Temporal trends in anticoagulation use and clinical outcomes among medicare beneficiaries with non-valvular atrial fibrillation.

PURPOSE: Oral anticoagulants effectively prevent stroke/systemic embolism among patients with non-valvular atrial fibrillation but remain under-prescribed. This study evaluated temporal trends in oral anticoagulant use, the incidence of stroke/systemic embolism and major bleeding, and economic outcomes among elderly patients with non-valvular atrial fibrillation and CHA2DS2-VASc scores ≥ 2. METHODS: Retrospective analyses were conducted on Medicare claims data from January 1, 2012 through December 31, 2017. Non-valvular atrial fibrillation patients aged ≥ 65 years with CHA2DS2-VASc scores ≥ 2 were stratified by calendar year (2013-2016) of care to create calendar-year cohorts. Patient characteristics were evaluated across all cohorts during the baseline period (12 months before diagnosis). Treatment patterns and clinical and economic outcomes were evaluated during the follow-up period (from diagnosis through 12 months). RESULTS: Baseline patient characteristics remained generally similar between 2013 and 2016. Although lack of oral anticoagulant prescriptions among eligible patients remained relatively high, utilization did increase progressively (53-58%). Among treated patients, there was a progressive decrease in warfarin use (79-52%) and a progressive increase in overall direct oral anticoagulant use (21-48%). There were progressive decreases in the incidence of stroke/systemic embolism 1.9-1.4 events per 100 person years) and major bleeding (4.6-3.3 events per 100 person years) as well as all-cause costs between 2013 and 2016. CONCLUSIONS: The proportions of patients with non-valvular atrial fibrillation who were not prescribed an oral anticoagulant decreased but remained high. We observed an increase in direct oral anticoagulant use that coincided with decreased incidence of clinical outcomes as well as decreasing total healthcare costs.

Geographic variation in clinical outcomes and anticoagulation among medicare beneficiaries with non-valvular atrial fibrillation.

Oral anticoagulants (OACs) have been used to prevent stroke/systemic embolism (SE) among patients with non-valvular atrial fibrillation (NVAF). To evaluate baseline clinical characteristics, incidence rates of stroke/SE and hospitalization for bleeding, and OAC use among elderly patients with NVAF in the US by geographic region. Patients with NVAF were selected from the US Centers for Medicare & Medicaid Services claims database (01JAN2013-31DEC2016). Twelve months of health plan enrollment was required before and after the NVAF diagnosis to evaluate baseline characteristics and outcomes, respectively. Each patient was assigned to a 3-digit zip code based on their primary residence, and geographic variation was visualized using ArcGIS Pro software. Over 2.8 million patients with NVAF were identified. Large geographic variation was observed in clinical characteristics, stroke/SE, hospitalization for bleeding, and OAC use among patients across the US. The zip codes with the highest mean CHA2DS2-VASc scores and frequency of prior bleeding also had the highest incidence of stroke/SE and hospitalization for bleeding. Across 3-digit zip codes, 35-63% of patients were untreated. Overall, the incidence of stroke/SE and hospitalization for bleeding were higher and OAC treatment was less frequent in zip codes located in the Southern US. Baseline clinical characteristics, incidence rates of stroke/SE and hospitalization for bleeding, and OAC usage vary considerably by 3-digit zip code in the US. The additional granularity provided in this study may help clinicians to identify small regions with high-risk of stroke/SE and hospitalization for bleeding and low use of OAC that may benefit from targeted care strategies.

Contemporary prevalence estimates of undiagnosed and diagnosed atrial fibrillation in the United States.

BACKGROUND: Atrial fibrillation (AF) prevalence estimates vary and have been based on cohorts with clinically established or diagnosed disease. Undiagnosed AF prevalence estimates are less certain as they are based on nongeneralizable convenience samples. HYPOTHESIS: Because AF is often asymptomatic, it my remain undiagnosed until the development of complications such as stroke or heart failure. Consequently, the observed prevalence of diagnosed AF from the literature may underestimate total disease burden. We therefore sought to estimate the total prevalence of both diagnosed and undiagnosed AF. METHODS: We performed a retrospective cohort study from 2012 to 2017 using data from five US medical claims data sets. Undiagnosed AF prevalence was estimated based on the observed incidence of ischemic stroke, systemic embolism (SE), and AF incidence after a stroke/SE. The diagnosed AF cohort included AF patients between Q1 2014 and Q3 2015. The undiagnosed AF cohort were patients with assumed undiagnosed AF in the year before a stroke/SE and who were newly diagnosed with AF in the 3-month poststroke/SE. Stroke/SE incidence was calculated among all AF patients and the ratio of number of undiagnosed AF patients to stroke rate was created. Age- and sex-adjusted estimates were stratified by period of assumed undiagnosed AF before poststroke/SE AF diagnosis (1 or 2 years). RESULTS: The estimated US prevalence of AF (diagnosed and undiagnosed) in Q3 2015 was 5 628 000 cases, of which 591 000 cases (11%) were undiagnosed. The assumed 2-year undiagnosed AF prevalence was 23% (1 531 000) of the total prevalent patients with AF (6 568 000). Undiagnosed (vs. diagnosed) AF patients were older and had higher CHA2DS2-VASc scores. Of undiagnosed AF, 93% had CHA2DS2-VASc ≥2 and met OAC criteria. CONCLUSIONS: These contemporary estimates demonstrate the high prevalence of undiagnosed AF in the United States. Undiagnosed AF patients are composed of primarily elderly individuals who if diagnosed, would meet criteria for stroke prevention therapy.

