Disparities in Access to Spasticity Chemodenervation Specialists in the United States: A Retrospective Cross-Sectional Study

OBJECTIVE

The aim of the study is to explore variations in access to spasticity chemodenervation specialists across several geographical, ethnic, racial, and population density factors.

DESIGN

This is a retrospective cross-sectional study on Medicare Provider Utilization and Payment Data. Providers with substantial adult spasticity chemodenervation practices were included. Ratios were assessed across geographical regions as well as hospital referral regions. A multivariate linear regression model for the top 100 hospital referral regions by beneficiary population was created, using backward stepwise selection to eliminate variables with P values > 0.10 from final model.

RESULTS

A total of 566 providers with spasticity chemodenervation practices were included. Unadjusted results showed lower access in nonurban versus urban areas in the form of higher patient:provider ratios (83,106 vs. 51,897). Access was also lower in areas with ≥25% Hispanic populations (141,800 vs. 58,600). Multivariate linear regression results showed similar findings with urban hospital referral regions having significantly lower ratios (-45,764 [ P = 0.004] vs. nonurban) and areas with ≥25% Hispanic populations having significantly higher ratios (+96,249 [ P = 0.003] vs. <25% Hispanic areas).

CONCLUSIONS

Patients in nonurban and highly Hispanic communities face inequities in access to chemodenervation specialists. The Medicare data set analyzed only includes 12% of the US patient population; however, this elderly national cross-sectional cohort represents a saturated share of patients needing access to spasticity chemodenervation therapy. Future studies should venture to confirm whether findings are limited to this specialization, and strategies to improve access for these underserved communities should be explored.

Cost Efficiency Analysis for Spasticity Management Based on Physician Botulinum Toxin Prescribing Habits

OBJECTIVE

To estimate differences in botulinum toxin type A (BoNT-A) treatment costs per patient for spasticity-injecting physicians, with a focus on physicians' use of alternative BoNT-A agents other than onabotulinumtoxinA.

DESIGN

Retrospective cohort study.

SETTING

National Medicare data for fee-for-service beneficiaries in 2017.

PARTICIPANTS

A total of 116 physicians, 6829 BoNT-A procedures, and 3051 patients were included in this analysis. Most physicians were physiatrists (84%) and used only onabotulinumtoxinA (82%).

INTERVENTIONS

Type of BoNT-A selected by physicians was the independent variable of interest. Included physicians were separated into 2 groups: (1) onabotulinumtoxinA only injectors and (2) abobotulinumtoxinA and/or incobotulinumtoxinA injectors (may still use onabotulinumtoxinA).

MAIN OUTCOME MEASURE

Average cost per patient per year.

RESULTS

The total average BoNT-A cost per patient per year was significantly less for physicians who used abobotulinumtoxinA and/or incobotulinumtoxinA vs those who used only onabotulinumtoxinA ($3684 vs $4739; P=.01). Patients' average annual out-of-pocket costs also reflected a similar difference ($855 vs $1082; P=.02) between the groups. Doses used and numbers of injections per patient per year were not significantly different between groups.

CONCLUSIONS

The present analysis demonstrated lower cost per patient for both the payer and patient when physicians used types of BoNT-A other than onabotulinumtoxinA for spasticity. Nevertheless, most physicians in this spasticity-focused study used exclusively onabotulinumtoxinA, the most expensive BoNT-A available. Reasons for this are complex and include history on the market and approved indications beyond those associated with spasticity. However, future research should continue to identify such issues with a goal of finding solutions to improve cost inefficiencies.

Real-World Six-Year National Cost-Minimization Analysis of IncobotulinumtoxinA and OnabotulinumtoxinA in the VA/DoD Healthcare Systems

Purpose

This study sought to perform a real-world, long-term cost-minimization analysis for incobotulinumtoxinA (Xeomin^®) versus onabotulinumtoxinA (Botox^®), given the established non-inferiority when utilized at similar doses.

Methods

The Department of Veterans Affairs (VA) and Department of Defense (DoD) national healthcare systems were included in this analysis. Real-world purchase data for incobotulinumtoxinA were used to estimate the direct drug costs between calendar years 2014 and 2019. Publicly available federal pharmaceutical prices (Federal Supply Schedule and Big 4) were used. The primary outcome was the difference in total direct costs nationally for incobotulinumtoxinA (real-world) versus having hypothetically utilized onabotulinumtoxinA (projected) for similar utilization. Sites utilizing ≥100 vials (of 100 Unit equivalents) of incobotulinumtoxinA annually were categorized as “major adopters”. IncobotulinumtoxinA 50 Unit vials were assumed to be an alternative to a 100 Unit vial of onabotulinumtoxinA for 50% of such vial purchases in the base case scenario to account for differences in wastage.

