About The Chronic Condition Data Warehouse

The Chronic Condition Data Warehouse (CCW) is a research database designed to:

• Identify areas for improving the quality of care provided to chronically ill Medicare beneficiaries
• Identify ways to reduce program spending
• Make current Medicare data more readily available to researchers studying chronic illness in the Medicare population

The Centers for Medicare & Medicaid Services (CMS) launched the Chronic Condition Data Warehouse (CCW), a research database, in response to the Medicare Modernization Act of 2003 (MMA). Section 723 of the MMA outlined a plan to improve the quality of care and reduce the cost of care for chronically ill Medicare beneficiaries.

An essential component of this plan was to establish a data warehouse that contains Medicare claims data and assessments, linked by beneficiary, across the continuum of care. CMS contracted with the Iowa Foundation for Medical Care to establish the CCW.

The CCW contains fee-for-service institutional and non-institutional claims, enrollment/eligibility, and assessment data from January 1, 1999, forward for a random 5% sample of Medicare beneficiaries (100% for 2005 forward). The CCW data are linked by a unique, unidentifiable beneficiary key, which allows researchers to analyze information across the continuum of care. (Explore this and more in our Key Features section.)

Prior to the availability of the CCW, researchers analyzing various Medicare data files were required to perform extensive analysis related to beneficiary matching, deduplication, and merging of the files in preparation for their analysis. With the CCW data, this linkage is already accomplished and delivered as part of the data files sent to researchers.

In order to fulfill data requests in a timely, efficient manner, the CCW offers 21 predefined chronic condition cohorts. CCW data files may be requested for any of the existing cohorts, or users may request a customized cohort(s) specific to research focus areas. The availability of predefined chronic condition cohorts makes data extraction from the CCW very efficient, allowing for data requests that utilize these predefined chronic conditions to be fulfilled in a timely and cost efficient manner.

Acute Myocardial Infarction	Chronic Obstructive Pulmonary Disease
Alzheimer's Disease	Depression
Alzheimer's Disease, Related Disorders, or Senile Dementia	Diabetes
Atrial Fibrillation	Glaucoma
Cancer, Colorectal	Heart Failure
Cancer, Endometrial	Hip / Pelvic Fracture
Cancer, Female Breast	Ischemic Heart Disease
Cancer, Lung	Osteoporosis
Cancer, Prostate	Rheumatoid arthritis / Osteoarthritis
Cataract	Stroke / Transient Ischemic Attack
Chronic Kidney Disease