Warfarin Time in Therapeutic INR Range and Direct Oral Anticoagulant Adherence for Venous Thromboembolism Across the Spectrum of Weight and Body Mass Index: Findings from Veterans Health Administration.

The evidence of direct oral anticoagulants (DOACs) usage for venous thromboembolism (VTE) in patients at extremes of body weight or mass index is limited. In such situations, warfarin may be more frequently used. We investigated warfarin time in the therapeutic international normalized ratio range (TTR) and DOAC adherence based on the calculated proportion of days covered (PDC) by pill coverage from a DOAC prescription in patients with VTE across all body sizes. Using data from the Veterans Health Administration (VA), we identified first-time patients with VTE between 2013 and 2018 treated with warfarin or DOACs. We analyzed 28,245 patients with warfarin TTR (N = 10,167) or DOAC PDC(N = 18,078). For warfarin-treated patients after index VTE, mean TTR was lower over shorter treatment durations (TTR 30 vs TTR 180 [mean ± SD]: 43.8% ± 33.5% vs 58.8% ± 23.5%). Mean TTR over 180 days after VTE was lowest for patients <60 kg (TTR 180 [mean ± SD]: <60kg: 49.3% ± 24.2% vs ≥60 to <100 kg: 57.8% ± 23.4%; P < .0001). For DOAC-treated patients over 180 days after index VTE, mean PDC was lowest for patients <60 kg (PDC 180 [mean ± SD]: < 60kg: 76.9% ± 33.2% vs ≥ 60 to <100 kg: 83.6% ± 27.7%; P < .0001).Most DOAC-treated patients attained sufficient adherence across the body size spectrum while warfarin-treated patients <60kg were at risk for low TTR.

Oral anticoagulant underutilization among elderly patients with atrial fibrillation: insights from the United States Medicare database.

BACKGROUND: Oral anticoagulants (OACs) mitigate stroke risk in patients with atrial fibrillation (AF). The study aim was to analyze prevalence and predictors of OAC underutilization. METHODS: Newly diagnosed AF patients with a CHA2DS2-VASc score ≥ 2 were identified from the US CMS Database (January 1, 2013-December 31, 2017). Patients were stratified based on having an OAC prescription versus not and the OAC prescription group was stratified by direct OAC (DOACs) versus warfarin. Multivariable logistic regression models were used to examine predictors of OAC underutilization. RESULTS: Among 1,204,507 identified AF patients, 617,611 patients (51.3%) were not prescribed an OAC during follow-up (mean: 2.4 years), and 586,896 patients (48.7%) were prescribed an OAC during this period (DOAC: 388,629 [66.2%]; warfarin: 198,267 [33.8%]). Age ≥ 85 years (odds ratio [OR] 0.55, 95% confidence interval [CI] 0.55-0.56), female sex (OR 0.96, 95% CI 0.95-0.96), Black race (OR 0.78, 95% CI 0.77-0.79) and comorbidities such as gastrointestinal (GI; OR 0.43, 95% CI 0.41-0.44) and intracranial bleeding (OR 0.29, 95% CI 0.28-0.31) were associated with lower utilization of OACs. Furthermore, age ≥ 85 years (OR 0.92, 95% CI 0.91-0.94), Black race (OR 0.78, 95% CI 0.76-0.80), ischemic stroke (OR 0.77, 95% CI 0.75-0.80), GI bleeding (OR 0.73, 95% CI 0.68-0.77), and intracranial bleeding (OR 0.72, 95% CI 0.65-0.80) predicted lower use of DOACs versus warfarin. CONCLUSIONS: Although OAC therapy prescription is the standard of care for stroke prevention in AF patients, its overall utilization is still low among Medicare patients ≥ 65 years old, with specific patient characteristics that predict underutilization.

