# Presentation: 104349

## Use of Primary Care in VA and Medicare among VAMC and CBOC Patients

- Chuan-Fen Liu, MPH PhD
- HERC Cyber Seminar
- September 17, 2008

## Dual Use, Continuity of Care, and Duplication of Services in VA and Medicare

- Funded by VA HSR&D, IIR 04-292
- Project team
- Seattle: Chuan-Fen Liu, PhD; Michael Chapko, PhD; Chris Bryson, MD; Nancy Sharp, PhD; Mark Perkins, PharmD
- Durham: Matt Maciejewski, PhD
- Little Rock: John Fortney, PhD
- Boston: Jim Burgess, PhD
- University of Chicago: Will Manning, PhD

## Outline

- Background
- Classification of primary care across VA and Medicare records
- Goal: consistent classification of primary care
- Preliminary results of comparisons of VAMC and CBOC patients in 2001 - 2004

## Background

- VA organizational reform
- Veterans Eligibility Reform Act of 1996
- Moving from inpatient to primary care-oriented outpatient care
- Establishment of Community Based Outpatient Clinics (CBOCs) in 1995
- Improve access to primary care
- Contain cost of VA care

## CBOCs

- Congressional approval process
- Services: primary care and mental health care (2001)
- Two types: VA-staffed and contract
- VA-staffed: VA providers or mixed; VA space
- Contract: non-VA providers; non-VA space; capitated or fee basis
- 718 CBOCs as of March 2008
- 162 contract and 556 VA-staffed CBOCs

## Previous CBOC Evaluations 

- CBOC and VAMC comparisons
- Comparable satisfaction and quality of care
- CBOC patients –
- More likely to be older, healthier, and new VA users
- More primary care visits, but similar primary care costs
- Lower odds of using specialty, mental health, ancillary and hospital services
- Among users, fewer visits and lower costs in specialty, mental health, ancillary, and inpatient care
*Lower total outpatient and total costs*
- 	Chapko et al., Borowsky et al., Hedeen et al., Maciejewski et al., and Fortney et al., *Medical Care* 2002; Maciejewski et al., *BMC HSR* 2007

## Issues with Previous Evaluations

- Only examined VA experience
- Were lower use and expenditure offset by higher non-VA use and expenditure?

## Objective

- Assess whether Medicare eligible veterans who get primary care at CBOCs have different primary care use than those who get primary care at VAMCs
- Primary care use = VA or Medicare

## Study Design

- Retrospective cohort study
- Study period: FY2000 – 2004
- Patient identification in FY2000
- Follow-up period: FY 2001 – FY 2004
- Study sample:
- Medicare eligible VA primary care patients from the previous CBOC cost evaluation study
- Random sample of primary care patients from 108 CBOCs and 72 VAMCs
- Data sources:
- Medicare claims
- VA administrative datasets

## Cohort Selection

|  | Exclusions | Count |
| --- | --- | --- |
| Initial Sample |  | 66,366 |
|   Death prior or during FY 2000-2001 | 2,337 |  |
|   Not Medicare eligible or Part A or B only | 36,050 |  |
|   Enrolled in an HMO | 5,825 |  |
|   Developed ESRD | 390 |  |
|   No VA primary care in FY00 | 8,290 |  |
|   Distance to VA facility unknown | 250 |  |
| Working cohort |  | 14,753 |
|    Age eligible |  | 12,295 |
|    Disabled |  | 2,458 |

## Matching VA and Medicare Outpatient Services

- Central challenge of identifying _primary care_ in VA and Medicare
- Data generating process
- Clinical data vs. billing records
- Financial incentives
- Medicare doesn’t have stop codes
- Goal: Classify VA and Medicare encounters as primary care or “other” in *consistent* way

## Context of Reconciling Patient Data in Two Systems

- _VA providers_
- Closed system
- Employed by VA
- Focus on treatment
- ICD-9 coding higher priority than CPT coding
- Providers code CPTs
- Clinic stops used to define outpatient care types

- _Medicare providers_
- Fee-for-service
- Individual practices
- Focus on billing payors
- CPT coding is priority
- Coders are instrumental
- UB-92 bill used to organize care
- Primary care not explicit

