Comparative outcomes associated with rivaroxaban versus warfarin use in elderly patients with atrial fibrillation or acute venous thromboembolism managed in the United States: a systematic review of observational studies

BACKGROUND

Advancing age is a risk factor for developing non-valvular atrial fibrillation (NVAF) or acute venous thromboembolism (VTE). We assessed the comparative effectiveness, safety, costs, and healthcare utilization associated with rivaroxaban versus warfarin in patients of advanced age managed in the United States (US).

METHODS

We conducted a systematic review of Medline and Embase through April 2023 to identify real-world evidence (RWE) studies of older adults (at least 65+ years of age) with either NVAF or VTE who received either rivaroxaban or warfarin in the US and reported an outcome of stroke or systemic embolism (SSE), ischemic stroke (IS), recurrent VTE, major bleeding, intracranial hemorrhage, costs, or healthcare resource utilization. We classified each outcome of interest per study as "positive" (lower risk), "negative" (higher risk), or "neutral" based upon the summary effect size of rivaroxaban versus warfarin.

RESULTS

Twenty-nine RWE studies met inclusion criteria, mostly (83%) in NVAF populations. For SSE with rivaroxaban versus warfarin, 68.8% of studies showed positive effects and 31.2% showed neutral outcome. For major bleeding, 57.7% showed neutral effects, 38.5% showed negative effects, and 3.8% of studies showed positive effects with rivaroxaban versus warfarin. Of the two studies reporting cost data, both were positive, showing lower costs for SSE for rivaroxaban versus warfarin and neutral cost for major bleeding costs.

CONCLUSIONS

This systematic review supports findings from subgroup analyses of randomized controlled trials that, compared with warfarin, rivaroxaban is associated with generally neutral or positive effects on thrombosis and a mixed picture on bleeding outcomes in older adults with either NVAF or VTE treated in the United States.

Weight and BMI Changes Following Initiation of Emtricitabine/Tenofovir Alafenamide Co-Formulated with Darunavir or Co-Administered with Dolutegravir in Overweight or Obese, ART-Naïve People Living with HIV-1

Introduction

Integrase strand transfer inhibitor-based regimens (eg, containing dolutegravir [DTG]) are associated with weight/body mass index (BMI) increases among people living with HIV-1 (PLWH). Assessing antiretroviral therapy (ART)-related weight/BMI changes is challenging, as PLWH may experience return-to-health weight gain as a result of viral suppression. This retrospective, longitudinal real-world study compared weight/BMI outcomes among overweight/obese (BMI ≥25 kg/m²; thus excluding return-to-health weight/BMI changes), treatment-naïve PLWH who initiated darunavir (DRV)/cobicistat (c)/emtricitabine (FTC)/tenofovir alafenamide (TAF) or DTG + FTC/TAF.

Methods

Treatment-naïve PLWH with BMI ≥25 kg/m² who initiated DRV/c/FTC/TAF or DTG + FTC/TAF (index date) had ≥12 months of baseline observation and ≥1 weight/BMI measurement in baseline and post-index periods in the Symphony Health IDV^® database (07/17/2017-12/31/2021) were included. Inverse probability of treatment weighting (IPTW) was used to balance differences in baseline characteristics between cohorts. On-treatment time-to-weight/BMI increases ≥5% were compared between cohorts using weighted adjusted Cox models.

Results

Post-IPTW, 76 overweight/obese DRV/c/FTC/TAF-treated (mean age = 51.2 years, 30.7% female, 35.6% Black, mean baseline BMI = 33.2 kg/m²) and 88 overweight/obese DTG + FTC/TAF-treated PLWH (mean age = 51.5 years, 31.4% female, 31.4% Black, mean baseline BMI = 32.7 kg/m²) were included. The median [interquartile range] time from ART initiation to weight/BMI increase ≥5% was shorter for the DTG + FTC/TAF cohort (21.8 [9.9, 32.3] months) than the DRV/c/FTC/TAF cohort (median and interquartile times not reached; Kaplan-Meier rate at 21.8 months = 20.8%). Over the entire follow-up, overweight/obese PLWH initiating DTG + FTC/TAF had a more than twofold greater risk of experiencing weight/BMI increase ≥5% compared to those initiating DRV/c/FTC/TAF (hazard ratio [95% confidence interval]=2.43 [1.02; 7.04]; p = 0.036).

Conclusion

Overweight/obese PLWH who initiated DTG + FTC/TAF had significantly greater risk of weight/BMI increase ≥5% compared to similar PLWH who initiated DRV/c/FTC/TAF and had shorter time-to-weight/BMI increase ≥5%, suggesting a need for additional monitoring to assess the risk of weight gain-related cardiometabolic disease.

Incidence of cardiometabolic outcomes among people living with HIV-1 initiated on integrase strand transfer inhibitor versus non-integrase strand transfer inhibitor antiretroviral therapies: a retrospective analysis of insurance claims in the United States

INTRODUCTION

Integrase strand transfer inhibitor (INSTI)-containing antiretroviral therapy (ART) has been associated with weight gain, though there is limited information on associations between ART-related weight gain and cardiometabolic outcomes among people living with HIV-1 (PLWH). We, therefore, evaluated risks of incident cardiometabolic outcomes following INSTI versus non-INSTI-based ART initiation in the United States.

METHODS

We conducted a retrospective study using IBM MarketScan Research Databases (12 August 2012-31 January 2021). Treatment-naïve PLWH initiating ART (index date) on/after 12 August 2013 (approval date of the first second-generation INSTI, dolutegravir) were included and censored at regimen switch/discontinuation, end of insurance eligibility or end of data availability. We used inverse probability of treatment weights constructed with baseline (12 months pre-index) characteristics to account for differences between INSTI- and non-INSTI-initiating cohorts. Doubly robust hazard ratios (HRs) obtained from weighted multivariable Cox regression were used to compare time to incident cardiometabolic outcomes (congestive heart failure [CHF], coronary artery disease, myocardial infarction, stroke/transient ischemic attack, hypertension, type II diabetes, lipid disorders, lipodystrophy and metabolic syndrome) by INSTI-initiation status.

RESULTS

Weighted INSTI (mean age = 39 years, 23% female, 70% commercially insured, 30% Medicaid insured) and non-INSTI (mean age = 39 years, 24% female, 71% commercially insured, 29% Medicaid insured) cohorts included 7059 and 7017 PLWH, respectively. The most common INSTI-containing regimens were elvitegravir-based (43.4%), dolutegravir-based (33.3%) and bictegravir-based (18.4%); the most common non-INSTI-containing regimens were darunavir-based (31.5%), rilpivirine-based (30.4%) and efavirenz-based (28.3%). Mean±standard deviation follow-up periods were 1.5±1.5 and 1.1±1.2 years in INSTI- and non-INSTI-initiating cohorts, respectively. INSTI initiators were at a clinically and significantly increased risk of experiencing incident CHF (HR = 2.12, 95% confidence interval [CI] = 1.08-4.05; p = 0.036), myocardial infarction (HR = 1.79, 95% CI = 1.03-5.65; p = 0.036) and lipid disorders (HR = 1.26, 95% CI = 1.04-1.58; p = 0.020); there was no evidence of an increased risk for other individual or composite outcomes.

CONCLUSIONS

Over a short average follow-up period of <2 years, INSTI use among treatment-naïve PLWH was associated with an increased risk of several cardiometabolic outcomes, such as CHF, myocardial infarction and lipid disorders, compared to non-INSTI use. Further research accounting for additional potential confounders and with longer follow-up is warranted to more accurately and precisely quantify the impact of INSTI-containing ART on long-term cardiometabolic outcomes.

Effectiveness and Safety of Rivaroxaban Versus Warfarin Among Nonvalvular Atrial Fibrillation Patients with Concomitant Obstructive Sleep Apnea

Background: Obstructive sleep apnea (OSA) is associated with an increased incidence of atrial fibrillation (AF), hypertension, diabetes, heart failure, coronary heart disease, stroke, and death. We sought to evaluate the effectiveness and safety of rivaroxaban versus warfarin in nonvalvular AF (NVAF) patients with concomitant OSA. Methods: This was an analysis of electronic health record (EHR) data from 11/2010–12/2021. We included adults with NVAF and OSA at baseline, newly initiated on rivaroxaban or warfarin and with ≥12-months of prior EHR activity. Patients with valvular disease, alternative indications for oral anticoagulation, or who were pregnant were excluded. The incidence rates of developing stroke or systemic embolism (SSE) and bleeding-related hospitalization were evaluated. Hazard ratios (HR) and 95% confidence intervals (CIs) were calculated using propensity score-overlap weighted proportional hazards regression. Multiple sensitivity and subgroup analyses were performed. Results: We included 21,940 rivaroxaban (20.1% at the 15 mg dose) and 38,213 warfarin (time-in-therapeutic range=47.3±28.3%) patients. Rivaroxaban was found to have similar hazard of SSE compared to warfarin (HR=0.92, 95%CI=0.82–1.03). Rivaroxaban was associated with a reduced rate of bleeding-related hospitalizations (HR=0.85, 95%CI=0.78–0.92) versus warfarin, as well as reductions in intracranial (HR=0.76, 95%CI=0.62–0.94) and extracranial (HR=0.89, 95%CI=0.81–0.97) bleeding. Upon sensitivity analysis restricting the population to men with a CHA2DS2VASC score ≥2 or women with a score ≥3, rivaroxaban was associated with significant 33% risk reductions in SSE and 43% reduction in the risk of bleeding-related hospitalization. No significant interaction for the SSE or bleeding-related hospitalization outcomes were observed upon subgroup analyses. Conclusions: Among patients with NVAF and OSA, rivaroxaban had similar SSE risk versus warfarin but was associated with reductions in any, intracranial, and extracranial bleeding-related hospitalizations. Rivaroxaban was associated with significant reductions in SSE and bleeding-related hospitalizations when the study population was restricted to patients with a moderate-to-high risk of SSE. These data should provide prescribers with additional confidence in selecting rivaroxaban in NVAF patients who have OSA at time of anticoagulation initiation.