Results

Over the six-year study time frame, 156 sites (76.8%) utilized incobotulinumtoxinA of the 203 total VA healthcare systems and DoD medical centers. Of these sites, 67 were major adopters for at least one year, with a mean of 3.4 years spent as a major adopter over the study period. Average annual savings per major adopter was $105,782. IncobotulinumtoxinA costs for all VA/DoD sites was $46.39 million for the six-year period versus a projected $71.92 million onabotulinumtoxinA cost—a total savings of $25.53 million (35.5% relative reduction). Approximately, 82.8% of savings stemmed from lower drug acquisition cost ($21.14 million) and 17.2% of savings ($4.39 million) was related to reduced wastage. It was estimated that a total of 9958 extra onabotulinumtoxinA 100 Unit vials would have been wasted during the six-year period, translating to the need for a 5.9% increase in vial purchases versus incobotulinumtoxinA.

Conclusion

Meaningful cost savings were realized related to incobotulinumtoxinA adoption over a long-term time frame in the VA/DoD healthcare systems.

Comparison of botulinum toxins for treatment of movement disorders: real-world utilization and cost analysis in a national Medicare population

BACKGROUND: The Centers for Medicare & Medicaid Services (CMS) is the single largest payer for health care in the United States and the largest payer by spending globally. Medicare Part B, with more than 50 million beneficiaries, currently has no broad mechanisms in place for promoting cost-effective care of injectable drugs. OBJECTIVE: To conduct a real-world utilization and cost analysis comparing botulinum toxins in movement disorders. METHODS: The 2017 Medicare Provider Utilization and Payment Data: Physician and Other Supplier dataset from CMS was used for this claims level analysis. Neurologists, ophthalmologists, or physiatrists who injected predominantly for movement disorders (defined as blepharospasm, cervical dystonia, sialorrhea, and/or spasticity) were included along with their patients. Botulinum toxins with FDA indications spanning these 3 specialties were included. RESULTS: A total of 891 physicians (406 ophthalmologists, 338 neurologists, and 147 physiatrists) along with their 29,954 botulinum toxin (27,441 onabotulinumtoxinA and 2,513 incobotulinumtoxinA) patients were included in the analysis. The average total drug cost per patient per year (PPPY) was significantly lower for incobotulinumtoxinA versus onabotulinumtoxinA ($2,099 vs. $3,115; P < 0.001), for an average savings of 32.6%. Annual average out-of-pocket costs were also significantly less expensive for incobotulinumtoxinA versus onabotulinumtoxinA ($486 vs. $719; P < 0.001), for an average savings of 32.4%. Across 74,346 total injection visits, there was no significant difference in dosing between the agents, with an average dosing ratio of 0.94 incobotulinumtoxinA to 1.0 onabotulinumtoxinA. Injections PPPY were 2.42 for onabotulinumtoxinA and 2.29 for incobotulinumtoxinA. Average reported wastage was 64% higher for onabotulinumtoxinA than it was for incobotulinumtoxinA. A budget impact analysis estimated that increasing incobotulinumtoxinA use in the movement disorder space to attain an overall 20% botulinum toxin market share would save Medicare $32.9 million over a 3-year period versus current use. CONCLUSIONS: IncobotulinumtoxinA was shown to be a less costly alternative than onabotulinumtoxinA with similar dosing in real-world practice in this large national Medicare population. Policies to increase use of agents that promote cost-effective evidence-based care should be further explored and implemented for this fundamental federal payer. DISCLOSURES: This research received no external funding. Kazerooni was an employee of Merz Pharmaceuticals at the time of the analysis. Watanabe received no compensation or funding for this research project. Watanabe is a member of the National Academies of Sciences, Engineering, and Medicine Forum on Drug, Discovery, Development, and Translation. This information, content, and conclusions are those of the authors and should not be construed as the official position or policy of, nor should any endorsements be inferred by the U.S. government or the National Academies of Sciences, Engineering.

Botulinum Toxin Type A Overdoses: Analysis of the FDA Adverse Event Reporting System Database

INTRODUCTION

Published literature on overdoses related to botulinum toxin A (BtxA) agents is scarce.

