunar cycle. Wien Klin Wochenschr. 2003, 115 (9): 298-301.View ArticlePubMedGoogle Scholar
- Culver RR, J Kelly IW: Geophysical variables and behavior: XLIX. Moon mechanisms and myths: A critical appraisal of explanations of purported lunar effects on human behavior. Psychol Rep. 1988, 62: 638-710.View ArticleGoogle Scholar
- Gutierrez-Garcia JM, Tusell F: Suicides and the lunar cycle. Psychol Rep. 1997, 80 (1): 243-250.View ArticlePubMedGoogle Scholar
- Martin SJ, Kelly IW, Saklofske DH: Suicide and lunar cycles: a critical review over 28 years. Psychol Rep. 1992, 71 (3 Pt 1): 787-795.View ArticlePubMedGoogle Scholar
- Nunez S, Perez Mendez L, Aguirre-Jaime A: Moon cycles and violent behaviours: myth or fact?. Eur J Emerg Med. 2002, 9 (2): 127-130.View ArticlePubMedGoogle Scholar
- Owen C, Tarantello C, Jones M, Tennant C: Lunar cycles and violent behaviour. Aust N Z J Psychiatry. 1998, 32 (4): 496-499. 10.1046/j.1440-1614.1998.00442.x.View ArticlePubMedGoogle Scholar
- Cohen-Mansfield J, Marx MS, Werner P: Full moon: does it influence agitated nursing home residents?. J Clin Psychol. 1989, 45 (4): 611-614.View ArticlePubMedGoogle Scholar
- Amaddeo F, Bisoffi G, Micciolo R, Piccinelli M, Tansella M: Frequency of contact with community-based psychiatric services and the lunar cycle: a 10-year case-register study. Soc Psychiatry Psychiatr Epidemiol. 1997, 32 (6): 323-326. 10.1007/BF00805436.View ArticlePubMedGoogle Scholar
- Gorvin JJ, Roberts MS: Lunar phases and psychiatric hospital admissions. Psychol Rep. 1994, 75 (3 Pt 2): 1435-1440.View ArticlePubMedGoogle Scholar
- Wolbank S, Prause G, Smolle-Juettner F, Smolle J, Heidinger D, Quehenberger F, Spernbauer P: The influence of lunar phenomena on the incidence of emergency cases. Resuscitation. 2003, 58 (1): 97-102. 10.1016/S0300-9572(03)00107-2.View ArticlePubMedGoogle Scholar
- Thompson DA, Adams SL: The full moon and ED patient volumes: unearthing a myth. Am J Emerg Med. 1996, 14 (2): 161-164. 10.1016/S0735-6757(96)90124-2.View ArticlePubMedGoogle Scholar
- Alves DW, Allegra JR, Cochrane DG, Cable G: Effect of lunar cycle on temporal variation in cardiopulmonary arrest in seven emergency departments during 11 years. Eur J Emerg Med. 2003, 10 (3): 225-228. 10.1097/00063110-200309000-00013.View ArticlePubMedGoogle Scholar
- Eisenburger P, Schreiber W, Vergeiner G, Sterz F, Holzer M, Herkner H, Havel C, Laggner AN: Lunar phases are not related to the occurrence of acute myocardial infarction and sudden cardiac death. Resuscitation. 2003, 56 (2): 187-189. 10.1016/S0300-9572(02)00298-8.View ArticlePubMedGoogle Scholar
- Sok M, Mikulecky M, Erzen J: Onset of spontaneous pneumothorax and the synodic lunar cycle. Med Hypotheses. 2001, 57 (5): 638-641. 10.1054/mehy.2001.1432.View ArticlePubMedGoogle Scholar
- Peters-Engl C, Frank W, Kerschbaum F, Denison U, Medl M, Sevelda P: Lunar phases and survival of breast cancer patients--a statistical analysis of 3,757 cases. Breast Cancer Res Treat. 2001, 70 (2): 131-135. 10.1023/A:1012907308443.View ArticlePubMedGoogle Scholar
- Holzheimer RG, Nitz C, Gresser U: Lunar phase does not influence surgical quality. Eur J Med Res. 2003, 8 (9): 414-418.PubMedGoogle Scholar
- Eberhart LH, Jakobi G, Winterhalter M, Georgieff M: Impact of environmental factors on the incidence of posteropative nausea and vomiting. Influence of the weather and cycle of the moon. Anasthesiol Intensivmed Notfallmed Schmerzther. 2000, 35 (10): 635-640. 10.1055/s-2000-7364.View ArticlePubMedGoogle Scholar
- Joshi R, Bharadwaj A, Gallousis S, Matthews R: Labor ward workload waxes and wanes with the lunar cycle, myth or reality?. Prim Care Update Ob Gyns. 1998, 5 (4): 184-10.1016/S1068-607X(98)00100-0.View ArticlePubMedGoogle Scholar
- Waldhoer T, Haidinger G, Vutuc C: The lunar cycle and the number of deliveries in Austria between 1970 and 1999. Gynecol Obstet Invest. 2002, 53 (2): 88-89. 10.1159/000052999.View ArticlePubMedGoogle Scholar
- Kelly IR, J Culver R: The moon was full and nothing happened: a review of studies of the moon and human behavior and human belief. The Outer Edge. Edited by: Nickell JK, B Genoni J. 1996, New York: CSIOP, 17-34.Google Scholar
- Chang JT, Morton SC, Rubenstein LZ, Mojica WA, Maglione M, Suttorp MJ, Roth EA, Shekelle PG: Interventions for the prevention of falls in older adults: systematic review and meta-analysis of randomised clinical trials. BMJ. 2004, 328 (7441): 680-10.1136/bmj.328.7441.680.View ArticlePubMedPubMed CentralGoogle Scholar
- Cho SH, Ketefian S, Barkauskas VH, Smith DG: The effects of nurse staffing on adverse events, morbidity, mortality, and medical costs. Nursing Research. 2003, 52 (2): 71-79. 10.1097/00006199-200303000-00003.View ArticlePubMedGoogle Scholar
- Mark BA, Burleson DL: Measurement of patient outcomes: data availability and consistency across hospitals. J Nurs Adm. 1995, 25 (4): 52-59.View ArticlePubMedGoogle Scholar
- Sovie MD, Jawad AF: Hospital restructuring and its impact on outcomes: nursing staff regulations are premature. J Nurs Adm. 2001, 31 (12): 588-600.View ArticlePubMedGoogle Scholar
- The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1472-6955/4/5/prepub
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.