Real-world weight changes in people with HIV-1 at risk of weight gain (female, Black or Hispanic) switching from integrase strand transfer inhibitors

Aim: Compare weight changes between people living with HIV-1 (PLWH) at high risk of weight gain (females, Blacks or Hispanics) switching from an integrase strand transfer inhibitor (INSTI) to a protease inhibitor (PI) or another INSTI. Materials & methods: Mean weight changes from pre-switch to up-to-12 months post-switch were retrospectively compared between PLWH switching to a PI or INSTI. Results: 356 PLWH were eligible. At 9- and 12-month post-switch, weight increases were observed for INSTI (weight: +1.55 kg and +1.59 kg), while decreases were observed for PI (-0.23 kg and -1.59 kg); differences between cohorts widened over time. Conclusion: These data suggest that switching off an INSTI may be a management tool to mitigate or reverse weight gain.

Association Between Weight Gain and the Incidence of Cardiometabolic Conditions Among People Living with HIV-1 at High Risk of Weight Gain Initiated on Antiretroviral Therapy

INTRODUCTION

Antiretroviral therapy (ART) has been associated with weight gain in people living with HIV-1 (PLWH); however, limited research has assessed whether early weight gain post-ART initiation is associated with metabolic or cardiovascular outcomes among PLWH at high risk of weight gain (i.e., female, Black or Hispanic). This study aimed to evaluate the incidence of metabolic and cardiovascular outcomes between PLWH at high risk of weight gain following an observed ≥ 5% or < 5% weight/body mass index (BMI) gain within 6 months following ART initiation.

METHODS

A retrospective longitudinal study using Symphony Health, an ICON plc Company, IDV® electronic medical records (October 1, 2014-March 31, 2021) identified adult female, Black, or Hispanic treatment-naïve PLWH who initiated ART and who had ≥ 1 weight or BMI measurement pre- and within 6 months post-treatment (landmark period). Inverse probability of treatment weighting was used to account for differences between PLWH who experienced ≥ 5% and < 5% weight/BMI gain. The time to each outcome was compared between cohorts using weighted hazard ratios (HRs) after the landmark period.

RESULTS

Weighted ≥ 5% and < 5% cohorts included 620 and 632 patients, respectively; baseline characteristics were similar between the two cohorts (mean age: ~ 48 years, ~ 59% female, ~ 49% Black, ~ 17% Hispanic). During a mean 2-year follow-up, PLWH with ≥ 5% weight/BMI gain were significantly more likely to be diagnosed with type 2 diabetes mellitus (T2DM; HR = 2.19; p = 0.044). There were no significant differences in the incidence of any other outcomes between the study cohorts.

CONCLUSION

Despite a short 2-year follow-up, female, Black or Hispanic PLWH experiencing ≥ 5% weight/BMI increase within 6 months following ART initiation had an increased risk of T2DM, but not other metabolic or cardiovascular outcomes, likely due to the short follow-up period. Further research with longer follow-up and specific ART regimens is warranted to examine the impact of ART-related weight gain on long-term clinical outcomes.

Healthcare costs of NVAF patients treated with rivaroxaban and apixaban in the US

OBJECTIVES

To provide the most current assessment of real-world healthcare resource utilization (HRU) and costs among patients with non-valvular atrial fibrillation (NVAF) who newly initiated rivaroxaban and apixaban using a large US database.

MATERIAL AND METHODS

A retrospective weighted cohort design was used with healthcare insurance claims from the Optum Clinformatics Data Mart databases (January 2012-December 2018). The index date was defined as the first dispensing of rivaroxaban or apixaban. Adult NVAF patients with an index date on or after 1 January 2016, ≥ 12 months of continuous eligibility before the index date and ≥ 1 month after, and without prior use of oral anticoagulant were included. The observation period spanned from the index date to the earliest of the end of data availability, end of insurance coverage, or death. Inverse probability of treatment weighting (IPTW) was used to adjust for differences in baseline characteristics between cohorts. All-cause healthcare resource utilization (HRU), including hospitalization, emergency room, and outpatient visits, and healthcare costs, including medical and pharmacy costs, were evaluated from the payer's perspective during the observation period up to 18 and 24 months, separately.

RESULTS

In total, 23,822 rivaroxaban and 53,666 apixaban users were included. After weighting, all baseline characteristics were well balanced between cohorts (mean age: 73.8 years, female: 46.6% in both cohorts). Up to 18 months of follow-up, rivaroxaban users incurred significantly lower total healthcare costs compared to apixaban users (cost difference = -$1,121; p = 0.020), driven by significantly lower rates of outpatient hospital visits and associated costs (cost difference = -$1,579; p < 0.001). Similar results were found in the analysis conducted for up to 24 months of follow-up (total cost difference = ‒$1,111; p = 0.020).

CONCLUSIONS

In this large retrospective analysis, patients with NVAF initiated on rivaroxaban incurred significantly lower healthcare costs compared to those initiated on apixaban, which were primarily driven by significantly lower outpatient visits and costs during the 18- and 24-month follow-up periods.

The impact of non-medical switching among ambulatory patients: an updated systematic literature review

Background: Non-medical switching (NMS) is defined as switching to a clinically similar but chemically distinct medication for reasons apart from lack of effectiveness, tolerability or adherence. Objective: To update a prior systematic review evaluating the impact of NMS on outcomes. Data sources: An updated search through 10/1/2018 in Medline and Web of Science was performed. Study selection: We included studies evaluating ≥25 patients and measuring the impact of NMS of drugs on ≥1 endpoint. Data extraction: The direction of association between NMS and endpoints was classified as negative, positive or neutral. Data synthesis: Thirty-eight studies contributed 154 endpoints. The direction of association was negative (n = 48; 31.2%) or neutral (n = 91; 59.1%) more often than it was positive (n = 15; 9.7%). Stratified by endpoint type, NMS was associated with a negative impact on clinical, economic, health-care utilization and medication-taking behavior in 26.9%,41.7%,30.3% and 75.0% of cases; with a positive effect seen in 3.0% (resource utilization) to 14.0% (clinical) of endpoints. Of the 92 endpoints from studies performed by the entity dictating the NMS, 88.0%were neutral or positive; whereas, only 40.3%of endpoints from studies conducted separately from the interested entity were neutral or positive. Conclusions: NMS was commonly associated with negative or neutral endpoints and was seldom associated with positive ones.

Real-world impact of glycated hemoglobin reduction on treatment intensification and glycated hemoglobin goal attainment in type 2 diabetes mellitus patients initiated on a sodium glucose co-transporter 2 (SGLT2) inhibitor (SGLT2i)

Objective: To evaluate the impact of a 0.2% reduction in glycated hemoglobin (HbA1c) on treatment intensification, poor HbA1c control and HbA1c goal attainment in patients with type 2 diabetes mellitus (T2DM) initiated on a sodium glucose co-transporter 2 (SGLT2) inhibitor (SGLT2i).Methods: IQVIATM Health Plan Claims Data - US and IQVIATM Ambulatory EMR Data - US databases (29 October 2012-31 March 2016) were used to identify adults with T2DM initiated on an SGLT2i (index date) who had HbA1c measurements pre- and post-index, and ≥6 months of eligibility pre-index (baseline). HbA1c change was defined as the difference between the first post-index and the last pre-index measurements. Cox regression models were used to assess treatment intensification, poor HbA1c control (i.e. HbA1c > 9%, among patients <9% at baseline) and goal attainment (HbA1c < 7%, <8%; among patients with HbA1c above goal at baseline) adjusting for HbA1c change and baseline characteristics. Patients were observed up to one year after the first HbA1c measurement or end of eligibility. Hazard ratios (HRs) and 95% confidence intervals (CIs) were reported.Results: A total of 938 patients (mean age 54.9, 42.5% female, mean HbA1c 8.5%) were selected. Following SGLT2i initiation, each 0.2% reduction in HbA1c levels was associated with a decreased risk of treatment intensification (HR [95% CI] = 0.90 [0.86-0.92]), a decreased likelihood of reaching HbA1c > 9% (HR [95% CI] = 0.85 [0.79-0.88]) and higher likelihoods of achieving a treatment goal of HbA1c < 7% (HR [95% CI] = 1.17 [1.12-1.21]) and HbA1c < 8% (HR [95% CI] = 1.08 [1.04-1.10]).Conclusions: In T2DM patients, each HbA1c reduction of 0.2% following the initiation of an SGLT2i was associated with a significant positive impact on treatment intensification and HbA1c goal attainment.

Policy Change for Deep Vein Thrombosis: Effects on Length of Stay and Hospitalization Costs of Moving From Warfarin to Direct Oral Anticoagulants

PURPOSE

Renown Health (Reno, Nevada), a large, locally owned, not-for-profit integrated health care network, has developed an institution-wide policy to shift the treatment of deep vein thrombosis (DVT) from a short-acting anticoagulant and vitamin K antagonist to the direct oral anticoagulant rivaroxaban combined with pharmacy-directed follow-up at an outpatient anticoagulation clinic. We examined data on hospitalizations and costs pre-/post-policy change.

METHODS

Data were obtained from the electronic health records of adults with newly diagnosed DVT treated at Renown Health. A quasi-experimental design was used to evaluate patients who received a DVT diagnosis before versus after the policy change. Primary outcomes were number of all-cause inpatient nights at 30 and 60 days post-DVT index date. Secondary outcomes were costs of all-cause overnight stays at 30 and 60 days post-DVT index. Outcomes were evaluated in propensity-weighted logistic regression and generalized linear models.

