Comparative Effectiveness Research for CAR-T Therapies in Multiple Myeloma: Appropriate Comparisons Require Careful Considerations of Data Sources and Patient Populations.

BACKGROUND AND OBJECTIVE: Registrational trials for ciltacabtagene autoleucel [cilta-cel]) and idecabtagene vicleucel [ide-cel] chimeric antigen receptor T-cell (CAR-T) therapies were single-arm studies conducted with relapse refractory multiple myeloma (MM) patients who were triple-class-exposed (TCE) or triple-class-refractory (TCR). It is critical for researchers conducting comparative effectiveness research (CER) to carefully consider the most appropriate data sources and comparable patient populations. The aim of this study was to identify potential data sources and populations for comparing to single-arm CAR-T trials CARTITUDE-1 (cilta-cel) and KarMMa (ide-cel). METHODS: A 2-part global systematic literature search produced a review of (1) clinical trials of National Comprehensive Cancer Network (NCCN) guideline preferred regimens in previously treated MM, and (2) real-world data cohorts of TCE or TCR populations, published between 1/1/2015 and 12/10/2020, with sample sizes of > 50 patients and reporting survival-related outcomes. Implications on CER and accepted best practices are discussed. RESULTS: Nine clinical trials of NCCN preferred regimens were identified along with five real-world data-based publications. No clinical trials evaluated patients with TCE or TCR MM. Among the real-world data-based publications, two evaluated patients exclusively with TCR MM, two analyzed a mixed population of patients with TCE or TCR MM, and one publication assessed patients exclusively with TCE MM. Real-world data treatment patterns were heterogeneous. CONCLUSION: Current NCCN preferred regimens were not specifically studied in TCE or TCR MM patients, although some studies do include a proportion of these types of patients. Therefore, appropriate matching of populations using either real-world data or patient level clinical trial data is critical to putting trials of novel CAR-Ts (i.e., CARTITUDE-1 or KarMMa) into appropriate comparative context.

Adherence to rivaroxaban versus apixaban among patients with non-valvular atrial fibrillation: Analysis of overall population and subgroups of prior oral anticoagulant users.

BACKGROUND: Medication non-adherence can result in poor health outcomes. Understanding differences in adherence rates to non-vitamin K oral anticoagulants (NOACs) could guide treatment decisions and improve clinical outcomes among patients with non-valvular atrial fibrillation (NVAF). OBJECTIVE: To compare adherence to rivaroxaban and apixaban among the overall NVAF population and subgroups of prior oral anticoagulant (OAC) users (e.g., multiple comorbidities, non-adherence risk factors). METHODS: Using healthcare claims from the Truven Health Analytics MarketScan (7/2012-7/2015), adult patients with ≥2 dispensings of rivaroxaban or apixaban ≥ 180 days apart with > 60 days of supply, ≥ 6 months of pre- and post-index eligibility, ≥ 1 atrial fibrillation diagnosis pre- or on the index date, and without valvular involvement were identified. Propensity-score methods adjusting for potential baseline confounders were used to create matched cohorts of rivaroxaban and apixaban patients. Adherence was assessed during the implementation phase using the percentage of patients with proportion of days covered (PDC) ≥0.8 at 6 months. Subgroups of patients with prior OAC use were evaluated; additional subgroups were identified and evaluated by Quan-Charlson Comorbidity index ≥2 and presence of non-adherence risk factors (i.e., mental disorders, stress, isolation, and rheumatoid arthritis). RESULTS: A total of 13,890 NVAF subjects were included in each of the 2 matched cohorts. All baseline characteristics were balanced between cohorts. At 6 months, significantly more rivaroxaban users were adherent to treatment compared to apixaban users (81.8% vs. 78.0%; absolute difference of 3.8%; p<.001). Rivaroxaban users had significantly higher adherence rates in all subgroups examined. CONCLUSION: Rivaroxaban users had consistently higher adherence rates than apixaban users overall and among all NVAF subgroups examined.

Effectiveness and safety of anticoagulants for the treatment of venous thromboembolism in patients with cancer.

