- Email: [email protected]
Postoperative falls in the acute hospital setting: characteristics, risk factors, and outcomes in males
The American Journal of Surgery (2011) 201, 197–202
Clinical Science
Postoperative falls in the acute hospital setting: characteristics, risk factors, and outcomes in males Skotti Church, B.S.a, Thomas N. Robinson, M.D.a,b,*, Erik M. Angles, B.S.a, Zung V. Tran, Ph.D.c, Jeffrey I. Wallace, M.D.d a
Department of Surgery, University of Colorado Denver School of Medicine, University of Colorado Denver Health Sciences Center Mail Stop C313, 12631 East 17th Ave., PO Box 6511, Aurora, CO 80045; bDepartment of Surgery, Denver Veterans Affairs Medical Center, Denver, CO; cDepartment of Biometrics, University of Colorado Denver School of Medicine, Aurora, CO; dDepartment of Medicine (Geriatrics), University of Colorado Denver School of Medicine, Aurora, CO, USA KEYWORDS: Hospital falls; Geriatric surgery; Elderly; Hospital-acquired condition
Abstract BACKGROUND: Hospital falls are an important cause of morbidity in older surgical patients. The objectives of this study were to describe the characteristics, risk factors, and outcomes for postoperative falls. METHODS: A retrospective study was performed on patients who were admitted to the hospital for more than 23 hours after surgery. Patients who fell within 30 days of their surgery were considered to have experienced a postoperative fall. RESULTS: Over 5 years and 9,625 inpatient surgical procedures, 154 patients experienced 190 falls. Injuries resulting from postoperative falls included major injury (hip fracture), less than 1%; injury requiring intervention, 2%; injury not requiring intervention, 27%; and no injury, 70%. Variables associated with postoperative falls included older age, functional dependence, lower albumin level, and higher American Society of Anesthesia score. CONCLUSIONS: One or more postoperative falls occurred in 1.6% of surgical inpatients and can lead to significant morbidity. Recognition of fall risk factors will help design postoperative fall prevention programs by identifying patients at highest risk for postoperative falls. Published by Elsevier Inc.
Falls among hospitalized patients recently gained wide recognition when the Centers for Medicare and Medicaid Services defined an inpatient fall as a hospital-acquired condition. Beginning in October 2008, hospitals stopped receiving any additional payment for care resulting from injuries sustained from an inpatient fall.11 Because of the * Corresponding author. Tel.: ⫹1-303-724-2728; fax: ⫹1-303-7242733. E-mail address: [email protected] Manuscript received June 13, 2009; revised manuscript December 2, 2009
0002-9610/$ - see front matter Published by Elsevier Inc. doi:10.1016/j.amjsurg.2009.12.013
excess morbidity related to inpatient falls, the Joint Commission on Accreditation of Healthcare Organizations lists hospital fall prevention programs as one of the key Patient Safety Goals of hospital programs.2 The first step to creating a hospital-based fall prevention program for surgical patients is to understand the risk factors and natural history of postoperative inpatient falls. Although there is limited information on inpatient falls after surgery, falls in hospitalized medical patients have been studied. Falls are an important cause of morbidity including fractures, closed head injuries, and lacerations in hospitalized patients.3–5 Worse outcomes in-
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cluding prolonged hospital stay and death are related to inpatient falls.6 Understanding risk factors related to inpatient falls (eg, older age)7 has lead to targeting hospital fall prevention programs to specific inpatient populations. Understanding the characteristics, risk factors, and outcomes related to postoperative falls will aid surgeons in the perioperative care of their patients. The objectives of this study were as follows: (1) to describe the characteristics of postoperative falls, (2) to identify preoperative and intraoperative risk factors that are associated with postoperative falls, and (3) to compare outcomes measures in subjects with and without postoperative falls.
Methods Patient population A retrospective study was performed at the Denver Veteran’s Affairs Medical Center. Subjects with falls in the fiscal years from 2003 to 2007 were identified using a hospital falls database maintained by a full-time nurse practitioner falls coordinator. Human research approval was obtained from the Colorado Multiple Institutional Review Board (08-1071). Inclusion criteria were any patient who was admitted for more than 23 hours after surgery. All subjects included were hospitalized in the acute care setting. A fall was defined as an unexpected sudden descent from a standing, sitting, or supine position. Patients found down on the floor were considered to have fallen. Exclusion criteria were inpatients who did not undergo surgery or postoperative patients who fell while on either the rehabilitation or nursing home services. Included subjects with and without falls were compared. A fall that occurred more than 30 days after surgery was not considered a postoperative fall and was excluded from analysis. Subjects were excluded if upon chart review there was insufficient information to confirm the fall. Figure 1 depicts the enrollment flow chart.
Data collection After the assembly of all subjects with postoperative falls from the fall coordinator’s database, index surgical numbers were used to identify subjects with falls in the Denver Veterans’ Affairs Medical Center’s National Surgical Quality Improvement Program (NSQIP) database. The NSQIP database records specific surgical procedures and does not record every postoperative inpatient. As a result, not every fall that occurred during the 5-year study period was recorded in the NSQIP database. The NSQIP database included 87 of the 154 subjects who fell. The NSQIP database records a mix of surgical cases that is a subset of all surgeries performed. Therefore, to compare subjects who fell with a group who underwent similar surgical proce-
Figure 1
Study enrollment flow chart.