OBJECTIVE

The aim of this study was to assess the BtxA drug class' respective agents for associations with overdose.

METHODS

United States Food and Drug Administration (FDA) adverse event reporting system (FAERS) database was utilized to search for overdoses. The analysis was conducted on data between second quarter 2014 and third quarter 2017. BtxA cases were included when they were considered the "Primary Suspect" drug. Overdose was defined as presence of 'overdose' being reported as an adverse event. Primary outcome was incidence of 'overdose' compared within the respective agents. Additionally, a disproportionality analysis was conducted utilizing reporting odds ratio (ROR) versus onabotulinumtoxinA as a referent while controlling for confounding variables.

RESULTS

A total of 3,837,406 unique adverse events were reported during the study period for all drugs in the FAERS database. Of which, 13,078 were BtxA cases. The rate of adverse events involving overdose for abobotulinumtoxinA (20.2%; 215/1065) was significantly higher than both onabotulinumtoxinA (0.4%; 48/11,323; p < 0.0001) and incobotulinumtoxinA (0.1%; 1/690; p < 0.0001). In the regression analysis, abobotulinumtoxinA (ROR 73.26; 95% CI 51.17-104.90) had a significant association with overdose, whereas incobotulinumtoxinA (ROR 0.73; 95% CI 0.10-5.36) did not, versus the referent onabotulinumtoxinA.

CONCLUSION

The present analysis showed adverse events of abobotulinumtoxinA were significantly associated with overdose versus the other two BtxA agents. Overdose can be difficult to research, particularly for in-clinic administered drugs. Future studies should venture to confirm these results in new and novel ways.

Topiramate-Associated Weight Loss in a Veteran Population

OBJECTIVE

This study aims to see whether patients in a real-world setting taking topiramate for varied indications experience significant weight loss.

METHODS

This was a retrospective cohort study from the Veterans Affairs San Diego Healthcare System. Patients were new topiramate users between January 1, 2000 and December 31, 2013 with body mass index > 25 kg/m(2) and medication possession ratio > 0.5. Primary outcome determined if topiramate users experienced significant changes in weight and body mass index. Secondary outcome analyzed predictive factors associated with 5% weight loss using logistic regression models. Patients were followed up 1 year post index date.

RESULTS

A total of 767 patients were included in the final analysis. Patients lost an average of 5.6 lbs (216.1 lbs preweight vs. 210.5 lbs postweight) at an average follow-up of 7.8 months. A total of 43.2% (92/213) of females lost 5% of their body weight compared to 29.4% (163/554) of males. Females (odds ratio 1.73; 95% confidence interval 1.21-2.48; p = 0.003), topiramate indication other than headache, and adherent patients (odds ratio 1.78; 95% confidence interval 1.28-2.49; p = 0.001) were more likely to lose 5% of body weight.

CONCLUSION

Topiramate should be considered with higher priority in overweight and obese patients for nonweight loss indications for dual benefit.

Predictors of Pregnancy in Female Veterans Receiving a Hormonal Contraceptive Pill, Patch, or Ring

BACKGROUND

Pregnancy rates in veterans are an understudied phenomenon.

OBJECTIVE

The objective of this study was to identify predictors of pregnancy within 1 year of starting hormonal contraception among female veterans.

METHODS

This was a retrospective, cohort study of female veterans from Veterans Affairs facilities within Southern California and Nevada, who newly started hormonal contraception (pill, patch, or ring only) between October 2008 and September 2012. Pregnancy was defined as any event corresponding to a pregnant state using ICD-9 codes. Patients were followed for 1 year post-initiation. Multivariate logistic regression analysis was performed.

RESULTS

The final analysis included a total of 2166 patients. Approximately 5.9% (n = 127) of patients became pregnant during follow-up. Increased odds of pregnancy were associated with the following: mental health disease (odds ratio [OR] 1.69, 95% confidence interval [CI] 1.15-2.58), lowest socioeconomic quintile (OR 1.50, 95% CI 1.05-2.09), and Christian faith (OR 1.69, 95% CI 1.31-2.41). Age groups 25 to 34 years (OR 0.55, 95% CI 0.38-0.92] and 35 to 44 years (OR 0.32, 95% CI 0.06-0.64) were both associated with decreased odds of pregnancy versus age group 18 to 24 years.

