Socioecologic Factors and Racial Differences in Breast Cancer Multigene Prognostic Scores in US Women

Importance

Disproportionately aggressive tumor biology among non-Hispanic Black women with early-stage, estrogen receptor (ER)-positive breast cancer contributes to racial disparities in breast cancer mortality. It is unclear whether socioecologic factors underlie racial differences in breast tumor biology.

Objective

To examine individual-level (insurance status) and contextual (area-level socioeconomic position and rural or urban residence) factors as possible mediators of racial and ethnic differences in the prevalence of ER-positive breast tumors with aggressive biology, as indicated by a high-risk gene expression profile.

Design, Setting, and Participants

This retrospective cohort study included women 18 years or older diagnosed with stage I to II, ER-positive breast cancer between January 1, 2007, and December 31, 2015. All data analyses were conducted between December 2022 and April 2023.

Main Outcomes and Measures

The primary outcome was the likelihood of a high-risk recurrence score (RS) (≥26) on the Oncotype DX 21-gene breast tumor prognostic genomic biomarker.

Results

Among 69 139 women (mean [SD] age, 57.7 [10.5] years; 6310 Hispanic [9.1%], 274 non-Hispanic American Indian and Alaskan Native [0.4%], 6017 non-Hispanic Asian and Pacific Islander [8.7%], 5380 non-Hispanic Black [7.8%], and 51 158 non-Hispanic White [74.0%]) included in our analysis, non-Hispanic Black (odds ratio [OR], 1.33; 95% CI, 1.23-1.43) and non-Hispanic American Indian and Alaska Native women (OR, 1.38; 95% CI, 1.01-1.86) had greater likelihood of a high-risk RS compared with non-Hispanic White women. There were no significant differences among other racial and ethnic groups. Compared with non-Hispanic White patients, there were greater odds of a high-risk RS for non-Hispanic Black women residing in urban areas (OR, 1.35; 95% CI, 1.24-1.46), but not among rural residents (OR, 1.05; 95% CI, 0.77-1.41). Mediation analysis demonstrated that lack of insurance, county-level disadvantage, and urban vs rural residence partially explained the greater odds of a high-risk RS among non-Hispanic Black women (proportion mediated, 17%; P < .001).

Conclusions and Relevance

The findings of this cohort study suggest that the consequences of structural racism extend beyond inequities in health care to drive disparities in breast cancer outcome. Additional research is needed with more comprehensive social and environmental measures to better understand the influence of social determinants on aggressive ER-positive tumor biology among racial and ethnic minoritized women from disadvantaged and historically marginalized communities.

The Relationship Between Signature Time and Functional Health Literacy: Results from a Prospective Study of an Urban Low-Income Population Receiving Long-Term Anticoagulation

INTRODUCTION

Low health literacy (HL) is consistently associated with worse health outcomes. Routine clinical screening with available instruments is impractical because of added time and effort. Prior findings suggested that signature time may be a reliable alternative measure of HL among general medicine patients.

METHODS

Our aim was to assess the screening performance of signature time and explore optimal thresholds for identifying patients with limited HL in a chronically anticoagulated population. English-speaking patients receiving long-term anticoagulation therapy were recruited. HL was assessed using the Short Test of Functional Health Literacy in Adults (STOFHLA). Signature time was measured using a stopwatch. Logistic regression models and receiver-operating characteristic (ROC) curves were used to evaluate the association and accuracy of signature time compared to HL, respectively.

RESULTS

Of 139 enrolled patients, mean age was 60.1 years, 70.5% were African-American, 48.9% reported < $25,000 income, and 27.3% had marginal or inadequate HL. Overall, median time to sign was 6.1 s. Signature time was longest with inadequate HL (median 9.5 s) compared to adequate HL (5.7 s; p < 0.01). Longer signature time was significantly associated with lower HL after adjusting for age and education (aOR 0.77, 95% CI: 0.68-0.88, p < 0.01). Signature time demonstrated high accuracy (area under the curve [AUC] > 0.8) in identifying HL levels. Thresholds of 5.1 s and 9.0 s showed appropriate screening performance in distinguishing patients with adequate vs. marginal and marginal vs. inadequate HL, respectively.

CONCLUSION

Signature time demonstrated strong screening performance and may offer a quick and practical approach to assessing HL among patients receiving long-term anticoagulation management.

Pharmacist-guided pharmacogenetic service lowered warfarin-related hospitalizations

Background: The authors aimed to assess outcomes with a pharmacogenetic (PGx)-informed, pharmacist-guided, personalized consult service for warfarin dosing. Methods: This retrospective cohort study included patients admitted with thromboembolic events. Eligible subjects received either PGx-informed (n = 389) or historical non-PGx pharmacist-guided warfarin dosing (Hx; n = 308) before hospital discharge. The composite of admission with bleeding or thromboembolic events over 90 days after the discharge was compared between the PGx and Hx groups. Results: The rate ratio (95% CI) of the composite of bleeding or thromboembolic admissions for PGx versus Hx was 0.32 (0.12-0.82). The estimated hazard ratio was 0.43 (0.16-1.12). Conclusion: A PGx-informed warfarin dosing service was associated with decreased bleeding and thromboembolic encounters.

Implementation of pharmacogenomics into inpatient general medicine

Pharmacogenomics is a crucial piece of personalized medicine. Preemptive pharmacogenomic testing is only used sparsely in the inpatient setting and there are few models to date for fostering the adoption of pharmacogenomic treatment in the inpatient setting. We created a multi-institutional project in Chicago to enable the translation of pharmacogenomics into inpatient practice. We are reporting our implementation process and barriers we encountered with solutions. This study, 'Implementation of Point-of-Care Pharmacogenomic Decision Support Accounting for Minority Disparities', sought to implement pharmacogenomics into inpatient practice at three sites: The University of Chicago, Northwestern Memorial Hospital, and the University of Illinois at Chicago. This study involved enrolling African American adult patients for preemptive genotyping across a panel of actionable germline variants predicting drug response or toxicity risk. We report our approach to implementation and the barriers we encountered engaging hospitalists and general medical providers in the inpatient pharmacogenomic intervention. Our strategies included: a streamlined delivery system for pharmacogenomic information, attendance at hospital medicine section meetings, use of physician and pharmacist champions, focus on hospitalists' care and optimizing system function to fit their workflow, hand-offs, and dealing with hospitalists turnover. Our work provides insights into strategies for the initial engagement of inpatient general medicine providers that we hope will benefit other institutions seeking to implement pharmacogenomics in the inpatient setting.

The Role of Global and Local Ancestry on Clopidogrel Response in African Americans

Pharmacogenomics has long lacked dedicated studies in African Americans, resulting in a lack of indepth data in this populations. The ACCOuNT consortium has collected a cohort of 167 African American patients on steady state clopidogrel with the goal of discovering population specific variation that may contribute to the response of this anti-platelet agent. Here we analyze the role of both global and local ancestry on the clinical phenotypes of P2Y12 reaction units (PRU) and high on-treatment platelet reactivity (HTPR) in this cohort. We found that local ancestry at the TSS of three genes, IRS-1, ABCB1 and KDR were nominally associated with PRU, and local ancestry-adjusted SNP association identified variants in ITGA2 associated to increased PRU. These finding help to explain the variability in drug response seen in African Americans, especially as few studies on genes outside of CYP2C19 has been conducted in this population.