Contemporary clinical and economic outcomes among oral anticoagulant treated and untreated elderly patients with atrial fibrillation: Insights from the United States Medicare database.

BACKGROUND: Oral anticoagulants (OACs) mitigate the risk of stroke in atrial fibrillation (AF) patients. OBJECTIVE: Elderly AF patients who were treated with OACs (apixaban, dabigatran, edoxaban, rivaroxaban, or warfarin) were compared against AF patients who were not treated with OACs with respect to their clinical and economic outcomes. METHODS: Newly diagnosed AF patients were identified between January 2013 and December 2017 in the Medicare database. Evidence of an OAC treatment claim on or after the first AF diagnosis was used to classify patients into treatment-defined cohorts, and these cohorts were further stratified based on the initial OAC prescribed. The risks of stroke/systemic embolism (SE), major bleeding (MB), and death were analyzed using inverse probability treatment weighted time-dependent Cox regression models, and costs were compared with marginal structural models. RESULTS: The two treatment groups were composed of 1,421,187 AF patients: OAC treated (N = 583,350, 41.0% [36.4% apixaban, 4.9% dabigatran, 0.1% edoxaban, 26.7% rivaroxaban, and 31.9% warfarin patients]) and untreated (N = 837,837, 59.0%). OAC-treated patients had a lower adjusted risk of stroke/SE compared to untreated patients (hazard ratio [HR]: 0.70; 95% confidence interval [CI]: 0.68-0.72). Additionally patients receiving OACs had a lower adjusted risk of death (HR: 0.56; 95% CI: 0.55-0.56) and a higher risk of MB (HR: 1.57; 95% CI: 1.54-1.59) and this trend was consistent across each OAC sub-group. The OAC-treated cohort had lower adjusted total healthcare costs per patient per month ($4,381 vs $7,172; p < .0001). CONCLUSION: For the OAC-treated cohort in this elderly US population, stroke/SE and all-cause death were lower, while risk of MB was higher. Among OAC treated patients, total healthcare costs were lower than those of the untreated cohort.

The burden of undertreatment and non-treatment among patients with non-valvular atrial fibrillation and elevated stroke risk: a systematic review.

OBJECTIVE: Global treatment guidelines recommend treatment with oral anticoagulants (OACs) for patients with non-valvular atrial fibrillation (NVAF) and an elevated stroke risk. However, not all patients with NVAF and an elevated stroke risk receive guideline-recommended therapy. A literature review and synthesis of observational studies were undertaken to identify the body of evidence on untreated and undertreated NVAF and the association with clinical and economic outcomes. METHODS: An extensive search (1/2010-4/2020) of MEDLINE, the Cochrane Library, conference proceedings, and health technology assessments (HTAs) was conducted. Studies must have evaluated rates of nontreatment or undertreatment in NVAF. Nontreatment was defined as absence of OACs (but with possible antiplatelet treatment), while undertreatment was defined as treatment with only antiplatelet agents. RESULTS: Sixteen studies met our inclusion criteria. Rates of nontreatment for patients with elevated stroke risk ranged from 2.0-51.1%, while rates of undertreatment ranged from 10.0-45.1%. The clinical benefits of anticoagulation were reported in the evaluated studies with reductions in stroke and mortality outcomes observed among patients treated with anticoagulants compared to untreated or undertreated patients. Adverse events associated with all bleeding types (i.e. hemorrhagic stroke, major bleeding or gastrointestinal hemorrhaging) were found to be higher for warfarin patients compared to untreated patients in real-world practice. Healthcare resource utilization was found to be lower among patients highly-adherent to warfarin compared to untreated patients. CONCLUSIONS: Rates of nontreatment and undertreatment among NVAF patients remain high and are associated with preventable cardiovascular events and death. Strategies to increase rates of treatment may improve clinical outcomes.

Anticoagulation Treatment and Outcomes of Venous Thromboembolism by Weight and Body Mass Index: Insights From the Veterans Health Administration.