dures, only 87 fall subjects who were included in the NSQIP database were included in the comparison. The group of subjects with falls in NSQIP (n ⫽ 87) was compared with all other inpatient surgical cases in the NSQIP database (n ⫽ 4,759). Surgical specialties included in the NSQIP database were general surgery (22%), orthopedics (21%), neurosurgery (20%), urology (12%), vascular surgery (11%), noncardiac thoracic (5%), and other (9%). Variables analyzed using the NSQIP database included: (1) age (in years); (2) hematocrit (%); (3) albumin level (g/dL); (4) comorbidities were quantified using the American Society of Anesthesia (ASA) score, which defines an individual’s preoperative physical health,8 and scores range from 1 (healthy) to 5 (moribund, expected to die) (for this study, subjects were grouped according to ASA classification of less than 3, or ASA classification of 3 or greater); (5) emergency case defined a surgical procedure that was performed as soon as possible, or within 12 hours of patient admission or after the onset of related symptoms; (6) functional health status was dichotomized into disability defined as dependence in one or more activities of daily living (bathing, dressing, toileting, transferring, continence, feeding) versus full independence; (7) weight loss of more than 10% in the 6 months before the surgery was recorded, and weight loss in an elderly patient is a marker of frailty; (8) body mass index; (9) all subjects treated with general endotracheal anesthesia were compared with all other anesthetic techniques; (10) number of units of blood transfusion during the surgery; (11) total surgical time was defined as the length in minutes of the procedure from first incision until closure; (12) length of hospital stay was calculated from the day after the procedure until discharge from the hospital or transfer to other care facilities; and (13) 30-day mortality. When calculating the risk factors and outcomes of postoperative falls, individuals who fell more than once were considered as 1 patient when the data were analyzed.
S. Church et al.
Postoperative falls
The characteristics (time/location of fall, etiology, and injury pattern) of postoperative falls were determined by chart review. The natural history of falls was determined using records of all postoperative patient falls (n ⫽ 154). Data were obtained from physician, nursing, therapy, and fall coordinator notes at the time of the fall. Falls during the day were defined as occurring between 7 AM and 7 PM; falls during the night were defined as occurring between 7 PM and 7 AM. The etiology was categorized as either intrinsic or extrinsic as previously described.9 Intrinsic falls described falls attributed to patient-related factors (eg, poor mobility, balance, or sensory impairments). Extrinsic falls described falls attributed to environmental-related factors (eg, poor lighting, obstacles on floor). Delirium was defined by a validated chart review process searching for evidence of an acute confusional state (mental status changes, inattention, disorientation, hallucinations, agitation).10 The incidence of postoperative falls was calculated using 2 methods. First, all postoperative fall patients were divided by the total number of patients admitted postoperatively for more than 23 hours during the 5-year study period. Second, all postoperative fall patients included in the NSQIP databases were divided by the total number of patients admitted postoperatively for more than 23 hours included in the NSQIP database during the 5-year study period. Patients who fell multiple times were considered as only 1 patient when calculating the incidence of falls.
Statistical analysis Statistical analysis was performed using a t test for equality of means and the Levene test for equality of variances for continuous variables. The Pearson chi-square and the Fisher exact tests were used for dichotomous variables. Results are reported as mean ⫾ standard deviation. Statistical significance was set at a P value of less than .05.
199 separate occasions. Subanalysis of individuals with multiple falls showed similar timing, location, and injury patterns to the original cohort. The etiology of postoperative falls included the following: delirium, 43%; disability, 34%; environmental factors, 13%; and miscellaneous, 10% (Table 1). Falls caused by delirium occurred at a similar frequency during the day (58%; 47 of 81) as during the night (42%; 34 of 81; P ⫽ .06). The reasons for falls in the delirium group were attempting to ambulate without assistance (75%; 61 of 81), falling because of an inability to use the walker appropriately (12%; 10 of 81), agitation or impulsiveness leading to falling out of bed (6%; 5 of 81), and falling while walking with assistance (6%; 5 of 81). For each instance of a fall, the specific causes of environmental factors that lead to falls included: use of assist devices (tripped while attempting to use walker in 3, tripped over wheelchair in 3, failure to lock wheelchair while sitting 2, breakdown of shower chair in 1, failure to have bedrails raised in 1, and breakdown of bedside commode in 1), slipped on wet/soiled floor (slipped on feces/urine in 8 and slipped on water on floor from shower in 2), tripped on tubing (intravenous line tubing in 2, and oxygen tubing in 1), and tripped on dressing (unraveled lower extremity dressing in 1). Injuries resulting from postoperative falls are described in Table 2.
