Incidence of venous thromboembolism in patients with peripheral arterial disease after endovascular intervention

OBJECTIVE

Venous thromboembolism (VTE) is a well-known postoperative complication; however, the incidence of VTE after peripheral vascular intervention (PVI) has not been well described. Despite the minimally invasive nature of these procedures, the patients undergoing PVI have significant risk factors for the development of VTE. In the present study, our objective was to describe the short-term incidence of VTE after PVI, identify differences between sexes, and examine the periprocedural antiplatelet and anticoagulation regimens.

METHODS

We identified adults (age >66 years) who had undergone PVI from January 1, 2008 to September 30, 2015 from the inpatient Medicare claims data. The patients were followed for 365 days after the procedure. VTE events during follow-up were identified using the International Classification of Diseases, 9th revision, diagnosis codes. The covariate-standardized 30- and 90-day cumulative incidence of VTE events, overall and stratified by sex, were estimated using Aalen-Johansen estimators, accounting for death as a competing risk. Differences in sex between females and males were identified using Gray's test. Any antiplatelet or anticoagulant prescription fill was defined as any fill from 14 days before the endovascular intervention through the date of the VTE event. Persistence with antiplatelet and anticoagulant therapy was assessed by creating daily logs of antiplatelet and anticoagulant coverage using the dispensing dates and days of supply. Over-the-counter medications (ie, aspirin) were not evaluated.

RESULTS

We identified 31,593 qualifying patients with a mean age of 76.8 ± 7.4 years. Of the 31,593 patients, 46% were male, and 12% had a history of VTE. After the procedure, deep vein thrombosis (DVT) was a commonly diagnosed complication (3.8% and 4.8% at 30 and 90 days, respectively). The cumulative incidence of pulmonary embolism was 0.9% and 1.2% at 30 and 90 days after the procedure, respectively. Throughout the 90-day postoperative period, females had had a slightly increased risk of DVT compared with males (30-day risk difference, 0.007; P < .01; 90-day risk difference, 0.008; P = .02). We found no sex-based differences in the risk of pulmonary embolism. Of the patients who had developed VTE at 90 days, 970 (55%) had had no prescription fill for an antiplatelet or anticoagulant. Assuming all the patients had been taking aspirin, only 15% of the patients who had developed VTE had been taking prescribed dual antiplatelet medication persistently after PVI. In addition, among the patients who had developed VTE at 90 days, females were less likely to have had a prescription fill for an anticoagulant.

CONCLUSIONS

The findings from our study have demonstrated that the incidence of VTE after PVI is high, with an increased risk of deep vein thrombosis for females. We also found that females were less likely to have been prescribed an anticoagulant after PVI. Future studies are needed to characterize the variables associated with an increased risk of VTE after PVI and to identify strategies to increase dual antiplatelet therapy or anticoagulant prescription adherence to reduce the risk of VTE.

TRANSLATION OF A MEDICARE CLAIMS-BASED FRAILTY ALGORITHM FROM ICD-9-CM TO ICD-10-CM

Clinical trials often have insufficient power to estimate drug effects in older adult populations. Medicare claims data are a valuable resource for studying healthcare delivery for older adults. The Faurot frailty index (FFI) is a validated algorithm that uses demographic, enrollment, and ICD-9-CM-based claims information to predict ADL dependency as a proxy for frailty. The original FFI consists of 20 constructs, including those related to geriatric syndromes, of which 16 are based on ICD-9-CM diagnosis codes (e.g., arthritis, dementia). In October 2015, the US healthcare system transitioned to ICD-10-CM. In this study, we updated and validated the FFI for the ICD-10-CM era . We used General Equivalence Mapping (GEM) to translate the ICD-9-CM codes to ICD-10-CM. For each construct, we manually reviewed the ICD-10-CM codes after GEM, assessed the suitability, and plotted the monthly prevalence before and after the transition (2013-2017). Code lists for all but 1 construct required editing after translation using GEM (adding and/or removing codes). We observed increasing monthly prevalence for several constructs, although trend lines were consistent across the ICD-9-CM and ICD-10-CM eras: bladder dysfunction (1.8-2.5%), weakness (2.7-3.9%), and psychiatric illnesses (6.9-9.1%). Rehabilitation services did not translate well using diagnosis codes, however, adding CPT codes improved capture. The updated FFI was strongly associated with frailty-related geriatric outcomes (1-year mortality, hospitalization, SNF admission). Studies of drug effects in older adults should use validated indices, such as the FFI, to reduce bias. Thorough evaluation of claims-based algorithms is essential to support healthcare services research using these measures.