BACKGROUND: Consensus statements have recommended against the use of direct oral anticoagulants (DOACs) in venous thromboembolism (VTE) for patients ≥120 kg and ≥40 kg/m2. We sought to determine use and outcomes of DOACs for VTE across weight and body mass index (BMI). METHODS: We performed a retrospective cohort study of patients with first-time VTE 2013 to 2018 that were treated with DOAC or warfarin in the Veterans Health Administration. The Veterans Health Administration has implemented system-wide guidance for patient selection and shared decision-making for use of DOACs in VTE at extremes of weight. We stratified patients by weight and BMI and assessed (1) association of weight and BMI category to outcomes in those prescribed DOAC; and (2) association of DOAC, as compared to warfarin, to outcomes by weight and BMI categories. Outcomes of interest included major bleeding, clinically relevant nonmajor bleeding, and recurrent VTE. RESULTS: The analysis cohort included 51 871 patients prescribed DOAC or warfarin within 30 days of index VTE diagnosis (age 64.5±13.1 years; 6.0% female; median weight 93.4 kg [25th-75th: 80.5-108.6 kg]). For patients ≥120 kg (N=6934 patients), 38.4% were treated with DOAC, as compared to 45.4% of those ≥60 to <100 kg (N=30 645; P<0.0001). DOAC prescription was not associated with major bleeds, clinically relevant nonmajor bleeds, or recurrent VTE for those in higher weight and BMI categories as compared to those in average weight and BMI categories. DOAC prescription, as compared to warfarin, was not associated with increased recurrent VTE in any weight or BMI category. CONCLUSIONS: Patients ≥120 kg and ≥40 kg/m2 with VTE are frequently prescribed DOAC by the Veterans Health Administration, without an increase in bleeding or recurrent VTE. These findings suggest DOACs can be safe and effective in this population and may argue for broader adoption of pharmacy policies that promote careful patient selection and shared decision making.

The IMPact of untReated nOn-Valvular atrial fibrillation on short-tErm clinical and economic outcomes in the US Medicare population: the IMPROVE-AF model.

BACKGROUND: Despite treatment guidelines recommending the use of oral anticoagulants (OACs) for patients with non-valvular atrial fibrillation (NVAF) and moderate to high risk of stroke (CHA2DS2-VASc score ≥1), many patients remain untreated. A study conducted among Medicare beneficiaries with AF and a CHA2DS2-VASc score of ≥2 found that 51% of patients were not prescribed an OAC despite being eligible for treatment. When left untreated, NVAF poses an enormous burden to society, as stroke events are estimated to cost the US healthcare system about $34 billion each year in both direct medical costs and indirect productivity losses. This research explored the short-term clinical implications and budget impact (BI) of increasing OAC use among Medicare beneficiaries with NVAF. METHODS: A decision-analytic model was developed from the payer and societal perspectives to estimate the impact of increasing treatment rates among Medicare-eligible NVAF patients with a moderate-to-high risk of stroke over 1 year. Results of the model compared (1) a base case scenario using literature-derived rates of OAC use, and (2) a hypothetical scenario assuming an absolute 5% increase in overall OAC use. Clinical outcomes included the incremental annual number of ischemic stroke, hemorrhagic stroke, and gastrointestinal bleeding events, and stroke-related deaths. Economic outcomes included incremental annual and per-member per-month (PMPM) direct medical costs for the payer perspective and the incremental sum of annual direct medical and indirect costs from productivity loss and caregiver burden for the societal perspective. RESULTS: In total, 1.95 million Medicare patients with NVAF were estimated to be treated with OACs in the base case (3.8% of beneficiaries). In the hypothetical scenario analysis, nearly 200,000 more patients were treated resulting in 3,705 fewer ischemic strokes, 14 fewer gastrointestinal bleeds, 141 more hemorrhagic strokes, and 175 fewer deaths. The total incremental BI was $399.16 million ($0.65 PMPM) from the payer perspective and $377.10 million from the societal perspective due to indirect cost savings ($22.06 million). CONCLUSION: Our findings suggest that increased overall OAC use has a positive clinical benefit on the annual number of ischemic stroke events and deaths avoided in the Medicare population, while maintaining a modest increase in the overall BI to the Medicare system.

Safety and effectiveness of apixaban compared with warfarin among clinically-relevant subgroups of venous thromboembolism patients in the United States Medicare population.

BACKGROUND: The AMPLIFY trial found significantly lower major bleeding (MB) and similar recurrent venous thromboembolism (VTE) risks associated with apixaban vs warfarin among patients with VTE. OBJECTIVES: To compare MB, clinically-relevant non-major (CRNM) bleeding, and recurrent VTE risks among clinically-relevant subgroups of newly diagnosed elderly patients with VTE prescribed apixaban vs warfarin. METHODS: US Medicare patients prescribed apixaban or warfarin within 30 days post-VTE encounter were identified. Propensity score matching (PSM) was used to control for patient characteristics. Cox models were used to assess MB, CRNM bleeding, and recurrent VTE. Subgroup analyses were conducted for index VTE encounter type, index VTE diagnosis type, index VTE etiology, sex, and frailty. RESULTS: Post-PSM, 11,363 matched pairs of patients prescribed apixaban or warfarin were identified. Apixaban had lower MB (Hazard Ratio [HR]:0.76; 95% CI:0.64-0.91) and similar recurrent VTE risks (HR:1.04; 95% CI:0.75-1.43) vs warfarin. No significant interactions were observed between treatment and index VTE encounter type, index VTE diagnosis type, or sex for risk of MB, CRNM bleeding, or recurrent VTE. Significant interactions: frail patients prescribed apixaban had a 15% lower, while non-frail patients prescribed apixaban had 32% lower CRNM bleeding risk vs those prescribed warfarin. Patients with provoked VTE prescribed apixaban trended toward a higher, while those with unprovoked VTE trended toward a lower risk of recurrent VTE vs patients prescribed warfarin. CONCLUSIONS: Apixaban was associated with significantly lower risks of MB and CRNM bleeding, and similar risk of recurrent VTE as compared with warfarin across the overall population and most subgroups.

