# Presentation: 486867

##   VIReC CyberSeminar Series 2006 VA Databases and Methods

**Assessing Healthcare Use Using **
**VA Inpatient Data**
- Presented by
- Kevin Stroupe, PhD
- Research Health Scientist, MCHSPR COE
- Research Assistant Professor, Feinberg School of Medicine,
- Northwestern University

## Session Objectives

- How has healthcare utilization been measured in VA studies?
- Overview of Medical SAS inpatient databases
- Finding information in the Inpatient Medical SAS databases
- Example of VA study that measured VA healthcare utilization
- Where to go for more help

## Session Objectives

- How has healthcare utilization been measured in VA studies?
- Overview of Medical SAS inpatient databases
- Finding information in the Inpatient Medical SAS databases
- Example of VA study that measured VA healthcare utilization
- Where to go for more help

## Assessing Healthcare Use: Data Sources

- How has healthcare utilization been measured in VA studies?
- Patient surveys (primary data collection)
- Payne et al, J Ambul Care Manage, 2005
- Washington et al, Am J Public Health, 2005
- VA Office of Quality and Performance (OQP)*
- External Peer Review Program (EPRP)
- medical record abstraction on several performance measures
- will only include information on services that are tracked by VHA performance measures
- data available from OQP through data use agreement
- See Weaver et al, J Am Med Inform Assoc, 2004
- * See: http://vaww.oqp.med.va.gov/oqp_services/performance_measurement/tech_man.asp

## Assessing Healthcare Use: Data Sources

- How has healthcare utilization been measured in VA studies? (cont’d)
- 2001 National Survey of Veterans*
- Conducted by VA Office of Policy, Planning, and Preparedness
- Veteran survey, including information on health care use
- Does not have identifiers that can be linked to other VA data
- See Final Report and Methodology**
- VistA***
- Local patient healthcare utilization information
- Permission to access obtained locally
- Data element may have a different meanings between different sites
- See Fuller et al, Psychiatr Serv, 2002
- * See http://www.virec.research.va.gov/DataSourcesName/NationalSurveyVeterans/2001NationalSurveyofVeterans.htm
- ** See http://www1.va.gov/vetdata/page.cfm?pg=5
- *** See: http://www.virec.research.va.gov/DataSourcesName/VISTA/VistA.htm

## Assessing Healthcare Use: Data Sources

- How has healthcare utilization been measured in VA studies? (cont’d)
- Medical SAS Inpatient and Outpatient Datasets*
- Most important database for VA healthcare utilization information
- National VHA health care delivery data
- SAS datasets housed on mainframe computer at Austin Automation Center (AAC)
- Divided into inpatient and outpatient datasets
- Datasets available on a quarterly basis
- In general, researchers are advised to use the annual, closed-out datasets
- Common element: patient identifier (scrambled SSN)
- Focus of this session
- * See: http://www.virec.research.va.gov/DataSourcesName/Medical-SAS-Datasets/SAS.htm

## Session Objectives

- How has healthcare utilization been measured in VA studies?
- Overview of Medical SAS inpatient databases
- Finding information in the Inpatient Medical SAS databases
- Example of VA study that measured VA healthcare utilization
- Where to go for more help

## Strengths of Medical SAS Datasets

- Centralized data source
- Large groups of patients
- Given good coding, reflective of general clinical status
- Unique identifier (SCRSSN: Scrambled Social Security Number) allows linking records across files/years
- Quality assessments are conducted on datasets

## Limitations of Medical SAS Datasets

- Not all care dimensions
- Nursing home utilization is not available at a national level
- VA databases contain limited information on the use of non-VA services
- Incentives for coding
- Some conditions may be under-reported in administrative data compared with medical records (coding errors)

## Inpatient Data Flow

## Inpatient Datasets

- Inpatient datasets cover four main categories of inpatient care:
**Acute**: Inpatient stays for acute care (generally referred to as “the Inpatient Data”, “the inpatient utilization data”)
**Extended**: Inpatient stays paid for by the VA that occur in domiciliaries, VA nursing homes, or community nursing homes
**Observation**: Hospital stays (generally less than 24 hours) for monitoring, evaluation, or assessment prior to inpatient admission or assignment to care in another setting
**Non-VA**: Data on care funded by the VA and provided in non-VA hospitals
- Within each category of care, cover four datasets:
**Main File:** A patient's inpatient stay (episode of care)
**Bed Section File:** A patient's inpatient stay under a specified physician treating specialty service
**Procedure File:** One day's procedure during an inpatient stay
**Surgery File:** One day's surgeries during an inpatient stay (not available for Observation Care)