Increased long-term bleeding complications in females undergoing endovascular revascularization for peripheral arterial disease

OBJECTIVE

Females with peripheral arterial disease (PAD) treated with endovascular interventions have increased limb-based procedural complications compared with males. Little is known regarding long-term bleeding risk in these patients who often require long-term antiplatelet or anticoagulation therapy. We hypothesize that females have a higher incidence of bleeding events compared with males in the year after endovascular intervention for PAD.

METHODS

Adults (aged ≥65 years) who underwent endovascular revascularization for PAD between 2008 and 2015 in Medicare claims data were identified. Patients were allocated by prescribed postprocedural antithrombotic therapy, including (1) antiplatelet therapy, (2) anticoagulation therapy, (3) dual antiplatelet and anticoagulation therapy, and (4) no prescription antithrombotic therapy. Bleeding events were classified as gastrointestinal, intracranial, hematoma, airway, or other. Crude and covariate-standardized 30-, 90-, and 365-day cumulative incidence of bleeding events, overall and by sex, were estimated using Aalen-Johansen estimators accounting for death as a competing risk. Sex differences were identified using Gray's test.

RESULTS

Of 31,593 eligible patients, 54% were females. Females were older (77.9 years vs 75.5 years) and tended to use antiplatelet therapy more often at 30, 90, and 365 days after the intervention. Clopidogrel was the most prescribed antiplatelet, and 32% of patients continued its use at 365 days. Anticoagulants were prescribed to 26.0% of patients at the time of the procedure, and only 8.8% continued anticoagulation at 365 days. Thirty-one percent of patients were diagnosed with a bleeding event within 1 year after the intervention. The cumulative incidence of any bleeding event during the postintervention period was higher in females compared with males with a risk difference of 3% between the sex cohorts (P < .01). Specifically, females had a higher incidence of gastrointestinal bleeding and hematoma (P < .01), but a lower incidence of airway-related bleeding at each time point as compared with males (P < .01).

CONCLUSIONS

Sex disparities in bleeding complications after endovascular intervention for PAD persist in the long term. Females are more likely to be readmitted with a bleeding complication up to 1 year after the procedure. Antithrombotic therapy disproportionately increases the risk of bleeding in females. Further research is necessary to understand the mechanisms responsible for abnormal coagulopathy in females after endovascular therapy.

Higher Admission Frailty Scores Predict Increased Mortality, Morbidity, and Healthcare Utilization in the Elderly Burn Population

The Rockwood Clinical Frailty Scale is a validated rapid assessment of frailty phenotype and predictor of mortality in the geriatric population. Using data from a large tertiary care burn center, we assessed the association between admission frailty in an elderly burn population and inpatient outcomes. This was a retrospective analysis of burn patients ≥ 65 years from 2015-2019. Patients were assigned to frailty subgroups based on comprehensive medical, social work, and therapy assessments. Cox proportional hazards regression was used to estimate associations between admission frailty and 30-day inpatient mortality. Our study included 644 patients (low frailty: 262, moderate frailty: 345, and high frailty: 37). Frailty was associated with higher median TBSA and age at admission. The 30-day cumulative incidence of mortality was 2.3%, 7.0%, and 24.3% among the low, moderate, and high frailty strata, respectively. After adjustment for age, TBSA, and inhalation injury, high frailty was associated with increased 30-day mortality, compared to low (HR 5.73; 95% CI 1.86, 17.62). Moderate frailty also appeared to increase 30-day mortality, although estimates were imprecise (HR 2.19; 95% CI 0.87-5.50). High frailty was associated with increased morbidity and healthcare utilization, including need for intensive care stay (68% vs 37% and 21%, p<0.001) and rehab or care facility at discharge (41% vs 25% and 6%, p<0.001), compared to moderate and low frailty subgroups. Our findings emphasize the need to consider pre-injury physiological state and the increased risk of death and morbidity in the elderly burn population.