CONCLUSION

This study successfully identified several predictors of pregnancy in female veterans starting a pill, patch, or ring form of hormonal contraception. Female veterans in the lowest socioeconomic quintile, aged 18 to 24 years, diagnosed with a mental health disorder, and of Christian faith were found to be at significantly higher odds of a pregnancy. Identification of these at-risk populations may help clinicians and policy makers choose strategies to identify which patients could benefit the most from more effective long-acting reversible contraception therapy.

IncobotulinumtoxinA for Migraine: A Retrospective Case Series

PURPOSE

IncobotulinumtoxinA is used for treating certain movement disorders but lacks published clinical data on use in chronic migraine.

METHODS

This retrospective case series was performed by using electronic chart reviews on patients receiving incobotulinumtoxinA for migraine at the Veterans Affairs San Diego Healthcare System between September 2013 and March 2014. Patients were administered 150 units each, with similar methods used for onabotulinumtoxinA injections.

FINDINGS

A total of 21 patients were included in the analysis. Patients were 40 years old on average, 67% white, and 52% female. Patients had trialed an average of 4.19 oral prophylactic agents for migraine with 43% having previous history of onabotulinumtoxinA use and 29% having a history of traumatic brain injury. Patients reported a decrease in headache days per month (19.1 vs 9.1; P < 0.001) and headache intensity (8.3 vs 4.1; P < 0.001) after incobotulinumtoxinA injections. Most patients experienced an improvement in headache frequency and/or intensity (81.8%). The duration of action for these patients averaged 81.9 days (median, 70 days).

IMPLICATIONS

Significant improvements in headache frequency and intensity were observed. Chronic migraine is not an indication approved by the US Food and Drug Administration for incobotulinumtoxinA; however, the drug's effectiveness was documented in this small patient population.

Predictors of long-term mortality in new start statin users

Background

Cardiovascular diseases are among the leading causes of death worldwide and studies have found a direct relationship between levels of low-density lipoprotein cholesterol and coronary heart disease. Statins are the most commonly prescribed medications to lower cholesterol, a major controllable risk factor for coronary heart disease.

Objective

This study aims to find what factors in the first year of statin therapy are predictive of long-term all-cause mortality.

Methods

Data for this retrospective cohort study were collected on patients identified as new statin users between December 1, 2006 and November 30, 2007 at five Veterans Affairs Healthcare Systems from Southern California and Nevada. Multiple independent variables were assessed utilizing a logistic regression model assessing for all cause mortality at 6 years follow-up. The independent variables included race, age, ethnicity, body mass index, socioeconomic status, and baseline comorbidities. Secondary analysis analyzed high-density lipoprotein levels, adherence, total cholesterol, and triglycerides.

Results

Increased age, increased medication count, hypertension, diabetes, tobacco use, chronic obstructive pulmonary disease, and congestive heart failure were all associated with an increased risk of mortality. Hispanic ethnicity, Asian race, and increased body mass index were associated with decreased risk of mortality. There were no significant associations between mortality and race, LDL outcomes at 1 year, or annual income level.

Conclusion

There is clear evidence that statin use is associated with decreased events in cardiovascular disease and total mortality. This study found multiple independent variables as predictors of mortality in new start statin users after a 6 year follow-up, but differences in lipid groups after 1 year were not predictive of long-term mortality in the cohort studied.

New start versus continuing users on aripiprazole: implications for policy

OBJECTIVES

To evaluate utilization of 90-day-supply prescriptions of aripiprazole.

STUDY DESIGN

One year (April 1, 2011, to March 31, 2012) retrospective cohort study from the Veterans Affairs San Diego Healthcare System.

METHODS

The primary outcome was to determine the difference in adherence for new starts versus continuing users on aripiprazole, as determined by medication possession ratio (MPR). Secondary outcomes included odds of adherence and refilling at least once associated with being a new start. Adherence was defined as MPR ≥ 0.8. Separate regression models (linear and logistic) were run for the entire population, as well as a subgroup analysis of 90-day prescription patients only.

RESULTS

A total of 749 patients, 328 of whom were new starts, were included in the analysis. Both new starts (41.2%) and continuing users (69.1%) had a large portion who received 90-day supplies. New-start patients had significantly lower MPR than continuing users (-0.13; 95% CI, -0.18 to -0.08). Logistic regressions showed that new starts also had lower odds of adherence (odds ratio [OR], 0.46; 95% CI, 0.33-0.65) and of refilling at least once (OR, 0.43; 95% CI, 0.28-0.66) compared with continuing users.