Clinical characteristics and treatment patterns of patients with venous thromboembolism (VTE) transitioning from hospital to post-discharge settings.

OBJECTIVE: This study examined anticoagulant use during and after a hospital encounter for venous thromboembolism (VTE), a transition of care largely uncharacterized in the literature. METHODS: Adults with a VTE diagnosis code during a hospital encounter (emergency department [ED], observation area [OBS], or inpatient hospital [IP]) from January 2012 to August 2017 were identified in an electronic health records database. The first such hospital encounter was defined as the index VTE encounter. Patients were linked to a claims database and required to be continuously enrolled for six months before the index admission date through six months after the index discharge date. Anticoagulants administered during the index VTE encounter and filled on or within 30 days of discharge were summarized descriptively overall, and by the type of index VTE encounter (IP, No IP) and anticoagulants administered during the index VTE encounter. RESULTS: Among 2,968 eligible patients, mean (SD) age was 64 (16) years, 51% were female, 67% had an IP index VTE encounter, and 77% received anticoagulation therapy during the index VTE encounter. In total, 60% filled a prescription order for anticoagulant within 30 days post-discharge. Of those who received a direct oral anticoagulant (DOAC), warfarin, or parenteral anticoagulant only during the index VTE encounter, 74%, 69%, and 34%, respectively, filled a prescription for the same anticoagulant post-discharge. Patients treated with a DOAC or warfarin during an ED or OBS VTE encounter without a subsequent inpatient hospitalization were more likely to remain on the same anticoagulation therapy post-discharge than those with an inpatient hospitalization (81% vs 69% for DOAC and 75% vs 68% for warfarin). CONCLUSIONS: Many patients treated with anticoagulation therapy during a VTE hospital encounter did not fill a prescription for an anticoagulant within 30 days post-discharge, highlighting an opportunity for improved management of care transitions in this patient population.

Comparative Clinical and Economic Outcomes Associated with Warfarin Versus Apixaban in the Treatment of Patients with Venous Thromboembolism in a Large U.S. Commercial Claims Database.

BACKGROUND: Venous thromboembolism (VTE), constituting deep vein thrombosis (DVT) and pulmonary embolism (PE), is a common cause of vascular-related morbidity and mortality, resulting in a significant clinical and economic burden in the United States each year. Clinical guidelines recommend that patients with DVT and PE without cancer should be initiated on anticoagulation therapy with a direct oral anticoagulant over a vitamin K antagonist. Yet there is limited real-world evidence comparing the economic burden of warfarin and apixaban in treating VTE patients in a large commercially insured population. OBJECTIVE: To compare safety and effectiveness of warfarin and apixaban and evaluate associated economic burden in treating VTE patients in a large U.S. commercial health care claims database. METHODS: The PharMetrics Plus database was used to identify oral anticoagulant (OAC)-naive patients aged ≥ 18 years who initiated apixaban or warfarin within 30 days of a qualifying VTE encounter and had continuous health plan enrollment with medical and pharmacy benefits for 6 months before treatment initiation. Apixaban initiators and warfarin initiators were matched using the propensity score matching (PSM) technique. Cox proportional hazard models were used to assess and compare the risk of major bleeding (MB), clinically relevant nonmajor (CRNM) bleeding, and recurrent VTE. Generalized linear models were used to assess and compare the all-cause health care costs. A 2-part model with bootstrapping was used to evaluate MB- and recurrent VTE-related medical costs. RESULTS: Among 25,193 prematched patients, 13,421 (53.3%) were prescribed warfarin and 11,772 (46.7%) were prescribed apixaban. After 1:1 PSM, 8,858 matched warfarin-apixaban pairs were selected with a mean follow-up of 109 days and 103 days, respectively. Warfarin was associated with a significantly higher risk of MB (HR = 1.52, 95% CI = 1.14-2.04), CRNM bleeding (HR = 1.27, 95% CI = 1017.15-1.40), and recurrent VTE (HR = 1.50, 95% CI = 1.24-1.82) compared with apixaban. Warfarin patients had significantly higher all-cause medical costs per patient per month (PPPM; $2,333 vs. $1,992; P = 0.001), MB-related costs PPPM ($112 vs. $65; P = 0.020), and recurrent VTE-related costs PPPM ($287 vs. $206; P = 0.014) compared with apixaban patients. Warfarin patients had similar all-cause total health care costs PPPM ($2,630 vs. $2,420; P = 0.051) compared with apixaban patients. CONCLUSIONS: Warfarin use was associated with a higher risk of MB, CRNM bleeding, and recurrent VTE compared with apixaban. Warfarin use was also associated with higher all-cause medical costs, MB-related medical costs, and recurrent VTE-related costs PPPM compared with apixaban. DISCLOSURES: This study was funded by Bristol Myers Squibb and Pfizer, which were also involved in the study design, as well as writing and revising of the manuscript. Guo, Rajpura, Okano, and Rosenblatt are employees of Bristol Myers Squibb. Hlavacek, Mardekian, and Russ are employees of Pfizer. Keshishian, Sah, Delinger, and Mu are employees of SIMR, LLC, which received funding from the study sponsors to conduct this study.