Reversal of Oral Anticoagulants: A Survey of Contemporary Practice Trends (ReACT)

This study evaluated practice patterns and factors influencing treatment decisions regarding urgent or emergent reversal of oral anticoagulants (OACs). A 30-question survey was electronically distributed to anticoagulation members of the Anticoagulation Forum. Questions were designed to capture practice trends in the reversal of warfarin, factor Xa inhibitors, and factor IIa inhibitors. Continuous and categorical data were analyzed to generate descriptive statistics. Open-ended questions were summarized by thematic categories. 173 responses were collected most from US-based pharmacists with direct patient care responsibilities. The majority of the respondents' institutions (90.2%) utilized a guideline or protocol for OACs reversal. Vitamin K (91.3%), activated charcoal (80.4%), and fresh frozen plasma (72.8%) were the most common reversal agents on formulary without restrictions. Most institutions (87.0%) reported having 4-factor prothrombin complex concentrate (4F-PCC) and idarucizumab on formulary, but most commonly (52.2%) with restrictions. Andexanet alfa was only reported on formulary at 35.9% of institutions. In contrast to current guideline recommendations, vitamin K (98.8%) was preferred over 4F-PCC and 4F-PCC (71.6%) was preferred over andexanet alfa as first-line agents used to reverse warfarin and factor Xa inhibitors, respectively. Weight-based dosing strategies for 4F-PCC were commonly utilized for different reversals (41.2%-59.4%). Cost, efficacy, and safety of 4F-PCC were identified as top facilitators and barriers for 4F-PCC adoption in practice. Our findings revealed that guideline recommendations for reversal of warfarin and factor Xa and IIa inhibitors are not followed by a majority of institutions. Studies are needed to investigate strategies to overcome barriers for implementing and following guideline recommendations.

Thromboembolic Events in Users of Warfarin Treated with Different Skeletal Muscle Relaxants

Background and Objectives: Warfarin and a skeletal muscle relaxant are co-treatments in nearly a quarter-million annual United States (US) office visits. Despite international calls to minimize patient harm arising from anticoagulant drug interactions, scant data exist on clinical outcomes in real-world populations. We examined effects of concomitant use of warfarin and individual muscle relaxants on rates of hospitalization for thromboembolism among economically disadvantaged persons. Materials and Methods: Using 1999−2012 administrative data of four US state Medicaid programs, we conducted 16 retrospective self-controlled case series studies: half included concomitant users of warfarin + one of eight muscle relaxants; half included concomitant users of an inhaled corticosteroid (ICS) + one of eight muscle relaxants. The ICS analyses served as negative control comparisons. In each study, we calculated incidence rate ratios (IRRs) comparing thromboembolism rates in the co-exposed versus warfarin/ICS-only exposed person-time, adjusting for time-varying confounders. Results: Among ~70 million persons, we identified 8693 warfarin-treated subjects who concomitantly used a muscle relaxant, were hospitalized for thromboembolism, and met all other inclusion criteria. Time-varying confounder-adjusted IRRs ranged from 0.31 (95% confidence interval: 0.13−0.77) for metaxalone to 3.44 (95% confidence interval: 1.53−7.78) for tizanidine. The tizanidine finding was robust after quantitatively adjusting for negative control ICS findings, and in numerous prespecified secondary analyses. Conclusions: We identified a potential >3-fold increase in the rate of hospitalized thromboembolism in concomitant users of warfarin + tizanidine vs. warfarin alone. Alternative explanations for this finding include confounding by indication, a native effect of tizanidine, or chance.

Apixaban Concentrations in Routine Clinical Care of Older Adults With Nonvalvular Atrial Fibrillation

BACKGROUND

Direct-acting oral anticoagulants are first-line agents for prevention of stroke in patients with nonvalvular atrial fibrillation (NVAF), but data are limited for the oldest patients, and with reduced dosing.

OBJECTIVES

To determine steady-state apixaban peak and trough concentrations during routine care of older adults with NVAF, compare concentrations to clinical trial concentrations, and explore factors associated with concentrations.

METHODS

A cross-sectional study of medically stable older adults with NVAF (≥75 years or ≥70 years if Black) receiving apixaban. Peak (2-4.4 hours post-dose) and trough (before next dose) concentrations were determined by anti-Xa activity calibrated chromogenic assay. Patient characteristics associated with concentrations were determined by multivariate modeling.

RESULTS

The median age of patients (n = 115) was 80 (interquartile range: 77-84) years. The cohort comprised 46 women and 69 men; of which 98 are White, 11 Black, and 6 Asian. With 5 mg twice daily per labelling (n = 88), peak concentrations were higher in women: 248 ± 105 vs 174 ± 67 ng/mL in men (P < 0.001) and exceeded expected 95% range in 6 of 30 vs 0 of 55 men (P = 0.002). With 2.5 mg twice daily per label (n = 11), concentrations were <5 mg twice daily (peak: 136 ± 87 vs 201 ± 90 ng/mL, P = 0.026; trough: 65 ± 28 vs 109 ± 56 ng/mL, P < 0.001), but not different than 2.5 mg twice daily without reduction criteria (n = 13; peak: 132 ± 88; trough: 65 ± 31 ng/mL). Covariates associated with concentrations included sex, number of daily medications, and creatinine clearance.

CONCLUSIONS

Older women had higher than expected peak apixaban concentrations, and 2.5 mg twice daily produced lower concentrations than standard dosing. Factors not currently included in dosing recommendations affected concentrations. The impact of apixaban concentrations on outcomes needs evaluation.

Changing from mandatory to optional genotyping results in higher acceptance of pharmacist-guided warfarin dosing

Aim: We evaluated the clinical acceptance and feasibility of a pharmacist-guided personalized consult service following its transition from a mandatory (mPGx) to optional (oPGx) CYP2C9/VKORC1/CYP4F2 genotyping for warfarin. Methods: A total of 1105 patients were included. Clinical acceptance and feasibility outcomes were analyzed using bivariate and multivariable analyses. Results: After transitioning to optional genotyping, genotype testing was still ordered in a large segment of the eligible population (52.1%). Physician acceptance of pharmacist-recommended doses improved from 83.9% (mPGx) to 86.6% (oPGx; OR: 1.3; 95% CI: 1.1-1.5; p = 0.01) with a shorter median genotype result turnaround time (oPGX: 23.6 h vs mPGX: 25.1 h; p < 0.01). Conclusion: Ordering of genotype testing and provider acceptance of dosing recommendations remained high after transitioning to optional genotyping.

Applicability of Pharmacogenomically Guided Medication Treatment during Hospitalization of At-Risk Minority Patients

Known disparities exist in the availability of pharmacogenomic information for minority populations, amplifying uncertainty around clinical utility for these groups. We conducted a multi-site inpatient pharmacogenomic implementation program among self-identified African-Americans (AA; n = 135) with numerous rehospitalizations (n = 341) from 2017 to 2020 (NIH-funded ACCOuNT project/clinicaltrials.gov#NCT03225820). We evaluated the point-of-care availability of patient pharmacogenomic results to healthcare providers via an electronic clinical decision support tool. Among newly added medications during hospitalizations and at discharge, we examined the most frequently utilized medications with associated pharmacogenomic results. The population was predominantly female (61%) with a mean age of 53 years (range 19-86). On average, six medications were newly prescribed during each individual hospital admission. For 48% of all hospitalizations, clinical pharmacogenomic information was applicable to at least one newly prescribed medication. Most results indicated genomic favorability, although nearly 29% of newly prescribed medications indicated increased genomic caution (increase in toxicity risk/suboptimal response). More than one of every five medications prescribed to AA patients at hospital discharge were associated with cautionary pharmacogenomic results (most commonly pantoprazole/suboptimal antacid effect). Notably, high-risk pharmacogenomic results (genomic contraindication) were exceedingly rare. We conclude that the applicability of pharmacogenomic information during hospitalizations for vulnerable populations at-risk for experiencing health disparities is substantial and warrants continued prospective investigation.

