Use of Outpatient Care by Use of Outpatient Care by

Medicare-Eli

gible Veteran

Matthew Maciejewski, PhDCenter for Health Services Research Center for Health Services Research

in Primary Care 

HERC Health Economics C

yberSemina

September 15, 2010
Dual Use, Continuity and Duplic

of Services in VA & Medicare

 Funded by VA HSR&D IIR 04 Funded by VA HSR&D, IIR 04

-292

 Project team 

 Durham: Matt Maciejewski PhD Durham: Matt Maciejewski, PhD Seattle: Chuan-Fen Liu, PhD; Michael Cha

Chris Bryson, MD; Nancy Sharp, PhD; MarChris Bryson, MD; Nancy Sharp, PhD; Mar

 Little Rock: John Fortney, PhD Boston: Jim Bur

g , ess PhD

 University of Chicago: Will Manning, PhD
Outline

 Background Study Objectives & Contribution Classification of primary care across V

Classification of primary care across V

Medicare records

 Goal: consistent classification of primary c

Goal: consistent classification of primary c

 Study Results

 CBOC VAMC CBOC vs. VAMC VA reliance
Policy Issue

 Veterans using Medicare and VA servic

increased significantly since mid-1990s

 Likely to increase significantly in coming ye

particularly for disability-eligible vets

 It appears that Medicare It appears that Medicare-eligible vetera

eligible vetera

VA services strategically

 Major inpatient procedures at non Major inpatient procedures at non-VA hosp

VA hosp

those with prior VA stays went to VA hospi

 More preventive services outside VA

 Few prior studies examined choice & a

of outpatient care in a national sample (Petersen, HSR 2010)

Fleming, 1992; Borowsky & Cowper, 1994; Wright, 1997; 1999; Jones, 2000; Ashton, 2003; & Weeks, 2007; Hynes, 2007; Carey 2008; Petersen 2010
Objectives

 Examine difference in use of VA and 

Medicare outpatient services among pMedicare outpatient services among p

care patients in 2001-2004

 Is lower VA use by CBOC patients offset 

Is lower VA use by CBOC patients offset 

higher Medicare use?

 Does VA reliance differ for age-eligible an

disability-eligible veterans?

 How has the distribution of VA reliance ch

over time?
Contribution of the Study

 Examination of outpatient care use in V

Medicare over time using national samMedicare over time using national sam

 Following cohort enables look at change o CBOC vs VAMC patients CBOC vs. VAMC patients Disability-eligible vs. age-eligible patients

 Develop algorithm to make VA and Me

Develop algorithm to make VA and Me

claims comparable

 Apply novel analytic method for exami

Apply novel analytic method for exami

unusual distribution of VA reliance
Study Design

 Retrospective cohort Study period: FY2000 – 2004

 Patient identification in FY2000 Follow-up period: FY2001 up period: FY2001 – FY2004

 Study p( j sample (Maciejewski BMC HSR ’07)

 Medicare eligible VA primary care patients from p

cost evaluation study

 Random sample of primary care patients from 108 

Random sample of primary care patients from 108 

and 72 VAMCs (all states but Alaska)

 M di & VA l i d t Medicare & VA claims data
Cohort Selection

Exclusions 

Initial Sample Initial Sample 

Death prior or during FY 2000-2001 4,033Not Medicare eligible or Part A or B only 33,360Developed ESRD 422Enrolled in an HMO 5,506No VA primary care in FY00 No VA primary care in FY00 7 525 ,

Working cohort 

A

g g e eli ible 

Disabled 
Classification of VA and 

Medicare Outpatient Daby Care TypeBur

g, , ess et al., Health Economics 2010 

(p ) in 

press

)
Matching VA and Medicare 

Outpatient Services

 Central challenge of identifying primary 

in VA and Medicare

 Data generating process

 Clinical data vs. billing records

 Financial incentives Financial incentives Medicare doesn’t have stop codes

 Goal: Classify VA and Medicare encou

Goal: Classify VA and Medicare encou

as primary care or “other” in consistent 
Context of Reconciling Patient 

in Two Systems

Incentives & organizational structures differ in tw

VA providers

 Closed s

ystem

Medicare prov

 Fee-fo

r-service

Incentives Incentives

& organizational organizational structures structures differ in tw

y

 Employed by VA Focus on treatment

 Individual practice Focus on billing pa

 ICD-9 coding higher priority 

than CPT coding

 Ph

ysicians code CPTs

 CPT coding is prio Coders are instrum

y

 UB

-92 bill used to 

 Clinic stops used to define 

outpatient care types

 UB 92 bill used to 

care

 Primary care not e
Philosophies of Matching

 Try to make VA look like Medicare

 Use CPTs and match as if VA data are bil

 Try to make Medicare look like VA

 Classif

y Medicare work into “Clinic Stops”

 Create a hybrid and transform both

 Pick and choose from data advantages an

disadvantages in each sector
Hybrid Approach

 Classify VA and Medicare outpatient encoun

“Visit Type Visit Type

” using variables common to both 

using variables common to both 

 Primary Care, Mental Health, Diagnostic, Specialt

 Combination of provider specialty and proce

(CPT-4) codes

 Goal: Identify primary care with face validity 

consi t s

tency

Prov CPT Spec PC
Provider Specialty Types

 Primary care: Primary care:

