1. Inpatient Falls after Total Knee Arthroplasty: Outcomes and National Trends
Colin Woon, MD
Hristo Piponov, MD
Vincent M Moretti, MD
Brian E Schwartz, MD
Alexander C Gordon, MD
March 2nd, 2016

3. Introduction In-hospital falls are 1 of 27 reportable events
Termed “never events” by the National Quality Forum
Since 2008, Centers for Medicare and Medicaid Services (CMS) has stopped paying for “never events”
Reasonably preventable
Should not occur after admission
Results in assignment to a higher DRG

4. Introduction Falls lead to morbidity/mortality
 hospitalization duration
 malpractice lawsuits
 hospitalization costs
Falls after TKA can lead to
Knee laceration / wound dehiscence / chronic infection
Extensor mechanism rupture
Stiffness
Fractures
Subdural hematoma
Death

5. Introduction TKA leads to  odds of falling
Gait / mobility / walking speed
Coordination / balance / proprioception
Postural responses
Lower quadriceps torque

6. Study Aims
To assess national trends in fall occurrences after TKA using the National Hospital Discharge Survey
To evaluate patient outcomes related to this adverse event

7. Materials & Methods National Hospital Discharge Survey (NHDS)
Conducted annually by CDC’s National Center for Health Statistics
Surveys short-stay hospitals (SSH)/year
SSH = average LOS <30days
Only includes hospitals with “general” specialty (medical/surgical) or children’s hospitals
Does not include federal, military and VA hospitals
Database contains medical & demographic information from a sample of surveyed individual patient discharge records

8. Materials & Methods ICD-9 codes were used
Searched NHDS database for patients admitted for primary TKA
Sustained a fall during this admission
Survey duration: years

9. Materials & Methods Additional data Patient demographics (age, gender)
Co-morbidities
Hospital length of stay
Discharge disposition
Mortality
Hospital size, location, type

10. Materials & Methods
Trends evaluated with linear regression with Pearson’s correlation coefficient (r)
Statistical comparisons
Student’s T-test
Chi-square test
Significance level (alpha) of 0.05

11. Results 35,220 patients in surveyed hospitals admitted for primary TKA
37 (0.11%) sustained a fall during the same admission
Rate of falls showed NO correlation with time

12. Results

13. Results Rate of falls varied based on hospital type
Government hospitals (0.22%)
Proprietary hospitals (0%)
Size and region did NOT impact fall rate

14. Results
*p = 0.03

15. Results
p = 0.38

16. Results
p = 0.14%

17. Results
Age of patients who fell (70.4y) > those who did not fall (66.6y) (p=0.03)
Length of stay greater in patients with fall (4.62 days) than without fall (3.73 days) (p<0.01)
Fall patients had more co-morbidities (6.3 diagnoses) than those who did not fall (4.99 diagnoses) (p<0.01)

18. Results No difference in rates of No difference in
DM (p=0.82)
Mental health problems (p=0.37)
Urinary incontinence (p=0.58)
Parkinson’s disease (p=0.64)
Orthostatic hypotension (p=0.78)
No difference in
Rate of bilateral TKA (p=0.61)
Gender ratio (p=0.7)
Discharge disposition (p=0.61)
Mortality (p=0.84)

19. Conclusions Patients who fall….
Older
Age-related reduction in motor strength, balance, reflexes
More medical co-morbidities
Government hospitals > proprietary hospitals
Higher nursing skill-mix, lower patient-nurse ratio, lower nursing hours per patient day (HPPD) associated with lower fall rates
Government teaching hospitals may do fast-track surgery
Get out of bed earlier
Discharged earlier

20. Conclusions Patients who fall….
Longer length of stay
Falls increase hospitalization duration (medical stabilization, imaging, additional surgery)
Longer stay increases likelihood of capturing falls
Longer stay implies decreased mobility, slower return to function – increasing risk of falls

21. Limitations Limitations of database studies
Unable to track falls after discharge
Unable to find out cause/consequence of falls (no chart review)
Sedative-hypnotic meds
Duration of surgery/blood loss
Use of femoral nerve blocks
Knee ROM (hip/trunk compensation)
Unable to identify activity leading to fall
Elimination-related (bathroom)

22. Thank You!