CONCLUSIONS

Patients who were continuing users of aripiprazole were more likely to be adherent and refill their medication. Overutilization of 90-day supplies of high-cost agents, particularly in new starts, may lead to waste. It is recommended that patients newly started on high-cost agents should initially be provided a 30-day-supply prescription until it is established that effectiveness and tolerance have been achieved.

Retrospective cohort study of anti-tumor necrosis factor agent use in a veteran population

Introduction. Anti-tumor necrosis factor (TNF) agents are effective for several immunologic conditions (rheumatoid arthritis (RA), Crohn’s disease (CD), and psoriasis). The purpose of this study was to evaluate the efficacy and safety of anti-TNF agents via chart review.

Methods. Single-site, retrospective cohort study that evaluated the efficacy and safety of anti-TNF agents in veterans initiated between 2010 and 2011. Primary aim evaluated response at 12 months post-index date. Secondary aims evaluated initial response prior to 12 months post-index date and infection events.

Results. A majority of patients were prescribed anti-TNF agents for CD (27%) and RA (24%). Patients were initiated on etanercept (41%), adalimumab (40%), and infliximab (18%) between 2010 and 2011. No differences in patient demographics were reported. Response rates were high overall. Sixty-five percent of etanercept patients, 82% of adalimumab patients, and 59% of infliximab patients were either partial or full responders, respectively. Approximately 16%, 11%, and 12% of etanercept, adalimumab, and infliximab were non-responders, respectively. Infections between the groups were non-significant. Etanercept and adalimumab patients had higher but non-significant odds of being a responder relative to infliximab.

Conclusions. Most patients initiated with anti-TNF agent were responders at 12 months follow-up for all indications in a veteran population.

Association of copayment with likelihood and level of adherence in new users of statins: a retrospective cohort study

BACKGROUND

Statins remain a fundamental component of pharmacologic therapy for hyperlipidemia. Health benefits of statin therapy are jeopardized when adherence is reduced.

OBJECTIVES

To (a) assess the association between copayment and copayment type on statin adherence using 2 different thresholds of adherence and (b) identify the incremental change in statin adherence associated with presence of copayment and copayment type.

METHODS

We executed a retrospective cohort study of new users of statins with dyslipidemia from the Veterans Health Administration (VHA) within the Veterans Integrated Service Network 22 who initiated a statin between November 30, 2006, and December 2, 2007. We used exposure categories of Any Copayment versus No Copayment, indicating a patient had a copayment or had no copayment in order to obtain medications, respectively. As a separate analysis, we varied the exposures to the standard VHA copayment categories: (a) Service-Connected (SC) Copayment (patients with service-related injury), (b) Non-Service-Connected (NSC) Copayment (patients without a service-related injury), and (c) No Copayment. Using each set of exposures, we conducted separate multiple logistic regression analyses using 2 different adherence outcomes based on medication possession ratio (MPR) threshold: (1) adherence defined as MPR ≥ 0.8 and (2) adherence defined as MPR ≥ 0.9. We then proceeded with multiple linear regression models to determine the incremental change in MPR associated with the 2 sets of exposures. Subjects were required to be enrolled in VHA services for at least 2 years prior to index date and throughout the 1-year study period.

RESULTS

A total of 4,886 subjects were identified for analysis based on the inclusion and exclusion criteria. Patients who did not pay a copayment for their statin medications were more likely to have adherence rates of ≥ 0.8 MPR and ≥ 0.9 MPR relative to the No Copayment Group with odds ratios (OR) of 1.19 (95% CI = 1.03-1.37) and 1.28 (95% CI = 1.11-1.48), respectively. The second analysis applied the VHA exposure categories of SC Copayment, NSC Copayment, and No Copayment. Using the 0.8 MPR or greater adherence threshold, the No Copayment group was associated with an increased likelihood of adherence versus the SC Copayment category as reference group with an OR of 1.31 (95% CI = 1.10-1.58). The NSC Copayment was associated with a nonsignificant increase in odds of adherence at the 0.8 MPR level or greater with OR of 1.12 (95% CI = 0.98-1.39). Using the 0.9 MPR level or greater, adherence threshold findings were similar. The No Copayment group produced an OR of 1.42 (95% CI = 1.17-1.71) compared with the SC Copayment group. The NSC Copayment group was associated with a nonsignificant increase in odds of adherence at the 0.9 MPR level or greater with an OR of 1.12 (95% CI = 0.97-1.38).The No Copayment group was associated with an increase in MPR of 0.02 (95% CI = 0.002-0.035) versus the Any Copayment category. Using the VHA copayment categories, we observed an increase in MPR for the No Copayment group versus the SC Copayment group of 0.03 (95% CI = 0.01-0.05). The NSC Copayment group was associated with a nonsignificant increase in MPR versus the SC Copayment group of 0.02 (95% CI = -0.003-0.036).