## Inpatient Datasets

- Datasets in AAC are named: **MDPPRD.MDP.SAS.(XXyy) **where XX = the two letter code below and yy = two digit FY
**Inpatient:**
- PM – Acute Care Main File
- PB – Acute Care Bed Section File
- PP – Acute Care Procedure File
- PS – Acute Care Surgery File
**Long Term/Extended Care:**
- XM – Extended Care Main File
- XB – Extended Care Bed Section File
- XP – Extended Care Procedure File
- XS – Extended Care Surgery File
**Observation Care**:
- PMO – Observation Care Main File
- PBO – Observation Care Bed Section File
- PPO – Observation Care Procedure File
- No surgery file
**Contract Care**:
- NM – Non – VA Care Main File
- NB – Non – VA Care Bed Section File
- NP – Non – VA Care Procedure File
- NS – Non – VA Care Surgery File

## Session Objectives

- How has healthcare utilization been measured in VA studies?
- Overview of Medical SAS inpatient databases
- Finding information in the Inpatient Medical SAS databases
- Example of VA study that measured VA healthcare utilization
- Where to go for more help

## Assessing Inpatient Healthcare Use: Finding info in Inpatient Medical SAS Datasets

**Question:**
**	****Where do I find information about ****	****admissions?**
**Answer:**
- All inpatient datasets include data on admission, discharge date and time, and discharge type (e.g., Regular, Death-Autopsy, Non-bed Care)
- VA Inpatient Main includes information on care characteristics, i.e., DRG and discharge disposition
- VA Inpatient Bed Section includes information on bed section DRG

## Assessing Inpatient Healthcare Use:Finding info in Inpatient Medical SAS Datasets

**Question:**
**	****Where can I find information on a patient’s diagnosis ****	****upon admission?**
**Answer:**
- All inpatient datasets include principal diagnosis (DXPRIME) for admission (condition determined to be chiefly responsible for the admission)
- Inpatient Main datasets includes diagnostic codes in ICD-9
- Primary Diagnosis: DXPRIME = diagnosis chiefly responsible for the admission
- DXLSF = Diagnosis responsible for the _major_ _part_ _of_ _the_ _full_ _stay_
- Secondary Diagnoses: DXF2 – DXF10 = ICD-9 codes that represent patient problems beyond the principal reason for the encounter.
- Bed Section Datasets include bed section diagnosis (max 5)
- No reliable date of diagnosis in claims or administrative data
- Cohort includes a mix of Incident cases + Prevalent cases

## Assessing Inpatient Healthcare Use: Finding info in Inpatient Medical SAS Datasets

**Question:**
**	****Where do I find information about inpatient ****	****procedures?**
**Answer:**
- Inpatient procedure datasets contain information on:
- Procedure, coded in ICD-9-CM (vs. CPT for outpatient procedures)
- Dialysis type & number of dialysis treatments
- Inpatient surgery datasets also include procedure information, including surgery or procedure day
- Note: Surgery = Procedure performed in main or specialized operating room. “Procedure” in Facility A may = “Surgery” in Facility B. Look at both datasets.

## Assessing Inpatient Healthcare Use: Finding info in Inpatient Medical SAS Datasets

**Question:**
**	****How do I identify the specialty of the ****	****physician providing inpatient care?**
**Answer:**
- Inpatient procedure datasets include information on physician’s specialty (bed section)
- Inpatient bed section datasets include information on physician specialty
- Bed section is *not* the physical location of care. Physical Location Code = PLBED
- Each record in the inpatient bed section dataset = One bed section stay
- Maximum of 25 bed section records per inpatient stay

## Assessing Inpatient Healthcare Use: Finding info in Inpatient Medical SAS Datasets

**Question:**
**	****How do I identify care for a defined period of time?**
**Answer:**
- Records for the inpatient databases are created at discharge for the full stay, even if the admission was in a prior year
- Exception: Claims for Non-VA Care are included in the dataset for the fiscal year they were submitted, not the year for which care was provided
- All inpatient datasets include data on admission and discharge date and time
- In the VA, there is a distinction between acute stays and non-acute stays. See subsequent slides for how to calculate acute length of stay (ALOS)