Association between transportation barriers and anticoagulation control among an inner-city, low-income population: A prospective observational cohort study

Background

Anticoagulation with warfarin represents a transportation-sensitive treatment state. Transportation barrier is a common reason for not using health care services.

Objective

To assess the association between transportation barriers to anticoagulation clinic and anticoagulation control (AC) among an inner-city, low-income population.

Patients/Methods

Adults expected to be on chronic warfarin therapy were recruited from an ambulatory anticoagulation clinic. Participants completed a validated questionnaire that assessed transportation barriers to clinic, defined as self-reported trouble getting transportation to a clinic and a composite score of the presence of transportation barriers. Suboptimal AC was defined as time in therapeutic range (TTR) <60% over 6 months. Prevalence ratios with 95% confidence intervals (CIs), adjusted for age, sex, and annual household income, described the association of transportation trouble and barriers with AC.

Results

Of 133 participants, 42.9% had suboptimal AC. Mean age was 60.4 (SD, 13.6) years, and the majority of participants were women (62.2%). Participants with transportation trouble were more likely to report being disabled/unable to work (63.6%) and annual household income <$15 000 (45.5%). Mean TTR was significantly lower for participants with transportation trouble compared to those without (53.8% [SD, 24.7%] vs 64.7% [SD, 25.0%]; P = .03). Participants reporting transportation trouble or at least one transportation barrier were 1.60 (95% CI, 1.07-2.39) and 1.68 (95% CI, 1.01-2.80) times more likely, respectively, to have suboptimal AC compared to those without.

Conclusion

Inner-city, low-income individuals with transportation barriers were more likely to have suboptimal AC. Further research is warranted to evaluate the impact of alleviating patient-specific transportation barriers on anticoagulation outcomes.

Evaluation of point-of-care International Normalized Ratio in sickle cell disease

Background

Point‐of‐care (POC) International Normalized Ratio (INR) measurement provides efficient monitoring of warfarin therapy; however, its reliability may be affected in patients with anemia, such as those with sickle cell disease (SCD).

Objectives

To evaluate the correlation of POC‐INR to clinical laboratory INR (CL‐INR) in SCD and use of a correction factor.

Patient/Methods

In this retrospective study, the accuracy of POC‐INR compared to CL‐INR was evaluated in a cohort of patients with SCD and in a non‐SCD Black cohort.

Results

Despite the difference in anemia, the SCD cohort showed a similar percentage of in‐range POC‐INR values as observed in the non‐SCD cohort (37% vs 42%). The SCD cohort was randomly divided to form discovery and validation cohorts. In the discovery cohort, 86% of POC‐INRs were in range when the POC‐INRs were ˂4.0, but only 24% were in range if POC‐INRs were ≥4.0. A linear regression of CL‐INR versus POC‐INR for POC‐INR values ≥4.0 yielded a coefficient of 0.72 (95% confidence interval, 0.69‐0.75); Multiplying POC‐INR by this correction factor, rounded to 0.7 for ease of use in clinical practice, improved the proportion of in‐range POC‐INR values ≥4.0 from 24% to 100% in the SCD discovery cohort and from 19% to 95% in the SCD validation cohort. Similar findings applied to analyses of the non‐SCD cohort.

Conclusions

POC‐INR and CL‐INR in patients with SCD are similar when POC‐INR is <4.0, and the accuracy of POC‐INR values ≥4.0 can be improved by applying an institution‐specific correction factor.

Racial Disparities in Intravenous Bisphosphonate Use Among Older Patients With Multiple Myeloma Enrolled in Medicare

PURPOSE

Intravenous (IV) bisphosphonates reduce the risk of skeletal-related events in patients with multiple myeloma (MM). However, data describing racial differences in IV bisphosphonate utilization outside of clinical trial settings are limited. We evaluated population-level IV bisphosphonate initiation and discontinuation among patients of age ≥ 65 years with MM.

METHODS

We conducted a retrospective cohort study of patients of age ≥ 65 years diagnosed with first primary MM between 2001 and 2011. Patients were identified using the SEER-Medicare linked database and followed through December 2013. Cumulative incidences of IV bisphosphonate initiation and time to discontinuation among users were compared between racial and ethnic groups. In Fine and Gray competing risk models, we estimated subdistribution hazard ratios (SHRs) and 95% CIs for initiation and discontinuation.

RESULTS

We included 14,231 eligible patients with MM (median age, 76 years; 52% male). Over a median follow-up of 23.1 months, 54% of patients received at least one IV bisphosphonate dose. Our final analytical sample included 10,456 non-Hispanic (NH) Whites, 2,267 NH Blacks, 548 Asian and Pacific islanders, and 815 Hispanic and Latino patients. A higher proportion of White patients (56.1%) newly received IV bisphosphonates after MM diagnosis compared with NH Blacks (45.4%). Compared with White patients, NH Black patients were less likely to initiate IV bisphosphonates (SHR, 0.74; 95% CI, 0.70 to 0.79) and slightly more likely to discontinue treatment (SHR, 1.10; 95% CI, 1.01 to 1.19).

CONCLUSION

Approximately half of the patients with MM of age ≥ 65 years did not receive IV bisphosphonates, with significant delay among racial minority groups. These findings highlight the need for improvement of IV bisphosphonate uptake in patients with MM of age ≥ 65 years.

Abstract 5748: Declines in health-related quality of life among older patients diagnosed with hematologic malignancies

Background: The diagnosis of cancer and its treatment have meaningful impacts on health-related quality of life (HRQOL). Although advances in novel therapy and stem cell transplantation have increased survival in patients with hematologic malignancies (HM), less evidence exists on the subsequent impacts of HM on HRQOL. The objective of this study was to evaluate changes in HRQOL following diagnosis of HM in a cohort of older Medicare beneficiaries.

Methods: This was a retrospective study utilizing the Surveillance, Epidemiology and End Results Medicare Health Outcomes Survey Data Resource, a linkage of longitudinal surveys and cancer registry data. We included patients ages ≥65 years diagnosed with first primary leukemia, lymphoma or multiple myeloma between 1998 and 2014 who completed at least one survey within two years pre- and post-diagnosis. HRQOL was measured using the Short Form Health Survey (SF-36) composite scores with a minimum clinically important difference of 2 points. We also measured self-reported general health, depressive symptoms, and the deficit-accumulation frailty index before and after HM diagnosis. Patients with HM were compared to up to four patients without cancer with exact matching on age, sex, race, marital status, smoking status, education, comorbid conditions, proxy response and calendar time of HM diagnosis. Comparisons of means were performed between groups using ANOVA with adjustment for survey type.

Results: Among 401 patients with HM included in our analysis, mean (SD) age of diagnosis was 75.98 (6.2) years and 26% were diagnosed with leukemia, 57% with lymphoma, and 17% with multiple myeloma. No significant differences in HRQOL, self-reported health, depressive symptoms, or frailty were observed between patients with HM and their non-cancer matches (n=1578) before diagnosis. Substantial declines in HRQOL were observed across all types of HM after cancer diagnosis. Mean decreases in composite SF-36 scores among patients with HM (physical component score [PCS] -7.1, 95% CI -8.8, -5.5; mental component score [MCS] -3.4, 95% CI -4.9, -1.8) were greater in magnitude compared to declines in matched non-cancer patients (PCS -1.6, 95% CI -2.4, -0.7; MCS -0.6, 95% CI -1.3, 0.1). During follow-up, patients with HM also had higher rates of low self-reported health (46% vs. 27%), depressive symptoms (34% vs. 25%) and frailty (56% vs. 43%).

