Description
The VHA Medical SAS Datasets are national administrative data for VHA-provided
health care utilized primarily by veterans, but also by some non-veterans
(e.g., employees, research participants). The datasets are provided in
SAS® format by fiscal year (Oct. 1 - Sept. 30). These data are extracted
from the National Patient Care Database (NPCD),
maintained by the VHA Office of Information at the Austin Information Technology Center (AITC formerly: CFD; formerly: AAC), the central repository for VA data. Together, the Medical SAS Datasets
often are called "NPCD" though that is not strictly correct because
NPCD is a relational database (a data warehouse).
In all of the Medical SAS Datasets, each patient has a unique identifier
referred to as the Scrambled SSN, which is a formula-based encryption of
the individual's Social Security Number. The identifier is consistent for
a given patient across datasets and fiscal years. Access to files that
translate Scrambled to real SSNs is possible with special authorization
(see information on Access to the Medical SAS Datasets).
Datasets Available
Medical SAS Inpatient Datasets
The Medical SAS Inpatient Datasets are sometimes referred to
as the Patient Treatment File (PTF). This could lead to confusion because there
is a Patient Treatment File that is a national collection of local
inpatient data housed at the Austin Information Technology Center (AITC formerly: CFD; formerly: AAC)
used for statistical reporting by
medical administrators. That is not, however, a SAS dataset; rather,
the Patient Treatment File is the source data for the Medical SAS Inpatient
Datasets.
The Medical SAS Inpatient Datasets cover four main categories of care:
- Acute
- Extended
- Observation
- Non-VA
Within each of these categories there are four datasets:
Datasets for Inpatient Care
|
Dataset
|
Record Definition
|
Example Variables
|
|
Main
|
A patient's inpatient stay (episode of care)
|
Patient demographics, primary/secondary diagnoses, length-of-stay
|
|
Bed Section
|
A patient's inpatient stay under a specified physician treating
specialty service
|
Primary/secondary diagnoses and length-of-stay for the treating
specialty portion of the stay
|
|
Procedure
|
One day's procedure during an inpatient stay
|
ICD-9-CM coded procedures
|
|
Surgery
|
One day's surgeries during an inpatient stay
|
ICD-9-CM coded surgeries (not available for Observation Care)
|
Medical SAS Outpatient Datasets
There currently are two Medical SAS Datasets for outpatient care, Visit
and Event. Two additional outpatient care datasets, Procedure and Diagnosis,
were discontinued after FY2001 but are available for historical analysis.
Together, the Medical SAS Datasets for outpatient care are sometimes called
the "the OPC" or "the Outpatient Care File".
Datasets for Outpatient Care
|
Dataset
|
Record Definition
|
Example Variables
|
|
Visit
|
One day's occasions of service for a patient
|
Date, patient demographics, codes for each clinic stop (up to
15) for the day
|
|
Event
|
One ambulatory encounter by a patient (coded as DSS Identifier/Clinic
Stop)
|
Date, appointment type (e.g., regular, employee, research), procedure
done (up to 15), surgeries performed (up to 15), provider type
|
Medical SAS Inpatient Encounter Dataset
Initiated in 2005, patients in this file have VHA outpatient event procedures and diagnostics, and providers while having inpatient status. Inpatient is defined as patients in acute care, extended care, observation care, or non-VA care status.
Dataset for Inpatient Encounters
|
Dataset
|
Record Definition
|
Example Variables
|
|
Inpatient Encounters (IE)
|
Outpatient events during an inpatient stay
|
CPT codes, ICD-9 procedure codes, and provider ids
|
|