CONCLUSIONS

Patients without out-of-pocket payments for their statins were more likely to adhere to therapy. Patients who pay a copayment for their statin medications were also compared with each other based on whether they (a) received any of their nonstatin prescriptions without a copayment or (b) paid a copayment on all of their prescriptions including statins. Our findings suggest that, among those that pay for their statins, patients are less adherent to their statins if other medications they are prescribed are copayment free. Thus, patient consumption behavior may be influenced by the relative cost of medications in patient prescription lists. Additional counseling on the necessity of adherence should be given to patients paying a copayment for their statin prescriptions.

Comparison of an Intensive Pharmacist-Managed Telephone Clinic With Standard of Care for Tobacco Cessation in a Veteran Population

Purpose. To evaluate the effectiveness of the Pharmacist-Managed Telephone Tobacco Cessation Clinic (PMTTCC) compared to the standard of care (SOC) at the Veterans Affairs San Diego Healthcare System. Method. A retrospective cohort study was performed investigating the proportion of veterans who quit smoking at 6 months while enrolled in the PMTTCC. Chart review was performed using the Veterans Affairs Computerized Patient Record System. The PMTTCC group included patients who had received medication and counseling from the tobacco cessation pharmacists. The cohort was compared to a matched SOC group who did not receive counseling, only tobacco cessation medication therapy through a primary care provider. The primary outcome for this study was patient-reported tobacco cessation at 6 months. Secondary outcomes were abstinence at 1 and 3 months. Results. A total of 1,006 patients were included in the analysis, 503 patients from the PMTTCC and 503 patients from SOC. The overall study population was 54 years old on average, 92.5% male, 70.0% Caucasian, 45.5% with history of psychiatric conditions, and had an average smoking history of 33-pack years. Patients in the PMTTCC group had statistically significant improvements in abstinence at 6 months versus the SOC group (81/503, 16.1% vs. 48/503, 9.5%; p < .0001). Quitters were older on average versus non-quitters (56.03 vs. 53.65 years; p = .01). Conclusion. Patients enrolled in the PMTTCC had improved tobacco abstinence rates at 6 months compared to SOC. Although the study was not designed to test for causality, the results lend support for using intensive tobacco cessation management in veteran population.

Association of copayment and statin adherence stratified by socioeconomic status

BACKGROUND

There is a growing body of evidence supporting means testing out of copayment for high-value therapies such as statins.

OBJECTIVE

To investigate association between statin adherence and copayment when stratified by socioeconomic status.

METHODS

This was a retrospective cohort study set in a network of VA facilities that includes Southern California and Nevada, with an enrollment of 1.4 million veterans. Socioeconomic status was estimated using zip code median household income. Differences in medication possession ratio (MPR) associated with copayment was the primary outcome measure. Odds of attaining low-density lipoprotein cholesterol (LDL) <100 mg/dL was the secondary outcome measure. Separate regression models for each income quintile were performed for each outcome measure, respectively.

RESULTS

A total of 4748 patients were included in the analysis. Patients in quintiles two (-0.057, 95% confidence interval [CI] = -0.095 to -0.020) and three (-0.044, CI = -0.081 to -0.007) had statistically significant decreases in MPR associated with having a copayment versus not having a copayment. Quintiles two (odds ratio [OR] = 0.68; 95% CI = 0.47 to 0.98) and three (OR = 0.66; 95% CI = 0.45 to 0.96) also had lower odds of attaining LDL <100 mg/dL when having a copayment. Patients in higher earning quintiles (four and five) did not show any associations with copayment.

CONCLUSION

In the veteran population studied, the association of statin copayment status with adherence varied by socioeconomic status. Middle-income and lower-middle-income patients were more likely to have adherence negatively influenced by having a copayment for statin therapy.

Association between statin adherence and cholesterol level reduction from baseline in a veteran population

STUDY OBJECTIVE

To investigate the association between statin adherence and changes in lipid panel outcomes from baseline in a veteran population.

DESIGN

Retrospective cohort study using multiple linear regression models.