Conclusion: Our study found decreases in HRQOL measures among older patients with HM that were more than three-fold higher than the minimum clinically important differences in the general population and twice that reported in older patients with common solid tumors. Prospective studies and clinical trials in patients with leukemia, lymphoma, and multiple myeloma should include measures that assess whether life-prolonging, novel therapies are also effective in preserving HRQOL.

Citation Format: Ashwini Zolekar, Nadia A. Nabulsi, Alemseged A. Asfaw, Jifang Zhou, Karen Sweiss, Pritesh R. Patel, Brian C.-H. Chiu, Edith A. Nutescu, Gregory S. Calip. Declines in health-related quality of life among older patients diagnosed with hematologic malignancies [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5748.

Immigration Status and Disparities in the Treatment of Cardiovascular Disease Risk Factors in the Hispanic Community Health Study/Study of Latinos (Visit 2, 2014-2017)

Objectives. To estimate treatment rates of high cholesterol, hypertension, and diabetes among Hispanic/Latino immigrants by immigration status (i.e., naturalized citizens, documented immigrants, or undocumented immigrants).Methods. We performed a cross-sectional analyses of the Hispanic Community Health Study/Study of Latinos (visit 2, 2014-2017). We restricted our analysis to Hispanic/Latino immigrants with high cholesterol (n = 3974), hypertension (n = 3353), or diabetes (n = 2406); treatment was defined as use of statins, antihypertensives, and antidiabetics, respectively.Results. When compared with naturalized citizens, undocumented and documented immigrants were less likely to receive treatment for high cholesterol (38.4% vs 14.1%; prevalence ratio [PR] = 0.37 [95% confidence interval [CI] = 0.27, 0.51] and 25.7%; PR = 0.67 [95% CI = 0.58, 0.76]), hypertension (77.7% vs 57.7%; PR = 0.74 [95% CI = 0.62, 0.89] and 68.1%; PR = 0.88 [95% CI = 0.82, 0.94]), and diabetes (60.3% vs. 50.4%; PR = 0.84 [95% CI = 0.68, 1.02] and 55.8%; PR = 0.93 [95% CI = 0.83, 1.03]); the latter did not reach statistical significance. Undocumented and documented immigrants had less access to health care, including insurance coverage or a usual health care provider, than naturalized citizens. Therefore, adjusting for health care access largely explained treatment disparities across immigration status.Conclusions. Preventing cardiovascular disease among Hispanic/Latino immigrants should focus on undertreatment of high cholesterol, hypertension, and diabetes by increasing health care access, especially among undocumented immigrants.

Antidiabetic drug use trends in patients with type 2 diabetes mellitus and chronic kidney disease: A cross-sectional analysis of the National Health and Nutrition Examination Survey

BACKGROUND

There is little information on medication use, trends across time, and the impact of guidelines on appropriate use of antidiabetic drugs in participants with type 2 diabetes mellitus (T2DM) with chronic kidney disease (CKD).

METHODS

A cross-sectional analysis of the National Health and Nutrition Examination Survey (NHANES) from 2005-2016 was carried out for participants with T2DM with and without CKD. Multivariate survey-weighted regression models were used to evaluate trends in antidiabetic drug use across the time periods and CKD severity. Guideline-discordant use of metformin and glyburide were assessed among those with glomerular filtration rate and serum creatinine-based contraindications.

RESULTS

Out of 3237 study participants with T2DM, 35.9% had CKD. Comparing 2013-2016 with 2005-2008, use of metformin (non-CKD: 69% vs 83.8%, CKD: 58.6% vs 68.2%) increased, whereas the use of sulfonylureas (non-CKD: 46.3% vs 27.2%, CKD: 54.7% vs 36.6%) and thiazolidinediones (non-CKD: 29.3% vs 3.9%, CKD: 24.6% vs 5.5%) decreased. In combined NHANES cycles and across stages of CKD severity, metformin use decreased (non-CKD, stage 1/2, stage 3, stage 4/5: 78.4%, 69.5%, 54.6%, 4.9%, respectively; P < .01), and insulin use increased (18.5%, 26.8%, 25%, 52.8%, respectively; P < .01) from non-CKD to progressed CKD. Guideline-discordant use of metformin and glyburide was observed in 8.3% and 2.8% of the participants, respectively, in 2013-2016.

CONCLUSIONS

Use of particular antidiabetic medications in patients with CKD changed noticeably over the years, most in accordance with guidelines and regulatory decisions. Gaps in quality of care still exist, which warrants increasing awareness and implementing programs to mitigate inappropriate use.

Clinical trajectories, healthcare resource use, and costs of long-term hematopoietic stem cell transplantation survivors: a latent class analysis

PURPOSE

To identify patterns of healthcare utilization in allogeneic and autologous hematopoietic stem cell transplantation (HSCT) recipients and evaluate factors associated with high-need and high-cost post-transplantation care.

METHODS

Latent class analysis of a retrospective cohort of long-term allogeneic (n = 436) and autologous (n = 888) HSCT survivors within the Truven MarketScan database (2009-2014). We assessed factors associated with the latent classes by comparing post-transplantation healthcare utilization including inpatient admissions and length of stay, emergency room visits, specialist visits, and primary care provider visits.

RESULTS

Four utilization classes were identified in allogeneic and autologous HSCT recipients: (i) outpatient specialist care dominant (51.8% and 57.3%), (ii) outpatient primary care dominant (10.3% and 25.7%), (iii) outpatient/inpatient balanced (20.6% and 13.5%), and (iv) inpatient dominant (17.2% and 3.5%). Mean monthly healthcare expenditures in the inpatient dominant utilization class were $41,097 and $25,556 for allogeneic and autologous survivors, respectively, which were two to five times higher compared with other classes during the 2-year post-transplantation period. Factors associated with the high utilization class were transfusion (OR = 1.87, 95% CI 1.06-3.30) and 100-day post-transplant graft-versus-host-disease (OR = 1.76, 95% CI 1.05-2.94) in allogeneic HSCT; higher baseline Charlson comorbidity index (OR = 1.45, 95% CI 1.19-1.76) in autologous HSCT.

CONCLUSION

Based on distinct patterns of healthcare utilization following HSCT, we identified factors associated with higher resource utilization and greater healthcare related expenditures.

IMPLICATIONS FOR CANCER SURVIVORS

Earlier identification of high-cost and high-need HSCT long-term survivors could pave the way for clinicians to offer more continuous engagement in survivorship care delivery.

Adherence and Persistence with DPP-4 Inhibitors Versus Pioglitazone in Type 2 Diabetes Patients with Chronic Kidney Disease: A Retrospective Claims Database Analysis

BACKGROUND

Adherence and persistence with diabetes medication play an important role in glycemic control and may differ by medication class. However, there is a lack of research comparing diabetes medications in patients with renal impairment, despite the challenges and higher burden associated with managing this population.

OBJECTIVE

To compare adherence and persistence among patients with type 2 diabetes mellitus (T2DM) and nondialysis chronic kidney disease (CKD) treated with dipeptidyl peptidase-4 (DPP-4) inhibitors versus pioglitazone.

METHODS

This retrospective cohort study used Truven MarketScan administrative claims databases from 2009 to 2015. One-year adherence for patients with T2DM and nondialysis CKD who initiated therapy with either a DPP-4 inhibitor or pioglitazone was measured by proportion of days covered (PDC) following an initial dispensing, and PDC ≥ 0.80 was coded as adherent. Persistence was calculated as the days between the index date and last day with the index medication on hand, based on the end of the last days supply or the end of follow-up (i.e., 365 days), whichever occurred first. Multivariate logistic regression and Cox proportional hazards models were used to estimate confounder-adjusted differences between the groups for adherence and persistence.