*Incentives & organizational structures differ in two systems*

## Philosophies of Matching

- Try to make VA look like Medicare
- Use CPTs and match as though VA data are billing data (severely undercounts VA work)
- Try to make Medicare look like VA
- Classify Medicare claims into “Clinic Stops”
- Create a hybrid and transform both
- Pick and choose from data advantages and disadvantages in each sector

## Classification of VA and Medicare Outpatient Databy Care Type 

## General Approach

- Classify VA and Medicare outpatient encounters into “Care Type” using variables common to both systems
- Primary Care
- Specialty
- Mental Health
- Diagnostic
- Combination of provider specialty and procedure
-     (CPT-4) codes
**Goal:  Identify primary care with face validity and consistency**

## Provider Specialty Types

- Primary care:
- Physicians: family practice; internal medicine
- Nurse practitioners: family practice; primary care; women’s health
- Specialty care
- Mental health
- Diagnostic care

## Classification of CPT Codes

| General Category | CPT code range |  |
| --- | --- | --- |
| Anesthesia | 00001 to 09999  |  |
|  | 99100 to 99150 * |  |
| Evaluation / Management (E&M) | 99201 to 99499 |  |
| Medicine | 90281 to 99602 * |  |
| Pathology/Laboratory | 80000 to 89999 |  |
| Psychiatry | 90800 to 90900 * |  |
| Radiology | 70000 to 79999 |  |
| Surgery | 10000 to 69999 |  |
| * Some codes classified into other categories |  |  |

## E&M Codes

- Specialty care E&M codes
- Performed by specialists
- Performed in acute care and hospital settings
- Primary Care E&M codes

## Data Management

- Outpatient encounter definition
- Same patient, same date and same provider specialty
- Omitted records for selected provider specialties
- Podiatrists, dentists, etc.
- Medicare claims
- Need to convert Medicare claims into encounters
- VA records: face-to-face encounters
- Exclude phone stops or stops without provider contacts
- Provider specialty
- Medicare – one per record
- VA – up to 3 per record
- Use the first physician or nurse practitioner specialty code
- Eliminate nurse, PA, intern, resident, nutritionist, or pharmacist as a provider

## General Principles

- If specialty provider, encounter cannot be primary care
- If specialty E/M procedure or “Medicine procedure” encounter cannot be primary care

## Hierarchical Algorithm

## Primary Care Type Classification between      		    Medicare and VA

| Classification Algorithm | Medicare
(N = 739 K) |  | VA
(N = 724 K) |  |
| --- | --- | --- | --- | --- |
|  | Number of encounters | % | Number of encounters | % |
| VA-specific stop code | N/A | N/A | 199,438 | 27.5 |
| Primary care E/M codes | 249,280 | 33.7 | 338,947 | 46.8 |
| Primary care provider type | 197,274 | 20.8 | 326,324 | 45.1 |
| Primary care type (E/M and provider type) | 103,032 | 13.9 | 123,504 | 17.1 |

## Comparisons of Primary Care Use among VAMC and CBOC Patients

## Variable Definitions

- VAMC/CBOC primary care user defined based on the majority of primary care visits in each year
- Primary care user status in each year:
- Dual users: at least one primary care visit in VA and one in Medicare
- VA-only
- Medicare only
- Non-user
- Number of VA, Medicare and total primary care visits in 2001 – 2004

## Data Analysis

- Generalized estimating equation (GEE) model with negative binomial distribution and log link with exchangeble correlation
- Adjusted for sampling weights from the original CBOC study

## Preliminary Results 

## Patient Characteristics

| Baseline Characteristic (2000) | CBOC (n=8301) | VAMC (n=6452) |
| --- | --- | --- |
| Age (mean/SD)*** | 69.9 (9.1) | 68.9 (9.9) |
|      Age < 45 (%) | 2.4 | 2.2 |
|      Age 45-54 (%)*** | 6.7 | 10.5 |
|      Age 55-64 (%) | 8.8 | 9.4 |
|      Age 65+ (%)*** | 82.2 | 77.9 |
| Female (%) | 2.7 | 2.8 |
| Race - White (%)*** | 90.6 | 86.5 |
| Married (%)* | 67.8 | 64.7 |
| Percent Service Connected Disability (mean/SD)*** | 17.2 (27.1) | 20.3 (30.5) |
| Medicaid Enrollee (%) | 5.2 | 5.8 |
| Free care - disability (%) | 38.3 | 40.5 |
|               - low income (%) | 42.7 | 44.3 |
| Distance to the closest VA (mi) (mean/SD)* | 16.9 (18.2) | 18.1 (17.2) |
| DCG FY00 (including VA and Medicare Diagnoses) (mean/SD) | 0.96 (0.67) | 0.99 (0.67) |
| Per Capita Income in Zip Code (mean/SD) | 19570 (6117) | 19463 (8877) |
| % High School Graduates in Zip Code | 79.6 (10.1) | 79.5 (11.3) |
| Population per SQ. Mile in County (mean/SD) | 861 (3320) | 1018 (5517) |