SETTING

Veterans Affairs health care system within the Veterans Integrated Service Network 22, a network of Veterans Affairs facilities in the southwest region of the United States that includes Los Angeles, San Diego, Loma Linda, and Long Beach, California, and Las Vegas, Nevada, with an enrollment of approximately 1.4 million veterans.

PATIENTS

A total of 5365 patients who were new statin users between December 1, 2006, and November 30, 2007; 2674 patients were in the adherent group and 2691 were in the nonadherent group.

MEASUREMENTS AND MAIN RESULTS

Adherence was determined by the medication possession ratio. Patients were categorized as adherent if the medication possession ratio at follow-up was 0.80 or more. Adherent patients exhibited significant differences in baseline demographic and clinical characteristics than nonadherent patients in our study sample. Baseline laboratory values for adherent patients were significantly lower for low-density lipoprotein cholesterol (LDL), high-density lipoprotein cholesterol (HDL), non-high-density lipoprotein cholesterol (non-HDL), and total cholesterol levels. The primary outcome was change in LDL level from baseline at 12 months. Secondary outcomes were changes in non-HDL and total cholesterol levels from baseline at 12 months. Independent variables controlled for in the multiple linear regression included age, sex, body mass index, race-ethnicity, baseline lipid panel (LDL, HDL, total cholesterol, and triglycerides), statin copayment status, income quintile (according to ZIP code median household income), baseline medication count, statin prescribed, and comorbidities. Multiple linear regression revealed that adherent patients demonstrated significantly greater reductions in LDL of 20.98 mg/dl versus nonadherent patients (p<0.0001). Adherent patients similarly demonstrated larger reductions of 24.31 mg/dl in non-HDL and 24.06 mg/dl in total cholesterol versus nonadherent patients (p<0.0001 for both comparisons).

CONCLUSION

Patients adherent to statin therapy had significant associations with clinically relevant reductions in LDL, non-HDL, and total cholesterol from baseline at 12 months compared with nonadherent patients when controlling for potential confounders. Adherence to statin therapy may have important consequences in decreasing clinical outcomes such as myocardial infarctions, strokes, and mortality due to large reductions in lipid panel outcomes from baseline at 12 months.

Cost utility of tumour necrosis factor-α inhibitors for rheumatoid arthritis: an application of Bayesian methods for evidence synthesis in a Markov model

BACKGROUND

Rheumatoid arthritis (RA) is a chronic autoimmune disease that affects approximately 1.5 million people in the US. Tumour necrosis factor (TNF)-α inhibitors have been shown to effectively treat and maintain remission in patients with moderately to severely active RA compared with conventional agents. The high acquisition cost of TNF-α inhibitors prohibits access, which mandates economic investigations into their affordability. The lack of head-to-head comparisons between these agents makes it difficult to determine which agent is the most cost effective.

OBJECTIVE

This study aimed to determine which TNF-α inhibitor was the most cost-effective agent for the treatment of moderately to severely active RA from the US healthcare payer's perspective.

METHODS

A Markov model was constructed to analyse the cost utility of five TNF-α inhibitors (in combination with methotrexate [+MTX]) versus MTX monotherapy using Bayesian methods for evidence synthesis. The model had a cycle length of 3 months and an overall time horizon of 5 years. Transition probabilities and utility scores were based on published studies. Total direct costs were adjusted to year 2009 $US using the medical component of the Consumer Price Index. All costs and QALYs were discounted at a rate of 3% per year. Patient response to the different strategies was determined by the American College of Rheumatology (ACR)50 criteria. One-way and probabilistic sensitivity analyses (PSAs) were performed to test the robustness of the base-case scenario. The base-case scenario was changed to ACR20 criteria (scenario 1) and ACR70 criteria (scenario 2) to determine the model's robustness. Cost-effectiveness acceptability curves and cost-effectiveness frontiers were used to estimate the cost-effectiveness probability of each treatment strategy. A willingness-to-pay (WTP) threshold was defined as three times the US GDP per capita ($US139,143 per additional QALY gained). Primary results were presented as incremental cost-effective ratios (ICERs).

RESULTS

Etanercept+MTX was the most cost-effective treatment strategy in the base-case scenario up to a WTP threshold of $US2 185,497 per QALY gained. At a WTP threshold of greater than $US2 185,497 per QALY gained, certolizumab+MTX was the most cost-effective treatment strategy. One-way analyses showed that the base-case scenario was sensitive to the probability of achieving ACR50 criteria for MTX and each TNF-α inhibitor, and changes in the utility score for patients who achieved the ACR50 criteria. With the exception of infliximab, all of the TNF-α inhibitors were sensitive to drug cost per cycle. In the scenario analyses, certolizumab+MTX was a dominant treatment strategy using ACR20 criteria, but etanercept+MTX was a dominant treatment strategy using ACR70 criteria.