FINDINGS

There were 343 patients pre-policy change and 266 post-policy change. In the first 30 days postindex, the mean (95% CI) numbers of propensity-weighted all-cause inpatient nights were 1.27 (0.83-1.95) prechange and 0.66 (0.42-1.02) postchange (P = 0.038). Mean propensity-weighted estimated all-cause hospital costs in patients diagnosed as outpatients were $7848 ($4990-$12,344) prechange and $2466 ($1553-$3915) postchange (P <0.001). Mean costs of all-cause overnight stays in inpatient-diagnosed DVT patients were $8907 prechange and $7449 postchange (P = 0.600). In the first 60 days postindex, the mean number of all-cause inpatient nights (P = 0.219) and mean costs of all-cause overnight stays (P = 0.275) were not significantly different before and after the policy change.

IMPLICATIONS

Changing institutional policy to increase the utilization of a direct oral anticoagulant and pharmacist-led outpatient anticoagulation clinics may reduce length of hospital stay and decrease health care expenditures in the treatment of DVT.

Novel Type 2 Diabetes Medication Access and Effect of Patient Cost Sharing

BACKGROUND

Although drug formulary restrictions may reduce use of prescription medication and pharmacy costs, the effect of patient cost sharing on medication adherence and health care utilization and cost is unclear.

OBJECTIVE

To evaluate the relationship between patient cost sharing for novel type 2 diabetes mellitus (T2DM) medications and medication adherence, persistence, and health care utilization and cost.

METHODS

This retrospective study used medical and pharmacy claims linked to pharmacy benefit plan design data. Patients with T2DM were identified via ICD-9-CM codes (medical claims), outpatient prescription fills (pharmacy claims), and pharmacy benefit design information. Patients with T2DM treated with novel T2DM medications (DPP4 or GLP-1) were enrolled in plans with fixed or coinsurance medication copayment structures and followed for 12-48 months. Endpoints included medication persistence and adherence and total all-cause health care cost. Multivariable regression analysis estimated the effect of benefit design parameters, adjusting for baseline patient characteristics.

RESULTS

The integrated database included 36,475 patients with T2DM. The majority (83.1%) had fixed copayment plans, and 3-tier plans were common (93.1%). Higher third-tier copayment was associated with poorer medication adherence and persistence but not total health care cost during follow-up. A $10 higher third-tier copayment was associated with 11% greater risk of novel T2DM medication discontinuation and 3% lower adherence. A comparison of patients with fixed versus coinsurance plans found that fixed plans were associated with higher adjusted persistence and total all-cause health care costs.

CONCLUSIONS

Higher medication copayment amounts were associated with lower patient medication adherence and persistence in T2DM but not total health care costs, as health plan costs decreased while patient out-of-pocket costs increased. We observed higher total all-cause health care costs among T2DM patients with a fixed copay (vs. coinsurance) pharmacy benefit. Additional research incorporating plan design information is needed to further examine this finding.

DISCLOSURES

This study was funded by Janssen Scientific Affairs, which was involved in study design, interpretation of data, editing manuscript content, and had final approval of the manuscript before submission. Lopez and Bookhart are employed by Janssen Scientific Affairs. At the time of this study, Henk was employed by Optum HEOR, which was contracted by Janssen to conduct this study. Portions of this study were presented at the 21st Annual International Meeting, ISPOR; May 21-25, 2016; in Washington, DC.

Consequences of non-medical switch among patients with type 2 diabetes

OBJECTIVE

This study aimed to describe real-world experiences following a non-medical switch among adults with type 2 diabetes mellitus (T2DM) in the United States.

METHODS

For this cross-sectional study, patients with T2DM (N = 451) provided data on demographics, and how a non-medical switch of their anti-hyperglycemic agent (AHA) affected their general health, HbA1c levels and medication management, via an Internet-based survey. Patients self-reported their level of satisfaction with the original medication and emotional reactions to the non-medical switch. Patients who recently experienced a non-medical switch of their AHA(s) (n = 379) were asked about the consequences of switching and their satisfaction with the switch (vs. the original) medication.

RESULTS

Patients most frequently reported feeling very/extremely frustrated, surprised, upset and angry in reaction to a non-medical switch. Patients were somewhat satisfied with their original medication. Between 20% and 30% of patients reported the non-medical switch had a moderate/major effect on their general health, diabetes, mental well-being and control over their health. The blood glucose levels of recent switchers were somewhat/much worse (20.7%) and medication management was somewhat/much worse (12.9%) on the switch (vs. the original) medication. Some recent switchers reported old symptoms returning (7.7%) and experiencing new side-effects (14.2%).

CONCLUSIONS

Approximately one in five patients reported a moderate/major negative impact on their blood glucose level, diabetes, mental well-being, general health and control over their health following a non-medical switch. Findings suggest that a non-medical switch may have unintended negative health consequences and results in considerable burden across multiple domains for a sizeable minority of patients with T2DM.

All-cause and disease-related health care costs associated with recurrent venous thromboembolism

It was the objective of this study to quantify the risk of complications and the incremental health care costs associated with recurrent VTE events. Health care insurance claims from the Ingenix IMPACT database from 01/2004−09/2008 were analysed. Subjects aged ≥18 years on the date of first recurrent VTE diagnosis with ≥12 months of baseline observation prior to the index recurrent VTE were matched 1:1 with no-recurrent VTE patients based on propensity scores. The risk of developing post-thrombotic syndrome (PTS) and other disease-related diagnoses (thrombocytopenia, superficial venous thrombosis, venous ulcer, pulmonary hypertension, stasis dermatitis, and venous insufficiency) was compared between the recurrent and no-recurrent VTE groups for up to one year. All-cause and disease-related costs per patient per year (PPPY) were calculated. The recurrent VTE and no-recurrent VTE cohorts (8,001 subjects in each group) were matched with respect to age, gender, and comorbidities. The risk ratios (RRs) indicated that the risk of developing post-event complications was significantly higher for the recurrent VTE group compared to the no-recurrent VTE group (RR [95% CI]: PTS: 2.7 [2.4 − 2.9], p-value <0.01). Patients with recurrent VTE had significantly higher average PPPY all-cause costs compared to no-recurrent VTE patients ($86,744 versus $37,525, cost difference: $49,219 [€33,617]; 95% CI= 46,253−51,989). Corresponding disease-related health care costs PPPY were also significantly higher for the recurrent VTE group ($11,120 vs $1,262, cost difference: $9,858 [€6,733]; 95% CI= $9,081-$10,476). In conclusion, in this large matched-cohort study, recurrent VTE patients had significantly higher risk of complications and health care costs compared to no-recurrent VTE patients.

Note: Parts of this manuscript were presented at the American College of Clinical Pharmacy (ACCP) Annual Meeting 2012, October 21–24, Hollywood, Florida and at the International Society for Pharmacoeconomics and Outcomes Research (ISPOR) 18th Annual International Meeting 2013, May 18–22, New Orleans, LA, USA.

Quality measures for anticoagulation care

OBJECTIVE

To systematically identify and assess current quality measures for anticoagulation in atrial fibrillation (AF), venous thromboembolism (VTE) treatment and surgical VTE prophylaxis.

RESEARCH DESIGN AND METHODS

Fifteen quality measure websites were searched as were bibliographic databases (January 2000-February 2016). Quality measures were included if developed in the United States and incorporating an aspect of anticoagulation for the aforementioned indications or if applicable but not indication specific (non-disease specific measure). Two reviewers independently extracted data regarding the characteristics of each quality measure.

RESULTS

Thirty-five measures were identified, mostly in VTE treatment (48.6%), followed by non-disease specific measures (25.7%), AF (17.6%) and surgical VTE prophylaxis (8.8%). Process measures predominated (82.9%). A majority of quality measures (65.7%) were focused on parenteral anticoagulants or warfarin and not applicable to novel oral anticoagulants (NOACs). Ten (28.6%) measures are used by the Centers for Medicare and Medicaid Services or as a core measure of The Joint Commission. Limitations include the inability to statistically pool data and possible publication bias given the nature of databases for quality measures.

CONCLUSIONS

Quality measures are recognized in anticoagulation care. Areas for improvement include expanding beyond process measures and capturing adverse events and the advantages offered by NOACs.

Impact of non-medical switching on clinical and economic outcomes, resource utilization and medication-taking behavior: a systematic literature review

OBJECTIVE

To evaluate current knowledge of the impact of non-medical switching on clinical and economic outcomes, resource utilization and medication-taking behavior.

METHODS

The literature was searched (Medline and Web of Science, January 2000-November 2015) to identify United States' studies evaluating ≥25 patients and measuring the impact of non-medical switching of drugs (switching to a chemically distinct but similar medication for reasons other than lack of clinical efficacy/response, side effects or poor adherence) on ≥1 clinical, economic, resource utilization or medication-taking behavior outcome. The direction of association between non-medical switching and outcomes was classified as negative or positive if a statistically significant worsening or improvement was reported, or neutral if no significant difference was observed.

RESULTS

Twenty-nine studies contributed 96 outcomes (60.4% clinical; 21.9% resource utilization; 13.5% economic; 4.2% medication-taking behavior) within six disease categories (cardio-metabolic, immune-mediated, acid suppression, psychiatric, hormone replacement therapy and pain). The direction of association was more frequently negative (33.3%) or neutral (55.2%) than it was positive (11.5%). Stratified by outcome type, non-medical switching was negatively associated with clinical, economic, healthcare utilization and medication-taking behavior outcomes in 20.7%, 69.2%, 38.1% and 75.0% of cases, respectively; and positively in only 4.8%-17.2% of outcomes subgroups. Of 32 outcomes in patients demonstrating stable/well controlled disease, 68.8% and 31.3% had a negative and neutral direction of association. In patients without demonstrated disease stability, outcomes were negatively, neutrally and positively impacted by non-medical switching in 15.6%, 67.2% and 17.2% of 64 outcomes.