RESULTS

The final cohort included 9,019 patients (DPP-4 inhibitors: 7,002; pioglitazone: 2,017). In the adjusted analysis, DPP-4 inhibitor users demonstrated a 1.41 (95% CI = 1.25-1.59) higher odds of being adherent compared with pioglitazone users. Overall adjusted HR for persistence was 0.74 (95% CI = 0.69-0.79), which favored DPP-4 inhibitors compared with pioglitazone. Relative to 2010, persistence with pioglitazone decreased in 2011-2012 and then increased in 2013-2014. In the subgroup analysis, DPP-4 inhibitors first had lower (2010: OR = 0.78, 95% CI = 0.70-0.87; 2011-2012: OR = 0.60, 95% CI = 0.54-0.66) and then similar (2013-2014: OR = 1.03, 95% CI = 0.88-1.19) hazards of nonpersistence compared with pioglitazone.

CONCLUSIONS

Among patients with T2DM and nondialysis CKD, the use of DPP-4 inhibitors was associated with better adherence compared with pioglitazone. However, following the approval of generic pioglitazone and associated lower cost sharing after 2012, the magnitude of difference in adherence between the medication classes reduced. Similarly, safety warnings in 2011 and approval of generic products in 2012 may have affected pioglitazone persistence, leading to first higher and then similar hazards for nonpersistence with pioglitazone as compared with DPP-4 inhibitors. These shifts in the results for pioglitazone warrant further investigation and close monitoring of the population initiating this medication.

DISCLOSURES

No funding was received for this study. The authors have no conflicts of interest to disclose. An abstract for this study was presented as a podium presentation at the International Society of Pharmacoeconomics and Outcomes Research (ISPOR) 2019 Annual Meeting; May 18-22, 2019; New Orleans, LA.

Bevacizumab Use and the Risk of Arterial and Venous Thromboembolism in Patients with High-Grade Gliomas: A Nested Case-Control Study

STUDY OBJECTIVE

Bevacizumab is used in the treatment of recurrent glioblastoma, but evidence is limited on the incidence of thromboembolic complications regarding the use of this drug in real-world settings. We evaluated the risk of arterial thromboembolism (ATE) and venous thromboembolism (VTE) associated with the use of bevacizumab among adults diagnosed with high-grade gliomas in a commercially insured U.S.

POPULATION

DESIGN

Nested case-control study.

DATA SOURCE

Truven Health MarketScan Commercial and Medicare Supplemental health claims databases (2009-2015).

PATIENTS

A total of 2157 patients with high-grade gliomas who underwent incident (first-time) craniotomy, radiation, and concurrent temozolomide treatment between 2009 and 2015 were identified. Overall, 25 cases of ATE and 99 cases of VTE were each identified in this cohort, and each case was matched to up to 10 controls (170 for ATE and 819 for VTE) based on sex, age, quarter year of index time, and follow-up duration by using incidence density sampling without replacement from the overall cohort. Controls were at risk for the outcome of interest (ATE or VTE) at the time of case occurrence and survived at least as long as their referent case.

MEASUREMENTS AND MAIN RESULTS

Exposure to bevacizumab was determined during inpatient or outpatient encounters between the index date (date of the incident craniotomy) and the ATE or VTE event or corresponding matched control date. Multivariable conditional logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the risk of ATE and VTE separately. A higher proportion of patients with ATE received bevacizumab compared with controls (28% vs 17%; adjusted OR 1.51, 95% CI 0.54-4.24), but this excess in odds was not statistically significant. Similarly, bevacizumab was not significantly associated with VTE (13% vs 9%; adjusted OR 1.40, 95% CI 0.71-2.75).

CONCLUSION

We found no significant association between the use of bevacizumab and the occurrence of thromboembolic events in patients with high-grade gliomas, although our study was limited by the small number of ATE events. Because the potential for complications from arterial thrombosis cannot be completely ruled out, further research is needed to confirm the thromboembolic safety of bevacizumab in a larger sample of patients with high-grade gliomas.

The ACCOuNT Consortium: A Model for the Discovery, Translation, and Implementation of Precision Medicine in African Americans

The majority of pharmacogenomic (PGx) studies have been conducted on European ancestry populations, thereby excluding minority populations and impeding the discovery and translation of African American–specific genetic variation into precision medicine. Without accounting for variants found in African Americans, clinical recommendations based solely on genetic biomarkers found in European populations could result in misclassification of drug response in African American patients. To address these challenges, we formed the Transdisciplinary Collaborative Center (TCC), African American Cardiovascular Pharmacogenetic Consortium (ACCOuNT), to discover novel genetic variants in African Americans related to clinically actionable cardiovascular phenotypes and to incorporate African American–specific sequence variations into clinical recommendations at the point of care. The TCC consists of two research projects focused on discovery and translation of genetic findings and four cores that support the projects. In addition, the largest repository of PGx information on African Americans is being established as well as lasting infrastructure that can be utilized to spur continued research in this understudied population.

Similar burden of type 2 diabetes among adult patients with sickle cell disease relative to African Americans in the U.S. population: a six-year population-based cohort analysis

Conflicting evidence exists on the epidemiology of type 2 diabetes mellitus (T2DM) among patients with sickle cell disease (SCD). This study measured the prevalence, incidence and clinical outcomes associated with T2DM in a large US population of commercially-insured adults aged ≥20 years with SCD between 2009 and 2014. Among 7070 patients with SCD, the mean age (median) was 39 (37) years and 60·8% were female. The standardized prevalence of T2DM among patients with SCD showed a modest increase, from 15·7% to 16·5% (P trend = 0·026), and was comparable to African-American respondents to the National Health and Nutrition Examination Survey (18·2%). Over 17 024 person-years, the crude incidence rate for T2DM was 25·4 per 1000 person-years. Incident T2DM was associated with comorbid hypertension (hazard ratio [HR] = 1·45, 95% confidence interval [CI] 1·14-1·83), and dyslipidaemia (HR = 1·43, 95%CI 1·04-1·96). Compared to SCD patients without T2DM, more SCD patients with T2DM had diagnoses of nephropathy (28·0% vs. 9·5%; P < 0·001), neuropathy (17·7% vs. 5·2%; P < 0·001) and stroke (24·1% vs. 9·2%; P < 0·001). Prevalence of T2DM in SCD patients is similar to the general African American population with an increasing trend in recent years. These trends support routine screening for T2DM in aging patients with SCD, especially those with comorbid hypertension and/or dyslipidaemia.

Discontinuation and Nonadherence to Medications for Chronic Conditions after Hematopoietic Cell Transplantation: A 6-Year Propensity Score-Matched Cohort Study

INTRODUCTION

Hematopoietic cell transplantation (HCT) is an established curative option for patients with hematological malignancies and other life-threatening conditions. Evidence on nonpersistence and nonadherence to oral medications for chronic conditions among patients following HCT is lacking.

OBJECTIVES

This study aims to examine patterns of oral medication use for chronic conditions following HCT in the U.S.

POPULATION

METHODS

Nonpersistence and nonadherence to oral medications for diabetes, hypertension, and dyslipidemia among HCT recipients were assessed in a cohort that included 1382 autologous and 650 allogeneic HCT recipients with hematological malignancies using the Truven Health MarketScan Research Database between 2009 and 2014. Recipients of HCT were compared to propensity score-matched cancer patients receiving chemotherapy without transplantation. Multivariable Cox proportional hazards models and generalized estimating equations were used to determine characteristics associated with nonpersistence and nonadherence to oral chronic medications, respectively.

