Evaluation of the Clinical and Economic Impact of a Brand Name—to‐Generic Warfarin Sodium Conversion Program

Witt, Daniel M.; Tillman, Donald J.; Evans, Christy M.; Plotkin, Tatyana V.; Sadler, Melanie A.

doi:10.1592/phco.23.3.360.32103

Cited by 22 publications

(25 citation statements)

References 16 publications

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“…[15][16][17][18][19][20][21][22][23][24][25][26][27][28] Our updated systematic search from January 2005 through February 2008 (as depicted in Figure 1) identified an additional 536 studies for full text review, of which 526 were excluded. Of the studies excluded, most were excluded because they were not conducted in the United States, or they were not a primary study.…”

Section: ■■ Resultsmentioning

confidence: 99%

“…Of these, 16 studies were excluded because patients were included for indications other than AF. 14,15,19,[22][23][24][25][27][28][29][30][32][33][34]36,37 Thus, 8 studies, including a total of 14 study groups, met all of the inclusion criteria and were included in the final analysis (Table 1). 17,18,20,21,26,31,35,38 The study groups enrolled a median of 317 patients (interquartile range, 150 to 482 patients; total = 22,237 warfarintreated patients), 31 who were followed for a median of 272.3 patient-years (range, 123.9 to 980.8 patient-years; total = 41,471.9 patient-years).…”

Section: ■■ Resultsmentioning

confidence: 99%

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Meta-Analysis to Assess the Quality of Warfarin Control in Atrial Fibrillation Patients in the United States

Baker

Cios²,

Sander³

et al. 2009

JMCP

368

223

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BACKGROUND: Atrial fibrillation (AF) affects a significant proportion of the American population and increases ischemic stroke risk by 4-to 5-fold. Oral vitamin K antagonists, such as warfarin, can significantly reduce this stroke risk but can be difficult to dose and monitor. Previous research on the effects of setting (e.g., randomized controlled trials, anticoagulation management by specialty clinics, usual care by community physicians) on the proportion of time spent within therapeutic range for the international normalized ratio (INR) has not specifically examined anticoagulation in AF patients.OBJECTIVES: Use traditional meta-analytic and meta-regressive techniques to evaluate the effect of specialty clinic versus usual care by community physicians on anticoagulation control, measured as the proportion of time spent in therapeutic INR range, for AF patients that received warfarin anticoagulation in the United States.METHODS: Studies included in a previously published meta-analysis (van Walraven et al., 2006), which systematically searched reports between 1987 and 2005, were also screened for inclusion in our analysis. A subsequent systematic literature search of MEDLINE, EMBASE, and the Cochrane Central Register of Clinical Trials from January 2005 through February 2008 was conducted. Studies were included if they (a) contained at least 1 warfarin-treated group including more than 25 patients for whom INR control was monitored for at least 3 weeks; (b) included patients treated for AF in the United States; (c) used a patient-time approach (patient-year) to report outcomes; and (d) reported data on the proportion of time spent in traditional therapeutic INR ranges (i.e., a lower limit INR between 1.8 and 2.0 and an upper limit INR between 3.0 and 3.5. Studies with INR goals outside this range were excluded). The proportion of time spent within the therapeutic INR range for each study group was expressed as an incidence density using a person-time approach (in years). All studies were pooled using a random effects model and were weighted by the inverse of the variance of proportion of time spent in the therapeutic range. In order to determine how study setting influenced the proportion of time spent within a therapeutic INR range, both subgroup and meta-regression analyses were conducted.RESULTS: This analysis included 8 studies and a total of 14 unique warfarin-treated groups; 3 of the 8 studies and 4 of the warfarin groups were not included in the previous meta-analysis (van Walraven et al., 2006). Overall, patients spent a mean 55% (95% CI = 51%-58%) of their time in the therapeutic INR range. Meta-regression suggested that AF patients treated in a community usual care setting compared with an anticoagulation clinic spent 11% (95% CI = 2%-20%, n = 6 studies with 9 study groups) less time in range.CONCLUSIONS: In the United States, AF patients spend only about one-half the time within therapeutic INR. Anticoagulation clinic services are associated with somewhat better INR control compared with stan...