## Assessing Inpatient Healthcare Use: Finding info in Inpatient Medical SAS Datasets

**Question:**
**	****How do I compute ****acute length of stay**** (LS)?**
**Answer:**
- Inpatient Main dataset includes information on care characteristics, including LOS, which may include extended care stay
- Use bed section data in Inpatient dataset
- Date & time of transfer into & out of bed section (BSINDAY & BSOUTDAY) to compute acute care LOS
- _[HERC inpatient Average Cost Datasets documentation ](http://www.herc.research.med.va.gov/ac%20inpatient%20fy98-02.pdf)_has details (pp. 29 - 32)

## Session Objectives

- How has healthcare utilization been measured in VA studies?
- Overview of Medical SAS inpatient and outpatient databases
- Finding information in the Inpatient Medical SAS databases
- Example of VA study that measured VA healthcare utilization
- Where to go for more help

## Research Example

- Cooperative Studies Program conducted a randomized controlled trial (RCT)
- the Angina With Extremely Serious Operative Mortality Evaluation (AWESOME) trial
- CSP #385, PI: D. Morrison MD, PhD
- This RCT compared Percutaneous Coronary Intervention (PCI) to Coronary Artery By-Pass Grafts (CABG) for
- the urgent revascularization of medically refractory,
- high-risk
- myocardial ischemia patients
- These patients, at high risk for major complications or death from surgery, have largely been excluded from other RCTs

## Research Example

- The AWESOME RCT
- Enrolled patients over a 5-year period
-  	from February 1995 through February 2000
- Compared survival and survival free of angina for men with medically refractory myocardial ischemia at high-risk for adverse outcomes
- 16 VA medical centers

## Research Example

- We conducted a cost-effectiveness analysis of the AWESOME trial
- (NIH R03 HL70287, PI: K. Stroupe, PhD)
- To compare costs of initial revascularization procedures for patients randomized to PCI or CABG
- To compare utilization and costs of follow-up care between patients randomized to PCI or CABG
- To compare the total direct healthcare costs for patients randomized to receive either PCI or CABG
- To examine the cost-effectiveness of PCI vs CABG in these patients – effectiveness measured in years of survival

## Research Example

- Of the clinically eligible patients, 454 consented to be randomized - 232 CABG and 222 PCI patients
- Insufficient information was available to identify 9 patients in the VA databases
- 445 patients have been included in the cost-effectiveness analysis
- 227 CABG patients
- 218 PCI patients

## Research Example:Methods:Data Sources - Utilization

- The original AWESOME trial ran from Feb. 1995 – Feb. 2000. Using data from national VA and Medicare databases we extended follow-up through Sep. 2004
- Data on hospital stays and outpatient visits in VA were from the VA Medical SAS Datasets
- Outpatient files: Outpatient Visit File; Outpatient Event File; Outpatient Procedure File
- Inpatient files: Acute Inpatient Files (PM, PB, PP, PS); Extended Care Files (XM, XB, XP, XS); Observation Files (PMO, PBO, PPO)
- Non-VA care paid for by VA was from the Fee Basis Files
- Non-VA hospitalizations for Medicare-enrolled patients came from Medicare claims data

## Research Example:Methods:Data Sources - Utilization

- To identify PCI or CABG, we used
- Procedure codes (ICD-9) in inpatient procedure files (PP, XP, PPO) and
- Surgery codes (ICD-9) in inpatient surgery files (PS, XS)
- CPT codes in outpatient event file and outpatient procedure files
- ICD-9 surgery codes and CPT codes in Fee basis
- ICD-9 surgery codes in Medicare data

## Research Example:Results: Healthcare Utilization

|  | PCI
N=218 | CABG
N=227 | P-Value |
| --- | --- | --- | --- |
| Initial revascularization, % patients  |  |  |  |
|    PCI | 98 | 5 | <0.0001  |
|    CABG | 1 | 94 | <0.0001  |
| 3 Years of Follow-up  |  |  |  |
| Subsequent revasc.% patients  |  |  |  |
|    PCI | 29 | 11 | <0.0001  |
|    CABG   | 15 | 7 | 0.004  |
| Non-revascularizations, mean  |  |  |  |
| Number of Acute Hospital Stay | 2.1  | 2.2  | 0.40  |
| Number of Non-Acute Stay  | 0.5  | 0.3  | 0.20  |
| Outpatients Visits  | 58.6  | 59.4  | 0.88  |