Risk factors and outcomes Risk factors and outcomes were determined using the NSQIP database. Of the 154 subjects with postoperative falls, 87 were included in the NSQIP database. These subjects were compared with 4,759 surgical inpatients included in the NSQIP who did not experience falls during the same time period. Preoperative variables associated with the occurrence of postoperative falls included older age, functional dependence, lower albumin level, greater anemia, ASA score of 3
Results Table 1
Characteristics Over 5 years, 190 falls occurred in 154 patients (152 men). The average age of patients who fell was 64 years ⫾ 11 years. The incidence of postoperative falls calculated using all patient falls was 1.6% (154 of 9,625) and the incidence of postoperative falls calculated using the NSQIP database was 1.8% (87 of 4,759). The average time to falling was 12 ⫾ 8 days postoperatively. Falls occurred more commonly on the ward (85%; 162 of 190) in comparison with the intensive care unit (15%; 28 of 190; P ⬍ .01). Falls occurred more commonly during the day (57%; 108 of 190) in comparison with the night (43%; 82 of 190; P ⫽ .01). Multiple falls occurred in 17% (26 of 154) of individuals. Specifically, 19 individuals fell 2 times, 5 individuals fell 3 times, 1 individual fell 4 times, and 1 person fell on 5
Etiology of postoperative falls
Cause of fall (n ⫽ 190) Intrinsic-related falls Delirium Disability Fall while transferring Loss of balance Weakness Other Dizzy/syncope Phantom limb Rolled out of bed Extrinsic-related falls Environmental factors Malfunction of assist devices Slip on wet/soiled floor Tripped on medical tubing Tripped on lower extremity dressing
n (%) 81 63 29 18 16
(43) (33) (15) (9) (8)
15 (8) 3 (2) 3 (2) 25 11 10 3 1
(13) (6) (5) (2) (⬍1)
200 Table 2
The American Journal of Surgery, Vol 201, No 2, February 2011 Injuries sustained from postoperative falls
n ⫽ 190
3.5
n (%)
Major injury Hip fracture Injury requiring intervention Central line requiring replacement Laceration requiring sutures Toenail avulsion requiring removal Injury not requiring intervention Abrasion/small laceration Hematoma Disrupted surgical incision Foley trauma Epistaxis No injury
1 1 4 2 1 1 52 31 15 2 2 2 133
(⬍1) (⬍1) (2) (1) (⬍1) (⬍1) (27) (16) (8) (1) (1) (1) (70)
or greater, and need for an emergency surgery (Table 3). Increasing age correlated with an increasing incidence of postoperative falls (Fig. 2). Intraoperative variables associated with falls were longer surgical time and increased transfusion requirement (Table 3). Outcomes analysis revealed subjects with postoperative falls had longer hospital stays (Table 3). Falls directly related to lengthening the postoperative hospital stay in 3 subjects were as follows: 1 subject who sustained a hip fracture, and 2 subjects who fell the night before planned discharge without sustaining major
Table 3
Risk factors and outcomes for postoperative falls Subjects with one or more postoperative falls
Preoperative variables Age, y Hematocrit, % Albumin level, g/dL Comorbidities (ASA class, ⱖ3) Emergency case, % Functional status, % dependent ⬎10% weight loss 6 mo prior Body mass index Intraoperative variables Total surgical time, min Blood transfusion, no. units Use of general anesthesia Outcome measures Length of hospital stay, d 30-d mortality
Yes (n ⫽ 87)
No (n ⫽ 4,759)
P
64.2 ⫾ 10.9 39.8 ⫾ 7.3 3.3 ⫾ .9
60.9 ⫾ 12.0 42.5 ⫾ 6.3 3.5 ⫾ .7
.01 ⬍.01 .04
91% 2.3 ⫾ 2.0
69% 1.7 ⫾ 1.7
⬍.01 .04
16.5
6.4
⬍.01
5.7% 27.8 ⫾ 6.1
4.6% 28.1 ⫾ 5.7
.60 .69
183 ⫾ 146
156 ⫾ 103
.01
.57 ⫾ 1.7
.26 ⫾ 1.3
.03
89% 25 ⫾ 30 5.7%
88% 8 ⫾ 11 3.6%
.95 ⬍.01 .29
3 2.5 Incidence of Falls (%)
2 1.5 1 0.5 0 <40
40-49
50-59
60-69
70-79
80-89
Age in Years
Figure 2 Statistical comparison of incidences of falls and age found falls in adjacent age groups by decade were similar for all groups. Incidence of falls was lower in subjects younger than age 50 (6 of 625) in comparison with subjects age 70 and older (29 of 1,056; P ⫽ .013).
injury but were retained as inpatients for continued observation before discharge.
Comments Falls occurred in 1.6% of patients admitted after surgery. Falls resulted in injuries requiring an intervention in 3% of subjects who fell and multiple falls occurred in 17% of individuals who fell. Preoperative variables that predicted postoperative falls included older age, functional dependence in any basic activity of daily living, ASA score of 3 or greater, and lower albumin level. Intraoperative variables that predicted postoperative falls included longer surgical time and increased blood transfusion requirements. Subjects with postoperative falls had longer hospital stays. Recognizing factors related to postoperative falls will aid the practicing surgeon by identifying patients most likely to fall in the postoperative setting and will provide focus for the design of postoperative fall prevention programs. Hospitalized falls are an important source of morbidity and mortality. Although a seemingly simple event, falls represent a complex medical issue resulting in a common cause of nonfatal hospital-acquired injuries. Falls are a geriatric syndrome that represents subthreshold failures of multiple physiological systems.11 Falls also signify the presence of frailty, which is becoming recognized as a marker for perioperative risk including 6-month mortality,12 postoperative complications,13 and the occurrence of delirium.14 The natural history and risk factors for hospitalized falls are studied most commonly in geriatric medical patients. In 2004, 55% of all surgeries in the United States were performed on patients age 65 years and older15; therefore the recognition of risk factors and natural history of hospitalized surgical falls has become an increasingly relevant topic. Risk factors for falls in hospitalized patients range from factors intrinsic to the individual to external factors that
