Publications by Year: 2006

2006
Choudhry NK, Anderson GM, Laupacis A, Ross-Degnan D, Normand SL, Soumerai SB. Impact of adverse events on prescribing warfarin in patients with atrial fibrillation: matched pair analysis [Internet]. BMJ 2006;332:141-5. Publisher's VersionAbstract
OBJECTIVES: To quantify the influence of physicians' experiences of adverse events in patients with atrial fibrillation who were taking warfarin. DESIGN: Population based, matched pair before and after analysis. SETTING: Database study in Ontario, Canada. PARTICIPANTS: The physicians of patients with atrial fibrillation admitted to hospital for adverse events (major haemorrhage while taking warfarin and thromboembolic strokes while not taking warfarin). Pairs of other patients with atrial fibrillation treated by the same physicians were selected. MAIN OUTCOME MEASURES: Odds of receiving warfarin by matched pairs of a given physician's patients (one treated after and one treated before the event) were compared, with adjustment for stroke and bleeding risk factors that might also influence warfarin use. The odds of prescriptions for angiotensin converting enzyme (ACE) inhibitor before and after the event was assessed as a neutral control. RESULTS: For the 530 physicians who had a patient with an adverse bleeding event (exposure) and who treated other patients with atrial fibrillation during the 90 days before and the 90 days after the exposure, the odds of prescribing warfarin was 21% lower for patients after the exposure (adjusted odds ratio 0.79, 95% confidence interval 0.62 to 1.00). Greater reductions in warfarin prescribing were found in analyses with patients for whom more time had elapsed between the physician's exposure and the patient's treatment. There were no significant changes in warfarin prescribing after a physician had a patient who had a stroke while not on warfarin or in the prescribing of ACE inhibitors by physicians who had patients with either bleeding events or strokes. CONCLUSIONS: A physician's experience with bleeding events associated with warfarin can influence prescribing warfarin. Adverse events that are possibly associated with underuse of warfarin may not affect subsequent prescribing.
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Udell JA, Fischer MA, Brookhart MA, Solomon DH, Choudhry NK. Effect of the Women's Health Initiative on osteoporosis therapy and expenditure in Medicaid [Internet]. Journal of Bone and Mineral Research 2006;21:765-71. Publisher's VersionAbstract

Decreasing HRT use among postmenopausal women may have a reciprocal impact on other osteoporosis therapy. Time series analysis of prescribing trends for millions of Medicaid beneficiaries revealed a 57% decline in HRT without augmenting the pace of bisphosphonate use. Prescribing changes dramatically increased Medicaid spending on osteoporosis therapy over the last decade and requires further evaluation of cost effectiveness. Introduction: Hormone replacement therapy (HRT) has been commonly prescribed to postmenopausal women, but its use is decreasing because adverse cardiac outcomes were reported by the Wome|$$|Aans Health Initiative (WHI) in July 2002. The reciprocal impact of the WHI on other osteoporosis medications use and expenditure is unknown. Materials and Methods: We conducted a time series analysis on prescription data from 50 state Medicaid programs between 1995 and 2004. Five medication categories were used: HRT, bisphosphonates, calcium, calcitonin, and raloxifene. Results: HRT was increasing before publication of the WHI, reaching 5 million prescriptions per year by mid-2002 (136 prescriptions per 1000 beneficiaries). Bisphosphonate prescribing rose in parallel until mid-2002. WHI publication was associated with a rapid reduction in HRT use, declining 57% by mid-2004 to an average of 59 prescriptions per 1000 beneficiaries (p = 0.01). WHI publication did not augment bisphosphonates' nearly linear rate of rise (p = 0.43) as their prescribing pace continued, whereas HRT declined. Medicaid spending on osteoporosis therapy also changed dramatically during the last decade, as yearly expenditure increased 664% from $1465 to $9742 per 1000 beneficiaries. Over this period, a significant shift from daily to weekly bisphosphonates also occurred. Conclusions: A dramatic decline in HRT and continued rise in bisphosphonate prescribing has occurred since the publication of the WHI. During this time, there have also been substantial increases in osteoporosis medication spending within Medicaid. Determining whether these trends are clinically appropriate and cost effective for osteoporosis therapy will have important implications for the development of future drug reimbursement programs, especially for elderly patients.

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Shrank WH, Joseph GJ, Choudhry NK, Young HN, Ettner SL, Glassman P, Asch SM, Kravitz RL. Physicians' perceptions of relevant prescription drug costs: do costs to the individual patient or to the population matter most? [Internet]. American Journal of Managed Care 2006;12:545-51. Publisher's VersionAbstract

