Appendix B – Length of Stay and Costs of Injury Rehabilitation by Injury Category

Introduction
Although the immediate hospitalization costs of various injuries have been examined, the longer-term costs of injury rehabilitation have not been fully addressed. In conducting cost analyses before adopting injury prevention programs or laws, the rehabilitation costs are an important but often overlooked element of the total cost. This section provides data on injury, rehabilitation costs, and rehabilitation hospital length of stay (LOS) by age group.

Cost and length of stay data were provided by the American Medical Rehabilitation Provider’s Association (AMRPA). These data are from 106 U.S. rehabilitation centers. This cost dataset on rehabilitation patients is considered the most reliable cost dataset available, as the cost data has been uniformly identified, quality-controlled, and cleaned. Diagnoses and cost data were available for 76 percent of the approximately 83,000 AMRPA patient records.

AMRPA provided data on average length of stay, average cost, and average cost per day by rehabilitation impairment category (RIC) and age group.

Methods

Data Collection and Analysis Methods

The AMRPA dataset contains records for 83,000 non-Medicare patients from rehabilitation hospitals for the years 1997 – 2001 from 106 facilities. The dataset overlaps heavily with the UDSMR, but contains additional cost data for 75 percent to 80 percent of the patients. We received data on 69,023 rehabilitation cases, of which 41,602 were injury cases.

Case Selection
Although the data contained a smattering of E-codes, these were too sparse to use in selecting cases for analysis. Diagnoses coded using the International Classification of Diseases were also limited in the rehabilitation data and thus unusable. Thus, we only could conduct our analysis using the rather limited RIC categories.

Rehabilitation Impairment Categories
RICs describe the impairments that serve as the primary cause for the inpatient rehabilitation admission. Most RICs differentiate traumatic injuries. This system was designed and validated by (Carter et al., 2000). The Department of Health and Human Services selected 21 RICs—ranging from Stroke (category 01) to Burns (category 21)—to form a Prospective Payment System for rehabilitation services (Department of Health and Human Services, 2001).

(Carter et al., 2000) examined specific facets of a rehabilitation Inpatient Rehabilitation Facility PPS — such as its system of categorization, its construction of weights, its procedures for handling univariate outliers, etc.— through use of cost data (from hospitals), discharge information, and FIM data for calendar years 1996–97. Of relevance to the present study, these researchers’ explicit goals included improving cost descriptions through the use of RIC definitions. With the exception of the creation of a new category for burns, variation in RIC definitions did not appreciably increase their ability to explain costs.

Data Years
Cases with a discharge date of fiscal year 1999 were selected for analysis. These data give us the last data in a free market rehabilitation system. Thereafter, HCFA (now CMS) moved the system to prospective payment at rates that do not necessarily reflect actual costs of care. The new PPS rates for 2002 are listed in the chapter reporting our analysis of UDSMR data.

Analysis
Cases were selected if they contained RICs and cost data. We calculated basic descriptive statistics on costs and length of stay by age groups. The average cost per day of inpatient rehabilitation was computed by dividing the average cost per rehab stay by the average length of stay per rehab patient.

Results
Table 1 presents the RIC injury data across all age groupings. Traumatic spinal cord injuries required the longest length of stay–on average 34.3 days, followed by major multiple trauma with brain or spinal cord injury (26.3 days); and traumatic brain injuries (25.8) days.

The average cost per rehab day ranged from $716 (hip fracture) to $991 (burns). The top five RICs in average costs for all age groupings were burns ($991), traumatic spinal cord ($860), major multiple trauma with brain or spinal cord injury ($854), traumatic brain injury ($807), and neurological ($802).

Table 1. Rehabilitation Costs for All Age Groups: Number of Cases, Average Length of Stay, Average Cost, and Average Cost per Day as a Function of RICs,
FY 1998–1999 Data in 1999 Dollars.

RICs

Cases

Average Length of Stay (LOS)

Standard Deviation (LOS)

Average Cost

Standard Deviation of Cost

Average Cost per Day (mean total cost/LOS)

Amputation, Lower Extremity

2,184

17.4

11.3

$13,468

$10,069

$774

Amputation, Other

282

16.9

10.6

$13,486

$9,017

$798

Burns

163

15.7

10.3

$15,555

$14,517

$991

Hip Fracture

6,203

15.2

7.8

$10,877

$6,590

$716

Major Multiple Trauma, With Brain or Spinal Cord Injury

593

26.3

24.3

$22,450

$24,104

$854

Major Multiple Trauma, With No Brain or Spinal Cord Injury

1,100

16.5

11.6

$12,585

$10,395

$763

Miscellaneous

6,226

16.0

10.0

$12,668

$11,213

$792

Neurological

2,873

17.7

11.4

$14,193

$10,986

$802

Other Orthopedic

3,220

14.1

8.4

$10,451

$7,262

$741

Pain Syndrome

844

13.7

8.6

$9,925

$6,662

$724

Replacement of Lower Extremity Joint

14,185

10.5

5.5

$7,613

$4,370

$725

Traumatic Brain Injury

2,372

25.8

22.5

$20,821

$21,435

$807

Traumatic Spinal Cord

1,357

34.3

30.1

$29,495

$29,583

$860

TOTALS

41,602

 

 

 

 

 

An examination of the RIC data by age group (tables 2–4) revealed a consistent trend in LOS and average costs by RICs similar to the aggregated age data.