S. Church et al.
Postoperative falls
challenge postural control. The distribution of inpatient medical falls appears to follow 2 patterns. Elderly frail medical patients are at risk of falling throughout their hospital course. In contrast, other patient groups tend to fall around the episode of their acute illness.16 After a systematic review of the literature using Cochrane methodology, Oliver et al17 pooled data from 13 studies evaluating falls in hospitalized patients. Significant risk factors identified for hospitalized falls included gait instability, lower limb weakness, urinary frequency or incontinence, history of previous falls, agitated confusion, and the prescription of culprit drugs (particularly sedatives and hypnotics).17 As a rule of thumb, the increased number of risk factors present in an individual, the higher the risk of falling. The fact that there have been multiple risk factors discovered by different studies evaluating risks for hospitalized falls suggests that there may be unaccounted for characteristics that promote falls that are not addressed.15 Developing fall prevention programs depends on identification of fall risk factors that subsequently can be modified.3 Risk factors for falls in our surgical group included older age and previous functional dependence; factors that are well established by previous hospitalized fall studies.18 Therefore, targeting older and functionally dependent individuals who undergo a surgery as participants in a postoperative fall prevention program appears appropriate. After the surgery is completed, the combination of delirium and environmental factors accounted for the etiology of more than half of all postoperative falls. Both delirium and environmental hazards represent potentially modifiable causes of postoperative falls and have been recognized as causes of nonsurgical falls.19,20 Although delirium is difficult to prevent and treat, there are 3 potential approaches to reducing postoperative delirium or improving the safety of patients who develop delirium. First, reducing delirium can be achieved through supportive protocols (eg, orientation, mobilization, hearing/vision protocols)21 Second, minimizing polypharmacy and avoiding individual medications with increased potential for adverse events in the elderly can minimize the occurrence of postoperative delirium.22 Third, increasing the presence of family members or sitters at the bedside can help prevent delirium-related adverse occurrences. Minimizing environmental hazards intuitively seems preventable through vigilant nursing, and occupational and physical therapy training targeted specifically toward the high-risk fall population. In summary, our findings both point out a high-risk population for postoperative falls and identify a modifiable etiology in more than half the patients who fell. The importance of our study is 2-fold. First, this study addressed postoperative falls in surgical inpatients from all specialties. As a result, by even reporting the incidence of postoperative falls this study adds to the current literature. Previous work on falls in surgery patients has focused specifically on orthopedic inpatients and may not capture the factors applicable to all surgical patients. Second, this
201 study found potentially modifiable factors to be related commonly to the occurrence of postoperative falls. Delirium was the most common, and potentially preventable, cause of inpatient falls after surgery. Recognition of the importance of delirium in postoperative falls provides the possibility that reducing the occurrence of postoperative delirium may reduce the incidence of falls. There were 3 main limitations of this study. First, the participants were 99% male; therefore the influence of sex on postoperative falls cannot be assessed. The gender distribution of our study reflects the population of the Denver Veterans’ Affairs Medical Center and not a selection bias. Second, because the study was retrospective it suffered from the limitations of data review, which relies on accurate chart documentation. Although this was a limitation, this retrospective review was less affected by such errors because a full-time nurse practitioner fall coordinator prospectively maintains the falls database. As a result, a fall-specific assessment of every fall occurred at the time of the event. Third, the NSQIP database included only 87 of the 154 subjects who fell during the 5-year study period. As a result, the risk factor and outcomes statistical analysis was performed on only a subset of the entire fall group. This study evaluated the characteristics, risk factors, and outcomes associated with postoperative falls. The purpose of the study was to determine perioperative risk factors to help identify a high-risk group for postoperative falls and to delineate etiologies for postoperative inpatient falls that potentially might be modifiable. Older age and functional dependence were preoperative characteristics that were related to the occurrence of postoperative falls. Delirium and environmental hazards are modifiable etiologies of falls that accounted for more than half of all inpatient falls. Future directions of this research are to implement a postoperative fall prevention protocol aimed to reduce the occurrence of falls in a high-risk group of surgical patients. The current study suggests that targeting the older and functionally dependent surgical population and attempting to reduce the occurrence of postoperative delirium and environmental hazards would be logical areas to focus a postoperative fall prevention protocol.
Acknowledgments This work was supported by the American Geriatric Society’s Jahnigen Scholars Award (T.N.R.) and the American Geriatric Society Geriatrics for Specialty Residents Award (T.N.R. and J.I.W.).
References 1. Hospital acquired conditions. 2008. Available at: http://www.cms. hhs.gov/HospitalAcqCond/01_Overview.asp#TopOfPage). Accessed: 14 May 2009.
202 2. National patient safety goals. 2008 Available at: http://www. jointcommission.org/PatientSafety/NationalPatientSafetyGoals/09_ hap_npsgs.htm. Accessed: April 17, 2009. 3. Schwendimann R, Buhler H, De Geest S, et al. Falls and consequent injuries in hospitalized patients: effects of an interdisciplinary falls prevention program. BMC Health Serv Res 2006;6:69. 4. Hitcho EB, Krauss MJ, Birge S, et al. Characteristics and circumstances of falls in a hospital setting: a prospective analysis. J Gen Intern Med 2004;19:732–9. 5. Fischer ID, Krauss MJ, Dunagan WC, et al. Patterns and predictors of inpatient falls and fall-related injuries in a large academic hospital. Infect Control Hosp Epidemiol 2005;26:822–7. 6. Ackerman DB, Trousdale RT, Bieber P, et al. Postoperative patient falls on an orthopedic Inpatient Unit. J Arthroplasty 2010;25:10 – 4. 7. Krauss MJ, Nguyen SL, Dunagan WC, et al. Circumstances of patient falls and injuries in 9 hospitals in a Midwestern healthcare system. Infect Control Hosp Epidemiol 2007;28:544 –50. 8. Keats AS. The ASA classification of physical status—a recapitulation. Anesthesiology 1978;49:233– 6. 9. Lach HW, Reed AT, Arfken CL, et al. Falls in the elderly: reliability of a classification system. J Am Geriatr Soc 1991;39:197–202. 10. Inouye SK, Leo-Summers L, Zhang Y, et al. A chart-based method for identification of delirium: validation compared with interviewer ratings using the confusion assessment method. J Am Geriatr Soc 2005; 53:312– 8. 11. Inouye SK, Studenski S, Tinetti ME, et al. Geriatric syndromes: clinical, research, and policy implications of a core geriatric concept. J Am Geriatr Soc 2007;55:780 –91.