 Physicians: family practice; internal medic

s

p yp orts medicine/famil

y

practice

 Nurse practitioners: family practice; prima

women’s health

 Specialty care Mental health  Diagnostic care
Classification of CPT Codes

General Category CPT code rangeAnesthesia

00001 to 09999 99100 to 99150 *

Evaluation / Management (E&M) 99201 to 99499Medicine 90281 to 99602 *Pathology/Laboratory 80000 to 89999Psychiatry 90800 to 90900 *Radiology 70000 to 79999Surgery 10000 to 69999*S f ome codes classified into other categories
Classification Algorithm

S

pecialt

y care E&M codes or medicine CPT

S

p y ecialt

y Car

VA n=264,7Medicare n=439,7Pi C

p y

Primary care provider + primary care E&M code

P

rimary 

Care

VA n=123,5Medicare n=103,0

Psychiatric CPT codes, orMental health provider + primary care E&M code

Mental Health VA n=29,325 Medicare n=20,07Specialty CarVA n=29,99Medicare n=58,35

Specialty care provider, orSurgical or anesthesiology CPT code
Positive and Negative Predictive Va

P S i l & CPT d S Prov

Spec

i

a

lty 

& CPT compare

d to 

S
Is Lower VA Use b

y CBOC P

offset by Higher Medicare UsLiu, et al. Health Services Research in press
CBOCs and Prior Work

 Compared CBOC & VAMC patients in 20 CBOC patients had...

 Primary care: More visits similar costs Primary care: More visits, similar costs Specialty, mental health, ancillary OP: Lower 

use, fewer visits & lower costs among users

 Inpatient: Lower odds of use, lower costs am Lower total outpatient and total costs

Chapko et al., Borowsky et al., Hedeen et al., Maciejewski et al., and FoMedical Care 2002; Maciejewski et al., BMC HSR 2007; Liu MCRR 200
Unanswered Question in Prior 

 Only examined VA experience

 Are lower outpatient use and lower total (O

expenditures offset by higher non-VA use?

 Story may change if Medicare use doe

parallel VA use

 Veterans’ comorbidity burden under-estima

Medicare diagnoses excluded
Variable Definitions

 VAMC/CBOC primary care user defined bas

majority of primary care visits in each year majority of primary care visits in each year

 Primary care user status in each year Primary care user status in each year

 Dual users VA-only Medicare only Non-user

 Outcome: VA, Medicare and total visits in 2
Data Analysis

 Generalized estimating equation (GEE

 Negative binomial distribution Log link Exchangeable correlation

 Adjusted for sampling weights from the 

orig y inal CBOC study

 Adjusted for covariates Adjusted for covariates
Patient Characteristics

Baseline Characteristic ( ) 2000 CBOC ( ) n=8301) VAAge (mean/SD)** 70.5 (9.1) 69

Age < 45 (%)** 1.7 2.5Age 45-54 ( ) % ** 5.8 8.1Age 55-64 (%)** 7.7 8.9Age 65+ (%)** 84.8 80

Female (%) 2.5 2.8

Race - White (%)** 91.4 84Married (%)** 69.8 62Percent Service Connected Disability (mean/SD)** 14.2 (27.1) 17Medicaid Enrollee (%)** 4.6 5.8Free care - disability (%)** 33.4 37

- low income (%)** 43.9 46

Distance to VA (mi) (mean/SD) 16.5 (18.2) 16DCG FY00 (from VA and Medicare Dx) (mean/SD) 0.92 (0.67) 0.9Per Ca

p p( ) ita Income in Zi

p Code (mean/SD)** 19763 ( ) 6117 20

% High School Graduates in Zip Code** 80.0 (10.1) 79Population per SQ. Mile in FIPS (mean/SD)** 628 (3320) 14
Primary Care Use Patterns

 VA onl

y was most 9.8 12 14 14.4 11.

100%

y

common for both groups, especially for VAMC patients

25.2 24.3 24.5 23.6 29.

14 14.4 

80%

patients

 CBOC patients more likely 

to be Medicare only 

6 7.3

9.4 8.7 9.7

40%60%

 Significant use of Medicare 

for both groups, including dual use or Medicare only

59.1 56.4 52.1 53.4 49.

20%

dual use or Medicare only

0%

2001 2002 2003 2004 200

Hospital 

VA only Medicare only Dual u
Primary Care Visits

 Compared to VAMC patients, 

5.00

CBOC patients had

 fewer VA visits and more 

Medicare visits 1.07 1.17

1.37 1.29

3 00 1 4.00

 fewer total visits

 VA visits decreased over time Adjusted analysis: CBOC

1.

2.003.00

Adjusted analysis: CBOC

patients had 

 0.37 fewer VA visits per year 0 14 more Medicare visits

2.89 2.71 2.48 2.50 2.

