US Department of Veterans Affairs

Hip Fractures in VA/Medicare-Eligible Veterans: Mortality and Costs

Elizabeth Bass, PhD,1 Dustin D. French, PhD,1 Douglas D. Bradham, DrPH,2  Laurence Z. Rubenstein, MD, MPH3

1VISN-8 Patient Safety Center of Inquiry, James A Haley VAMC

2VA Cooperative Studies Program Coordinating Center at Perry Point, MD and University of Maryland School of Medicine 

3UCLA David Geffen School of Medicine and VA Greater Los Angeles Healthcare System Geriatric Research, Education and Clinical Center

HERC Cyber Seminar

July 25, 2007

Outline
        - Brief overview of previous literature
        - Data sources
        - Model, including comorbidity adjuster
        - Mortality outcomes
        - Cost outcomes
        - Implications

Background
        - Why hip fractures are a real problem in the elderly

Usually includes inpatient stay and rehab

Leads to other clinical issues

High rates of mortality
        - Previous research

Used small samples

Used mostly female samples

What’s going on in the VA?

Goals
        - establish risk-adjusted mortality rates for elderly veterans who sustained a hip fracture over a 12 month time period
        - confirm gender difference
        - estimate costs to Medicare

Data sources
        - Medicare (Standard Analytical Files and Denominator File) for veterans supplied by the VA Information Resource Center (VIReC): 4.7 million individuals

VHA-eligible

enrolled in the VHA

use VHA care

receive compensation from the Department of Veterans Affairs
        - Covers enrollment phase and follow-up period for fracture patients in 1999-2002 (2003) to address right-censoring (VIREC now has data through 2004)

Methods
        - Retrospective, incident-hip fracture cohort analysis of veterans aged 65+
        - Patients selected by a “first-ever” admitting diagnosis of hip fracture (ICD-9-CM codes 820-820.9 or 905.3) to a Medicare facility from 1999-2002
        - Mortality viewed at several time points up to 1 year
        - Costs defined as Medicare payments
        - Selection of comorbidity adjuster

Comorbidity adjuster
        - What are the options?
        - Why an Elixhauser?

Model  & Methods:365-day Mortality

Model

Mortality= f(age, gender, comorbidity adjuster)

Statistical Analysis: Cox’s proportional hazard

Duration(t)*Death = age, gender, comorbidities

Model & Methods:365-day Costs

Model

Total Costs= f(age, gender, inpatient length of stay, death within one year, comorbidity adjuster)

Statistical Analysis: OLS regression (no transformation after testing several functional forms)

Total Medicare payments* = age, gender, length of stay, death, comorbidities

*beginning with first admission date

Results

Demographics (n=43,165)

87% male

94% Caucasian

80 mean age

7 days median length of stay

49% discharged to a skilled nursing facility (SNF)

Results: mortality

Unadjusted one year mortality rates

 (30 days = 9.7%, 90 days = 17.5%, 180 days = 24%, 365 days = 32.2%)

were approximately 10% higher than the adjusted rates (30 days = 8.9%, 90 days = 15.6%, 180 days = 21.8%, one year = 29.9%).

Results: mortality

Results: mortality

Big differences by gender: the mortality odds for women 12 months after hip fracture were 18%, compared to 32% for men. 

In other words, men were about twice as likely to die within one year of the hip fracture compared to women. 

Results: mortality

Results: mortality

The comorbidity adjustment coefficients suggest that:
        -  metastasic cancer increased the risk of death by almost four times (hazard ratio 3.57) 
        - congestive heart failure increased risk by 63%
        - renal failure increased risk by 95%
        - lymphoma increased risk by 63%
        - weight loss increased risk by 90%

Contrary to expectation, hypertension and alcohol abuse were negatively correlated with one-year mortality. 

Results: Medicare payments
        - Medicare spent nearly $3 billion for patients in this cohort from 1999-2003
        - 70% of total annual Medicare payments for all services occurred within the first 30 days following hospital admission 
        - Hospital and physician reimbursements were approximately 3/4 of payments

Results: Medicare payments

Service use

			Inpatient			100%

			Physician			99.1%

			Outpatient care 			83.6% 

		            Skilled nursing facilities 		64.1% 

		           Durable Medical Equipment 	57.2% 

		           Home Health Agency		45.8% 

			Hospice 			2.7% 

With the exception of DME and hospice (70.1% for DME, 8.4% for hospice), these percentages showed only a modest increase at the end of 365 days. 

Results: Medicare payments

Average Medicare Payments within 365 Days for Hip Fracture Patients 1999-2003 (N=43,104)

Provider Type 		Mean ($)  99% Confidence Interval ($)

Inpatient		26,884		26,545-27,223

Carrier 			24,401	    	23,895-24,906

SNF			12,208		12,058-12,358		

Hospice 	  	 7,073		   6,605-7,541

Home Health Agency     5,249		   5,146-5,352

DME		              4,447		   4,217-4,676

Outpatient                       3,200	           	   3,085-3,315

Total All Services	 69,389		68,539-70,239

SOURCE: Medicare SAFs 1999-2003.

Results: Medicare payments

Cost function (OLS regression):

Variable			Coefficient estimate ($)

Age (years)				  -575

Gender (1=female)		-3,557

1 year mortality (1=died)	 3,270

Inpatient LOS (days)		 1,944

SOURCE: Medicare SAFs 1999-2003

Results: Medicare payments

Variable			Coefficient estimate ($)

Renal failure			52,043

Lymphoma				47,185

Metastastic cancer		35,359

Diabetes w/complications	34,332

Alcohol abuse			-15,193

More common comorbidities (COPD, CHF & arrhythmias added between $6,200-$10,000)

SOURCE: Medicare SAFs 1999-2003.

Limitations
        - Did not control for provider characteristics
        - Risk adjuster for broad patient population
        - Varying levels of comorbidities
        - Unable to fully explain gender difference in mortality and costs, alcohol effect and why older patients cost less

Concluding Remarks

Economic implications:
        - High loss of life (downward spiral)
        - Resource use intense
        - What to do? Clinical intervention strategies such as

gait and balance testing

osteoporosis diagnosis

medication review

use of hip protectors 

Tips for VA-Medicare projects
        - Apply for Medicare data from VIReC as soon as possible
        - Contact ResDAC frequently
        - Have a good data manager
        - Include researchers with varied backgrounds

Contact Information

Elizabeth Bass

VA Patient Safety Center of Inquiry

Tampa, FL

Elizabeth.Bass@va.gov

813-558-3908