## Research Example:Results: Healthcare Utilization

|  | PCI
N=218 | CABG
N=227 | P-Value |
| --- | --- | --- | --- |
| 3 to 5 Years of Follow-up  |  |  |  |
| Subsequent revascularizations, % patients  |  |  |  |
|    PCI | 3 | 3 | 0.95 |
|    CABG | 6 | 3 | 0.09 |
| Non-revascularizations, mean  |  |  |  |
| Number of Acute Hospital Stay | 0.7 | 0.8 | 0.61 |
| Number of Non-Acute Stay  | 0.1 | 0.2 | 0.43 |
| Outpatients Visits  | 28 | 30 | 0.59 |

## Research Example

- Cost Effectiveness Analysis concluded that the PCI-assigned patients had lower medical costs and survival was at least as good at 5 years, suggesting that PCI is the “economically dominant strategy” in high-risk patient

## Session Objectives

- How has healthcare utilization been measured in VA studies?
- Overview of Medical SAS inpatient and outpatient databases
- Finding information in the Inpatient Medical SAS databases
- Example of VA study that measured VA healthcare utilization
- Where to go for more help

## VIReC Help

- VIReC Webpage
-     _[http://www.virec.research.va.gov](http://www.virec.research.va.gov/)_
- Information on VA data sources and how to access data
- Documentation on some VA datasets, i.e., Medical SAS datasets:
- _[http://www.virec.research.va.gov/DataSourcesName/Medical-SAS-Datasets/SASdocumentation.htm](http://www.virec.research.va.gov/DataSourcesName/Medical-SAS-Datasets/SASdocumentation.htm)_
- Includes lists of variables and their dataset locations
- Descriptions of each of the variables
- Values for selected variables

## VIReC Help (cont’d)

- HSRData Listserv
- Join at VIReC Web site
- Discussion among > 200 data stewards, managers, and users
- Past messages in archive (on intranet)
- VIReC Help Desk
- VIReC staff will answer your question and/or direct you to available resources on topics
- _[VIReC@va.gov](mailto:VIReC@va.gov)_
- (708) 202-2413

## Bibliography

- Fuller MA, Shermock KM, Secic M, Laich JS, Durkin MB. 2002. Service use and costs among VA patients with schizophrenia taking risperidone or olanzapine. Psychiatr Serv. 53(7):855-60.
- Payne SM, Lee A, Clark JA, Rogers WH, Miller DR, Skinner KM, Ren XS, Kazis LE. 2005. Utilization of medical services by Veterans Health Study (VHS) respondents. J Ambul Care Manage. Apr-Jun;28(2):125-40.
- Washington DL, Villa V, Brown A, Damron-Rodriguez J, Harada N. 2005. Racial/ethnic variations in veterans' ambulatory care use. Am J Public Health. 95(12):2231-7. Epub 2005 Oct 27.
- Weaver FM, Hatzakis M, Evans CT, Smith B, LaVela SL, Wallace C, Legro MW, Goldstein B. 2004. A comparison of multiple data sources to identify vaccinations for veterans with spinal cord injuries and disorders. J Am Med Inform Assoc. 11(5):377-9. Epub 2004 Jun 7.

## Suggested other resources: Medical SAS Datasets:Data Quality Information

- Quality assessments performed by the Office of Inspector General, the Medical Care Cost Recovery program, and special workgroups
- Data Quality, Information Assurance, Office of Information  (http://vaww.vhaco.va.gov/dataquality/  default.htm).
- VHA Coding Council (http://vaww1.va.gov/health/him/VHACC/VA_HIM_P/coding_council1.htm) - VHA Coding Handbook
- HSRData e-mail listserv

## Suggested other resources:

- Murphy PA, Cowper DC, Seppala G, Stroupe KT, Hynes DM. 2002. Veterans Health Administration inpatient and outpatient care data: a rich resource of research data. _Effective Clinical Practice_. 5:e4. Available at _[http://](http://www.acponline.org/journals/ecp)__[www.acponline.org/journals/ecp](http://www.acponline.org/journals/ecp)_.