1.00



0.14 more Medicare visits

 0.22 fewer total visits

0.00

2001 2002 2003 2004 20

Hospital 

VA Medicar
Specialty Care Use Patterns

 Dual use was most 4.6 4.1 3.8 4.4 4

100%

common for both groups

 CBOC patients likely to 

be Medicare only users

47.7 47.1 48.9 46.1 50

80%

be Medicare only users

 Medicare only users 

increased over time, 

hil VA l

12.2 14.6 15.6 17.9

21 

40%60%

while VA only users 

decreased over time

35.6 34.2 31.8 31.6

23

21

20%

0%

2001 2002 2003 2004 20

Hospital 

VA only Medicare only Dua
Specialty Care Visits

 VAMC patients had more 

VA visits 12 00

14.00

 CBOC patients had more 

Medicare visitsL VA f CBOC

5.33 6.23 6.68 6.83 

10.0012.00



Lower VA use o

f CBOC

patients offset by more Medicare use

5 33

7.30 

6.008.00



Adjusted analysis: 

CBOC patients had 

 1.06 fewer VA visits per year

5.78 5.58 5.56 5.32

4.04 

2.004.00

 1.06 fewer VA visits per year 1.43 more Medicare visits No difference in total visits

0.00

2001 2002 2003 2004 2001 

Hospital 

VA Medicare 
Mental Health Use Patterns

 No use was most common 

for both groups followed by

100%

for both groups, followed by

VA only

 VAMC patients more likely 

t b VA l

72 73.1 70.9 73.4

60%80%

to 

be VA only users

 Small proportion of no use 

or Medicare only for both 

8

40%

60%

groups

 Similar patterns across 

years 24.3 22.9 24.9 23.3 1

20%

years 1

0%

2001 2002 2003 2004 20

Hospital 

VA only Medicare only Dua
Mental Health Visits

 CBOCs patients had fewer 

VA and total mental health 

3.00

visits than VAMCs patients

 No difference in Medicare 

use

0.27

0 33

2.00

 Similar patterns across 

years

0.24

0.33 0.31

0 24

1.00

 Adjusted analysis: CBOC 

patients had 

 0.16 fewer VA visits per year

1.72

1.45 1.56 1.54

0.82 

0.24

 0.14 fewer total visits No difference in Medicare 

visits

0.00

2001 2002 2003 2004 200

Hospital 

VA Medicare 
Summary

 Significant use of Medicare primary and spec

care for both VAMC and CBOC patients care for both VAMC and CBOC patients

 CBOC patients had fewer total primary care visits CBOC p p

atients had similar number of total special

 CBOC patients had fewer total mental health visits

 Lower VA use by CBOC patients was offset b

Med ca e se ces icare services

 Not fully offset for primary care Fully py offset for specialty care
How Does VA Reliance Chan

Over Time?Work in Progress
Research Question

 What factors influence veterans’ use of primary c

and M di i 2001 d

M

edicare in 2001

-2004?

 Operationalize dual use by examining Medica

veterans’ reliance on VA for primary care serv

reliance on VA for primary care serv

 Reliance = VA Primary Care Visits .

VA + Medicare Primary Care Visits
On Pop , ulation Basis, Mean VA 

Reliance is High but Drops Ove

Primary care visit copay introduced

December 6, 2001
Distribution & Mean of VA 

Reliance Are Not Consistent

Mean VA Reliance for S i lt C = 48% Spec

i

alty 

Care 

= 48%
Data Analysis

 Beta-binomial regression in Stata VA reliance has unique distribution

 Mass of points at 1 (VA only users) Mass of points at 0 (Medicare only users)

Guimaraes, P. Stata Journal, 5(3), pp. 385-394, 2005
Summary

 Conventional wisdom (vets strategically use 

may not hold may not hold

 Most Medicare-eligible veterans who used VA prim

are dedicated to VA

 M di e care-eli ibl h i M di ligible veterans who get care via Medic

switch quickly

 Small p p pp p roportion appear to be “persistent” dual use

 Mean of VA reliance is misleading These results need updating to post These results need updating to post-Pa
Limitations

 Not a random sample of VA primary care us

 Original sample: Primary care users in large CBO

Original sample: Primary care users in large CBO

VAMCs in 2000

 Doesn’t exactly match all Medicare-eligible vetera

 Imperfect classification of outpatient visits ac

and Medicare systems with hybrid algorithm

 Need to refine to improve NPV & PPV of specialty 

mental health care 

 No Medicaid data on non No Medicaid data on non-elderly Medicare elderly Medicare-e

e

veterans

 May not generalize to post May not generalize to post-Part D world Part D world
Overall Conclusions from Stud

 A significant % of Medicare-eligible veterans 

use 

py py rimar

y care in VA also use 

primar

y care 

specialty care in Medicare

 Lower VA use by CBOC patients offset by Medica M t t l h lth i bt i d i VA Mos

t men

t

al health services obt

aine

d in VA

 Disability-eligible veterans use more service

age

-eligible veterans which is likely to mirro

eligible veterans, which is likely to mirro

OEF/OIF veterans using both systems

 Most Medicare-eli

g y ible veterans are “VA onl

y

“Medicare only”, but population-average VA (63-73%) suggests a large % of dual users

 VA li i d i ti PC VA reliance is 

decreasing over time among PC us
Questions?