Publications by Year: 2007

2007
Choudhry NK, Levin R, Winkelmayer WC. Statins in elderly patients with acute coronary syndrome: an analysis of dose and class effects in typical practice [Internet]. Heart 2007;93:945-51. Publisher's VersionAbstract
OBJECTIVE: To compare the effectiveness of statins of different treatment intensity used to treat elderly patients with acute coronary syndrome (ACS) in typical care settings. DESIGN: Retrospective cohort study using linked hospital and pharmacy claims data. SETTING: Statewide pharmacy benefits programmes in Pennsylvania and New Jersey. PARTICIPANTS: 18,311 Medicare patients discharged alive after ACS who received a prescription for a statin within 90 days of hospital discharge. MAIN OUTCOME MEASURES: Using multivariable and propensity-matched Cox proportional hazards regression models, patients who were prescribed high-intensity and moderate-intensity statins were compared based on the drug-dose combination that they initially received. Individual drug-dose combinations were also compared. Our primary outcome was the composite of all-cause death or recurrent ACS. RESULTS: Patients who received moderate-intensity statins were as likely to experience a primary outcome as patients treated with high-intensity statins (adjusted HR 1.02, 95% CI 0.96 to 1.08). Propensity matching did not change the results. Individually, all moderate-intensity statins were as effective as high-intensity atorvastatin with the exception of lovastatin (adjusted HR 1.22, 95% CI 1.09 to 1.36). Similarly, all high-intensity statins seem as effective as high-intensity atorvastatin but the CIs surrounding these estimates were wide. CONCLUSIONS: This analysis of elderly patients with ACS treated in typical care settings does not demonstrate the superiority of high-intensity over moderate-intensity statin treatment or significant differences among individual statins.
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Roy CL, Minor MA, Brookhart MA, Choudhry NK. Does this patient with a pericardial effusion have cardiac tamponade? [Internet]. Journal of the American Medical Association 2007;297:1810-8. Publisher's VersionAbstract

CONTEXT: Cardiac tamponade is a state of hemodynamic compromise resulting from cardiac compression by fluid trapped in the pericardial space. The clinical examination may assist in the decision to perform pericardiocentesis in patients with cardiac tamponade diagnosed by echocardiography. OBJECTIVE: To systematically review the accuracy of the history, physical examination, and basic diagnostic tests for the diagnosis of cardiac tamponade. DATA SOURCES: MEDLINE search of English-language articles published between 1966 and 2006, reference lists of these articles, and reference lists of relevant textbooks. STUDY SELECTION: We included articles that compared aspects of the clinical examination to a reference standard for the diagnosis of cardiac tamponade. We excluded studies with fewer than 15 patients. Of 787 studies identified by our search strategy, 8 were included in our final analysis. DATA EXTRACTION: Two authors independently reviewed articles for study results and quality. A third reviewer resolved disagreements. DATA SYNTHESIS: All studies evaluated patients with known tamponade or those referred for pericardiocentesis with known effusion. Five features occur in the majority of patients with tamponade: dyspnea (sensitivity range, 87%-89%), tachycardia (pooled sensitivity, 77%; 95% confidence interval [CI], 69%-85%), pulsus paradoxus (pooled sensitivity, 82%; 95% CI, 72%-92%), elevated jugular venous pressure (pooled sensitivity, 76%; 95% CI, 62%-90%), and cardiomegaly on chest radiograph (pooled sensitivity, 89%; 95% CI, 73%-100%). Based on 1 study, the presence of pulsus paradoxus greater than 10 mm Hg in a patient with a pericardial effusion increases the likelihood of tamponade (likelihood ratio, 3.3; 95% CI, 1.8-6.3), while a pulsus paradoxus of 10 mm Hg or less greatly lowers the likelihood (likelihood ratio, 0.03; 95% CI, 0.01-0.24). CONCLUSIONS: Among patients with cardiac tamponade, a minority will not have dyspnea, tachycardia, elevated jugular venous pressure, or cardiomegaly on chest radiograph. A pulsus paradoxus greater than 10 mm Hg among patients with a pericardial effusion helps distinguish those with cardiac tamponade from those without. Diagnostic certainty of the presence of tamponade requires additional testing.

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Fischer MA, Choudhry NK, Winkelmayer WC. Impact of Medicaid prior authorization on angiotensin-receptor blockers: can policy promote rational prescribing? [Internet]. Health Affairs (Millwood) 2007;26:800-7. Publisher's VersionAbstract

Prescription drug cost containment is a key health policy priority. State Medicaid programs have implemented policies requiring prior authorization before paying for angiotensin-receptor blockers (ARBs), a costly class of blood pressure medications. We examined the impact of these policies on drug use. We found that policies using a stepped-therapy approach reduced ARB use by 1.6 percent when first implemented and decreased the subsequent trend in ARB use by 1.3 percent per quarter; alternative approaches were unsuccessful. These findings have important implications for the development of rational drug reimbursement policy under Medicare Part D and other health insurance plans.