Anticoagulation is used to treat venous thromboembolism (VTE) in cancer patients, but may be associated with an increased risk of bleeding. VTE recurrence and major bleeding were assessed in cancer patients treated for VTE with the most currently prescribed anticoagulants in clinical practice. Newly diagnosed cancer patients (first VTE 1/1/2013-05/31/2015) who initiated rivaroxaban, low-molecular-weight heparin (LMWH), or warfarin were identified from Humana claims data and observed until end of eligibility or end of data availability. VTE recurrence was a hospitalization with a primary diagnosis of VTE ≥7 days after first VTE. Major bleeding events on treatment were identified using validated criteria. Cohorts were compared using Kaplan-Meier rates at 6 and 12 months and Cox proportional hazards models. Cohorts were adjusted for their differences at baseline. A total of 2428 patients (rivaroxaban: 707; LMWH: 660; warfarin: 1061) met inclusion criteria. Patient characteristics were well balanced after weighting. There was a trend for lower VTE recurrence rates in rivaroxaban users compared to LMWH users at 6 months (13.2% vs. 17.1%; P = .060) and significantly lower at 12 months (16.5% vs. 22.2%; P = .030) [HR: 0.72, 95% CI: (0.52-0.95); P = .024]. VTE recurrence rates were also lower for rivaroxaban than warfarin users at 6 months (13.2% vs. 17.5%; P = .014) and 12 months (15.7% vs. 19.9%; P = .017) [HR: 0.74, 95% CI: (0.56-0.96); P = .028]. Major bleeding rates were similar across cohorts. This real-world analysis suggests cancer patients with VTE treated with rivaroxaban had significantly lower risk of recurrent VTE and similar risk of bleeding compared to those treated with LMWH or warfarin.

Evaluation of clinical outcomes among nonvalvular atrial fibrillation patients treated with rivaroxaban or warfarin, stratified by renal function
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BACKGROUND: Renal dysfunction increases the risk of thromboembolic and bleeding events in patients with nonvalvular atrial fibrillation (NVAF). MATERIALS AND METHODS: Adult NVAF patients with ≥ 6 months prior to first warfarin or rivaroxaban dispensing were selected from the IMS Health Real-World Data Adjudicated Claims database (05/2011 - 06/2015) with electronic medical records. Ischemic stroke events, thromboembolic events (venous thromboembolism, myocardial infarction, or ischemic stroke), and major bleeding events were compared between patients by renal function identified by 1) relevant ICD-9-CM diagnosis codes and 2) estimated creatinine clearance (eCrCl). Baseline confounders were adjusted using inverse probability of treatment weights. RESULTS: The diagnosis-based analysis included 39,872 rivaroxaban and 48,637 warfarin users (3,572 and 8,230 with renal dysfunction, respectively). The eCrCl-based analysis included 874 rivaroxaban and 1,069 warfarin users (66 and 208 with eCrCl < 60 mL/min, respectively). In the diagnosis-based analysis, rivaroxaban users with renal dysfunction had a significantly lower stroke rate (HR = 0.55, p = 0.0004) compared to warfarin users; rivaroxaban users with and without renal dysfunction had significantly lower thromboembolic event rates (HR = 0.62, p < 0.0001; and HR = 0.64, p < 0.0001, respectively), and similar major bleeding rates to warfarin users. In the eCrCl-based analysis, rivaroxaban users with eCrCl ≥ 60 mL/min had a significantly lower thromboembolic event rate, but other outcomes were not statistically significant. CONCLUSION: Rivaroxaban-treated NVAF patients with diagnosed renal dysfunction had a significantly lower stroke rate compared to warfarin-treated patients. Regardless of renal dysfunction diagnoses, rivaroxaban users had lower thromboembolic event rates compared to warfarin users, and a similar rate of major bleeding. eCrCl-based analysis was limited by a small sample size.
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Adherence to Rivaroxaban Compared with Other Oral Anticoagulant Agents Among Patients with Nonvalvular Atrial Fibrillation.