Bleeding and recurrent VTE with apixaban vs warfarin as outpatient treatment: time-course and subgroup analyses.

In the phase 3 trial Apixaban for the Initial Management of Pulmonary Embolism and Deep-Vein Thrombosis as First-Line Therapy, apixaban was noninferior to enoxaparin, overlapped and followed by warfarin, in the treatment of venous thromboembolism (VTE) with significantly less bleeding; in a real-world evaluation, risks for bleeding and recurrent VTE were lower with apixaban vs warfarin plus parenteral anticoagulant (PAC) bridge therapy. The present study extends this research by comparing outcomes over time and within selected subgroups. A retrospective observational cohort design and 4 US private health care claims databases were used. Study population included patients who initiated outpatient treatment with apixaban or warfarin (plus PAC bridge therapy) for VTE. Major bleeding, clinically relevant nonmajor (CRNM) bleeding, and recurrent VTE were compared during the 180-day follow-up period, at selected follow-up time points (days 21, 90, 180), and within subgroups (pulmonary embolism [PE] with or without deep vein thrombosis [DVT], DVT only, provoked VTE, unprovoked VTE) using multivariable shared frailty models. Study population consisted of 20 561 apixaban patients and 35 080 warfarin patients; baseline characteristics were comparable. Overall, at selected follow-up time points, and within the aforementioned subgroups, adjusted risks were lower among apixaban vs warfarin patients: major bleeding, by 27% to 39%, CRNM bleeding, by 17% to 28%, and recurrent VTE, by 25% to 39% (all P ≤ .01). In this real-world study of VTE patients, risks of bleeding and recurrent VTE were lower among apixaban (vs warfarin) patients during the 180-day follow-up period, at selected follow-up time points, and within subgroups defined by index VTE episode.

Comparison of inpatient admission rates of patients treated with apixaban vs. warfarin for venous thromboembolism in the emergency department.

Objectives: This study evaluated inpatient admission status, hospitalization length of stay (LOS), hospital costs, and readmissions of patients who were diagnosed with venous thromboembolism (VTE) and treated with apixaban or warfarin in the emergency department (ED).Methods: Patients (≥18 years) with an ED visit with a primary discharge diagnosis code of VTE were identified from the Premier Hospital database (8/1/2014-5/31/2018). Patients who received apixaban or warfarin during the ED visit were selected and grouped into two treatment cohorts. Outcomes of ED disposition (discharged or admitted to the inpatient setting), hospital LOS, hospital cost of index event, and rate of 1-month readmissions were compared for the study cohorts.Results: Of the overall study population, 30.5% (n = 12,174; mean age: 59.7 years) received apixaban and 69.5% (n = 27,767; mean age: 59.3 years) received warfarin for VTE in the ED. After adjusting for patient and hospital characteristics, the regression analysis showed that apixaban was associated with a significantly lower likelihood of admission to the inpatient setting vs. warfarin (Odds Ratio [OR]: 0.12, 95% Confidence Interval [CI]: 0.12 to 0.13; p < 0.001). Correspondingly, mean index hospital LOS was 1.42 days shorter (95% CI: -1.47 to -1.36; p < 0.001) and mean index event hospital cost per patient was significantly lower by $4,276 ($3,732 [95% CI: $3,565 to $3,907] vs. $8,008 [95% CI: $7,676 to $8,355]; p < 0.001). Also, the likelihood of all-cause 1-month readmission was significantly lower for patients treated with apixaban vs. warfarin (OR: 0.85, 95% CI: 0.79 to 0.92; p < 0.001).Conclusions: In the real-world setting, VTE patients with an ED visit who were treated with apixaban vs. warfarin had a lower likelihood of being admitted to the inpatient setting, which was reflected in shorter average LOS and lower average index event cost. Additionally, the risk of 1-month readmission was also lower for patients treated with apixaban vs. warfarin.