LIMITATIONS

Our inability to evaluate specific disease state categories and studies/outcomes received equal weight regardless of sample size or magnitude of effect.

CONCLUSIONS

Non-medical switching was more often associated with negative or neutral effects than positive effects on an array of important outcomes. Among patients with stable/well controlled disease, non-medical switching was associated with mostly negative effects.

Recurrent hospitalization and healthcare resource use among patients with deep vein thrombosis and pulmonary embolism: findings from a multi-payer analysis

The objective of this study was to assess deep vein thrombosis and pulmonary embolism (DVT/PE) recurrence rates and resource utilization among patients with an initial DVT or PE event across multiple payer perspectives. Retrospective analyses were performed using a software tool that analyzes health plan claims to evaluate treatment patterns and resource utilization for various cardiovascular conditions. Six databases were analyzed from three payer perspectives (Commercial, Medicare, and Medicaid). Patients were ≥18 years old with a primary diagnosis of DVT or PE associated with an inpatient and/or emergency room claim, had received an antithrombotic within 7 days before or 14 days after index, and had no diagnosis of atrial fibrillation during follow-up. Outcomes were assessed over a 1 year period following index. More PE patients were hospitalized for their index event than DVT patients (42–59 % DVT and 69–86 % PE) and had longer mean length of stay (2.35–2.95 days DVT and 3.26–3.76 days PE). Recurrent event rates among PE patients (12–32 %) were higher than those for DVT patients (6–16 %) across all payers. The highest rate of recurrence was observed among the Medicaid population [23 % overall (VTE); 16 % DVT; 32 % PE]. All-cause hospitalization in the year following their VTE episode occurred in 23–67 % DVT patients and 30–68 % PE patients. Medicaid had the highest proportion of patients with hospitalizations and ER visits. Recurrent VTE events and all-cause hospitalizations are relatively common, especially for patients who had a PE, and among those in the Medicaid payer population.

Risk of recurrent venous thromboembolism among deep vein thrombosis and pulmonary embolism patients treated with warfarin

OBJECTIVE

Guidelines for warfarin treatment of venous thromboembolism (VTE) recommend targeting an international normalized ratio (INR) level of 2-3. This study examines the association between INR levels and VTE recurrence among warfarin-treated patients.

METHODS

A retrospective cohort study in the MedMining electronic health record database included adults treated with warfarin for VTE in 2004-2011. INR levels during warfarin use were categorized as below therapeutic range (<2), in range (2-3), or above range (>3), with time in each category estimated using the Rosendaal method. Recurrent VTE was noted from 30 days after the initial VTE to end of follow-up, which ranged up to 8 years. The incidence of recurrent VTE was calculated, and association with time-varying INR levels estimated using Cox models.

RESULTS

Of 1753 qualifying patients, 867 had deep vein thrombosis, and 886 had pulmonary embolism. Mean age was 58 years, and 50.7% were female. Across all follow-up time, VTE recurrences were observed in 134 (7.6%) patients, at a rate of 3.2 (95% confidence interval [CI]: 0.7-9.1) events per 100 person-years. The risk of VTE recurrence was greater during time spent with INR <2 than with INR in the therapeutic range (hazard ratio [HR]: 3.37; 95% CI: 2.16-5.27). Low platelet counts also predicted greater risk of VTE recurrence (HR: 2.13; 95% CI: 1.24-3.67).

LIMITATIONS

Exposure to warfarin and other anticoagulants was estimated based on prescription data and may be inaccurate. The study data include care within a single health system; thus, care received outside of the health system may be missing, and results may not be generalizable to the broader US population.

CONCLUSIONS

Approximately 8% of patients experienced a recurrent VTE during follow-up. Subtherapeutic INR levels were associated with a more than three-fold increased risk of VTE recurrence.

Incidence of hospital readmission in patients diagnosed with DVT and PE: clinical burden of recurrent events

BACKGROUND

Venous thromboembolism (VTE), which comprises deep-vein thrombosis (DVT) and pulmonary embolism (PE), is associated with significant morbidity and mortality and represents a considerable economic burden to the US healthcare system. Although it is well established that patients with an initial VTE are at increased risk for recurrent VTE, limited data exist on the clinical burden of a secondary DVT or PE event. The objective of this retrospective observational study was to conduct an epidemiologic evaluation, from a hospital perspective, of patients with an initial DVT or PE who experienced a recurrent event postdischarge requiring hospital readmission.

METHODS

Hospital claims containing DVT or PE as a primary diagnosis for hospitalisation during the period October 2009 to April 2013 were identified by retrospective analysis using the MarketScan database. The time to hospital readmission for DVT or PE was assessed using the MarketScan Treatment Pathways tool.

RESULTS

Of 214,901 patient admissions identified with a diagnosis of DVT or PE at hospital admission, approximately 4% were subsequently readmitted to the hospital with a diagnosis of PE (8217) or DVT (9138). Of all readmitted patients with a diagnosis of DVT on initial admission, 66% were rehospitalised with a diagnosis of DVT, and 34% were rehospitalised with a diagnosis of PE. Of all readmitted patients with a diagnosis of PE on initial admission, 63% were rehospitalised with a diagnosis of PE and 37% with a diagnosis of DVT. Of all hospital readmissions with a diagnosis of PE or DVT, 62% and 58% occurred within the first 30 days following an initial PE or DVT event, respectively.

CONCLUSIONS

The burden of DVT or PE is large, not only because of the initial hospitalisation event but also because of the high number of hospital readmissions, more than half of which occur within 30 days.

Daily costs of hospitalization in non-valvular atrial fibrillation patients treated with anticoagulant therapy

BACKGROUND

Atrial fibrillation (AF) is the most common cardiac rhythm disturbance in the US, with an estimated prevalence of 2.7-6.1 million persons in 2010.

OBJECTIVE

This study evaluates the progression of daily hospitalization costs among non-valvular atrial fibrillation (NVAF) patients treated with anticoagulant therapy.

METHODS

A claims analysis was conducted with Premier Perspective Comparative Hospital Database records from January 2009-March 2013. Patients of 18 years or older who were diagnosed with NVAF and used anticoagulant therapy were studied. Treatment patterns and mean daily costs of hospitalization per patient as well as total costs of hospitalization were reported. Comparisons of mean daily costs with those of the previous day were presented to identify statistical cost differences between hospitalization days.

RESULTS

A total of 375,560 patients were identified; 67,017 with AF as admitting/primary diagnosis, and 308,543 with AF as a secondary diagnosis. The mean age of the overall population, primary AF diagnosis cohort, and secondary AF diagnosis cohort was 73.8, 67.9, and 75.0 years, while their proportion of females was 46.3%, 45.6%, and 46.5%, respectively. The mean length of stay was 6.8 days, 3.7 days, and 7.5 days for the overall population, the primary AF diagnosis cohort, and the secondary AF diagnosis cohort, respectively. For all cohorts, mean daily costs stabilized on the third day (overall population: $2103; primary AF diagnosis cohort: $1505; secondary AF diagnosis cohort: $2208).

LIMITATIONS

Claims data may have contained inaccuracies or omissions in coded procedures, diagnoses, or pharmacy claims.

CONCLUSION

The study showed that daily hospitalization costs for NVAF patients stabilized on the third day of hospitalization and that any reduction or prolongation in hospital length of stay could have a significant impact on the cost burden associated with AF.

Inpatient resource use and cost burden of deep vein thrombosis and pulmonary embolism in the United States

PURPOSE

Venous thromboembolism (VTE), which comprises deep vein thrombosis (DVT) and pulmonary embolism (PE), is associated with significant morbidity and mortality. VTE frequently leads to hospitalization and represents a considerable economic burden to the US health care system. However, little information exists on the duration of hospitalization and associated charges among patients with an admitting or primary diagnosis of DVT or PE. This study assessed the charges associated with hospitalization length of stay in patients with DVT or PE discharged from US hospitals in 2011.

METHODS

Using data from the Nationwide Inpatient Sample of the Healthcare Utilization Project database, this analysis examined hospital length of stay and associated charges in patients with DVT or PE discharged from US hospitals in 2011. Both initial and subsequent hospitalizations were analyzed.

FINDINGS

DVT was responsible for fewer hospitalizations than PE. In 2011, among 330,044 patients with VTE discharged from US hospitals, 143,417 had DVT and 186,627 had PE. Mean length of stay for patients with DVT was 4.7 days (median, 3.9 days) compared with 5.1 days (median, 4.5 days) for patients with PE. For initial hospitalizations, the mean (SE) charge amounted to $30,051 ($246) for DVT compared with $37,006 ($214) for PE. Older patients with PE incurred greater hospital charges than younger ones, and for both DVT and PE patients, women incurred greater charges than men. Of 31,463 patients admitted to the hospital with PE, 4.0% had a subsequent admission, which was more costly than the initial admission. Many patients with both DVT and PE were discharged to specialist nursing facilities, indicating continuing posthospitalization charges.

IMPLICATIONS

Hospital stays for DVT and PE represent a substantial cost burden to the US health care system. Health care systems have the potential to reduce the clinical and economic burden of VTE by ensuring that evidence-based, guideline-recommended anticoagulation therapy is adhered to by patients with an initial VTE. Appropriate anticoagulant therapy and continuity of care in these patients may reduce the incidence and frequency of hospital readmissions and VTE-related morbidity and mortality and have a potential effect on health care resources.