BACKGROUND: Adherence to oral anticoagulant (OAC) agents is important for patients with nonvalvular atrial fibrillation (NVAF) to prevent potentially severe adverse events. OBJECTIVE: To compare real-world adherence rates and time to discontinuation for rivaroxaban versus other OACs (apixaban, dabigatran, and warfarin) among patients with NVAF using claims-based data. METHODS: Health care claims from the IMS Health Real-World Data Adjudicated Claims database (July 2012-June 2015) were analyzed. Adherence rate was defined as the percentage of patients with proportion of days covered (PDC) ≥ 0.80 and ≥ 0.90. Discontinuation was defined as a gap of more than 30 days between the end of a dispensing days of supply and the start date of the next fill, if any. Patients were included if they had ≥ 2 dispensings of rivaroxaban, apixaban, dabigatran, or warfarin at least 180 days apart (the first was considered the index date), had > 60 days of supply, had ≥ 6 months of pre-index eligibility, had ≥ 1 atrial fibrillation (AF) diagnosis pre-index or at index date, and had no valvular involvement. A logistic regression model was used to evaluate adherence to OAC therapy, while a Cox model was used to compare time to discontinuation; both models adjusted for baseline confounders. RESULTS: A total of 13,645 rivaroxaban, 6,304 apixaban, 3,360 dabigatran, and 13,366 warfarin patients were identified. A significantly higher proportion of rivaroxaban users (80.1%) was adherent to therapy (PDC ≥ 0.80 at 6 months) versus apixaban (75.8%), dabigatran (69.2%), and warfarin users (64.5%). After adjustment, the proportion of patients adherent to therapy remained significantly higher for rivaroxaban users versus apixaban (absolute difference [AD] = 5.8%), dabigatran (AD = 9.5%), and warfarin users (AD = 13.6%; all P < 0.001). More pronounced differences were found with a PDC ≥0.90. In addition, rivaroxaban users were significantly less likely to discontinue therapy compared with other OACs after adjustments (all P < 0.05). CONCLUSIONS: Among NVAF patients, rivaroxaban was associated with significantly higher adherence rates relative to other OACs whether using either a PDC of > 0.80 or > 0.90. Such differences in adherence could translate into improved patient outcomes and lower health care costs. DISCLOSURES: This research was funded by Janssen Scientific Affairs. Ashton, Crivera, and Schein are employees and stockholders of Janssen Scientific Affairs. Laliberté, Germain, Wynant, and Lefebvre are employees of Analysis Group, a consulting company that received research grants from Janssen Scientific Affairs in connection with this study. McHorney is an employee of Evidera, a consulting company that received research grants from Janssen Scientific Affairs in connection with this study. Peterson received research grants from Janssen Scientific Affairs in connection with this study. All authors contributed to concept and design. The data were collected by Germain, Wynant, Laliberté, and Lefebvre and interpreted primarily by McHorney and Peterson, with the assistance of Lefebvre, Laliberté, Ashton, Crivera, and Schein. The manuscript was written primarily by Laliberté, Germain, and Lefebvre, with the assistance of Wynant. Revisions were made primarily by Ashton, Crivera, McHorney, Schein, and Peterson.

Association between rivaroxaban use and length of hospital stay, treatment costs and early outcomes in patients with pulmonary embolism: a systematic review of real-world studies.

BACKGROUND: In the EINSTEIN-Pulmonary Embolism (PE) trial, subjects randomized to rivaroxaban versus enoxaparin bridging to vitamin K antagonist (VKA) therapy experienced a reduced index hospital length of stay (LOS). We sought to conduct a systematic review of real-world studies comparing LOS, costs and early outcomes among patients treated with rivaroxaban or parenterally bridged VKA in routine practice. METHODS: We searched Medline and Scopus from 1 January 2011 to 30 November 2016 to identify observational studies comparing acute PE patients anticoagulated with rivaroxaban or parenterally bridged VKA and reporting data on index hospital LOS, costs and/or early post-PE outcomes. Studies not using appropriate methods for minimizing confounding bias or not published in English were excluded. RESULTS: Five studies met inclusion criteria. Rivaroxaban use was associated with decreased index hospital LOS (range: 1.36-1.70 days) and treatment costs (range: $1818-$2688) during an index stay compared to parenterally bridged warfarin. No differences in early readmission for recurrent thrombosis were noted between anticoagulation strategies. Readmission for major bleeding was rare in both cohorts. Similar reductions in LOS (range: 0.23-4.3 days) and costs (range: $251-$7094) were observed with rivaroxaban in studies restricted to patients deemed low risk for early complications by clinical gestalt or by a clinical- or claims-based risk stratification tool. CONCLUSIONS: Regardless of patient predicted risk of post-PE complications, real-world studies suggest that rivaroxaban is associated with a reduced hospital LOS and costs versus parenterally bridged warfarin, without increasing readmission.

Risk for Venous Thromboembolism Recurrence Among Rivaroxaban-treated Patients Who Continued Versus Discontinued Therapy: Analyses Among Patients with VTE.