A Budget Impact Analysis of the Introduction of Copanlisib for Treatment of Relapsed Follicular Lymphoma in the United States

BACKGROUND

Copanlisib was recently granted accelerated approval by the FDA for the treatment of adult patients with relapsed follicular lymphoma (FL) after 2 previous systemic therapies. It is important to assess the effect that this and other changes in the treatment landscape of relapsed FL have on a payer's budget to inform formulary decisions.

OBJECTIVE

To assess the budget impact associated with the addition of copanlisib to a formulary as third- or higher-line treatment for adult patients with relapsed FL who have received at least 2 previous systemic therapies, from the perspective of a U.S. third-party payer.

METHODS

A budget impact model was developed over a 1-year horizon. The model considered a hypothetical population of 1 million people enrolled in a commercial health plan; patients with relapsed FL were identified based on epidemiology data. Treatments included copanlisib and approved and off-label therapies used for management of relapsed FL. Treatment distributions within the target population were based on a market research survey. Drug acquisition, administration, prophylaxis, and monitoring costs were based on prescribing information, clinical trials, literature, and expert opinion. All costs were inflated to 2017 U.S. dollars. Total costs were compared between 2 scenarios, 1 without and 1 with copanlisib on a formulary. A deterministic sensitivity analysis (DSA) was conducted to evaluate the robustness of the model.

RESULTS

Within the 1 million-member health care plan, 18 patients had relapsed FL and had received at least 2 previous systemic therapies. Over 1 year, the addition of copanlisib and an increase in the use of obinutuzumab + bendamustine (from 9.0% without copanlisib to 13.1% with copanlisib) and lenalidomide + rituximab (from 0.3% to 12.0%) were estimated to increase drug acquisition costs by $238,536, drug administration and prophylaxis costs by $3,565, and monitoring costs by $539. The increase in total budget was $242,641, corresponding to $0.02 per member per month; 21.8% of this increase was attributable to copanlisib, 12.9% to obinutuzumab + bendamustine, and 65.3% to lenalidomide + rituximab. Results were generally robust in the DSA.

CONCLUSIONS

Over a 1-year period, the model found that the addition of copanlisib to a formulary resulted in a small increase in total budget of $242,641, corresponding to $0.02 per patient per month and taking into account a concurrent increase in the use of obinutuzumab + bendamustine and lenalidomide + rituximab. Therefore, adding copanlisib to a formulary appears to be an affordable option for payers. Further studies should be conducted to more comprehensively assess the clinical and economic implications of adding copanlisib to the treatment armamentarium of relapsed FL.

DISCLOSURES

This study was funded by Bayer HealthCare Pharmaceuticals. The study sponsor was involved in study design, data interpretation. and data review. All authors contributed to the development of the manuscript and maintained control over the final content. Appukkuttan, Yaldo, Gharibo, and Babajanyan report employment with Bayer HealthCare Pharmaceuticals at the time of this study. Duchesneau, Zichlin, Bhak, and Duh report employment with Analysis Group, which received research funds from Bayer HealthCare Pharmaceuticals for work on this study. A synopsis of the current research was presented in poster format at the AMCP Managed Care & Specialty Pharmacy Annual Meeting; April 23-26, 2018; Boston, MA.

Cost Effectiveness of Midostaurin in the Treatment of Newly Diagnosed FLT3-Mutated Acute Myeloid Leukemia in the United States

OBJECTIVES

The aim of this study was to assess the cost effectiveness of midostaurin + cytarabine + daunorubicin (midostaurin arm) versus placebo + cytarabine + daunorubicin (placebo arm) in the treatment of adult patients with newly diagnosed FLT3-mutated acute myeloid leukemia (AML) who are eligible for standard cytarabine + daunorubicin chemotherapy, from a US third-party payer perspective.

METHODS

A lifetime partitioned survival model with four health states (active disease, complete remission [CR], relapse, and death) was constructed. Efficacy inputs (time to CR or death, time to relapse or death, and overall survival) were estimated using data from the RATIFY trial (NCT00651261). Costs (inflated to 2016 US dollars) included treatment, drug monitoring, stem cell transplantation (SCT), adverse events costs, and medical costs associated with health states. Incremental costs per quality-adjusted life-year (QALY) and life-year (LY) gained were estimated. Deterministic (DSA) and probabilistic sensitivity analyses (and PSA) were performed to assess model robustness.