Length of stay and economic consequences with rivaroxaban vs enoxaparin/vitamin K antagonist in patients with DVT and PE: findings from the North American EINSTEIN clinical trial program

OBJECTIVE

Venous thromboembolism (VTE) (deep vein thrombosis [DVT] and pulmonary embolism [(PE]) represents a substantial economic burden to the healthcare system. Using data from the randomized EINSTEIN DVT and PE trials, this North American sub-group analysis investigated the potential of rivaroxaban to reduce the length of initial hospitalization in patients with acute symptomatic DVT or PE.

METHODS

A post-hoc analysis of hospitalization and length-of-stay (LOS) data was conducted in the North American sub-set of patients from the randomized, open-label EINSTEIN trial program. Patients received either rivaroxaban (15 mg twice daily for 3 weeks followed by 20 mg once daily; n = 405) or dose-adjusted subcutaneous enoxaparin overlapping with (guideline-recommended 'bridging' therapy) and followed by a vitamin K antagonist (VKA) (international normalized ratio = 2.0-3.0; n = 401). The open-label study design allowed for the comparison of LOS between treatment arms under conditions reflecting normal clinical practice. LOS was evaluated using investigator records of dates of admission and discharge. Analyses were carried out in the intention-to-treat population using parametric tests. Costs were applied to the LOS based on weighted mean cost per day for DVT and PE diagnoses obtained from the Healthcare Cost and Utilization Project dataset.

RESULTS

Of 382 patients hospitalized, 321 (84%), had acute symptomatic PE; few DVT patients required hospitalization. Similar rates of VTE patients were hospitalized in the rivaroxaban and enoxaparin/VKA treatment groups, 189/405 (47%) and 193/401 (48%), respectively. In hospitalized VTE patients, rivaroxaban treatment produced a 1.6-day mean reduction in LOS (median = 1 day) compared with enoxaparin/VKA (mean = 4.5 vs 6.1; median = 3 vs 4), translating to total costs that were $3419 lower in rivaroxaban-treated patients.

CONCLUSION

In hospitalized North American patients with VTE, treatment with rivaroxaban produced a statistically significant reduction in LOS. When treating DVT and PE patients, clinicians should consider newer anti-coagulants with less complex treatment regimens.

Association between anticoagulant treatment duration and risk of venous thromboembolism recurrence and bleeding in clinical practice

INTRODUCTION

This retrospective observational study examined whether anticoagulant treatment duration varies by risks of venous thromboembolism (VTE) recurrence and bleeding.

MATERIALS AND METHODS

VTE patients naïve to anticoagulants were identified from the HealthCore Integrated Research Database between 06/01/2007 and 09/30/2011 and categorized into three groups: provoked, cancer-related, and unprovoked VTE. Treatment duration was from initiation to discontinuation of anticoagulation, based on a 60-day gap in prescription fill unless there was an international normalized ratio test every 42 days. Bleeding risk was estimated using RIETE score, and VTE risk categories were based on ACCP guidelines. Kaplan-Meier curves and Cox proportional hazards models were used to evaluate association between VTE recurrence/bleeding and anticoagulation duration.

RESULTS

Of 2002 patients identified (52.3% males, mean age 57 ±15 years), 21.4% had provoked, 16.4% had cancer-related, and 62.1% had unprovoked VTE. Average anticoagulant treatment duration was 294 ± 261 days. After adjusting for demographics and clinical characteristics, provoked and cancer-related VTE patients were 32% (95% CI=14-54%, P<0.001) and 35% (95% CI=7-70%, P=0.013) more likely, respectively, to discontinue anticoagulants than unprovoked VTE patients. No differences were observed between provoked and cancer-related VTE patients. Patients with an intermediate/high bleeding risk were 26% (95% CI=14-36%, P<0.001) less likely to discontinue treatment than those with a low bleeding risk.

CONCLUSIONS

The observed anticoagulation duration for VTE may not be concordant with guidelines, due to the challenge of counterbalancing risks of VTE recurrence and bleeding. Further studies are needed to explore this.

Prior myocardial infarction and presence of upper gastrointestinal conditions among patients with venous thromboembolism: prevalence, associated comorbidities and burden

WHAT IS KNOWN AND OBJECTIVES

Venous thromboembolism (VTE), comprising deep vein thrombosis (DVT) and pulmonary embolism (PE), is a serious, life-threatening condition that often complicates treatment of individuals who are already ill and increases in risk with age. The comorbidity burden of VTE can complicate treatment; therefore, treatment should be influenced by the presence of comorbidities (Kearon 2012). The prevalence of common conditions in the VTE population is, therefore, an important subject of research. Prevalence of two common comorbid burdens, prior myocardial infarction (MI) and upper gastrointestinal (GI) conditions, was studied among survey respondents who reported DVT or PE.

METHODS

Responses to the 2010 wave of the National Health and Wellness Survey (NHWS), a self-administered, internet-based questionnaire from a nationwide, demographically representative sample of adults, were evaluated.

RESULTS AND DISCUSSION

Among the 814 participants reporting a history of VTE, 9·7% (n = 60) of the DVT subpopulation and 13·2% (n = 39) of the PE subpopulation also reported prior MI. In respondents with prior MI, cardiovascular, urological, and pain comorbidities were each reported as additional comorbidities by at least two thirds of respondents in both the PE and DVT subpopulations, with cardiovascular and urological conditions reported significantly (P < 0·05) more often than among respondents with no prior MI. Among the respondents reporting VTE, 48·9% (n = 302) of the subpopulation reporting DVT and 52·2% (n = 154) of those reporting PE also reported upper GI comorbidities. Cardiovascular and pain conditions in the respondents reporting upper GI comorbidities were each reported by more than three quarters of VTE patients in both the DVT and PE subpopulations and were significantly more common (P < 0·05) than among their counterparts without upper GI comorbidities.

WHAT IS NEW AND CONCLUSION

The results of the NHWS indicate that VTE patients who have either of two common comorbid burdens, prior MI and concomitant upper GI conditions, also showed high levels of additional, concurrent comorbidities and generally poor health status. Clinicians must be aware of the total comorbidity profile of their patients who have experienced VTE in order to best manage them and prescribe appropriate therapy.

Risk factors associated with myocardial infarction in venous thromboembolism patients

BACKGROUND

Although risk factors for MI have been described in the general population, there is a lack of data on the assessment of risk factors associated with MI in venous thromboembolism (VTE) patients.

OBJECTIVE

The purpose of this study was to identify risk factors associated with MI in VTE patients.

PATIENTS AND METHODS

Health insurance claims between January 2004 and September 2008 from the Ingenix IMPACT database were analyzed. Patients aged ≥18 years were identified as of the date of their first VTE diagnosis with ≥1 year of continuous insurance coverage before the index VTE. The risk of MI for VTE patients with 1, 2, and ≥3 major risk factors as identified by published guidelines was calculated. Multivariate Cox proportional hazard models were conducted to identify the most predictive risk factors associated with MI.

RESULTS

A total of 177,885 VTE patients were identified; 4412 (2.5%) developed an MI during a mean follow-up period of 1.3 years. Previous MI, age (≥65 years), and coronary artery disease were the most predictive risk factors of MI with adjusted hazard ratios (HRs; 95% CI) of 5.47 (5.01-5.97), 1.78 (1.66-1.91), and 1.60 (1.48-1.74), respectively. Adjusted HRs (95% CI) for VTE patients with 1, 2, and ≥3 major risk factors relative to no major risk factor were 2.34 (1.94-2.81), 3.21 (2.67-3.85), and 6.93 (5.85-8.22), respectively.

LIMITATIONS

These included possible inaccuracies or omissions in diagnoses, classification bias such as the identification of false-positive MI events, and the likely undercoding of some risk factors such as social issues.

CONCLUSIONS

Traditional major cardiovascular risk factors are also predictive of MI in VTE patients. Having multiple major risk factors significantly increases the probability of developing MI events in VTE patients.

Cost-effectiveness of rivaroxaban compared with enoxaparin plus a vitamin K antagonist for the treatment of venous thromboembolism

BACKGROUND

Venous thromboembolism (VTE), comprised of deep vein thrombosis (DVT) and pulmonary embolism (PE), is commonly treated with a low-molecular-weight heparin such as enoxaparin plus a vitamin K antagonist (VKA) to prevent recurrence. Administration of enoxaparin + VKA is hampered by complexities of laboratory monitoring and frequent dose adjustments. Rivaroxaban, an orally administered anticoagulant, has been compared with enoxaparin + VKA in the EINSTEIN trials. The objective was to evaluate the cost-effectiveness of rivaroxaban compared with enoxaparin + VKA as anticoagulation treatment for acute, symptomatic, objectively-confirmed DVT or PE.

METHODS

A Markov model was built to evaluate the costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios associated with rivaroxaban compared to enoxaparin + VKA in adult patients treated for acute DVT or PE. All patients entered the model in the 'on-treatment' state upon commencement of oral rivaroxaban or enoxaparin + VKA for 3, 6, or 12 months. Transition probabilities were obtained from the EINSTEIN trials during treatment and published literature after treatment. A 3-month cycle length, US payer perspective ($2012), 5-year time horizon and a 3% annual discount rate were used.

RESULTS

Treatment with rivaroxaban cost $2,448 per-patient less and was associated with 0.0058 more QALYs compared with enoxaparin + VKA, making it a dominant economic strategy. Upon one-way sensitivity analysis, the model's results were sensitive to the reduction in index VTE hospitalization length-of-stay associated with rivaroxaban compared with enoxaparin + VKA. At a willingness-to-pay threshold of $50,000/QALY, probabilistic sensitivity analysis showed rivaroxaban to be cost-effective compared with enoxaparin + VKA approximately 76% of the time.

LIMITATIONS

The model did not account for the benefits associated with an oral and minimally invasive administration of rivaroxaban. 'Real-world' applicability is limited because data from the EINSTEIN trials were used in the model. Also, resource utilization and costs were based on the US healthcare system.