PURPOSE: The EINSTEIN-Extension trial showed that an extended rivaroxaban treatment significantly reduced the risk for venous thromboembolic (VTE) recurrence. The present study assessed the risk for VTE recurrence and major bleeding associated with extended rivaroxaban treatment in a clinical practice setting among patients with VTE. METHODS: A retrospective study was conducted using claims data from February 2011 to April 2015. It included adult patients who initiated rivaroxaban therapy within 7 days after their first VTE and who continuously used rivaroxaban for at least 3 months (index date: end of initial 3-month treatment). Categorized into discontinued and continued cohorts, patients were followed up from the index date until the end of continuous treatment (continued cohort) or end of data or reinitiation of oral anticoagulant therapy (discontinued cohort). Using inverse probability of treatment weights controlling for confounders, adjusted Kaplan-Meier rates of recurrent VTE and major bleeding events were compared. FINDINGS: The analysis showed that, compared with the discontinued cohort (n = 1,536), the continued cohort (n = 5,933) had a significantly lower VTE recurrence rate after an additional 3 months (0.70% vs 1.70%), 6 months (1.41% vs 2.34%), 9 months (1.82% vs 3.01%), and 12 months (1.97% vs 3.01%) of treatment (all, p < 0.05). The difference in the cumulative event rates for major bleeding was not statistically significant. Similar results were obtained in an analysis among patients with VTE receiving rivaroxaban for ≥6 months. IMPLICATIONS: Our results suggest that, in clinical practice settings, patients with VTE who continued rivaroxaban therapy after the initial 3- or 6-month treatment period had a significantly lower risk for VTE recurrence without a statistically significant increased risk for major bleeding.

Overall Effectiveness of Rivaroxaban in Patients with Pulmonary Embolism.

PURPOSE: Due to limited evidence on the impact of rivaroxaban in clinical practice, we compared the effectiveness of rivaroxaban versus standard of care (SOC) among patients in the Veterans Health Administration. METHODS: Adult patients with continuous enrollment in a health plan with medical and pharmacy benefits for ≥12 months before and ≥3 months after an inpatient diagnosis of pulmonary embolism (PE) between October 1, 2011, and June 30, 2015, and a prescription claim for an anticoagulant during the index hospitalization, were included. SOC drugs were low-molecular-weight heparin, unfractionated heparin, and warfarin. Propensity score matching was used in comparing PE-related outcomes (recurrent venous thromboembolism, major bleeding, and death), hospital-acquired complications (HACs), health care resource utilization, and costs among patients receiving SOC versus rivaroxaban. We defined net clinical benefit as 1 minus the combined rate of PE-related outcomes and HACs. FINDINGS: Among 6746 patients with PE, 208 received rivaroxaban, 4641 received SOC and 1897 received other anticoagulants. Most (95%) were male; 22% were black. After 1:3 propensity score matching, there were 203 rivaroxaban and 609 SOC patients. During the 90-day follow-up, rivaroxaban users had similar rates of PE-related outcomes, but fewer had experienced at least 1 HAC (10.3% vs 15.9%; P = 0.0506), resulting in better net clinical benefit (82.8% vs 71.1%; P = 0.001). Rivaroxaban users had fewer outpatient visits per patient (17.0 vs 19.9; P = 0.0005), a similar rehospitalization rate (0.2 vs 0.3; P = 0.084), lesser inpatient costs (US $3501 vs $6189; P < 0.0001), lesser inpatient costs and lesser total costs ($10,545 vs $14,192; P = 0.0002). When the sample was limited to patients with low-risk PE, we found similar patterns. IMPLICATIONS: Patients with PE prescribed rivaroxaban had similar PE-related outcomes, but fewer HACs and lesser total costs, than did patients on SOC.

Importance of balancing follow-up time and impact of oral-anticoagulant users' selection when evaluating medication adherence in atrial fibrillation patients treated with rivaroxaban and apixaban.

OBJECTIVE: Studies comparing medications adherence have become common yet they often do not account for differences in relative follow-up. Patient selection criteria may impact validity and comparability of these studies as well. METHODS: Adults with non-valvular atrial fibrillation, ≥1 rivaroxaban or apixaban dispensing (index date), and ≥1 year of pre-index eligibility were selected from IMS Health Real World Data Adjudicated Claims (IMS RWD Adjudicated Claims) and Truven Health MarketScan Research (Truven MarketScan) databases. Adherence was evaluated using proportion of days covered (PDC) ≥ 0.8 for treatment cohorts: (1) unmatched, with different follow-up, (2) propensity-score matched with similar follow-up, (3) matched, with similar follow-up and ≥2 rivaroxaban or apixaban dispensings, and (4) matched, with similar follow-up and chronic medication users only. Robustness was verified with PDC ≥0.9. RESULTS: In the IMS RWD Adjudicated Claims database, rivaroxaban users had a longer mean follow-up than apixaban users (408 versus 254 days, respectively; p < .01). While crude comparisons demonstrated lower adherence rates for rivaroxaban than apixaban (-12.4 percentage points [pp]; p < .05), these difference attenuated after matching and (1) balancing follow-up (-2.2 pp; p < .05), (2) excluding single-time medication users (0.2 pp; p > .05), and reversed after (3) excluding non-chronic medication users (5.0 pp; p < .05). Results obtained were consistent when these analyses were repeated within the Truven MarketScan databases and when using a PDC ≥0.9. CONCLUSION: Medication adherence comparisons need to account for differences in follow-up. Selection of chronic medication users may impact comparative adherence advantage between medications.