The American Journal of Surgery, Vol 201, No 2, February 2011 12. Robinson TN, Eiseman B, Wallace JI, et al. Redefining geriatric pre-operative assessment using frailty, disability and Co-morbidity. Ann Surg 2009;250:449 –55. 13. Dasgupta M, Dumbrell AC. Preoperative risk assessment for delirium after noncardiac surgery: a systematic review. J Am Geriatr Soc 2006;54:1578 – 89. 14. Robinson TN, Raeburn CD, Tran ZV, et al. Postoperative delirium in the elderly: risk factors and outcomes. Ann Surg 2009;249:173– 8. 15. Geriatric Review Syllabus—A Core Curriculum in Geriatric Medicine. 6th ed. Pompei P, editor. New York: American Geriatrics Society; 2006. 16. Mahoney JE. Immobility and falls. Clin Geriatr Med 1998;14:699 –726. 17. Oliver D, Daly F, Martin FC, et al. Risk factors and risk assessment tools for falls in hospital in-patients: a systematic review. Age Ageing 2004;33:122–30. 18. Corsinovi L, Bo M, Ricauda Aimonino N, et al. Predictors of falls and hospitalization outcomes in elderly patients admitted to an acute geriatric unit. Arch Gerontol Geriatr 2009;49:142–5. 19. Bates DW, Pruess K, Souney P, et al. Serious falls in hospitalized patients: correlates and resource utilization. Am J Med 1995;99:137– 43. 20. Rubenstein LZ, Josephson KR. Falls and their prevention in elderly people: what does the evidence show? Med Clin North Am 2006;90: 807–24. 21. Inouye SK, Bogardus ST Jr, Charpentier PA, et al. A multicomponent intervention to prevent delirium in hospitalized older patients. N Engl J Med 1999;340:669 –76. 22. Fick DM, Cooper JW, Wade WE, et al. Updating the beers criteria for potentially inappropriate medication use in older adults: results of a US consensus panel of experts. Arch Intern Med 2003;163: 2716 –24.
Clinical Science
Postoperative falls in the acute hospital setting: characteristics, risk factors, and outcomes in males Skotti Church, B.S.a, Thomas N. Robinson, M.D.a,b,*, Erik M. Angles, B.S.a, Zung V. Tran, Ph.D.c, Jeffrey I. Wallace, M.D.d a
Department of Surgery, University of Colorado Denver School of Medicine, University of Colorado Denver Health Sciences Center Mail Stop C313, 12631 East 17th Ave., PO Box 6511, Aurora, CO 80045; bDepartment of Surgery, Denver Veterans Affairs Medical Center, Denver, CO; cDepartment of Biometrics, University of Colorado Denver School of Medicine, Aurora, CO; dDepartment of Medicine (Geriatrics), University of Colorado Denver School of Medicine, Aurora, CO, USA KEYWORDS: Hospital falls; Geriatric surgery; Elderly; Hospital-acquired condition
Abstract BACKGROUND: Hospital falls are an important cause of morbidity in older surgical patients. The objectives of this study were to describe the characteristics, risk factors, and outcomes for postoperative falls. METHODS: A retrospective study was performed on patients who were admitted to the hospital for more than 23 hours after surgery. Patients who fell within 30 days of their surgery were considered to have experienced a postoperative fall. RESULTS: Over 5 years and 9,625 inpatient surgical procedures, 154 patients experienced 190 falls. Injuries resulting from postoperative falls included major injury (hip fracture), less than 1%; injury requiring intervention, 2%; injury not requiring intervention, 27%; and no injury, 70%. Variables associated with postoperative falls included older age, functional dependence, lower albumin level, and higher American Society of Anesthesia score. CONCLUSIONS: One or more postoperative falls occurred in 1.6% of surgical inpatients and can lead to significant morbidity. Recognition of fall risk factors will help design postoperative fall prevention programs by identifying patients at highest risk for postoperative falls. Published by Elsevier Inc.
Falls among hospitalized patients recently gained wide recognition when the Centers for Medicare and Medicaid Services defined an inpatient fall as a hospital-acquired condition. Beginning in October 2008, hospitals stopped receiving any additional payment for care resulting from injuries sustained from an inpatient fall.11 Because of the * Corresponding author. Tel.: ⫹1-303-724-2728; fax: ⫹1-303-7242733. E-mail address: [email protected] Manuscript received June 13, 2009; revised manuscript December 2, 2009
0002-9610/$ - see front matter Published by Elsevier Inc. doi:10.1016/j.amjsurg.2009.12.013
excess morbidity related to inpatient falls, the Joint Commission on Accreditation of Healthcare Organizations lists hospital fall prevention programs as one of the key Patient Safety Goals of hospital programs.2 The first step to creating a hospital-based fall prevention program for surgical patients is to understand the risk factors and natural history of postoperative inpatient falls. Although there is limited information on inpatient falls after surgery, falls in hospitalized medical patients have been studied. Falls are an important cause of morbidity including fractures, closed head injuries, and lacerations in hospitalized patients.3–5 Worse outcomes in-
198
The American Journal of Surgery, Vol 201, No 2, February 2011
cluding prolonged hospital stay and death are related to inpatient falls.6 Understanding risk factors related to inpatient falls (eg, older age)7 has lead to targeting hospital fall prevention programs to specific inpatient populations. Understanding the characteristics, risk factors, and outcomes related to postoperative falls will aid surgeons in the perioperative care of their patients. The objectives of this study were as follows: (1) to describe the characteristics of postoperative falls, (2) to identify preoperative and intraoperative risk factors that are associated with postoperative falls, and (3) to compare outcomes measures in subjects with and without postoperative falls.