RESULTS

Recipients of HCT had higher risks of discontinuing medication for diabetes mellitus (allogeneic HCT hazard ratio [HR] = 1.93, 95% confidence interval [CI] 1.10-3.39; autologous HCT HR = 1.49, 95% CI 1.04-2.15); hypertension (allogeneic HCT HR = 1.75, 95% CI 1.21-2.53; autologous HCT HR = 1.32, 95% CI 1.07-1.62), and dyslipidemia (allogeneic HCT HR = 2.02, 95% CI 1.39-2.93; autologous HCT, HR = 1.26, 95% CI 0.98-1.61) compared to patients treated with only chemotherapy. Lower odds of adherence to antihypertensive medications (odds ratio [OR] = 0.58, 95% CI 0.38-0.89) and to lipid-lowering medications (OR = 0.38, 95% CI 0.22-0.65) were observed in allogeneic HCT recipients compared with propensity score-matched patients who underwent chemotherapy only.

CONCLUSIONS

Poor medication persistence and adherence to chronic disease medications are common after HCT. Further research to improve long-term outcomes following HCT should include management of medication therapy for chronic comorbid conditions.

High number of newly initiated direct oral anticoagulant users switch to alternate anticoagulant therapy

Real-world evidence focusing on medication switching patterns amongst direct oral anticoagulant (DOACs) has not been well studied. The objective of this study is to evaluate patterns of prescription switching in non-valvular atrial fibrillation (NVAF) patients initiated on a DOAC and previously naïve to anticoagulation (AC) therapy. Data was obtained from Truven Health MarketScan^® Commercial and Medicare Supplemental database (2009-2013). AC naïve (those without prior anticoagulant use) NVAF patients initiated on a DOAC, with 6 months of continuous health plan enrollment before and after treatment initiation and maintained on continuous therapy for a minimum of 6 months were included. Of 34,022 AC naïve NVAF patients initiating a DOAC, 6613 (19.4%) patients switched from an index DOAC prescription to an alternate anticoagulant and 27,409 (80.6%) remained on the DOAC [age: 68.5 ± 11.7 vs. 67.1 ± 12.7 years, p < 0.001; males: 3781 (57.2%) vs. 17,160 (62.6%), p < 0.001]. Amongst those that switched medication, 3196 (48.3%) did so within the first 6 months of therapy. Overall, 2945 (44.5%) patients switched to warfarin, 2912 (44.0%) switched to another DOAC and 756 (11.4%) switched to an injectable anticoagulant. The highest proportion of patients switched from dabigatran to warfarin (N = 2320; 42.5%) or rivaroxaban (N = 2252; 41.3%). The median time to switch from the index DOAC to another DOAC was 309.5 days versus 118.0 days (p < 0.001) to switch to warfarin. In NVAF patients newly initiated on DOAC therapy, one in five patients switch to an alternate anticoagulant and one of every two patients do so within the first 6 months of therapy. Switching from an initial DOAC prescription to traditional anticoagulants occurs as frequently as switching to an alternate DOAC.

Hydroxycarbamide adherence and cumulative dose associated with hospital readmission in sickle cell disease: a 6-year population-based cohort study

Sickle cell disease (SCD) is a congenital haemoglobinopathy that causes frequent acute care/emergency room visits and hospital admissions for affected individuals. Evidence from population-based studies demonstrating the role of hydroxycarbamide (HC, also termed hydroxyurea) in reducing hospital readmission rates is limited. Our objective was to describe the use of HC and its association with acute care utilization and readmission rates using a large, nationally-representative US health insurance claims database over a 6-year period between 2009 and 2014. We identified 20 721 SCD-related inpatient and acute care encounters. Patients had been exposed to HC within 6 months prior to admission in 4263 (21%) of SCD-related admission events. HC use was more common among children aged 10-17 years and young adults aged 18-29 years. HC was associated with lower 30-day all-cause readmission rates in adults treated with average daily doses ≥1 g (odds ratio [OR], 0·72, 95% confidence interval [CI] 0·52-0·99) and doses of 0·5-1 g (OR, 0·73, 95% CI 0·57-0·93), compared to HC treatment with average daily doses of <0·5 g; adherence to HC with proportion of days covered of ≥0·80 was also associated with significantly lower 30-day all-cause readmission risks (OR, 0·59, 95% CI 0·41-0·84). Optimal therapeutic dosing and adherence to HC treatment significantly reduces 30-day readmissions among patients with SCD.

A New Approach towards Minimizing the Risk of Misdosing Warfarin Initiation Doses

It is a challenge to be able to prescribe the optimal initial dose of warfarin. There have been many studies focused on an efficient strategy to determine the optimal initial dose. Numerous clinical, genetic, and environmental factors affect the warfarin dose response. In practice, it is common that the initial warfarin dose is substantially different from the stable maintenance dose, which may increase the risk of bleeding or thrombosis prior to achieving the stable maintenance dose. In order to minimize the risk of misdosing, despite popular warfarin dose prediction models in the literature which create dose predictions solely based on patients' attributes, we have taken physicians' opinions towards the initial dose into consideration. The initial doses selected by clinicians, along with other standard clinical factors, are used to determine an estimate of the difference between the initial dose and estimated maintenance dose using shrinkage methods. The selected shrinkage method was LASSO (Least Absolute Shrinkage and Selection Operator). The estimated maintenance dose was more accurate than the original initial dose, the dose predicted by a linear model without involving the clinicians initial dose, and the values predicted by the most commonly used model in the literature, the Gage clinical model.

Implementation of inpatient models of pharmacogenetics programs

PURPOSE

The operational elements essential for establishing an inpatient pharmacogenetic service are reviewed, and the role of the pharmacist in the provision of genotype-guided drug therapy in pharmacogenetics programs at three institutions is highlighted.

SUMMARY

Pharmacists are well positioned to assume important roles in facilitating the clinical use of genetic information to optimize drug therapy given their expertise in clinical pharmacology and therapeutics. Pharmacists have assumed important roles in implementing inpatient pharmacogenetics programs. This includes programs designed to incorporate genetic test results to optimize antiplatelet drug selection after percutaneous coronary intervention and personalize warfarin dosing. Pharmacist involvement occurs on many levels, including championing and leading pharmacogenetics implementation efforts, establishing clinical processes to support genotype-guided therapy, assisting the clinical staff with interpreting genetic test results and applying them to prescribing decisions, and educating other healthcare providers and patients on genomic medicine. The three inpatient pharmacogenetics programs described use reactive versus preemptive genotyping, the most feasible approach under the current third-party payment structure. All three sites also follow Clinical Pharmacogenetics Implementation Consortium guidelines for drug therapy recommendations based on genetic test results.

CONCLUSION

With the clinical emergence of pharmacogenetics into the inpatient setting, it is important that pharmacists caring for hospitalized patients are well prepared to serve as experts in interpreting and applying genetic test results to guide drug therapy decisions. Since genetic test results may not be available until after patient discharge, pharmacists practicing in the ambulatory care setting should also be prepared to assist with genotype-guided drug therapy as part of transitions in care.

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.

Multisite Investigation of Outcomes With Implementation of CYP2C19 Genotype-Guided Antiplatelet Therapy After Percutaneous Coronary Intervention

OBJECTIVES

This multicenter pragmatic investigation assessed outcomes following clinical implementation of CYP2C19 genotype-guided antiplatelet therapy after percutaneous coronary intervention (PCI).

BACKGROUND

CYP2C19 loss-of-function alleles impair clopidogrel effectiveness after PCI.