Shortened hospital length of stay and lower costs associated with rivaroxaban in patients with pulmonary embolism managed as observation status.

BACKGROUND: Unlike rivaroxaban, treatment of patients with pulmonary embolism (PE) with warfarin requires parenteral bridging and coagulation monitoring that may prolong length-of-stay (LOS) and increase hospital costs. AIMS: The aim of this study was to compare LOS, hospital costs and readmissions in PE patients managed through observation stays treated with rivaroxaban or parenterally bridged warfarin. METHODS: Premier Hospital claims data from November 2012 to March 2015 were used to identify patients with a primary diagnosis code for PE managed through an observation stay and with ≥1 claim for a PE-related diagnostic test on day 0-2. Rivaroxaban users, allowing ≤2 days of prior parenteral therapy, were 1:1 propensity-score matched to patients receiving parenterally bridged warfarin. LOS, the proportion of encounters lasting >2 midnights, total hospital costs of the index visit and risk of readmission for venous thromboembolism (VTE) or major bleeding during the same month or 2 months subsequent to the index event were compared between matched cohorts using multivariable regression. RESULTS: A total of 312 rivaroxaban users were matched to 312 patients receiving parenterally bridged warfarin. Rivaroxaban was associated with an average of 0.27-day shorter LOS, a 52% decreased odds of an encounter lasting >2 midnights and a $403 mean reduction in costs vs parenterally bridged warfarin (P≤.002 for all). The readmission rate for VTE during the same or subsequent 2 months following the index PE was similar between cohorts (P=.75). No patient in either cohort was readmitted for major bleeding. CONCLUSION: Rivaroxaban was associated with shortened LOS and lowered cost vs parenterally bridged warfarin in PE observation stay patients, without increases in the short-term rate of complications or readmission.

Is Rivaroxaban Associated With Shorter Hospital Stays and Reduced Costs Versus Parenteral Bridging to Warfarin Among Patients With Pulmonary Embolism?

OBJECTIVE: We sought to compare the length of stay (LOS) and total costs for patients with pulmonary embolism (PE) treated with either rivaroxaban or parenterally bridged warfarin. METHODS: This retrospective claims analysis was performed in the Premier Database from November 2012 to March 2015. Adult patients were included if they had a hospital encounter for PE (an International Classification of Diseases, Ninth Revision code = 415.1×) in the primary position, a claim for ≥1 diagnostic test for PE on day 0 to 2, and initiated rivaroxaban or parenteral anticoagulation/warfarin. Rivaroxaban users (allowing ≤2 days of prior parenteral therapy) were 1:1 propensity score matched to patients receiving parenterally bridged warfarin. Length of stay, total costs, and readmission for venous thromboembolism (VTE) or major bleeding during the same or subsequent 2 months following the index event were compared between cohorts. Analysis restricted to patients with low-risk PE was also performed. RESULTS: Characteristics of the matched PE cohorts (n = 3466 per treatment) were well balanced. Rivaroxaban use was associated with a 1.36-day shorter LOS and $2304 reduction in total costs compared to parenterally bridged warfarin ( P < .001 for both). Rates of readmission for VTE were similar between cohorts (1.7% vs 1.6%; P = .64). No difference was observed between treatments for readmission for major bleeding (0.2% vs 0.2%; P > .99). In analyses restricted to low-risk patients (n = 1551 per treatment), rivaroxaban was associated with a 1.01-day and a $1855 reduction in LOS and costs, respectively ( P < .001 for both). Rates of readmission were again similar between treatments ( P > .56 for all). CONCLUSION: Rivaroxaban significantly reduced hospital LOS and costs compared to parenterally bridged warfarin, without increasing the risk of readmission.

Healthcare costs associated with rivaroxaban or warfarin use for the treatment of venous thromboembolism.

