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Does the Supply of Long-term Acute Care Hospitals Matter? Geographic Location and Outcomes of Care

for Medicare Ventilator Cases

Presented byKathleen Dalton, PhD

Co-investigatorsSara Freeman, MS, and Barbara Gage, PhD

RTI International

Presented atAcademy Health, June 2008

Funding Source: Centers for Medicare and Medicaid Services

3040 Cornwallis Road ■ P.O. Box 12194 ■ Research Triangle Park, NC 27709Phone 919-541-5919 E-mail kdalton@rti.orgFax 919-541-7384

Background

Definition: Acute facility w/ ALOS> 25 days

High-acuity, medically complex patients Ventilator support; other respiratory diseases;

wound care; sepsis Account for <2% Medicare discharges nationally

Post-discharge LTCH referral generates a new DRG payment

LTCHs have the highest costs and highest DRG rates of any Medicare PPS

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Background

Number of LTCH facilities is growing 281 in 2001 increased to 392 by 2006 (+40%) New facilities tend to be for-profit and specialize in

respiratory care

Great geographic variation in supply of LTCH facilities and beds Highest in South and Southwest Many geographic areas have none

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Background

Most common LTCH referrals from short-stay acute hospitals are ventilator support DRGs Vent cases can also be discharged to SNF and inpatient

rehab (IRF) Majority of non-LTCH vent cases finish their care in the

original acute setting Local vent LTCH referral rates are as high as 40% in parts

of Texas

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Study Question:

What happens in areas that have no LTCHs?

If we look at clinically similar vent patients, are there area-level differences in episode outcomes? Medicare inpatient days or costs? Mortality? Time to home discharge? Readmissions following a home discharge?

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Design: Sample

From licensure files: identify matched metropolitan study areas with and without LTCHs

From FY 2004 Medicare claims, identify all index cases with IPPS ventilator support DRGs(“Index” = no previous admission within 60 days)

From FY 2004 and 2005 hospital and SNF claims, follow beneficiary until episode is closed by: Discharge home followed by 60+ days without further admission Discharge into long-term care (non-Medicare, without further

readmission) Death

Exclude cases with death <=7 days from index admission

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Design: Analysis

1. From intervention area cases only, construct probability model for LTCH referral using patient-level predictors

2. Use coefficients to compute predicted pr(LTCH) for all vent episodes

3. Group all episodes into low, medium and high probability

4. By probability group, examine area-level differences in post-acute referral, utilization, cost and clinical outcomes.

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LTCH Locations at Time of Study Sample (2004)

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Matched Study Areas (1):

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New YorkMichigan

Matched Study Areas (2):

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North Carolina Virginia

Matched Study Areas (3):

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OregonWashington

Matched Study Areas (4):

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Southern California Northern California

Descriptive Statistics

Control areas LTCH areasN=1,571 N=5,147

Index admission disposition (verified):

Remain in index hospital 0.54 0.49

Transfer to other acute 0.15 0.15LTCH referral 0.01 0.16

IRF referral 0.08 0.04

SNF referral 0.22 0.17

Outcome measures:

Episode days 48.9 52.3

Part A days 41.7 44.3

Part A payments 61,291$ 73,151$

Mortality (episode + 30 days) 0.40 0.43

Home discharge within 30 days 0.27 0.24

Acute readmission within 30 days of home discharge (1 or more) 0.06 0.10

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LTCH Referral =f (demographics, pr_dx, co-morbidities, trach, other proc codes)

0 .1 .3 1probability

estimation sample(LTCH areas) Out-of-sample (control areas)

random effects logit (by hospital)

estimation sample compared to out-of-sample predictions on control groupDistribution of LTCH referral probabilities:

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Group Sizes by Predicted Referral Probabilities

Low: p <=.10

Medium (.10 <p <=.30)

High (p> .30)

LTCH Areas 3,401 557 1,189 5,147

Control Areas 1,038 204 329 1,571

Full sample 4,439 761 1,518 6,71866% 11% 23% 100%

Referral Probability Group

All

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Substitution Effects: What Levels of Care are LTCHs Replacing?

PAC Referral: LOW group

0%

20%

40%

60%

80%

100%

control areas LTCH areas

LTCH

SNF

IRF

RemainAcute

``

PAC Referral: MEDIUM group

0%

20%

40%

60%

80%

100%

control areas LTCH areas

LTCH

SNF

IRF

RemainAcute

PAC referral: HIGH group

0%

20%

40%

60%

80%

100%

control areas LTCH areas

LTCH

SNF

IRF

RemainAcute

LTCHs substitute for some SNF and rehab referrals in all groups

In "high likelihood" group only substitute for extended acute-care stays

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Adjusted Episode Outcomes:

Y = f(LTCHarea, patient level variables, index hospital characteristics, location, other PAC) Stratified by low / medium / high Prob(LTCH) Coefficient on LTCH area indicator identifies average area-

level difference in outcomes Referent is case remaining in acute setting

Outcome measures: Episode length; Medicare days; Part A payments (all log-

linear) Mortality; home discharge; acute readmission (all as logit)

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Findings Summary

LTCH supply may be associated with Lower utilization per episode Similar Medicare Part A costs per episode

No significant differences between LTCH areas and non-LTCH areas in clinical outcomes Similar mortality and readmissions Marginal evidence suggesting more rapid discharge to

home

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Area-level Differences in Utilization:

EPISODE DAYS:Estimated differential, LTCH areas versus control areas

-30%

-25%

-20%

-15%-10%

-5%

0%

5%

10%

low (<0.1) med (0.1 to 0.3) high (>=0.3)

Probability of LTCH referral

diff

eren

ce w

/ 95%

CI

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Area-level Differences in Payments:

TOTAL PART A MEDICARE PAYMENTS:Estimated differential, LTCH areas versus control areas

-20%

-10%

0%

10%

20%

low (<0.1) med (0.1 to 0.3) high (>=0.3)

Probability of LTCH referral

diff

eren

ce w

/ 95%

CI

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Area-level Differences in Mortality:

30-DAY MORTALITYAdjusted Odds Ratios, LTCH areas versus control areas

0.00

0.50

1.00

1.50

2.00

2.50

low (<0.1) med (0.1 to 0.3) high (>=0.3)

Probability of LTCH referral

OD

DS

RA

TIO

w/ 9

5% C

I

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Area-level Differences in Home Discharge:

DISCHARGE HOME WITHIN 30 DAYSAdjusted Odds Ratios, LTCH areas versus control areas

0.00

1.00

2.00

3.00

4.00

5.00

6.00

low (<0.1) med (0.1 to 0.3) high (>=0.3)

Probability of LTCH referral

OD

DS

RA

TIO

w/ 9

5% C

I

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Area-level Differences in Readmissions:

30-DAY READMISSION (at least 1)Adjusted Odds Ratios, LTCH areas versus control areas

0.00

0.50

1.00

1.50

2.00

2.50

3.00

low (<0.1) med (0.1 to 0.3) high (>=0.3)

Probability of LTCH referral

OD

DS

RA

TIO

w/ 9

5% C

I

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Discussion

Unadjusted area-level differences are misleading

Lower utilization and no differences in episode costs for high-probability groups are both unexpected findings Possible policy implications would be to try to limit

LTCH referral for less complicated cases

Finding of no differences in mortality is at odds with previous work (Rand, MedPAC, RTI), associating LTCH referral with lower mortality

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Limitations / Other Design Issues

Referral model lacks important clinical information not found on claims Needs consistent patient assessment tool across

inpatient settings

Average area-level differences is a blunt measure of impact

Time-to-event model might be better for assessing differences in clinical outcomes

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