Cost of illness of chronic angina.

BACKGROUND: Angina pectoris is one of the principal manifestations of coronary artery disease (CAD). Chronic angina is a debilitating condition that affects millions of people in the United States.
OBJECTIVE: The objective of the study is to estimate, from a societal perspective, the direct costs of chronic angina in the year 2000.
METHODS: Data on medical utilization related to chronic angina were extracted from National Center for Health Statistics public-use databases and from IMS databases on medications (nitrates, beta-blockers, and calcium channel blockers). National average Medicare reimbursement rates were used to estimate costs. We identified medical utilization related to chronic angina based on International Classification of Diseases, Ninth Revision (ICD-9) codes. When ICD-9 codes that do not explicitly identify angina are used in medical databases, people with chronic angina may be coded as having CAD only. To address this, we developed upper- and lower-boundary estimates of the costs of chronic angina. The lower-boundary estimate is based on diagnoses that narrowly define the presence of chronic angina, and is termed "narrowly defined chronic angina." The upper-boundary estimate is based on diagnoses of CAD.
RESULTS: The lower boundary on the cost of chronic angina is the estimated direct medical cost of narrowly defined chronic angina ($1.9 billion when it is the first-listed diagnosis and $8.9 billion when it is listed in any position). The upper boundary on the cost of chronic angina is the estimated total direct medical cost of CAD, which is $33 billion when it is the first-listed diagnosis and $75 billion when it is listed in any position.
CONCLUSION: These analyses capture the range of direct costs that might be attributed to the care of chronic angina in the United States for the year 2000. Some components of care were not available, and estimated costs will be significantly higher if private payer reimbursement rates are used.