Methods Patient population A retrospective study was performed at the Denver Veteran’s Affairs Medical Center. Subjects with falls in the fiscal years from 2003 to 2007 were identified using a hospital falls database maintained by a full-time nurse practitioner falls coordinator. Human research approval was obtained from the Colorado Multiple Institutional Review Board (08-1071). Inclusion criteria were any patient who was admitted for more than 23 hours after surgery. All subjects included were hospitalized in the acute care setting. A fall was defined as an unexpected sudden descent from a standing, sitting, or supine position. Patients found down on the floor were considered to have fallen. Exclusion criteria were inpatients who did not undergo surgery or postoperative patients who fell while on either the rehabilitation or nursing home services. Included subjects with and without falls were compared. A fall that occurred more than 30 days after surgery was not considered a postoperative fall and was excluded from analysis. Subjects were excluded if upon chart review there was insufficient information to confirm the fall. Figure 1 depicts the enrollment flow chart.
Data collection After the assembly of all subjects with postoperative falls from the fall coordinator’s database, index surgical numbers were used to identify subjects with falls in the Denver Veterans’ Affairs Medical Center’s National Surgical Quality Improvement Program (NSQIP) database. The NSQIP database records specific surgical procedures and does not record every postoperative inpatient. As a result, not every fall that occurred during the 5-year study period was recorded in the NSQIP database. The NSQIP database included 87 of the 154 subjects who fell. The NSQIP database records a mix of surgical cases that is a subset of all surgeries performed. Therefore, to compare subjects who fell with a group who underwent similar surgical proce-
Figure 1
Study enrollment flow chart.
dures, only 87 fall subjects who were included in the NSQIP database were included in the comparison. The group of subjects with falls in NSQIP (n ⫽ 87) was compared with all other inpatient surgical cases in the NSQIP database (n ⫽ 4,759). Surgical specialties included in the NSQIP database were general surgery (22%), orthopedics (21%), neurosurgery (20%), urology (12%), vascular surgery (11%), noncardiac thoracic (5%), and other (9%). Variables analyzed using the NSQIP database included: (1) age (in years); (2) hematocrit (%); (3) albumin level (g/dL); (4) comorbidities were quantified using the American Society of Anesthesia (ASA) score, which defines an individual’s preoperative physical health,8 and scores range from 1 (healthy) to 5 (moribund, expected to die) (for this study, subjects were grouped according to ASA classification of less than 3, or ASA classification of 3 or greater); (5) emergency case defined a surgical procedure that was performed as soon as possible, or within 12 hours of patient admission or after the onset of related symptoms; (6) functional health status was dichotomized into disability defined as dependence in one or more activities of daily living (bathing, dressing, toileting, transferring, continence, feeding) versus full independence; (7) weight loss of more than 10% in the 6 months before the surgery was recorded, and weight loss in an elderly patient is a marker of frailty; (8) body mass index; (9) all subjects treated with general endotracheal anesthesia were compared with all other anesthetic techniques; (10) number of units of blood transfusion during the surgery; (11) total surgical time was defined as the length in minutes of the procedure from first incision until closure; (12) length of hospital stay was calculated from the day after the procedure until discharge from the hospital or transfer to other care facilities; and (13) 30-day mortality. When calculating the risk factors and outcomes of postoperative falls, individuals who fell more than once were considered as 1 patient when the data were analyzed.
S. Church et al.
Postoperative falls
The characteristics (time/location of fall, etiology, and injury pattern) of postoperative falls were determined by chart review. The natural history of falls was determined using records of all postoperative patient falls (n ⫽ 154). Data were obtained from physician, nursing, therapy, and fall coordinator notes at the time of the fall. Falls during the day were defined as occurring between 7 AM and 7 PM; falls during the night were defined as occurring between 7 PM and 7 AM. The etiology was categorized as either intrinsic or extrinsic as previously described.9 Intrinsic falls described falls attributed to patient-related factors (eg, poor mobility, balance, or sensory impairments). Extrinsic falls described falls attributed to environmental-related factors (eg, poor lighting, obstacles on floor). Delirium was defined by a validated chart review process searching for evidence of an acute confusional state (mental status changes, inattention, disorientation, hallucinations, agitation).10 The incidence of postoperative falls was calculated using 2 methods. First, all postoperative fall patients were divided by the total number of patients admitted postoperatively for more than 23 hours during the 5-year study period. Second, all postoperative fall patients included in the NSQIP databases were divided by the total number of patients admitted postoperatively for more than 23 hours included in the NSQIP database during the 5-year study period. Patients who fell multiple times were considered as only 1 patient when calculating the incidence of falls.
Statistical analysis Statistical analysis was performed using a t test for equality of means and the Levene test for equality of variances for continuous variables. The Pearson chi-square and the Fisher exact tests were used for dichotomous variables. Results are reported as mean ⫾ standard deviation. Statistical significance was set at a P value of less than .05.