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Kulik A, Levin R, Ruel M, Mesana TG, Solomon DH, Choudhry NK. Patterns and predictors of statin use after coronary artery bypass graft surgery [Internet]. Journal of Thoracic and Cardiovascular Surgery 2007;134:932-8. Publisher's VersionAbstract

OBJECTIVES: The benefits of statin therapy for patients with coronary artery disease have been well documented, including those occurring after coronary artery bypass graft surgery. The purposes of this study were to assess statin prescription rates in patients who have undergone coronary artery bypass graft surgery and to identify the determinants of postoperative statin administration. METHODS: A retrospective cohort of 9284 Medicare patients aged 65 years or older who underwent coronary artery bypass graft surgery (1995-2004) was assembled by using linked hospital and pharmacy claims data. Rates of statin use after hospital discharge were calculated, and predictors of postoperative statin use were identified by using generalized estimating equations. RESULTS: Overall, 35.9% of patients received statins within 90 days of coronary artery bypass graft surgery discharge. Use of statins within 90 days after coronary artery bypass graft surgery steadily improved during the study period, from 13.1% in 1995 to 60.9% in 2004. Patient factors independently associated with an increase in postoperative statin therapy included preoperative statin use (odds ratio, 7.69), later year of operation (odds ratio, 1.22 per additional year), and additional postoperative medications (odds ratio, 1.16 per additional medication). Factors independently associated with a decrease in postoperative statin therapy included peripheral vascular disease (odds ratio, 0.60), diabetes mellitus (odds ratio, 0.67), stroke (odds ratio, 0.77), and older age (odds ratio, 0.96 per additional year). Surgeon and hospital characteristics were not independently associated with postoperative statin use. CONCLUSIONS: Statins are considerably underused after coronary artery bypass graft surgery, although recent prescription rates are increasing. Patterns of use do not appear to correlate with coronary artery disease risk. These findings highlight the need for targeted quality improvement initiatives to increase the rate of statin administration to this at-risk population.

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Choudhry NK, Avorn J, Antman EM, Schneeweiss S, Shrank WH. Should patients receive secondary prevention medications for free after a myocardial infarction? An economic analysis [Internet]. Health Affairs (Millwood) 2007;26:186-94. Publisher's VersionAbstract

Taken in combination, aspirin, beta-blockers, angiotensin-converting enzyme (ACE) inhibitors, and statins (combination pharmacotherapy) greatly reduce cardiac events. These therapies are underused, even among patients with drug insurance. Out-of-pocket spending is a key barrier to adherence. We estimated the impact of providing combination pharmacotherapy without cost sharing ("full coverage") to insured patients after a myocardial infarction (MI). Under base-case assumptions, compared to standard coverage, three years of full coverage will reduce mortality and reinfarction rates and will save 5,974 per patient. Our analysis suggests that covering combination therapy for such patients will save both lives and money.

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Shrank WH, Agnew-Blais J, Choudhry NK, Wolf MS, Kesselheim AS, Avorn J, Shekelle P. The variability and quality of medication container labels [Internet]. Archives of Internal Medicine 2007;167:1760-5. Publisher's VersionAbstract

BACKGROUND: Medication errors occur frequently, and poor medication labeling is cited as a potential cause. We assessed the format, content, and variability of prescription drug container labels dispensed in the community. METHODS: Identically written prescriptions for 4 commonly used medications (atorvastatin calcium [Lipitor], alendronate sodium [Fosamax], trimethoprim-sulfamethoxazole [Bactrim], and ibuprofen) were filled in 6 pharmacies (the 2 largest chains, 2 grocery stores, and 2 independent pharmacies) in 4 cities (Boston, Chicago, Los Angeles, and Austin [Texas]). Characteristics of the format and content of the main container label and auxiliary stickers were evaluated. Labels were coded independently by 2 abstractors, and differences were reconciled by consensus. RESULTS: We evaluated 85 labels after excluding 11 ibuprofen prescriptions that were filled with over-the-counter containers that lacked labels printed at the pharmacy. The pharmacy name or logo was the most prominent item on 71 (84%) of the labels, with a mean font size of 13.6 point. Font sizes were smaller for medication instructions (9.3 point), medication name (8.9 point), and warning and instruction stickers (6.5 point). Color, boldfacing, and highlighting were most often used to identify the pharmacy and items most useful to pharmacists. While the content of the main label was generally consistent, there was substantial variability in the content of instruction and warning stickers from different pharmacies, and independent pharmacies were less likely to use such stickers (P < .001). None of the ibuprofen containers were delivered with Food and Drug Administration-approved medication guides, as required by law. CONCLUSIONS: The format of most container labels emphasizes pharmacy characteristics and items frequently used by pharmacists rather than use instructions or medication warnings. The content of warning and instruction stickers is highly variable depending on the pharmacy selected.

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Wang PS, Schneeweiss S, Setoguchi S, Patrick A, Avorn J, Mogun H, Choudhry NK, Brookhart MA. Ventricular Arrhythmias and Cerebrovascular Events in the Elderly Using Conventional and Atypical Antipsychotic Medications [Internet]. Journal of Clinical Psychopharmacology 2007;27:707-710. Publisher's Version PDF