Impact of alemtuzumab on health-related quality of life over 6 years in CARE-MS II trial extension patients with relapsing-remitting multiple sclerosis.

BACKGROUND: In CARE-MS II (Comparison of Alemtuzumab and Rebif® Efficacy in Multiple Sclerosis; NCT00548405), alemtuzumab (12 mg/day; baseline: 5 days; 12 months later: 3 days) significantly improved health-related quality of life (HRQL) outcomes versus subcutaneous interferon beta-1a (SC IFNB-1a) in relapsing-remitting multiple sclerosis (RRMS) patients over 2 years. Patients completing CARE-MS II could enter a 4-year extension study (NCT00930553). OBJECTIVE: The aim of this study is to assess 6-year HRQL outcomes in alemtuzumab-treated CARE-MS II patients, including those with highly active disease (HAD). METHODS: During extension, patients could receive additional alemtuzumab for clinical/magnetic resonance imaging (MRI) activity or other disease-modifying therapies per investigator's discretion. Assessments include Functional Assessment of Multiple Sclerosis (FAMS), 36-Item Short-Form Health Survey (SF-36), and EQ-5D visual analog scale (EQ-VAS). RESULTS: Alemtuzumab-treated patients improved or stabilized all HRQL measures over 6 years with significant improvements from baseline at all time points on EQ-VAS and for up to 5 years on FAMS, SF-36 MCS, and SF-36 PCS. Alemtuzumab-treated patients with HAD showed significant improvements versus baseline at Year 2 on all HRQL measures, and significant improvements versus SC IFNB-1a on SF-36 PCS and EQ-VAS; however, the improvements did not reach the threshold for clinical relevance. CONCLUSION: Alemtuzumab-treated CARE-MS II patients improved or stabilized HRQL versus baseline over 6 years. This is the first study to show long-term HRQL benefits in patients with HAD.

Safety, effectiveness, and health care cost comparisons among elderly patients with venous thromboembolism prescribed warfarin or apixaban in the United States Medicare population.

Objective: To compare safety, effectiveness, and healthcare costs of major bleeding (MB), clinically relevant non-major (CRNM) bleeding, recurrent venous thromboembolism (VTE), and all-cause hospitalization among elderly Medicare VTE patients prescribed warfarin vs apixaban.Methods: Using 100% Medicare data, elderly patients prescribed apixaban or warfarin within 30 days after a VTE encounter were identified. Patients had continuous health plan enrollment and no parenteral or oral anticoagulant use ≤6 months preceding the VTE encounter. Cohorts were balanced using 1:1 propensity score matching (PSM). Cox proportional hazard models were used to assess the risk of MB, CRNM bleeding, recurrent VTE, and all-cause hospitalization. Generalized linear and two-part models were used to estimate MB-, recurrent VTE-, and all-cause related costs (per patient per month [PPPM]).Results: In the pre-matched cohort, 25,284 (66.9%) patients were prescribed warfarin and 12,515 (33.1%) apixaban. After 1:1 PSM, 11,363 matched pairs of apixaban-warfarin patients were included for a mean follow-up of 4.0 and 4.4 months, respectively. Matched cohorts had a mean age of 78 years and mean Charlson Comorbidity Index score of 2.9. Warfarin was associated with a higher risk of MB (hazard ratio [HR] = 1.31; 95% confidence interval [CI] = 1.10-1.57) and CRNM bleeding (HR = 1.31; 95% CI = 1.19-1.43) vs apixaban. The risks of recurrent VTE (HR = 0.96; 95% CI = 0.70-1.33) and all-cause hospitalization (HR = 1.05; 95% CI = 0.99-1.12) were similar among warfarin and apixaban patients. Warfarin patients had higher MB-related ($147 vs $75; p = .003) and all-cause costs PPPM ($3,267 vs $3,033; p < .001), but similar recurrent VTE-related medical costs PPPM ($30 vs $36; p = .516) vs apixaban patients.Conclusions: Warfarin was associated with significantly higher risk of MB and CRNM bleeding as well as higher MB-related and all-cause costs vs apixaban patients. Recurrent VTE risk and costs were similar among warfarin and apixaban patients.