CONCLUSION

Rivaroxaban is a cost-effective option for anticoagulation treatment of acute VTE patients.

Abstract 229: Economic Burden of Deep Vein Thrombosis and Pulmonary Embolism for Employees and Employers

Introduction: Though, deep vein thrombosis (DVT) and pulmonary embolism (PE) impose a major burden on US healthcare system, limited data exists on the economic impact of DVT and PE on younger working population. DVT, which occurs in approximately 1 in every 1,000 adults every year, is estimated to cost between $5-8 billion annually or on average $20,000 per treated patient per year. PE occurs in 0.6 million patients annually and results in 50,000 to 200,000 deaths every year. This study examined the total burden of illness, including the direct and indirect healthcare costs to employers and employees with DVT and PE.

Methods: Retrospective analyses from 2007-2010 were performed using two datasets: (1) Integrated Benefits Institute’s Health and Productivity Benchmarking Database was used for short-term disability (STD) and long term disability (LTD) claims, and (2) IMS LifeLink data was used for medical and pharmacy claims. Indirect costs analyses included costs of lost work days from STD and LTD claims and wage replacement costs. Direct costs included annual pharmacy and medical claims for newly diagnosed DVT and/or PE individuals. Total healthcare cost estimates between the two datasets were linked by derived age and gender analytic weights.

Results: 5,445 (female=54%) and 6,199 (female=50%) disability claims were filed for DVT and PE, respectively. Employees with DVT lost on average 57 (SEM 4.6) STD and 440 (SEM 30.5) LTD days per disability incident. For employers, estimated lost productivity costs per DVT claim were STD=$7,414±625 and LTD= $58,181±4,332. Total annual DVT healthcare costs per employee including out of pocket costs were $2,449 + 106 with $2,160±102 for annual medical and $290 ±20 for total pharmacy costs. Employees with PE lost on average 56 (SEM 3.0) STD and 364 (SEM 26.1) LTD days per disability incident. For employers, the estimated lost productivity costs per PE claim for STD and LTD were $7,605±402 and $48,751±3,615, respectively. Total annual PE healthcare costs per employee including out of pocket costs were $5,040 + 460 with $4,851±457 for annual medical and $190 ±22 for total pharmacy costs. Hospitalizations accounted for 84% of total annual PE health costs.

Conclusion: DVT and PE constitute a heavy economic and lost productivity burden for both employers and their employees. Direct and disability costs to employees are substantial. Productivity losses for employers are also significantly high. Appropriate management of DVT and PE may help improve lost days from work, reduce healthcare resource utilization, improve workforce productivity, and reduce total economic burden.

One-year adherence to warfarin treatment for venous thromboembolism in high-risk patients and its association with long-term risk of recurrent events

BACKGROUNDS

Warfarin is the predominant oral anticoagulant used for the prevention of recurrent venous thromboembolism (VTE) events. However, its long-term use is complicated by the need to manage the drug within a narrow therapeutic range and by possible food and drug interactions.

OBJECTIVE

To examine the association between 1-year adherence, measured through compliance with and persistence on warfarin treatment for VTE, and long-term risk of recurrent events among patients at high risk.

METHODS

Medical and pharmacy claims for patients with commercial or Medicare supplemental insurance in the Thomson Reuters MarketScan database were analyzed. Adult patients with medical claims with an associated VTE diagnosis between January 1, 2006, and March 31, 2008, were identified. The index date was defined as the date of the first observed VTE claim or the date of discharge if the index event was a hospital stay. High-risk patients (patients with cancer, or noncancer patients who did not have reversible risk factors during the 3-month period prior to the index date) who filled a warfarin prescription within 2 weeks of the index date were included. Persistence was evaluated in terms of discontinuation, defined as a 90-day gap in warfarin supply during a 1-year assessment period following the index date. Compliance was measured by the proportion of days covered (PDC) over the 1-year assessment period, with PDC less than 0.8 defined as noncompliance. Recurrent VTE events were identified as hospitalizations where VTE was the primary diagnosis after the 1-year assessment period and until patients were lost to follow-up. The association between adherence to warfarin therapy and VTE recurrence was evaluated descriptively via Kaplan-Meier curves and a Cox proportional hazards model, adjusted for patient demographic and clinical characteristics. A similar analysis using the medication possession ratio (MPR) as a measure of compliance was also performed in a subset of patients who had filled at least 2 warfarin prescriptions.

RESULTS

The study included 8,040 VTE patients identified as being at high risk of recurrence (mean age 61 years, 59.4% male), of whom 76.9% were not compliant with warfarin therapy based on PDC, and 51.5% discontinued therapy. Among those with at least 2 warfarin prescriptions (n = 7612), 34.1% of high-risk patients were not compliant with warfarin therapy between the first and last refills based on MPR. Kaplan-Meier curves showed that patients who were compliant or continued warfarin therapy were less likely to experience a VTE event (all P less than 0.05). Noncompliant patients had a 3 times greater risk of VTE recurrence than compliant patients, based on PDC (hazard ratio [HR] = 3.01, 95% confidence interval [CI]: 1.28-4.97). Among the subpopulation who filled at least 2 warfarin prescriptions, noncompliant patients (based on MPR) were also found to be more likely to have recurrent VTE events, compared with compliant patients (HR = 1.60, 95% CI: 1.18-2.16). Patients who discontinued warfarin were more likely to have recurrent VTE events compared with patients who did not discontinue on warfarin treatment (HR = 1.48, 95% CI: 1.09-2.01).

CONCLUSION

Adherence to a year of therapy was low in patients at high risk of recurrent VTE, even though long-term therapy should be considered in this population. Noncompliance and discontinuation of warfarin treatment over a 1-year period was associated with a higher risk of recurrent VTE. Future research should investigate and differentiate between patient and provider discontinuation to develop strategies to improve compliance and persistence with appropriate anticoagulation therapy that may potentially reduce recurrent VTE.

All-cause and potentially disease-related health care costs associated with venous thromboembolism in commercial, Medicare, and Medicaid beneficiaries

BACKGROUND

Patients with venous thromboembolism (VTE) are at increased risk of developing recurrent VTE and post-thrombotic syndrome (PTS), a complication of deep vein thrombosis (DVT) characterized by venous reflux and residual venous obstruction that may manifest as chronic pain and swelling. Therefore, formulary/policy decision makers should understand the clinical and economic consequences associated with VTE.

OBJECTIVES

To describe the real-world clinical complications, such as recurrent VTE and PTS, associated with VTE and quantify the incremental direct all-cause and potentially disease-related health care costs associated with VTE.

METHODS

Health insurance claims between January 2004 and December 2008 from the Ingenix Impact database were used. Adult patients with an initial VTE diagnosis (index DVT, pulmonary embolism [PE], or both) with at least 12 months of enrollment prior to the index VTE were matched 1:1 with comparison patients without VTE. Matching criteria included demographic factors, baseline health care costs, and diagnoses of VTE risk factors such as multiple traumas, malignant cancer, or major surgery. Each patient's observation period began on the date of the index VTE, or corresponding study index date for comparison cases, and ended on the earliest of 1 year after the study index date, the health plan disenrollment date, or December 31, 2008. The proportions of patients with (a) recurrent hospital-documented VTE, defined as an inpatient episode with a diagnosis of VTE in any claim field; (b) PTS; and (c) other potentially disease-related diagnoses (thrombocytopenia, superficial venous thrombosis, venous ulcer, pulmonary hypertension, stasis dermatitis, and venous insufficiency) were calculated. Health care costs were defined as standardized net provider payments after subtraction of member cost-sharing amounts. All-cause incremental health care costs and disease-related costs, defined as provider payments for hospitalization or outpatient claims with a primary or secondary diagnosis of VTE, PTS, or any of the potentially disease-related diagnoses, were computed. Costs were calculated per patient per year (PPPY) by weighting each patient's total cost for up to 1 year post-index by the length of follow-up.

RESULTS

The matched VTE and no-VTE cohorts included 16,969 subjects in each group. The index VTE event was DVT, PE, or both in 12,711, 2,473, and 1,785 patients, respectively. In the VTE cohort, the risks of recurrent VTE and PTS during the follow-up period (mean [SD] observation of 271.7 [121.6] days) were 3.6% and 7.1%, respectively. Patients with VTE had significantly higher average PPPY all-cause costs compared with the no-VTE patients (mean [SD] $33,531 [$70,393] vs. $17,590 [$42,011]; cost difference = $15,941, 95% CI = $14,819-$17,012). Corresponding potentially disease-related health care costs PPPY were also significantly higher for the VTE group (mean [SD] $3,141 [$17,055] vs. $228 [$3,221]; cost difference = $2,913, 95% CI = $2,693-$3,157) and represented 18.3% (i.e., $2,913 of $15,941) of the all-cause cost difference between the 2 groups.

CONCLUSIONS

In this large matched-cohort study, VTE was associated with a 3.6% risk of hospital-documented recurrence and a 7.1% risk of PTS up to 1 year after index VTE. Potentially disease-related costs represented approximately one-fifth of the incremental all-cause costs associated with VTE.

In-hospital risk of venous thromboembolism and bleeding and associated costs for patients undergoing total hip or knee arthroplasty

OBJECTIVE

Benefits of anti-coagulation for venous thromboembolism (VTE) prevention in total hip and knee arthroplasty (THA/TKA) may be offset by increased risk of bleeding. The aim was to assess in-hospital risk of VTE and bleeding after THA/TKA and quantify any increased costs.