INTRODUCTION: Rivaroxaban has been shown to have similar efficacy but less major bleeding than warfarin in randomized trials of patients experiencing venous thromboembolism (VTE). This report sought to assess healthcare costs up to 12-months following an index VTE in patients prescribed either rivaroxaban or warfarin. MATERIALS AND METHODS: This study analyzed claims from the MarketScan Commercial Claims and Encounters Database from November 2011-July 2015. It selected adults newly-diagnosed with VTE (deep vein thrombosis [DVT] or pulmonary embolism [PE]) if they had an outpatient prescription claim for rivaroxaban or warfarin within 7-days of the index event. Warfarin users were 2:1 propensity-score matched to rivaroxaban users and followed until the end of insurance coverage, end of data availability or 12-months of follow-up. Total per patient healthcare costs, including inpatient, outpatient, and overall pharmacy costs, were compared using a multivariable generalized linear model. RESULTS: In total, 10,929 rivaroxaban patients were matched to 21,858 warfarin patients. Mean follow-up for rivaroxaban and warfarin patients was 317- and 321-days for those experiencing an index DVT, and 313- and 318-days for those with PE. Mean overall treatment costs per patient were lower for rivaroxaban vs warfarin users (-$1,116, p = .0016). This cost difference was driven by lower inpatient (-$622) and outpatient (-$1,156) treatment costs, and the higher pharmacy costs ($661) were, therefore, fully offset. Results were similar when analysis was restricted to DVT patients. No significant difference in total costs was observed in patients experiencing an index PE. LIMITATIONS: Claims databases are subject to inaccuracies and missing data. Prescription claims may not fully reflect actual medication utilization. Despite propensity-score matching and regression, residual confounding cannot be excluded. CONCLUSIONS: Rivaroxaban was associated with significantly lower total per patient VTE treatment costs, despite higher pharmacy costs. These savings are the result of decreased inpatient and outpatient healthcare utilization costs associated with rivaroxaban.

Pulmonary Embolism Inpatients Treated With Rivaroxaban Had Shorter Hospital Stays and Lower Costs Compared With Warfarin.

PURPOSE: Using real-world data, this study compares inpatient length of stay (LOS) and costs for patients with a primary diagnosis of pulmonary embolism (PE) initiating treatment with oral anticoagulation with rivaroxaban versus warfarin. METHODS: Hospitalizations from MarketScan's Hospital Drug Database were selected from November 1, 2012, through December 31, 2013, for adults with a primary diagnosis of PE initiating treatment with rivaroxaban or warfarin. Warfarin patients were matched 1:1 to rivaroxaban patients using exact and propensity score matching. Hospital LOS, treatment patterns, and hospitalization costs were evaluated. FINDINGS: Matched cohorts included 751 rivaroxaban-treated patients and 751 warfarin-treated patients. Adjusted mean LOS was 3.77 days for rivaroxaban patients (95% CI, 3.66-3.87 days) and 5.48 days for warfarin patients (95% CI, 5.33-5.63 days; P < .001). Mean (SD) LOS was shorter for patients taking rivaroxaban whether admission was for provoked PE (rivaroxaban: 5.2 [5.1] days; warfarin: 7.0 [6.5] days; P < .001) or unprovoked PE (rivaroxaban: 3.4 [2.3] days; warfarin: 5.1 [2.7] days; P < .001). Mean (SD) days from first dose to discharge were 2.5 (1.7) (rivaroxaban) and 4.0 (2.9) (warfarin) when initiated with parenteral anticoagulants (P < .001) and 2.7 (1.7) (rivaroxaban) and 4.0 (2.2) (warfarin) without parenteral anticoagulants (P < .001). The rivaroxaban cohort incurred significantly lower unadjusted mean (SD) hospitalization costs (rivaroxaban: $8473 [$9105]; warfarin: $10,291 [$9185]; P < .001), confirmed by covariate adjustment with generalized linear modeling estimating predicted mean hospitalization costs of $8266 for rivaroxaban patients (95% CI, $7851-$8681) and $10,511 for warfarin patients (95% CI, $10,031-$10,992; P < .001). IMPLICATIONS: patients with PE treated with rivaroxaban incurred significantly lower hospitalization costs by $2245 per admission compared with patients treated with warfarin, which was attributable to cost offsets from 1.71 fewer days of stay in the hospital.

Shorter Hospital Stays and Lower Costs for Rivaroxaban Compared With Warfarin for Venous Thrombosis Admissions.