Table 2. Individuals Less Than 30 Years Old: Number of Cases, Average Length of Stay, Average Cost, and Average Cost per Day as a
Function of Rehabilitation Impairment Categories

RICs

Cases

Average Length of Stay (LOS)

Standard Deviation (LOS)

Average Cost

Standard Deviation of Cost

Average Cost per Day (mean total cost/LOS)

Amputation, Lower Extremity

33

24.0

36.0

$17,735

$25,388

$739

Amputation, Other

7

20.8

22.9

$16,539

$16,183

$795

Burns

14

19.2

7.7

$14,288

$6,890

$744

Hip Fracture

75

11.2

6.1

$7,809

$4,285

$697

Major Multiple Trauma, With Brain or Spinal Cord Injury

209

26.9

29.4

$23,594

$29,791

$877

Major Multiple Trauma, With No Brain or Spinal Cord Injury

159

13.5

9.8

$10,374

$8,474

$768

Miscellaneous

101

20.0

14.9

$16,507

$13,318

$825

Neurological

111

18.2

11.9

$15,737

$13,099

$865

Other Orthopedic

108

12.6

8.2

$9,966

$7,024

$791

Pain Syndrome

15

17.6

10.4

$12,721

$10,474

$723

Replacement of Lower-Extremity Joint

41

11.2

7.0

$8,700

$6,617

$777

Traumatic Brain Injury

735

28.8

27.9

$24,401

$28,606

$847

Traumatic Spinal Cord

353

40.6

36.1

$35,696

$36,347

$879

TOTALS

1,961

 

 

 

 

 


Table 3. Individuals 30 to 64 Years Old: Number of Cases, Average Length of Stay, Average Cost, and Average Cost per Day as a Function of Rehabilitation Impairment Categories

RICs

Cases

Average Length of Stay (LOS)

Standard Deviation (LOS)

Average Cost

Standard Deviation of Cost

Average Cost per Day (mean total cost/LOS)

Amputation, Lower Extremity

805

15.7

9.9

$12,611

$10,592

$803

Amputation, Other

99

15.7

10.7

$12,469

$8,652

$794

Burns

54

18.8

12.3

$19,477

$20,806

$1,036

Hip Fracture

715

12.9

8.2

$9,595

$7,446

$744

Major Multiple Trauma, With Brain or Spinal Cord Injury

286

27.3

22.6

$23,191

$22,094

$849

Major Multiple Trauma, With No Brain or Spinal Cord Injury

485

16.6

12.4

$12,699

$10,479

$765

Miscellaneous

1,537

16.4

11.5

$13,669

$14,690

$833

Neurological

1,159

18.3

13.0

$14,988

$12,196

$819

Other Orthopedic

864

13.1

9.9

$10,120

$8,912

$773

Pain Syndrome

250

13.3

9.8

$9,856

$7,115

$741

Replacement of Lower-Extremity Joint

3,410

9.1

4.8

$6,786

$3,932

$746

Traumatic Brain Injury

961

26.8

22.6

$21,355

$19,967

$797

Traumatic Spinal Cord

713

34.5

28.2

$28,915

$26,277

$838

TOTALS

11,338

 

 

 

 

 


Table 4. Individuals 65 and Older: Number of Cases, Average Length of Stay, Average Cost, and Average Cost per Day as a Function of Rehabilitation Impairment Categories

RICs

Cases

Average Length of Stay (LOS)

Standard Deviation (LOS)

Average Cost

Standard Deviation of Cost

Average Cost per Day (mean total cost/LOS)

Amputation, Lower Extremity

1,346

18.3

10.7

$13,877

$9,005

$758

Amputation, Other

176

17.4

9.8

$13,937

$8,860

$801

Burns

95

13.5

8.9

$13,512

$9,962

$1,001

Hip Fracture

5,413

15.6

7.7

$11,089

$6,466

$711

Major Multiple Trauma, With Brain or Spinal Cord Injury

98

22.3

15.6

$17,849

$13,518

$800

Major Multiple Trauma, With No Brain or Spinal Cord Injury

456

17.5

11.0

$13,235

$10,821

$756

Miscellaneous

4,588

15.7

9.2

$12,248

$9,679

$780

Neurological

1,603

17.2

10.1

$13,511

$9,797

$786

Other Orthopedic

2,248

14.5

7.8

$10,601

$6,529

$731

Pain Syndrome

579

13.8

8.0

$9,882

$6,328

$716

Replacement of Lower-Extremity Joint

10,734

11.0

5.6

$7,871

$4,458

$716

Traumatic Brain Injury

676

21.2

13.2

$16,170

$11,001

$763

Traumatic Spinal Cord

291

26.5

24.5

$23,396

$26,616

$883

TOTALS

28,303

 

 

 

 

 

Discussion
If all ages are considered, rehabilitation hospital costs in 1999 ranged from $7,613 for the replacement of a lower-extremity joint to $29,495 for a traumatic spinal cord injury. Average cost per day ranged from $716 for a hip fracture to $991 for burns. Traumatic spinal cord injuries required the longest length of stay – on average 34.3 days -- while replacement of a lower-extremity joint had the shortest – on average 10.5 days. These finding are relatively consistent among age groups.

One caveat on our analysis is length of stay reportedly has been dropping for at least 10 years and more notably since 1999, due to market distortions related to the implementation of prospective payment system. With PPS, rehabilitation hospitals are paid a set fee for each patient, providing an incentive to shorten hospital stay to conform to the available payment.