199 separate occasions. Subanalysis of individuals with multiple falls showed similar timing, location, and injury patterns to the original cohort. The etiology of postoperative falls included the following: delirium, 43%; disability, 34%; environmental factors, 13%; and miscellaneous, 10% (Table 1). Falls caused by delirium occurred at a similar frequency during the day (58%; 47 of 81) as during the night (42%; 34 of 81; P ⫽ .06). The reasons for falls in the delirium group were attempting to ambulate without assistance (75%; 61 of 81), falling because of an inability to use the walker appropriately (12%; 10 of 81), agitation or impulsiveness leading to falling out of bed (6%; 5 of 81), and falling while walking with assistance (6%; 5 of 81). For each instance of a fall, the specific causes of environmental factors that lead to falls included: use of assist devices (tripped while attempting to use walker in 3, tripped over wheelchair in 3, failure to lock wheelchair while sitting 2, breakdown of shower chair in 1, failure to have bedrails raised in 1, and breakdown of bedside commode in 1), slipped on wet/soiled floor (slipped on feces/urine in 8 and slipped on water on floor from shower in 2), tripped on tubing (intravenous line tubing in 2, and oxygen tubing in 1), and tripped on dressing (unraveled lower extremity dressing in 1). Injuries resulting from postoperative falls are described in Table 2.
Risk factors and outcomes Risk factors and outcomes were determined using the NSQIP database. Of the 154 subjects with postoperative falls, 87 were included in the NSQIP database. These subjects were compared with 4,759 surgical inpatients included in the NSQIP who did not experience falls during the same time period. Preoperative variables associated with the occurrence of postoperative falls included older age, functional dependence, lower albumin level, greater anemia, ASA score of 3
Results Table 1
Characteristics Over 5 years, 190 falls occurred in 154 patients (152 men). The average age of patients who fell was 64 years ⫾ 11 years. The incidence of postoperative falls calculated using all patient falls was 1.6% (154 of 9,625) and the incidence of postoperative falls calculated using the NSQIP database was 1.8% (87 of 4,759). The average time to falling was 12 ⫾ 8 days postoperatively. Falls occurred more commonly on the ward (85%; 162 of 190) in comparison with the intensive care unit (15%; 28 of 190; P ⬍ .01). Falls occurred more commonly during the day (57%; 108 of 190) in comparison with the night (43%; 82 of 190; P ⫽ .01). Multiple falls occurred in 17% (26 of 154) of individuals. Specifically, 19 individuals fell 2 times, 5 individuals fell 3 times, 1 individual fell 4 times, and 1 person fell on 5
Etiology of postoperative falls
Cause of fall (n ⫽ 190) Intrinsic-related falls Delirium Disability Fall while transferring Loss of balance Weakness Other Dizzy/syncope Phantom limb Rolled out of bed Extrinsic-related falls Environmental factors Malfunction of assist devices Slip on wet/soiled floor Tripped on medical tubing Tripped on lower extremity dressing
n (%) 81 63 29 18 16
(43) (33) (15) (9) (8)
15 (8) 3 (2) 3 (2) 25 11 10 3 1
(13) (6) (5) (2) (⬍1)
200 Table 2
The American Journal of Surgery, Vol 201, No 2, February 2011 Injuries sustained from postoperative falls
n ⫽ 190
3.5
n (%)
Major injury Hip fracture Injury requiring intervention Central line requiring replacement Laceration requiring sutures Toenail avulsion requiring removal Injury not requiring intervention Abrasion/small laceration Hematoma Disrupted surgical incision Foley trauma Epistaxis No injury
1 1 4 2 1 1 52 31 15 2 2 2 133
(⬍1) (⬍1) (2) (1) (⬍1) (⬍1) (27) (16) (8) (1) (1) (1) (70)
or greater, and need for an emergency surgery (Table 3). Increasing age correlated with an increasing incidence of postoperative falls (Fig. 2). Intraoperative variables associated with falls were longer surgical time and increased transfusion requirement (Table 3). Outcomes analysis revealed subjects with postoperative falls had longer hospital stays (Table 3). Falls directly related to lengthening the postoperative hospital stay in 3 subjects were as follows: 1 subject who sustained a hip fracture, and 2 subjects who fell the night before planned discharge without sustaining major
Table 3
Risk factors and outcomes for postoperative falls Subjects with one or more postoperative falls
Preoperative variables Age, y Hematocrit, % Albumin level, g/dL Comorbidities (ASA class, ⱖ3) Emergency case, % Functional status, % dependent ⬎10% weight loss 6 mo prior Body mass index Intraoperative variables Total surgical time, min Blood transfusion, no. units Use of general anesthesia Outcome measures Length of hospital stay, d 30-d mortality
Yes (n ⫽ 87)
No (n ⫽ 4,759)
P
64.2 ⫾ 10.9 39.8 ⫾ 7.3 3.3 ⫾ .9
60.9 ⫾ 12.0 42.5 ⫾ 6.3 3.5 ⫾ .7
.01 ⬍.01 .04
91% 2.3 ⫾ 2.0
69% 1.7 ⫾ 1.7
⬍.01 .04
16.5
6.4
⬍.01
5.7% 27.8 ⫾ 6.1
4.6% 28.1 ⫾ 5.7
.60 .69
183 ⫾ 146
156 ⫾ 103
.01
.57 ⫾ 1.7
.26 ⫾ 1.3
.03
89% 25 ⫾ 30 5.7%
88% 8 ⫾ 11 3.6%
.95 ⬍.01 .29
3 2.5 Incidence of Falls (%)
2 1.5 1 0.5 0 <40
40-49
50-59
60-69
70-79
80-89
Age in Years
Figure 2 Statistical comparison of incidences of falls and age found falls in adjacent age groups by decade were similar for all groups. Incidence of falls was lower in subjects younger than age 50 (6 of 625) in comparison with subjects age 70 and older (29 of 1,056; P ⫽ .013).
injury but were retained as inpatients for continued observation before discharge.