BACKGROUND: Venous thromboembolism, including deep vein thrombosis and pulmonary embolism, results in a substantial healthcare system burden. This retrospective observational study compared hospital length of stay (LOS) and hospitalization costs for patients with venous thromboembolism treated with rivaroxaban versus those treated with warfarin. METHODS AND RESULTS: Hospitalizations for adult patients with a primary diagnosis of deep vein thrombosis or pulmonary embolism who were initiated on rivaroxaban or warfarin were selected from MarketScan's Hospital Drug Database between November 1, 2012, and December 31, 2013. Patients treated with warfarin were matched 1:1 to patients treated with rivaroxaban using exact and propensity score matching. Hospital LOS, time from first dose to discharge, and hospitalization costs were reported descriptively and with generalized linear models (GLMs). The final study cohorts each included 1223 patients (751 with pulmonary embolism and 472 with deep vein thrombosis). Cohorts were well matched for demographic and clinical characteristics. Mean (±SD) LOS was 3.7±3.1 days for patients taking rivaroxaban and 5.2±3.7 days for patients taking warfarin, confirmed by GLM-adjusted results (rivaroxaban 3.7 days, warfarin 5.3 days, P<0.001). Patients with provoked venous thromboembolism admissions showed longer LOSs (rivaroxaban 5.1±4.5 days, warfarin 6.5±5.6 days, P<0.001) than those with unprovoked venous thromboembolism (rivaroxaban 3.3±2.4 days, warfarin 4.8±2.8 days, P<0.001). Days from first dose to discharge were 2.4±1.7 for patients treated with rivaroxaban and 3.9±3.7 for patients treated with warfarin when initiated with parenteral anticoagulants (P<0.001), and 2.7±1.7 and 3.7±2.1, respectively, when initiated without parenteral anticoagulants (P<0.001). Patients initiated on rivaroxaban incurred significantly lower mean total hospitalization costs ($8688±$9927 versus $9823±$9319, P=0.004), confirmed by modeling (rivaroxaban $8387 [95% confidence interval, $8035-$8739]; warfarin $10 275 [95% confidence interval, $9842-$10 708]). CONCLUSIONS: Rivaroxaban was associated with significantly shorter hospital LOS and lower hospitalization costs compared with warfarin.

Hospitalizations and Other Health Care Resource Utilization Among Patients with Deep Vein Thrombosis Treated with Rivaroxaban Versus Low-molecular-weight Heparin and Warfarin in the Outpatient Setting.

PURPOSE: Compared with low-molecular-weight heparin (LMWH) and warfarin, the oral anticoagulant rivaroxaban has advantages, such as simplified care, that may lead to less health care resource utilization. METHODS: A retrospective, matched-cohort analysis was conducted using claims dated between January 2011 and December 2013 from the Truven Health Analytics MarketScan databases. Adult patients who had a primary diagnosis of deep vein thrombosis (DVT) during an outpatient or emergency room (ER) visit after November 2, 2012, and who were treated with rivaroxaban or LMWH/warfarin on the same day, were identified. Patients were observed over 1, 2, 3, and 4 weeks after the DVT diagnosis. The mean numbers of hospitalizations for all causes and for venous thromboembolism (VTE) (which included those for DVT or pulmonary embolism), as well as other health care resource utilization (ER, outpatient, and other visits), and the associated health care costs and pharmacy costs, were evaluated and compared between cohorts using the Lin method. FINDINGS: All of the 512 rivaroxaban-treated patients were well matched with the LMWH/warfarin-treated patients. The mean numbers of all-cause hospitalizations were significantly lower in the rivaroxaban users compared with those in the LMWH/warfarin users over 1 week (0.012 vs 0.032; P = 0.044) and 2 weeks (0.022 vs 0.048; P = 0.040). The corresponding mean numbers of VTE-related hospitalizations were significantly lower with rivaroxaban over 1 week (0.008 vs 0.028; P = 0.020), 2 weeks (0.016 vs 0.042; P = 0.020), and 4 weeks (0.034 vs 0.068; P = 0.036). The mean numbers of all-cause and VTE-related outpatient visits were also significantly lower in rivaroxaban users compared with those in LMWH/warfarin users over 1, 2, 3, and 4 weeks (all, P < 0.001). In terms of all-cause and VTE-related ER and other visits, no statistically significant differences were found between cohorts over the first 4 weeks. The associated mean all-cause total health care costs were significantly lower in the rivaroxaban users compared with those in the LMWH/warfarin users over 1 week (US $2332 vs $3428; P < 0.001) and 2 weeks ($3108 vs $4524; P < 0.001); moreover, significantly lower mean costs related to all-cause hospitalizations (weeks 1 and 2) and pharmacy (weeks 1-4) were observed in patients treated with rivaroxaban, while no differences were found in costs related to ER visits (weeks 1-4), outpatient visits (weeks 1-4), or other visits (with the exception of week 1). IMPLICATIONS: Patients with DVT treated with rivaroxaban after an outpatient/ER visit had significantly lower mean numbers of hospitalizations and outpatient visits, as well as lower mean total, hospitalization, and pharmacy costs during the first 2 weeks of treatment compared with those in matched LMWH/warfarin users.

Rivaroxaban versus Heparin Bridging to Warfarin Therapy: Impact on Hospital Length of Stay and Treatment Costs for Low-Risk Patients with Pulmonary Embolism.