CONCLUSIONS

Etanercept+MTX was a cost-effective treatment strategy in the base-case scenario; however, the model was sensitive to parameter uncertainties and ACR response criteria. Although Bayesian methods were used to determine transition probabilities, future studies will need to focus on head-to-head comparisons of multiple TNF-α inhibitors to provide valid comparisons.

Cost-effectiveness analysis of intravenous levetiracetam versus intravenous phenytoin for early onset seizure prophylaxis after neurosurgery and traumatic brain injury

Objective:

There has been growing interest in newer anti-epileptic drugs (AEDs) for seizure prophylaxis in the intensive care setting because of safety and monitoring issues associated with conventional AEDs like phenytoin. This analysis assessed the cost-effectiveness of levetiracetam versus phenytoin for early onset seizure prophylaxis after neurosurgery and traumatic brain injury (TBI).

Methods:

A cost-effectiveness analysis was conducted from the US hospital perspective using a decision analysis model. Probabilities of the model were taken from three studies comparing levetiracetam and phenytoin in post neurosurgery or TBI patients. The outcome measure was successful seizure prophylaxis regimen (SSPR) within 7 days, which was defined as patients who did not seize or require discontinuation of the AED due to adverse drug reactions (ADRs). One-way sensitivity analyses and probabilistic sensitivity analysis were conducted to test robustness of the base-case results.

Results:

The total direct costs for seizure prophylaxis were $8,784.63 and $8,743.78 for levetiracetam and phenytoin, respectively. The cost-effectiveness ratio of levetiracetam was $10,044.91 per SSPR compared to $11,525.63 per SSPR with phenytoin. The effectiveness probability (patients with no seizures and no ADR requiring change in therapy) was higher in the levetiracetam group (87.5%) versus the phenytoin group (75.9%). The incremental cost effectiveness ratio for levetiracetam versus phenytoin was $360.82 per additional SSPR gained.

Conclusions:

Levetiracetam has the potential to be more cost-effective than phenytoin for early onset seizure prophylaxis after neurosurgery if the payer’s willingness-to-pay is greater than $360.82 per additional SSPR gained.

Phase I clinical pharmacokinetics of RTA 744: A blood brain barrier penetrating anthracycline active against high-grade glioma

2045

Background: Preclinical studies demonstrated that RTA 744, a 4’-O benzyl anthracycline designed to circumvent P-gp and MRP1-mediated efflux, effectively crosses the BBB, is retained in brain & brain tumor tissue for >24 hrs, and has demonstrated in vivo activity against glioblastoma multiforme (GBM) in an orthotopic model. Methods: We designed a multicenter, phase I dose- escalation study of RTA 744 administered as a short intravenous infusion for 3 consecutive days, every 3 weeks. Patients enrolled in the study were adult patients with recurrent or refractory GBM, anaplastic astrocytoma, or other primary brain tumors. Peripheral blood samples for PK analysis were collected prior to and at selected timepoints from 5 min to 96 hrs after drug administration, and quantified by LC/MS/MS. PK parameters describing RTA 744 disposition were determined by fitting compartmental models to individual patient plasma concentration-time data. Results: Twenty patients have been enrolled at daily doses ranging from 1.2 to 9.6 mg/m2. Mean (range) population terminal half-life was 34.6 (20.5–89.2) hrs, plasma drug clearance was 45.0 (27.4–86.9) L/hr/m2, and Vss was 1942 (684.9–4721.7) L/m2; population PK values reported for doxorubicin are 20–32 hrs, 24–35 L/hr/m2, and 700–1100 L/m2, respectively. Regimen related toxicity has been minimal with the most common adverse event being myelosuppression. Percentage of unchanged parent drug renally eliminated was 2.4% (0.42–6.03%). Several partial responses and one complete response have been noted, even at dose levels below the observed MTD of 7.5 mg/m2/day. Conclusions: These results are similar to what we have observed in our preclinical studies, demonstrating increased lipophillicity and enhanced biodistribution of RTA 744 when compared to doxorubicin. Direct confirmation of drug penetration into the CNS has not been determined in this study, however this is the focus of an ongoing trial in patients with leptomenigeal malignancies.

No significant financial relationships to disclose.