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Section: ■■ Resultsmentioning

confidence: 99%

Section: ■■ Resultsmentioning

confidence: 99%

Meta-Analysis to Assess the Quality of Warfarin Control in Atrial Fibrillation Patients in the United States

Baker

Cios²,

Sander³

et al. 2009

JMCP

368

223

View full text Add to dashboard Cite

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“…Therapeutic interchange programs have successfully shifted patients, at least initially, to the desired therapeutic alternatives under both mandated [50][51][52][53] or voluntary programs 49,53 although the voluntary programs observed that over 10% of patients switched back to their original drug. The findings on the cost savings associated with therapeutic interchange programs were mixed, as were the studies that examined clinical outcomes (although the studies examined different therapeutic classes).…”

Section: Prior Authorization: Summary Of the Literaturementioning

confidence: 99%

“…Fugit and Resch (2000) and Witt et al (2003) examined conversion program interventions in which patients were converted at the time of a pharmacist-managed outpatient clinic visit and assessed for conversion outcomes at follow-up visits. 51,52 Fugit and Resch assessed the effects of a therapeutic interchange conversion in a Veteran's Administration (VA) medical center for statins (HMG-CoA), specifically for lowdose simvastatin to lovastatin.…”

Section: Drug Utilization Review: Summary Of the Literaturementioning

confidence: 99%

“…51,52 Fugit and Resch assessed the effects of a therapeutic interchange conversion in a Veteran's Administration (VA) medical center for statins (HMG-CoA), specifically for lowdose simvastatin to lovastatin. Among the 96 patients eligible for evaluating the conversion, the authors found no statistically significant differences between the 2 different conversion (simvastatin 5 milligrams (mg) to lovastatin 5 mg, and simvastatin 10 mg to lovastatin 10 mg) groups' lipid and liver function tests.…”

Section: Drug Utilization Review: Summary Of the Literaturementioning

confidence: 99%

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Effect of 6 Managed Care Pharmacy Tools: A Review of the Literature

2010

JMCP

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Clinical Equivalence of Generic and Brand-Name Drugs Used in Cardiovascular Disease

Kesselheim¹

2008

JAMA

399

316

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Context Use of generic drugs, which are bioequivalent to brand-name drugs, can help contain prescription drug spending. However, there is concern among patients and physicians that brand-name drugs may be clinically superior to generic drugs. Objectives To summarize clinical evidence comparing generic and brand-name drugs used in cardiovascular disease and to assess the perspectives of editorialists on this issue. Data Sources Systematic searches of peer-reviewed publications in MEDLINE, EMBASE, and International Pharmaceutical Abstracts from January 1984 to August 2008. Study Selection Studies compared generic and brand-name cardiovascular drugs using clinical efficacy and safety end points. We separately identified editorials addressing generic substitution. Data Extraction We extracted variables related to the study design, setting, participants, clinical end points, and funding. Methodological quality of the trials was assessed by Jadad and Newcastle-Ottawa scores, and a meta-analysis was performed to determine an aggregate effect size. For editorials, we categorized authors’ positions on generic substitution as negative, positive, or neutral. Results We identified 47 articles covering 9 subclasses of cardiovascular medications, of which 38 (81%) were randomized controlled trials (RCTs). Clinical equivalence was noted in 7 of 7 RCTs (100%) of β-blockers, 10 of 11 RCTs (91%) of diuretics, 5 of 7 RCTs (71%) of calcium channel blockers, 3 of 3 RCTs (100%) of antiplatelet agents, 2 of 2 RCTs (100%) of statins, 1 of 1 RCT (100%) of angiotensin-converting enzyme inhibitors, and 1 of 1 RCT (100%) of α-blockers. Among narrow therapeutic index drugs, clinical equivalence was reported in 1 of 1 RCT (100%) of class 1 antiarrhythmic agents and 5 of 5 RCTs (100%) of warfarin. Aggregate effect size (n = 837) was −0.03 (95% confidence interval, −0.15 to 0.08), indicating no evidence of superiority of brand-name to generic drugs. Among 43 editorials, 23 (53%) expressed a negative view of generic drug substitution. Conclusions Whereas evidence does not support the notion that brand-name drugs used in cardiovascular disease are superior to generic drugs, a substantial number of editorials counsel against the interchangeability of generic drugs.

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Evaluation of the Clinical and Economic Impact of a Brand Name—to‐Generic Warfarin Sodium Conversion Program

Cited by 22 publications

References 16 publications

Meta-Analysis to Assess the Quality of Warfarin Control in Atrial Fibrillation Patients in the United States

Meta-Analysis to Assess the Quality of Warfarin Control in Atrial Fibrillation Patients in the United States

Effect of 6 Managed Care Pharmacy Tools: A Review of the Literature

Clinical Equivalence of Generic and Brand-Name Drugs Used in Cardiovascular Disease

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