National Trends in Visits to Physician Offices and Outpatient Clinics for Angina 1995 to 2010

Study Questions:

What are secular changes in angina visits in the outpatient setting from 1995 to 2010?


This was an analysis of combined office-based physician visit data from the National Ambulatory Medical Care Survey (NAMCS) and the National Hospital Ambulatory Medical Care Survey (NHAMCS) for the years 1995 to 2010. The authors calculated both crude and standardized visit rates for angina.


From 1995 to 1998, there were on average 3.6 million office/clinic visits each year, compared to 2.3 million visits each year from 2007 to 2010. The greatest decline in angina visit rates per 100,000 occurred from 1995 through 1998 to 2003 through 2007 (p < 0.05). Visits varied according to geographical region. While one-quarter of visits occurred in the Southern US census region from 1995 to 1998, one-half of the visits occurred in this region from 2007 to 2010. During some study periods, stress testing and referrals (as to another provider, hospital, or facility) doubled.


The authors concluded that from 1995 to 2010, angina visit rates to physician offices and hospital outpatient clinics in the United States have declined.


The authors report that physician office and hospital outpatient clinic visits for angina have declined, an observation that parallels secular trends in decreasing hospitalizations and emergency department visits for angina. There are still unanswered questions about mechanisms for this decline. While a true decline in the prevalence of angina (owing to risk factor modification and treatment) is possible, changes in coding guidelines (which discourage the coding of angina as a primary diagnosis when a more specific cause is known) cannot be overlooked. The geographical variations observed are also puzzling; the authors postulate that such regional differences may reflect regional lags in the ‘aggressiveness of diagnosing coronary artery disease or a lag in the adoption of ICD-9 coding changes.’

Clinical Topics: Atherosclerotic Disease (CAD/PAD)

Keywords: Prevalence, Coronary Artery Disease, Physicians' Offices, International Classification of Diseases, Clinical Coding, Risk Factors, Health Care Surveys, Hospitalization, Office Visits, United States, Outpatient Clinics, Hospital

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