Comments Falls occurred in 1.6% of patients admitted after surgery. Falls resulted in injuries requiring an intervention in 3% of subjects who fell and multiple falls occurred in 17% of individuals who fell. Preoperative variables that predicted postoperative falls included older age, functional dependence in any basic activity of daily living, ASA score of 3 or greater, and lower albumin level. Intraoperative variables that predicted postoperative falls included longer surgical time and increased blood transfusion requirements. Subjects with postoperative falls had longer hospital stays. Recognizing factors related to postoperative falls will aid the practicing surgeon by identifying patients most likely to fall in the postoperative setting and will provide focus for the design of postoperative fall prevention programs. Hospitalized falls are an important source of morbidity and mortality. Although a seemingly simple event, falls represent a complex medical issue resulting in a common cause of nonfatal hospital-acquired injuries. Falls are a geriatric syndrome that represents subthreshold failures of multiple physiological systems.11 Falls also signify the presence of frailty, which is becoming recognized as a marker for perioperative risk including 6-month mortality,12 postoperative complications,13 and the occurrence of delirium.14 The natural history and risk factors for hospitalized falls are studied most commonly in geriatric medical patients. In 2004, 55% of all surgeries in the United States were performed on patients age 65 years and older15; therefore the recognition of risk factors and natural history of hospitalized surgical falls has become an increasingly relevant topic. Risk factors for falls in hospitalized patients range from factors intrinsic to the individual to external factors that
S. Church et al.
Postoperative falls
challenge postural control. The distribution of inpatient medical falls appears to follow 2 patterns. Elderly frail medical patients are at risk of falling throughout their hospital course. In contrast, other patient groups tend to fall around the episode of their acute illness.16 After a systematic review of the literature using Cochrane methodology, Oliver et al17 pooled data from 13 studies evaluating falls in hospitalized patients. Significant risk factors identified for hospitalized falls included gait instability, lower limb weakness, urinary frequency or incontinence, history of previous falls, agitated confusion, and the prescription of culprit drugs (particularly sedatives and hypnotics).17 As a rule of thumb, the increased number of risk factors present in an individual, the higher the risk of falling. The fact that there have been multiple risk factors discovered by different studies evaluating risks for hospitalized falls suggests that there may be unaccounted for characteristics that promote falls that are not addressed.15 Developing fall prevention programs depends on identification of fall risk factors that subsequently can be modified.3 Risk factors for falls in our surgical group included older age and previous functional dependence; factors that are well established by previous hospitalized fall studies.18 Therefore, targeting older and functionally dependent individuals who undergo a surgery as participants in a postoperative fall prevention program appears appropriate. After the surgery is completed, the combination of delirium and environmental factors accounted for the etiology of more than half of all postoperative falls. Both delirium and environmental hazards represent potentially modifiable causes of postoperative falls and have been recognized as causes of nonsurgical falls.19,20 Although delirium is difficult to prevent and treat, there are 3 potential approaches to reducing postoperative delirium or improving the safety of patients who develop delirium. First, reducing delirium can be achieved through supportive protocols (eg, orientation, mobilization, hearing/vision protocols)21 Second, minimizing polypharmacy and avoiding individual medications with increased potential for adverse events in the elderly can minimize the occurrence of postoperative delirium.22 Third, increasing the presence of family members or sitters at the bedside can help prevent delirium-related adverse occurrences. Minimizing environmental hazards intuitively seems preventable through vigilant nursing, and occupational and physical therapy training targeted specifically toward the high-risk fall population. In summary, our findings both point out a high-risk population for postoperative falls and identify a modifiable etiology in more than half the patients who fell. The importance of our study is 2-fold. First, this study addressed postoperative falls in surgical inpatients from all specialties. As a result, by even reporting the incidence of postoperative falls this study adds to the current literature. Previous work on falls in surgery patients has focused specifically on orthopedic inpatients and may not capture the factors applicable to all surgical patients. Second, this
201 study found potentially modifiable factors to be related commonly to the occurrence of postoperative falls. Delirium was the most common, and potentially preventable, cause of inpatient falls after surgery. Recognition of the importance of delirium in postoperative falls provides the possibility that reducing the occurrence of postoperative delirium may reduce the incidence of falls. There were 3 main limitations of this study. First, the participants were 99% male; therefore the influence of sex on postoperative falls cannot be assessed. The gender distribution of our study reflects the population of the Denver Veterans’ Affairs Medical Center and not a selection bias. Second, because the study was retrospective it suffered from the limitations of data review, which relies on accurate chart documentation. Although this was a limitation, this retrospective review was less affected by such errors because a full-time nurse practitioner fall coordinator prospectively maintains the falls database. As a result, a fall-specific assessment of every fall occurred at the time of the event. Third, the NSQIP database included only 87 of the 154 subjects who fell during the 5-year study period. As a result, the risk factor and outcomes statistical analysis was performed on only a subset of the entire fall group. This study evaluated the characteristics, risk factors, and outcomes associated with postoperative falls. The purpose of the study was to determine perioperative risk factors to help identify a high-risk group for postoperative falls and to delineate etiologies for postoperative inpatient falls that potentially might be modifiable. Older age and functional dependence were preoperative characteristics that were related to the occurrence of postoperative falls. Delirium and environmental hazards are modifiable etiologies of falls that accounted for more than half of all inpatient falls. Future directions of this research are to implement a postoperative fall prevention protocol aimed to reduce the occurrence of falls in a high-risk group of surgical patients. The current study suggests that targeting the older and functionally dependent surgical population and attempting to reduce the occurrence of postoperative delirium and environmental hazards would be logical areas to focus a postoperative fall prevention protocol.
Acknowledgments This work was supported by the American Geriatric Society’s Jahnigen Scholars Award (T.N.R.) and the American Geriatric Society Geriatrics for Specialty Residents Award (T.N.R. and J.I.W.).
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