METHODS

Healthcare claims from the Premier Perspective(TM) Comparative Hospital Database (January 2000-September 2008) were selected for subjects ≥ 18 years with ≥ 1 diagnosis code for THA/TKA. VTE was defined as ≥ 1 code for deep vein thrombosis or pulmonary embolism. Bleeding was classified as major/non-major. Incremental in-hospital costs associated with VTE and bleeding were calculated as cost differences between inpatients with VTE or bleeding matched 1:1 with inpatients without VTE or bleeding.

RESULTS

A total of 820,197 inpatient stays were identified: 8042 had a VTE event and 7401 a bleeding event (2740 major bleeding). The risks of VTE, any bleeding, and major bleeding were 0.98, 0.90, and 0.33/100 inpatient stays, respectively. Mean incremental in-hospital costs per inpatient were $2663 for VTE, $2028 for bleeding, and $3198 for major bleeding.

LIMITATIONS

These included possible inaccuracies or omissions in procedures, diagnoses, or costs of claims data; no information on the amount of blood transfused or decreases in the hemoglobin level to evaluate bleeding event severity; and potential biases due to the observational design of the study.

CONCLUSIONS

In-hospital risk and incremental all-cause costs with THA/TKA were higher for VTE than for bleeding. Despite higher costs, major bleeding occurred less frequently than VTE, suggesting a favorable benefit/risk profile for VTE prophylaxis in THA/TKA.

Abstract P105: A Single-Center Experience with Low-Dose Warfarin in Patients Undergoing Total Hip or Total Knee Replacement Surgery

Background: Current guidelines recommend thromboprophylaxis to prevent venous thromboembolism (VTE) (deep vein thrombosis [DVT]; pulmonary embolism [PE]) after total hip and total knee replacement (THR/TKR) surgery. We describe international normalized ratio (INR) levels and risks of VTE and bleeding among THR/TKR patients receiving low-dose warfarin postsurgery in a single center. Although such real-world observational data are limited by relatively small numbers, single-center analysis eliminates many confounding variables.

Methods: Claims data and laboratory information were used to identify patients who (i) underwent TKR/THR between January 2000 and October 2009, (ii) had no warfarin use 60-30 days before surgery, (iii) were ≥18 years old at warfarin initiation, (iv) received warfarin <30 days before or ≤15 days after surgery, and (v) were continuously enrolled in a health plan from 30 days before to 90 days after warfarin initiation. INR levels and VTE/bleeding outcomes were recorded during continuous warfarin use 5-90 days after warfarin initiation.

Results: Mean (SD) ages of THR (N=269) and TKR (N=423) patients were 67.7 (13.2) and 70.0 (9.8) years, respectively. During the study period, THR and TKR patients received warfarin for a mean (SD) of 30.8 (18.2) and 30.6 (17.8) days, respectively; the mean number of INRs performed in patients with ≥1 available INR measurement was 3.9 for both THR (N=110) and TKR (N=202) patients. Of those measurements, 2.3 in THR and 2.1 in TKR patients were <2.0; 47% (52 of 110) of THR and 53% (107 of 202) of TKR patients failed to ever achieve the American College of Chest Physicians-recommended INR range (2.0-3.0). Of THR patients with no prior VTE, 10% (26 of 261) had DVT and 0.8% (2 of 261) had PE; of TKR patients, 8% (32 of 401) had DVT and 1.5% (6 of 401) had PE; 2.6% (7 of 266) of THR and 1.7% (7 of 415) of TKR patients developed minor or major bleeds. Multivariate regression found that the risk of VTE in TKR patients who failed to achieve an INR of 2.0-3.0 was significantly higher than in those who did (HR=4.10; p =015), but this effect was not seen in THR patients (HR=0.51; p =0.30).

Conclusion: These data suggest that ∼50% of patients receiving low-dose perioperative warfarin fail to achieve recommended INR levels.

Warfarin prophylaxis in patients after total knee or hip arthroplasty--international normalized ratio patterns and venous thromboembolism

OBJECTIVE

Warfarin is frequently used for the prevention of venous thromboembolism (VTE) after total hip or knee arthroplasty (THA/TKA). The current study was conducted to determine the association between international normalized ratio (INR) levels and VTE outcomes.

METHODS

Patients who received warfarin following THA/TKA were followed for up to 90 days using an electronic health record database. INR measurements were categorized based on American College of Chest Physicians (ACCP) guidelines. Cox proportional hazards models were used to compare the risk of VTE between patients with INR levels below and within the ACCP-recommended range in patients with ≥2 available INR level measurements.

RESULTS

On or after Day 5, 33.3% and 28.6% of INR levels fell within the ACCP-recommended range for THA and TKA, respectively. VTE was diagnosed in 3% of each cohort. INR levels varied over time and were frequently below the ACCP-recommended range. Below-range INR levels were associated with greater risk of VTE in both THA (hazard ratio [HR]: 5.29; 95% CI: 2.64-10.61) and TKA (HR: 4.64; 95% CI: 2.59-8.29).

CONCLUSIONS

In the current study, the majority of patients had INR levels below the ACCP-recommended range of 2.0-3.0 during warfarin exposure following orthopedic surgery. INR levels below 2.0 were associated with a four- to five-fold increase in the risk of VTE.

Risks and cost burden of venous thromboembolism and bleeding for patients undergoing total hip or knee replacement in a managed-care population

BACKGROUND

Total hip and total knee replacement (THR/TKR) patients are at increased risk of developing venous thromboembolism (VTE). VTE prevention using anticoagulation therapy increases the risk of bleeding. Therefore, any assessment of the cost of VTE and its prevention should also take into consideration risks and costs of bleeding.

OBJECTIVE

To assess the risks of developing VTE and bleeding in patients after THR or TKR given real-world use of thromboprophylaxis, and to quantify the incremental cost associated with each.

METHODS

Analyses of insurance healthcare claims from the Ingenix IMPACT National Managed Care Database(TM) from January 2004 to December 2008 were conducted. Subjects were ≥18 years and had ≥1 procedure code for THR or TKR. Patients had to have ≥180 days of observation prior to surgery and were observed for ≤3 months after THR or TKR. VTE was defined as ≥1 diagnosis code for deep vein thrombosis or pulmonary embolism. Bleeding events were classified as major or non-major. Risks of VTE or bleeding events were calculated as number of patients with an event divided by number of patients with the procedure. Incremental all-cause healthcare costs associated with VTE or bleeding were calculated as the difference between cohorts of patients without VTE or bleeding matched 1:1 to patients with VTE or bleeding.

RESULTS

Of 119,729 patients (43,670 THR and 76,059 TKR), 7974 had a VTE event and 4849 had a bleeding event (2216 major bleeding [a subset of 'any bleeding']). The risks of VTE, any bleeding, and major bleeding were 6.7, 4.0, and 1.9 events, respectively, per 100 patients. Up to 3 months after THR/TKR, mean incremental all-cause healthcare costs per patient per month associated with VTE, bleeding, and major bleeding were $2729, $2696, and $4304, respectively. Total monthly costs versus matched controls over 3 months were: VTE: $12,333 vs. $9604; any bleeding: $12,481 vs. $9785; major bleeding: $14,015 vs. $9710; p < 0.001 for all.

LIMITATIONS

Key limitations included potential inaccuracies or omissions in procedures, diagnoses, or costs of claims data; lack of information on the amount of blood transfused or decreases in the hemoglobin level to evaluate the severity of a bleeding event; and potential biases due to the observational design of the study.

CONCLUSION

From the managed-care population perspective, in THR/TKR patients the greater incidence of VTE compared to any bleeding and major bleeding translated into a higher cumulative cost burden.

Direct all-cause health care costs associated with chronic kidney disease in patients with diabetes and hypertension: a managed care perspective

BACKGROUND

Diabetes and hypertension are the 2 major causes of endstage renal disease. The rate of chronic kidney disease (CKD) secondary to diabetes and/or hypertension is on the rise, and the related health care costs represent a significant economic burden.

OBJECTIVE

To quantify from a health system perspective the incremental direct all-cause health care costs associated with a diagnosis of CKD in patients with diabetes and/or hypertension.

METHODS

An analysis was conducted of medical claims and laboratory data with dates of service between January 1, 2000, and February 28, 2006, from a managed care database for approximately 30 million members enrolled in 35 health plans. Each patient's observation period began on the date of the first diabetes or hypertension diagnosis (index date) and ended on the earlier of the health plan disenrollment date or February 28, 2006. Inclusion criteria were continuous insurance coverage in the 6 months prior to the index date and during the observation period, age at least 18 years, and at least 2 claims less than 90 days apart with a primary or secondary diagnosis for diabetes or hypertension. Exclusion criteria were cancer, lupus, or organ transplantation or chemotherapy at any time during the observation period. CKD was defined as at least 1 claim with a primary or secondary diagnosis for CKD and at least 2 glomerular filtration rate values of below 60 milliliters per minute per 1.73 square meters of body surface area (60 mL/min/1.73 m(2)) at any time during the observation period. Bivariate and Tobit regression analyses were conducted to compare patients who developed CKD versus those who did not for annualized (per patient per month [PPPM] multiplied by 12) direct, all-cause, health care costs, defined as standardized net provider payments after subtraction of member cost-share. These costs consisted of outpatient services, inpatient services, and pharmacy claims. A subset analysis of the post-versus pre- CKD medical costs was also conducted for cohorts of patients with at least 60 days of observation before and after the development of CKD; that analysis measured both all-cause costs and costs for services directly related to CKD treatment (i.e., claims with a primary or secondary diagnosis of CKD or claims for dialysis services).