STUDY OBJECTIVE: To compare hospital length of stay (LOS) and hospital treatment costs in low-risk patients with pulmonary embolism (PE) anticoagulated with rivaroxaban or heparin bridging to warfarin therapy. DESIGN: Retrospective review of electronic health records and hospital billing records. SETTING: Large, teaching hospital in the northeastern United States. PATIENTS: One hundred ninety adults with objectively confirmed acute PE presenting to the emergency department between November 1, 2012, and May, 12, 2015, who were classified as low risk of early mortality and received anticoagulation with either rivaroxaban or heparin (i.e., unfractionated heparin or low-molecular-weight heparin) bridging to warfarin therapy were included in the analysis. Patients were identified as low risk by at least one of the following prediction rules: simplified Pulmonary Embolism Severity Index (sPESI; 115 patients), Hestia criteria (87 patients), or In-hospital Mortality for Pulmonary Embolism using Claims Data (IMPACT; 108 patients); these were not mutually exclusive, as patients could be classified as low risk by more than one risk stratification tool. MEASUREMENTS AND MAIN RESULTS: We divided low-risk patients identified by each prediction rule into two cohorts: those receiving rivaroxaban (allowing ≤ 2 days of prior heparin use) or heparin bridging to warfarin therapy. The primary end points for this study were LOS (number of days from the patient's arrival at our institution until discharge) and total hospital treatment costs (our institution's actual costs to provide treatment) for the index PE hospital encounter. Using multivariable generalized linear model regression (gamma-distributed error and log-link), we estimated differences in LOS and hospital costs (in 2015 U.S. dollars) between the two cohorts after covariate adjustment. Rivaroxaban was associated with significantly shorter adjusted LOS (range -2.1 to -4.3 days) and significantly lower index hospital costs (range -$3835 to -$7094) versus heparin bridging to warfarin, regardless of the prediction rule used to identify low-risk patients. CONCLUSION: Among low-risk PE patients identified by using sPESI, Hestia or IMPACT, rivaroxaban was associated with significantly shorter LOS and lower hospital treatment costs versus heparin bridging to warfarin.

Effects of rivaroxaban versus warfarin on hospitalization days and other health care resource utilization in patients with nonvalvular atrial fibrillation: an observational study from a cohort of matched users.

PURPOSE: Compared with warfarin, the new target-specific oral anticoagulant agents may have advantages, such as shorter hospital length of stay, in patients with nonvalvular atrial fibrillation (NVAF). The objective of the present study was to assess, among patients with NVAF, the effects of rivaroxaban versus warfarin on the number of hospitalization days and other health care resource utilization in a cohort of rivaroxaban users and matched warfarin users. METHODS: Data from health care claims dated from May 2011 to December 2012 from the Humana database were analyzed. Adult patients newly initiated on treatment with rivaroxaban or warfarin, with ≥2 diagnoses of AF (ICD-9-CM code 427.31), and without valvular AF were identified. Based on propensity score methods, warfarin recipients were matched 1:1 to rivaroxaban recipients. The end of the observation period was defined as the end of data availability, the end of insurance coverage, death, the date of a switch to another anticoagulant agent, or day 14 of treatment nonpersistence. The total number of hospitalization days and other health care resource utilization parameters (numbers of hospitalizations, emergency department [ED] visits, and outpatient visits) were evaluated using the method by Lin et al. FINDINGS: Matches for all rivaroxaban recipients were found, and the characteristics of the matched groups (n = 2253 per group) were well balanced. The mean age of both cohorts was 74 years; 46% were female. The estimated mean total numbers of hospitalization days were significantly less in rivaroxaban users compared with those in warfarin users (all-cause, 2.71 vs 3.87 days [P = 0.032]; AF-related, 2.11 vs 3.02 days [P = 0.014]). The numbers of outpatient visits were also significantly less (all-cause, 25.26 vs 35.79 visits [P < 0.001]; AF-related, 5.48 vs 9.06 visits [P < 0.001]). Rivaroxaban users had a lesser estimated mean number of all-cause hospitalizations compared with warfarin users (0.55 vs 0.73; P = 0.084), and a significantly lesser estimated mean number of AF-related hospitalizations (0.40 vs 0.57; P = 0.022). The difference in the estimated mean numbers of all-cause ED visits was not statistically significant between the rivaroxaban and warfarin users. IMPLICATIONS: In this study conducted in clinical practice, the estimated mean numbers of hospitalization days, outpatient visits, and AF-related hospitalizations associated with rivaroxaban were significantly less than were those associated with warfarin in these patients with NVAF. The corresponding estimated difference in all-cause ED visits was not statistically significant.