- *p<0.05; ***p<0.001

## VA and Medicare Primary Care Use

|  | 2001 | 2002 | 2003 | 2004 |
| --- | --- | --- | --- | --- |
| CBOC | % | % | % | % |
| Primary care in VA only  | 47.7 | 41.9 | 37.2 | 36.5 |
| Primary care in Medicare only | 10.9 | 14.5 | 18.6 | 18.2 |
| Dual use | 29.1 | 28.9 | 27.2 | 28.7 |
| No primary care use | 12.3 | 14.3 | 17.0 | 16.6 |
| VAMC |  |  |  |  |
| Primary care in VA only  | 59.3 | 56.2 | 51.9 | 52.9 |
| Primary care in Medicare only | 5.8 | 7.9 | 10.3 | 9.5 |
| Dual use | 25.4 | 24.0 | 24.3 | 24.2 |
| No primary care use | 9.6 | 12.0 | 13.6 | 13.4 |

## Unadjusted Primary Care Visits

- ***p<0.001

| YEAR | VA |  | Medicare |  | Total |  |
| --- | --- | --- | --- | --- | --- | --- |
|  | CBOC | VAMC | CBOC | VAMC | CBOC | VAMC |
| 2001 | 2.38 (2.36)*** | 3.21 (3.59) | 1.47 (2.76)*** | 1.08 (2.60) | 3.84 (3.44)*** | 4.29 (4.25) |
| 2002 | 2.06 (2.21)*** | 3.05 (3.04) | 1.62
(2.85)*** | 1.20
(2.58) | 3.68 (3.41)*** | 4.26 (3.74) |
| 2003 | 1.80 (2.10)*** | 2.96 (2.87) | 1.84 (3.12)*** | 1.45 (2.79) | 3.63 
(3.58)*** | 4.41 (3.80) |
| 2004 | 1.91 (2.28)*** | 3.11 (3.00) | 1.98 (3.32)*** | 1.30 (2.87) | 
3.89 (3.80)*** | 3.42 (3.93) |

## Multivariate Results of Primary Care Use

- Adjusted for patient characteristics
- ***p<0.001

|  | Coefficient  |  |  |
| --- | --- | --- | --- |
|  | VA | Medicare | Total |
| CBOC (reference group = VAMC) | -0.24*** | 0.13*** | -0.09*** |

## Summary

- CBOC patients were more likely than VAMC patients to use primary care services in Medicare
- Similar time trends between CBOC and VAMC patients
- The proportion of VA only primary care users decreased
- Dual use stayed stable
- Medicare only increased over time
- Compared to VAMC patients, CBOC patients had
- Fewer VA primary care visits
- More Medicare primary care visits
- Fewer total primary care visits, including both VA and Medicare

## Limitations

- Not a random sample of VA primary care users: original sample is primary care users in large CBOCs & VAMCs in 2000
- Imperfect classification of primary care visits across VA and Medicare systems with hybrid algorithm
- No Medicaid data on non-elderly Medicare-eligible vets

## Conclusions

- Among Medicare eligible veterans:
- CBOC patients use less VA primary care than VAMC patients
- CBOC patients use more Medicare primary care
- Difference between CBOC and VAMC patients in total primary care use decreases when Medicare use is included
- Continuity of care, chronic disease management and performance assessment may be impacted by dual use of VA and Medicare primary care services, particularly for CBOC users.

## Highlights of the Project

- Determinants of primary care reliance in VA
- Comparisons of continuity of primary care among VA-only primary care users, Medicare only primary care users and dual users
- Duplication of services among dual users