Who receives statins? Variations in physician prescribing patterns for patients with coronary heart disease

Abstract

Using a nationally representative data set including patients most likely to benefit from statins, we find racial/ethnic and insurance-related disparities in physician prescribing patterns. Whites and patients who have private insurance are more likely to be prescribed a statin than nonwhites and those with public insurance. Because coronary heart disease is the leading cause of death in the USA and currently is estimated to cost over $150 billion annually, observed differences in prescribing patterns along these dimensions should be part of discussions dealing with health care reform.

Notes

¹Direct costs include hospitals, nursing home, physicians/other professionals, drugs and other medical durables and home health care. Indirect costs include lost productivity/morbidity and lost productivity/mortality.

²See also Kaiser Family Foundation, American College of Cardiology Foundation (2002). The existence of racial disparities in general health care is important enough to have resulted in a whole issue of Health Affairs (2005) being devoted to the topic.

³Data were obtained on the National Center for Health Statistics (NCHS) website in the format of self-extracting files, which contained all survey data as well as descriptions of the survey, record format, codes for medications, generic drugs and various other information files.

⁴See http://www.cdc.gov/nchs/about/major/ahcd/namcsdes.htm

⁵Patients with CHD had a code between 410.00 and 414.90 and are broadly defined as having ischaemic heart disease. Patients with dyslipidaemia were those whose primary diagnosis was between 272.00 and 272.90, a group defined as having disorders of lipid metabolism. Patients coded with 250 for the first three digits include a group broadly defined as having type-1 or type-2 diabetes.

⁶Statins include Atorvastatin or Lipitor, Cerivastatin or Baycol, Fluvastatin or Lescol, Lovastatin or Mevacor (Altocor), Pravastatin or Pravachol, Rosuvastatin or Crestor, Simvastatin or Zocor, Simvastatin  +  Ezetimibe or Vytorin. Note that Baycol was withdrawn from the market in 2001. The FDA approved Crestor in August 2003 and Vytorin in July 2004.

⁷The following drugs are included in the other lipid-lowering drugs: Cholestyramine, Questran, Lo-Cholest, Prevalite, Colesevelam,WelChol, Colestipol, Colestid, Fenofibrate, Tricor, Gemfibrozil, Lopid, Clofibrate, Atromid S, Niacin (nicotinic acid), Ezetimibe, Zetia and Ezetrol.

⁸Also to note is the likelihood that these insurance data are reflective of more than a price variable. As socioeconomic data are not available in the NAMCS, method of payment may also be picking up effects of factors such as family income and education of the patient.

⁹The presence of secondary conditions is based on the ICD-9 classifications (CHD2 (codes 410.00–414.90); Hypertension (401.00–405.90); Other Heart Disease (420.00–429.90); Vascular Disease (440.00–448.90); Diabetes (250.00–250.93); Dyslipidemia (272.00–272.90); and All Other ICD-9 groups). For the diabetes sample only, we also include a variable to measure whether a patient's secondary diagnosis is both dyslipidaemia and CHD.

¹⁰The only negative coefficients never approached statistical significance.

¹¹See CDC (2006a, b).