METHODS

After clinical genotyping, each institution recommended alternative antiplatelet therapy (prasugrel, ticagrelor) in PCI patients with a loss-of-function allele. Major adverse cardiovascular events (defined as myocardial infarction, stroke, or death) within 12 months of PCI were compared between patients with a loss-of-function allele prescribed clopidogrel versus alternative therapy. Risk was also compared between patients without a loss-of-function allele and loss-of-function allele carriers prescribed alternative therapy. Cox regression was performed, adjusting for group differences with inverse probability of treatment weights.

RESULTS

Among 1,815 patients, 572 (31.5%) had a loss-of-function allele. The risk for major adverse cardiovascular events was significantly higher in patients with a loss-of-function allele prescribed clopidogrel versus alternative therapy (23.4 vs. 8.7 per 100 patient-years; adjusted hazard ratio: 2.26; 95% confidence interval: 1.18 to 4.32; p = 0.013). Similar results were observed among 1,210 patients with acute coronary syndromes at the time of PCI (adjusted hazard ratio: 2.87; 95% confidence interval: 1.35 to 6.09; p = 0.013). There was no difference in major adverse cardiovascular events between patients without a loss-of-function allele and loss-of-function allele carriers prescribed alternative therapy (adjusted hazard ratio: 1.14; 95% confidence interval: 0.69 to 1.88; p = 0.60).

CONCLUSIONS

These data from real-world observations demonstrate a higher risk for cardiovascular events in patients with a CYP2C19 loss-of-function allele if clopidogrel versus alternative therapy is prescribed. A future randomized study of genotype-guided antiplatelet therapy may be of value.

Quality of Pharmacist-Managed Anticoagulation Therapy in Long-Term Ambulatory Settings: A Systematic Review

OBJECTIVE

To perform a systematic review to evaluate the quality of warfarin anticoagulation control in outpatient pharmacist-managed anticoagulation services (PMAS) compared with routine medical care (RMC).

DATA SOURCES

MEDLINE, SCOPUS, EMBASE, IPA, CINAHL, and Cochrane CENTRAL, from inception to May 2017. Search terms employed: ("pharmacist-managed" OR "pharmacist-provided" OR "pharmacist-led" OR "pharmacist-directed") AND ("anticoagulation services" OR "anticoagulation clinic" OR "anticoagulation management" OR "anticoagulant care") AND ("quality of care" OR "outcomes" OR "bleeding" OR "thromboembolism" OR "mortality" OR "hospitalization" OR "length of stay" OR "emergency department visit" OR "cost" OR "patient satisfaction").

STUDY SELECTION AND DATA EXTRACTION

Criteria used to identify selected articles: English language; original studies (comments, letters, reviews, systematic reviews, meta-analyses, editorials were excluded); warfarin use; outpatient setting; comparison group present; time in therapeutic range (TTR) included as a measure of quality of anticoagulant control; study design was not a case report.

DATA SYNTHESIS

Of 177 articles identified, 25 met inclusion criteria. Quality of anticoagulation control was better in the PMAS group compared with RMC in majority of the studies (N = 23 of 25, 92.0%). Clinical outcomes were also favorable in the PMAS group as evidenced by lower or equal risk of major bleeding (N = 10 of 12, 83.3%) or thromboembolic events (N = 9 of 10, 90.0%), and lower rates of hospitalization or emergency department visits (N = 9 of 9, 100%). When reported, PMAS have also resulted in cost-savings in all (N=6 of 6, 100%) of studies.

CONCLUSIONS

Compared with routine care, pharmacist-managed outpatient-based anticoagulation services attained better quality of anticoagulation control, lower bleeding and thromboembolic events, and resulted in lower health care utilization.

Anticoagulation Monitoring Part 1: Warfarin and Parenteral Direct Thrombin Inhibitors

OBJECTIVE:

To review the availability, mechanisms, limitations, and clinical application of point-of-care (POC) devices used in the management of warfarin and parenteral direct thrombin inhibitors.

DATA SOURCES:

Scientific articles were identified through a MEDLINE search (1966–August 2004), manufacturer Web sites, additional references listed in articles and Web sites, and abstracts from scientific meetings.

STUDY SELECTION AND DATA EXTRACTION:

English-language literature from clinical trials was reviewed to evaluate the accuracy, reliability, and clinical application of POC monitoring devices.

DATA SYNTHESIS:

The prothrombin time expressed as the international normalized ratio (PT—INR) is a well-established test for monitoring warfarin anticoagulation. Multiple devices are available for POC testing. Because there is no universally accepted standard, the performance of each device is typically tested against a standard test performed in a reference laboratory. Performance of currently available devices, as measured by correlations to a standard reference laboratory PT—INR, may be considered very good and acceptable for use in patient care. Utilization of patient self-testing and patient self-monitoring of warfarin anticoagulation using POC devices is increasing. Parenteral direct thrombin inhibitors are typically monitored using a standard laboratory activated partial thromboplastin time. Some research has shown that POC monitoring of direct thrombin inhibitors using the ecarin clotting time is helpful for patients undergoing cardiopulmonary bypass surgery, although that test is not readily available.

CONCLUSIONS:

POC testing for anticoagulation therapy has been available for >20 years. Multiple POC devices are available to monitor warfarin. There is some variability in results between devices and between reagents used in the same device. Despite these limitations, POC monitoring of warfarin via the PT—INR is an integral part of clinical practice. Additional research evaluating POC monitoring of direct thrombin inhibitors is necessary.

Anticoagulation endpoints with clinical implementation of warfarin pharmacogenetic dosing in a real-world setting: A proposal for a new pharmacogenetic dosing approach

Achieving therapeutic anticoagulation efficiently with warfarin is important to reduce thrombotic and bleeding risks and is influenced by genotype. Utilizing data from a diverse population of 257 patients who received VKORC1 and CYP2C9 genotype-guided warfarin dosing, we aimed to examine genotype-associated differences in anticoagulation endpoints and derive a novel pharmacogenetic nomogram to more optimally dose warfarin. We observed significant differences across patients with 0, 1, or ≥2 reduced-function VKORC1 or CYP2C9 alleles, respectively, in time to achieve therapeutic international normalized ratio (INR) (7.8 ± 5.8, 7.2 ± 4.7, and 5.4 ± 4.6 days, P = 0.0004) and mean percentage of time in therapeutic range in the first 28 days (22.2, 27.8, and 32.2%, P = 0.0127) with use of existing pharmacogenetic algorithms. These data suggest that more aggressive dosing is necessary for patients with 0 to 1 VKORC1/CYP2C9 variants to more efficiently achieve therapeutic anticoagulation. Herein, we provide a novel kinetic/pharmacodynamic-derived dosing nomogram optimized for a heterogeneous patient population.

Correlations between the enantio- and regio-selective metabolisms of warfarin

AIM

To clarify whether the activities of multiple CYPs associated with warfarin metabolism would be correlated with each other.

METHODS

Oral clearances (CLpo) of warfarin enantiomers were estimated in 378 Chinese, Caucasians and African-Americans. The partial metabolic clearances (CLm) for 7-hydroxywarfarin enantiomers were also measured. In addition, CLpo and CLm were determined in a patient on warfarin and rifampicin.

RESULTS

Correlations between CLpo for warfarin enantiomers existed across the three populations. In addition, there was a significant correlation between the CLm for 7-hydroxylation of warfarin enantiomers. Under induced conditions by rifampicin, there were significant correlations between the enantio- and regio-selective metabolisms of warfarin.

CONCLUSION

Metabolic activities of CYP2C9, CYP1A2 and CYP3A4 may be regulated by common transcriptional mechanism(s).

Choosing the Appropriate Antithrombotic Agent for the Prevention and Treatment of VTE: A Case-Based Approach

Objective:

To review the risk of venous thromboembolism (VTE) in various patient populations and evaluate the agents available for the prevention and treatment of VTE using a case-based approach.