RESULTS

In the base case, patients in the midostaurin arm incurred higher total direct costs over a lifetime compared with the placebo arm ($4,043,470 vs. $3,959,741), resulting in an incremental cost of $83,729; however, the midostaurin arm had better effectiveness, with 1.59 more LYs and 1.37 more QALYs. These led to a base-case incremental cost-effectiveness ratio (ICER) of $52,596 per LY, or $61,167 per QALY. Results were robust in the DSA. In the PSA, the probability of the midostaurin arm being cost-effective compared with the placebo arm was 65.9%, at a willingness to pay of $150,000/QALY.

CONCLUSIONS

This analysis suggests that midostaurin is a cost-effective treatment for adult patients with newly diagnosed FLT3-mutated AML, from a US third-party payer perspective.

Hepatitis A, B, and A/B vaccination series completion among US adults: A claims-based analysis

Hepatitis A and B disease burden persists in the US. We assessed hepatitis A and hepatitis B vaccination series completion rates among 350,240 commercial/Medicare and 12,599 Medicaid enrollees aged ≥19 years. A vaccination series was considered as completed provided that the minimum interval between doses, as defined by the CDC, and the minimum number of doses were reached. We stratified completion rates by vaccine type (i.e. monovalent or bivalent) at initial vaccination for each cohort. In the commercial/Medicare cohort, the series completion rate was 32.0% for hepatitis A and 39.6% for hepatitis B among those who initiated with a monovalent vaccine, and it was 36.2% for hepatitis A and 48.9% for hepatitis B among those who initiated with a bivalent vaccine. In the Medicaid cohort, the series completion rate was 21.0% for hepatitis A and 24.0% for hepatitis B among those who initiated with a monovalent vaccine, and it was 19.0% for hepatitis A and 24.6% for hepatitis B among those who initiated with a bivalent vaccine. In conclusion, hepatitis A and B vaccination series completion rates were low, and appeared to be lower among Medicaid than among commercial/Medicare enrollees. Commercial/Medicare enrollees who initiated with a bivalent vaccine had higher series completion rates than those who initiated with monovalent vaccines - an observation that was not made among Medicaid enrollees.

The Additional Costs per Month of Progression-Free Survival and Overall Survival: An Economic Model Comparing Everolimus with Cabozantinib, Nivolumab, and Axitinib for Second-Line Treatment of Metastatic Renal Cell Carcinoma

BACKGROUND

When considering optimal second-line treatments for metastatic renal cell carcinoma (mRCC), clinicians and payers seek to understand the relative clinical benefits and costs of treatment.

OBJECTIVE

To use an economic model to compare the additional cost per month of overall survival (OS) and of progression-free survival (PFS) for cabozantinib, nivolumab, and axitinib with everolimus for the second-line treatment of mRCC from a third-party U.S. payer perspective.

METHODS

The model evaluated mean OS and PFS and costs associated with drug acquisition/administration; adverse event (AE) treatment; monitoring; and postprogression (third-line treatment, monitoring, and end-of-life costs) over 1- and 2-year horizons. Efficacy, safety, and treatment duration inputs were estimated from regimens' pivotal clinical trials; for everolimus, results were weighted across trials. Mean 1- and 2-year OS and mean 1-year PFS were estimated using regimens' reported OS and PFS Kaplan-Meier curves. Dosing and administration inputs were consistent with approved prescribing information and the clinical trials used to estimate efficacy and safety inputs. Cost inputs came from published literature and public data. Additional cost per additional month of OS or PFS was calculated using the ratio of the cost difference per treated patient and the corresponding difference in mean OS or PFS between everolimus and each comparator. One-way sensitivity analyses were conducted by varying efficacy and cost inputs.