RESULTS

11,531 patients with diabetes, 74,759 patients with hypertension, and 4,779 patients with both conditions were identified, of whom 123 (1.1%), 1,137 (1.5%), and 712 (14.9%), respectively, developed CKD during the observation period. The CKD group was older than the no-CKD group in each cohort (mean ages for CKD vs. no-CKD were, respectively, diabetes only cohort: 60.7 vs. 49.9 years, P < 0.001; hypertension only cohort: 63.6 vs. 53.6 years, P < 0.001; diabetes and hypertension cohort: 63.4 vs. 61.8 years, P < 0.001). CKD was associated with significantly higher total direct all-cause health care costs, with unadjusted annualized per patient mean [median] cost differences of $11,814 [$6,895], $8,412 [$4,115], and $10,625 [$7,203], respectively (diabetes: $18,444 [$11,025] vs. $6,631 [$4,131], P < 0.001; hypertension: $14,638 [$7,817] vs. $6,226 [$3,703], P < 0.001; diabetes and hypertension: $21,452 [$13,840] vs. $10,827 [$6,637], P < 0.001). The largest driver of the all-cause mean cost difference associated with CKD for each cohort was hospitalization cost (diabetes: $6,410, P < 0.001; hypertension: $5,498, P < 0.001; diabetes and hypertension: $6,467, P < 0.001). Among patients developing CKD, all-cause mean [median] annualized costs increased significantly following CKD onset (increases for patients with diabetes: $8,829 [$4,899], P = 0.026; hypertension: $4,175 [$2,741], P = 0.004; diabetes and hypertension: $9,397 [$7,240], P < 0.001). In the post-CKD period, costs directly related to treatment of CKD accounted for 9%--19% of all-cause medical service costs--9.2% for patients with diabetes, 11.6% for patients with hypertension, and 18.8% for patients with both diabetes and hypertension.

CONCLUSION

CKD was associated with significantly higher all-cause health care costs in managed care patients with diabetes and/or hypertension.

Drug utilisation and cost considerations of erythropoiesis stimulating agents in oncology patients receiving chemotherapy: observations from a large managed-care database

OBJECTIVE

Erythropoiesis stimulating agent (ESA) resource utilisation in cancer chemotherapy patients is of importance to managed-care organisations. To understand current real-world utilisation of ESAs, this study examined epoetin alfa (EPO) and darbepoetin alfa (DARB) treatment patterns (dosing and treatment duration), dose ratio and ESA treatment costs.

METHODS

An analysis of medical claims data from January 2006 through to January 2008 was conducted using the PharMetrics Patient-Centric database of over 85 health plans. Patients included in the study were > or =18 years of age, had at least one cancer claim within 90 days prior to ESA treatment initiation, were newly initiated on EPO or DARB, received at least two doses, and were treated with concomitant chemotherapy (at least one chemotherapy claim during ESA treatment). Mean cumulative ESA dose was used to calculate drug cost (based on April 2008 wholesale acquisition cost) and dose ratio (units EPO : microg DARB).

RESULTS

A total of 4,111 EPO patients and 6,817 DARB patients met inclusion criteria and formed the study population. EPO-treated patients were slightly older (mean age: EPO 63.6, DARB 61.8, p<0.0001) with a greater proportion of women in the DARB-treated group (EPO 60.9%, DARB 64.1%, p=0.0007). The mean treatment duration was slightly longer in the EPO group (EPO 58.4 days, DARB 55.4 days, p=0.0019). The mean cumulative ESA dose administered was EPO 329,129 units and DARB 1,289 microg, resulting in a dose ratio of 255:1 (units EPO:microg DARB). Mean drug cost per treatment episode was significantly lower in the EPO group by $1,768 (EPO $4,321, DARB $6,089, p<0.0001). After controlling for covariates, the incremental cost associated with DARB treatment remained stable and statistically significant (adjusted cost difference: $1,806 per treatment episode higher for DARB patients than EPO, p<0.0001).

CONCLUSIONS

This study of 10,928 oncology patients receiving chemotherapy reported a dose ratio of 255:1 (units EPO:microg DARB) with 29% lower treatment cost in the EPO group. These findings are similar to those previously reported from published clinical trials and real-world utilisation studies.

Dosing patterns, drug costs, and hematologic outcome in anemic patients with chronic kidney disease switching from darbepoetin alfa to epoetin alfa

OBJECTIVE

To compare real-world dosing patterns, drug costs, and hematologic outcome in anemic chronic kidney disease (CKD) patients, not receiving dialysis, who switched from darbepoetin alfa (DARB) to epoetin alfa (EPO) in a community practice setting.

RESEARCH DESIGN AND METHODS

This retrospective observational chart review from a US nephrology clinic included 153 anemic CKD patients > or = 18 years of age who did not receive dialysis during the study period, switched from DARB to EPO between 8/2003 and 8/2005, and received > or = 2 doses of both agents. Paired t-test and McNemar's chi-square were performed comparing pre-switch and post-switch outcomes.

RESULTS

Mean interval between doses increased from 24.3 +/- 11.1 days with DARB to 28.8 +/- 19.8 days with EPO (p = 0.001). Weighted mean pre-switch weekly dose for DARB was 25 mug, while weighted mean post-switch weekly dose for EPO was 7090 Units, resulting in a dose ratio (Units EPO:microg DARB) of 287:1. These doses resulted in mean weekly costs of $110 (DARB) and $86 (EPO). Mean hemoglobin (Hb) levels increased over time from 10.8 g/dL at 6 months pre-switch to 11.1 g/dL 6 months after EPO initiation (p = 0.0132). Mean Hb levels were > 11 g/dL, but below 12 g/dL, while patients received EPO.

CONCLUSIONS

Patients switching from DARB to EPO had a greater mean interval between doses, lower drug costs, and consistently maintained recommended Hb levels over time.

LIMITATIONS

The reverse direction (EPO to DARB) was not investigated. Although treatment outcomes were not assessed in a randomized, controlled setting, the study's observational nature provided actual evidence in a real-world setting.

Dosing Patterns and Treatment Costs of Erythropoietic Agents in Elderly Patients with Pre-Dialysis Chronic Kidney Disease in Managed Care Organisations

OBJECTIVES

To investigate dosing patterns and drug costs of erythropoietic agents and assess the frequency of outpatient nephrologist visits in an elderly population with pre-dialysis chronic kidney disease (pCKD) newly initiated on epoetin alfa (EPO) or darbepoetin alfa (DARB).

METHODS

An analysis of medical claims from more than 30 healthcare plans covering all census regions of the US in the period July 2002 through February 2005 was conducted. Patients were included if they were > or = 65 years of age, had at least one claim for CKD within 90 days prior to the initiation of any erythropoietic agent, were newly commenced on either EPO or DARB, and had received at least two treatment doses. If a patient received renal dialysis, data were censored 30 days prior to the first date of dialysis. Patients diagnosed with cancer or those who had undergone chemotherapy were excluded from the analysis. The average dosing interval for both EPO and DARB was calculated and classified as once weekly (qw), every 2 weeks (q2w) or every 3 weeks or less frequently (> or = q3w). Weighted average weekly doses were scaled based on treatment duration. The frequency of outpatient nephrologist visits was analysed. Average weekly treatment costs were calculated and presented using the May 2005 Wholesale Acquisition Costs.

RESULTS

A total of 293 EPO and 102 DARB patients met the inclusion criteria. The two groups of patients had similar mean age (74.4 years for EPO vs 74.3 years for DARB) and gender distribution (47.4% female for EPO vs 51.0% for DARB). Extended dosing (every 2 weeks or less frequently: > or = q2w) during treatment was observed in both groups (EPO: qw 49.8%, q2w 31.7%, > or = q3w 18.4%; DARB: qw 19.6%, q2w 52.9%, > or = q3w 27.5%). The average dosing interval between injections was 13.6 days for the EPO group and 17.3 days for the DARB group. The weighted average weekly dose was 12,748 units for EPO and 43.5 microg for DARB. The average weekly erythropoietic treatment cost was significantly greater for DARB compared with EPO (190 US dollars vs 155 US dollars per week [2005 values]; p = 0.028). After controlling for covariates, the cost difference between the two groups was more pronounced and remained statistically significant (adjusted cost difference 41 US dollars/week higher for DARB patients; p = 0.013). The frequency of outpatient nephrologist visits during treatment was similar between the two groups (EPO 3.4 vs DARB 3.0 visits).

CONCLUSIONS

Based on this analysis of claims data from more than 30 US healthcare plans, extended dosing (> or = q2w) of EPO and DARB was common in elderly pCKD patients treated with erythropoietic agents, with significantly higher weekly drug costs observed in the DARB group compared with the EPO group. The number of outpatient nephrologist visits was not significantly different between EPO and DARB patients. This study was the first to evaluate the dosing patterns of EPO and DARB in elderly pCKD patients in a large managed care population.

Population-based persistency rates for topical glaucoma medications measured with pharmacy claims data

BACKGROUND

Persistency with drug therapy reflects a number of factors, including patient tolerability of adverse events resulting from therapy and clinician satisfaction with the medication's effectiveness in reducing intraocular pressure.

OBJECTIVE

This study assesses persistency with topical glaucoma medications administered as initial therapy by evaluating rates of discontinuation and change in therapy.

METHODS

A retrospective cohort study was conducted using pharmacy claims data from 3 geographically diverse healthcare plans. Newly treated glaucoma patients younger than 65 years of age were selected based on an initial glaucoma medication fill during a 12-month period. Patients were followed for persistency, defined as discontinuation or change (switch or add-on) of initial glaucoma therapy; discontinuation of therapy was also evaluated as a separate end point.

RESULTS

In all, 1330 patients (followed for 1126 person-years) met the eligibility criteria. Compared with latanoprost users, patients initiated on other topical monotherapies were more likely to discontinue or change therapy, and patients initiated on other topical monotherapies were more likely than latanoprost users to discontinue therapy.

CONCLUSION

Population-based data indicate that latanoprost offers superior persistency compared to agents from other popular classes of topical ocular hypotensives.