OBJECTIVES: Physicians may be aware of at least 2 types of costs when prescribing: patient's out-of-pocket costs and the actual costs of the medication. We evaluated physicians' perceptions about relevant costs for prescription drugs and the importance of communication about these costs. STUDY DESIGN: Mailed survey to a random sample of 1200 physician members of the California Medical Association, and a phone survey of a sample of nonresponders. METHODS: Descriptive statistics of survey items, McNemar's test to compare survey item responses, and logistic regression to evaluate the relationship between physician, practice, and system variables and physicians' perceptions of relevant medication costs. RESULTS: Of respondents with correct addresses, 49.6% responded to the survey; 13% of nonresponders were contacted by phone. Approximately 91% and 80% of physicians reported that it is important to manage patients' out-of-pocket costs and total medication costs, respectively. When comparing the relative importance of managing the 2 types of costs, 59% of physicians agreed that managing patients' out-of-pocket costs was more important than managing the total medication costs and only 16% disagreed. Physicians believed it was more important to discuss out-of-pocket costs than total costs with patients (P < .0001), but only 15% of physicians reported discussing out-of-pocket costs frequently and 5% reported talking about total medication costs frequently. Physicians who managed more Medicare patients had a greater likelihood than physicians managing fewer Medicare patients of prioritizing out-of-pocket cost rather than total cost management (P = .038), and generalists had a greater likelihood than medical subspecialists (P = .046). CONCLUSIONS: Physicians prioritize managing out-of-pocket costs over total medication costs. Pharmacy benefit designs that use patient out-of-pocket cost incentives to influence utilization are addressing the costs to which physicians may be most responsive. When physicians face conflicts between managing patients' out-of-pocket costs and total costs, they will likely try to protect the patients' resources at the expense of the insurer or society. Efforts to align patients', insurers', and societies' incentives will simplify prescribing decisions and result in better value in prescribing.

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Thavendiranathan P, Bagai A, Brookhart MA, Choudhry NK. Primary Prevention of Cardiovascular Diseases With Statin Therapy: A Meta-analysis of Randomized Controlled Trials [Internet]. Archives of Internal Medicine 2006;166:2307-2313. Publisher's VersionAbstract

Background While the role of hydroxymethyl glutaryl coenzyme A reductase inhibitors (statins) in secondary prevention of cardiovascular (CV) events and mortality is established, their value for primary prevention is less clear. To clarify the role of statins for patients without CV disease, we performed a meta-analysis of randomized controlled trials (RCTs). Methods MEDLINE, EMBASE, Cochrane Collaboration, and American College of Physicians Journal Club databases were searched for RCTs published between 1966 and June 2005. We included RCTs with follow-up of 1 year or longer, more than 100 major CV events, and 80% or more of the population without CV disease. From each trial, demographic data, lipid profile, CV outcomes, mortality, and adverse outcomes were recorded. Summary relative risk (RR) ratios with 95% confidence intervals (CIs) were calculated using a random effects model. Results Seven trials with 42 848 patients were included. Ninety percent had no history of CV disease. Mean follow-up was 4.3 years. Statin therapy reduced the RR of major coronary events, major cerebrovascular events, and revascularizations by 29.2% (95% CI, 16.7%-39.8%) (P<.001), 14.4% (95% CI, 2.8%-24.6%) (P = .02), and 33.8% (95% CI, 19.6%-45.5%) (P<.001), respectively. Statins produced a nonsignificant 22.6% RR reduction in coronary heart disease mortality (95% CI, 0.56-1.08) (P = .13). No significant reduction in overall mortality (RR, 0.92 [95% CI, 0.84-1.01]) (P = .09) or increases in cancer or levels of liver enzymes or creatine kinase were observed. Conclusion In patients without CV disease, statin therapy decreases the incidence of major coronary and cerebrovascular events and revascularizations but not coronary heart disease or overall mortality.

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Choudhry NK, Soumerai SB, Normand SL, Ross-Degnan D, Laupacis A, Anderson GM. Warfarin prescribing in atrial fibrillation: the impact of physician, patient, and hospital characteristics [Internet]. American Journal of Medicine 2006;119:607-15. Publisher's VersionAbstract

PURPOSE: The study investigated the determinants of warfarin use in patients with atrial fibrillation (AF). METHODS: We assembled a retrospective cohort of community-dwelling elderly patients (aged > or = 66 years) with AF using linked administrative databases. We identified the physicians responsible for the ambulatory care of these patients using physician service claims and compared patients who did and did not have an identifiable provider. For those patients with an identifiable provider, we assessed the association between patient, physician, and hospital factors and warfarin use. RESULTS: Our cohort consisted of 140,185 patients, of whom 116,200 (83%) had an identifiable cardiac provider. Patients without a provider were significantly more likely to have comorbid conditions that increase their risk of warfarin-associated bleeding. After adjustment for clinical factors, patients without a provider were significantly less likely to receive warfarin (odds ratio 0.37, 95% confidence interval: 0.36-0.38). Of patients with providers, 50,551 patients (43.5%) received warfarin within 180 days after hospital discharge. Warfarin use was positively associated with AF-associated stroke risk factors (eg, prior stroke, congestive heart failure) and negatively associated with warfarin-associated bleeding risk factors (eg, history of intracerebral hemorrhage). After controlling for patient and hospital factors, patients cared for by noncardiologist physicians with cardiology consultation were more likely to receive warfarin then patients treated in noncollaborative environments. CONCLUSIONS: Warfarin continues to be substantially underprescribed to patients who are at high risk for AF-associated cardioembolic stroke. Our findings highlight the need for targeted quality improvement interventions and suggest preferred models of AF care involving routine collaboration between cardiologists and other physicians.

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