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.