RESULTS

Compared with everolimus, cabozantinib, nivolumab, and axitinib were associated with 1.6, 0.3, and 0.5 additional months of PFS, respectively, over 1 year. Cabozantinib and nivolumab were associated with additional months of OS compared with everolimus (1 year: 0.7 and 0.8 months; 2 years: 1.6 and 2.3 months; respectively); axitinib was associated with fewer months (1 year: -0.2 months; 2 years: -0.7 months). The additional costs of treatment with cabozantinib, nivolumab, or axitinib versus everolimus over 1 year were $34,141, $19,371, and $17,506 higher, respectively. Everolimus had similar OS and lower costs compared with axitinib. The additional cost per month of OS was $48,773 for cabozantinib and $24,214 for nivolumab versus everolimus. The additional treatment cost with cabozantinib, nivolumab, or axitinib versus everolimus for each additional month of PFS was estimated at $21,338, $64,570, and $35,012, respectively. Over 2 years, the additional costs per additional month of OS for nivolumab and axitinib versus everolimus were similar to the 1-year analysis; for cabozantinib, the cost was lower. Results were sensitive to changes in mean OS, mean PFS, therapy duration, and drug costs estimates.

CONCLUSIONS

Everolimus for second-line mRCC was associated with similar OS and lower costs compared with axitinib over 1- and 2-year horizons. The additional cost per additional month of OS and PFS associated with cabozantinib or nivolumab versus everolimus creates a metric for evaluating the cost of second-line therapies in relation to their respective treatment effects.

DISCLOSURES

Funding for this research was provided by Novartis, which was involved in all stages of study research and manuscript preparation. Ghate and Perez are employees of Novartis and own stock/stock options. Swallow, Messali, McDonald, and Duchesneau are employees of Analysis Group, which has received consultancy fees from Novartis. Study concept and design were contributed by Swallow, Messali, Ghate, and Perez, along with McDonald and Duchesneau. Swallow, Messali, McDonald, and Duchesneau collected the data, and all authors participated in data interpretation. The manuscript was written by Swallow, Messali, and Ghate, along with the other authors, and revised by Swallow, Messali, Ghate, and Perez. A synopsis of the current research was presented in poster format at the 15th International Kidney Cancer Symposium on November 4-5, 2016, in Miami, Florida.

Cost-effectiveness analysis of ocrelizumab versus subcutaneous interferon beta-1a for the treatment of relapsing multiple sclerosis

AIM

To conduct a cost-effectiveness analysis to compare ocrelizumab vs subcutaneous (SC) interferon beta-1a for the treatment of relapsing multiple sclerosis (RMS).

METHODS

A Markov cohort model with a 20-year horizon was developed to compare ocrelizumab with SC interferon beta-1a from a US payer perspective. A cohort of patients with relapsing-remitting MS (RRMS) and Expanded Disability Status Scale (EDSS) scores of 0-6, who initiated treatment with ocrelizumab or SC interferon beta-1a, were entered into the model. The model considered 21 health states: EDSS 0-9 in RRMS, EDSS 0-9 in secondary-progressive multiple sclerosis (SPMS), and death. Patients with RRMS could transition across EDSS scores, progress to SPMS, experience relapses, or die. Transition probabilities within RRMS while patients received ocrelizumab or SC interferon beta-1a were based on data from the two SC interferon beta-1a-controlled Phase III OPERA I and OPERA II trials of ocrelizumab in RMS. Transitions within RRMS when off-treatment, RRMS-to-SPMS transitions, transitions within SPMS, and transitions to death were based on the literature. Utilities of health states, disutilities of relapses, costs of therapies, and medical costs associated with health states, relapse, and adverse events were from the literature and publicly available data sources. The model estimated per-patient total costs, incremental cost per life year (LY) gained, and incremental cost per quality-adjusted LY (QALY) gained. Deterministic sensitivity analyses (DSA) and probabilistic sensitivity analysis (PSA) were conducted to evaluate the robustness of the model results.

RESULTS

Ocrelizumab was associated with a cost savings of $63,822 and longer LYs (Δ = 0.046) and QALYs (Δ = 0.556) over a 20-year time horizon. The results of the model were robust in the DSA and PSA.

LIMITATIONS

The model did not consider subsequent treatments and their impact on disease progression.

CONCLUSIONS

The results suggest that ocrelizumab is more cost-effective than SC interferon beta-1a for the treatment of RMS.