Data Sources:

A MEDLINE search (1995–July 2006) was conducted to identify relevant literature. Additional references were reviewed from selected articles.

Study Selection and Data Extraction:

Articles related to the prevention of VTE in orthopedic surgery, general surgery, and medically ill patients, as well as the treatment of VTE, were reviewed.

Data Synthesis:

Pharmacologic options for the prevention and treatment of VTE include warfarin, unfractionated heparin (UFH), low-molecular-weight heparins (LMWH), and fondaparinux. Current guidelines support the use of warfarin, LMWH, or fondaparinux for VTE prophylaxis following lower limb major orthopedic surgery. For VTE prophylaxis in hospitalized medical patients or patients undergoing general surgery, use of UFH and LMWH is supported; however, recent data on fondaparinux suggest that it is also effective in these patient populations. The use of UFH or LMWH (both in conjunction with warfarin) for treatment of acute deep venous thrombosis or nonmassive pulmonary embolism is recommended. Recent data suggest that fondaparinux (in conjunction with warfarin) is also effective for the treatment of VTE. A variety of pharmacokinetic, pharmacodynamic, and pharmacoeconomic factors differentiate each agent for the various indications.

Conclusions:

Currently, a “one-size-fits-all” anticoagulant is not available for treatment of VTE. A variety of patient factors, including type of surgery, medical indication, thrombotic risk factors, bleeding risk, history of heparin-induced thrombocytopenia, and a variety of comorbid conditions can affect the safety, efficacy, and selection of appropriate VTE therapy.

Erratum to: Pharmacology of anticoagulants used in the treatment of venous thromboembolism

Anticoagulant drugs are the foundation of therapy for patients with VTE. While effective therapeutic agents, anticoagulants can also result in hemorrhage and other side effects. Thus, anticoagulant therapy selection should be guided by the risks, benefits and pharmacologic characteristics of each agent for each patient. Safe use of anticoagulants requires not only an in-depth knowledge of their pharmacologic properties but also a comprehensive approach to patient management and education. This paper will summarize the key pharmacologic properties of the anticoagulant agents used in the treatment of patients with VTE.

Upper-Extremity Deep-Vein Thrombosis: A Retrospective Cohort Evaluation of Thrombotic Risk Factors at a University Teaching Hospital Antithrombosis Clinic

BACKGROUND

Upper-extremity deep-vein thrombosis (UEDVT) causes significant morbidity and mortality and is not well characterized in the existing literature, particularly in underrepresented minorities such as African Americans.

OBJECTIVE

To describe the characteristics of a cohort of patients with UEDVT seen at an urban academic medical center.

METHODS

This was a retrospective cohort study among patients with a confirmed UEDVT at the University of Illinois Hospital and Health Sciences System between 1996 and 2011. Patients were identified by ICD-9 code for UEDVT. Variables collected include thrombotic risk factors and outcomes, including recurrent thrombosis and bleeding.

RESULTS

We identified 229 patients with UEDVT; 71% were African American, and 11% were diagnosed with sickle cell disease. The average number of UEDVT risk factors was 4.40 ± 1.5, the most common being central venous catheter (CVC) use (178, 78%). In the year following UEDVT, 13% experienced recurrent thrombosis, and 6% experienced major bleeding. Of 181 patients receiving warfarin after an UEDVT, 36% of international normalized ratio (INR) values were therapeutic. Patients with sickle cell disease had a lower proportion of INRs within the target range (25% vs 38%, P < 0.01), and were more likely to be lost to follow-up (67% vs 46%, P = 0.05) and experience a recurrent thrombotic event (29% vs 11%, P = 0.02).

CONCLUSION

A CVC is the most common risk factor for UEDVT; however, patients with sickle cell disease demonstrate additional unique demographics and risk factors. Patients included in this underrepresented demographic cohort had a low quality of anticoagulation control, particularly those with sickle cell disease.

Pharmacology of anticoagulants used in the treatment of venous thromboembolism

Anticoagulant drugs are the foundation of therapy for patients with VTE. While effective therapeutic agents, anticoagulants can also result in hemorrhage and other side effects. Thus, anticoagulant therapy selection should be guided by the risks, benefits and pharmacologic characteristics of each agent for each patient. Safe use of anticoagulants requires not only an in-depth knowledge of their pharmacologic properties but also a comprehensive approach to patient management and education. This paper will summarize the key pharmacologic properties of the anticoagulant agents used in the treatment of patients with VTE.

Factors influencing pharmacokinetics of warfarin in African-Americans: implications for pharmacogenetic dosing algorithms

AIM

This study attempted to identify predictors of S-warfarin clearance (CL[S]) and to make a pharmacokinetic evaluation of genotype-based dosing algorithms in African-Americans.

METHODS

Using plasma S-warfarin concentration (Cp[S]) at a steady state and eight SNPs previously shown to influence warfarin dose in African-Americans, CL(S) and its predictors were estimated by population pharmacokinetic analysis in 60 African-Americans. The time courses of Cp(S) following either the loading dose or maintenance dose were simulated using the population pharmacokinetic estimates.

RESULTS

CYP2C9*8 and body surface area or body weight were predictors of CL(S) (-30 and -5% per -0.1 m(2)/-10 kg reduction in CL[S], respectively) in African-Americans. Simulations of Cp(S) showed that Cp(S) at steady state was 1.4-times higher in patients with CYP2C9*8 than in those with CYP2C9*1/*1, irrespective of the algorithm for loading dose or maintenance dose.

CONCLUSION

African-Americans possess independent predictors of CL(S), possibly leading to a prediction error of any dosing algorithm that excludes African-specific variant(s). Original submitted 3 September 2014; Revision submitted 3 November 2014.

Integrating electronic health records in the delivery of optimized anticoagulation therapy

Integration of accepted practice standards into electronic health record systems can facilitate standardization of anticoagulation care delivery and result in improved anticoagulation safety. However, the majority of commonly used electronic health record systems are lacking the specialized features necessary for optimal anticoagulation management. The Task Force on Electronic Health Records of the New York State Anticoagulation Coalition provides such a Consensus Statement in this issue of the journal. The Anticoagulation Forum endorses these recommendations and advises the electronic health record industry and health information technology programmers at the institutional level to adopt these recommendations in a comprehensive and timely manner.

The evolving role of dabigatran etexilate in clinical practice

INTRODUCTION

Stroke and venous thromboembolism (VTE) affect millions of patients. The vitamin K antagonist, warfarin, has been the main oral anticoagulant used to treat these conditions despite many limitations associated with its use. Recently, multiple novel oral anticoagulants have been approved and are reshaping how patients with atrial fibrillation (AF) at risk of stroke and patients with VTE are treated. The direct thrombin inhibitor, dabigatran etexilate , is among these novel agents that have been developed to overcome limitations with warfarin.

AREAS COVERED

In this article, authors describe the pharmacokinetic and pharmacodynamic properties of dabigatran etexilate and summarize the clinical evidence and controversy surrounding its use in the US, Canada and Europe.

EXPERT OPINION

Dabigatran has demonstrated similar efficacy and safety to enoxaparin for VTE prevention in patients undergoing hip and knee arthroplasty, and to warfarin for the treatment of VTE. Dabigatran (110 mg) is noninferior and dabigatran (150 mg) is superior to warfarin for stroke prevention in patients with nonvalvular AF, with a lower rate of intracranial hemorrhage reported at both doses. Apixaban, rivaroxaban and edoxaban provide alternate anticoagulant options to dabigatran. While there are many similarities, there are also significant differences to consider in agent selection based on patient-specific characteristics.

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.