Hospital Resource Utilization and Costs Associated With Warfarin Versus Apixaban Treatment Among Patients Hospitalized for Venous Thromboembolism in the United States.

A real-world US database analysis was conducted to evaluate the hospital resource utilization and costs of patients hospitalized for venous thromboembolism (VTE) treated with warfarin versus apixaban. Additionally, 1-month readmissions were evaluated. Of 28 612 patients with VTE identified from the Premier Hospital database (August 2014-May 2016), 91% (N = 26 088) received warfarin and 9% (N = 2524) received apixaban. Outcomes were assessed after controlling for key patient/hospital characteristics. For index hospitalizations, the average length of stay (LOS) was longer (3.8 vs 3.1 days, P < .001; difference: 0.7 days) and mean hospitalization cost higher (US$3224 vs US$2,740, P < .001; difference: US$484) for warfarin versus apixaban-treated patients. During the 1-month follow-up period, warfarin treatment was associated with a greater risk of all-cause readmission (odds ratio [OR]: 1.27; 95% confidence interval [CI]: 1.09-1.48, P = .003), major bleeding (MB)-related readmission (OR: 2.10; 95% CI: 1.03-4.27, P = .04), and any bleeding-related readmission (OR: 1.67; 95% CI: 1.09-2.56, P = .02) versus apixaban. The results of this real-world analysis show that compared to warfarin, apixaban treatment was associated with shorter index hospital stays, lower index hospitalization costs, and reduced risk of MB-related readmissions among hospitalized patients with VTE.

Meta-analysis of safety for low event-rate binomial trials.

This article focuses on meta-analysis of low event-rate binomial trials. We introduce two forms of random effects: (1) 'studies at random' (SR), where we assume no more than independence between studies; and (2) 'effects at random' (ER), which forces the effect size distribution to be independent of the study design. On the basis of the summary estimates of proportions, we present both unweighted and study-size weighted methods, which, under SR, target different population parameters. We demonstrate mechanistically that the popular DerSimonian-Laird (DL) method, as DL actually warned in their paper, should never be used in this setting. We conducted a survey of the major cardiovascular literature on low event-rate studies and found that DL using odds ratios or relative risks to be the clear method of choice. We looked at two high profile examples from diabetes and cancer, respectively, where the choice of weighted versus unweighted methods makes a large difference. A large simulation study supports the accuracy of the coverage of our approximate confidence intervals. We recommend that before looking at their data, users should prespecify which target parameter they intend to estimate (weighted vs. unweighted) but estimate the other as a secondary analysis. Copyright © 2012 John Wiley & Sons, Ltd.

How well have practices followed guidelines in prescribing antihypertensive drugs: the role of health insurance.

BACKGROUND: The US Joint National Committee (JNC) on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure issues guidelines on the optimal first-line drug therapy in treating hypertension. Despite broad dissemination of these guidelines, prescribing practices have long remained discrepant with recommendations. The purpose of this study was to examine the role of insurance type in the selection of drugs for hypertension treatment in light of the JNC guidelines. METHODS: Subjects were derived from the 1996 Medical Expenditures Panel Survey who had a diagnosis of essential hypertension and who were prescribed a diuretic, beta-blocker, calcium channel blocker (CCB), or ACE inhibitor (ACEI) as monotherapy. Using the nationally representative sample, this study presents the first estimates of the impact of insurance policies on the choice of antihypertensive drugs while controlling for predisposing, enabling, and need variables in the context of a logistic health-care utilization model. RESULTS: Nationally in 1996, more than twice as many subjects (7.3 million) were taking ACEIs or CCBs compared to diuretics or beta-blockers (3.1 million) as the first-line drug therapy, a sharp contrast to the JNC guidelines. Patients with health maintenance organization (HMO) insurance were much less likely than fee for service (FFS) patients to follow the JNC guidelines in this respect (odds ratio 0.50, P <.01), controlling for all other factors. Individuals with all other public insurance and no insurance were not statistically different from the FFS group in the use of the study drugs. Other significant factors in the regression model were being of African American descent, being unmarried, having higher out-of-pocket payment, being in excellent physical health, having diabetes, and being diagnosed with essential hypertension after 1988. Each was associated with a decreased likelihood of following the JNC recommendations for the use of diuretics or beta-blockers. CONCLUSIONS: After controlling for other predisposing, enabling, and need variables, patients who had HMO coverage were significantly more likely than FFS patients to receive ACEIs or CCBs. Given a popular public perception of HMOs being most cost conscious in providing health care, further research is needed to understand why prescribing patterns associated with HMOs have poorly followed the JNC recommendations.