Evaluation of Medicare claims data to ascertain peripheral vascular events in the Women's Health Initiative

Toward Uniform Case Identification Criteria in Observational Studies on Peripheral Arterial Disease: A Scoping Review

BACKGROUND

The diagnosis of peripheral arterial disease (PAD) is commonly applied for symptoms related to atherosclerotic obstructions in the lower extremity, though its clinical manifestations range from an abnormal ankle-brachial index to critical limb ischemia. Subsequently, management and prognosis of PAD vary widely with the disease stage. A critical aspect is how this variation is addressed in administrative database-based studies that rely on diagnosis codes for case identification. The objective of this scoping review is to inventory the identification strategies used in studies on PAD that rely on administrative databases, to map the pros and cons of the International Classification of Diseases (ICD) codes applied, and to propose a first outline for a consensus framework for case identification in administrative databases.

METHODS

Registry-based reports published between 2010 and 2021 were identified through a systematic PubMed search. Studies were subcategorized on the basis of the expressed study focus: claudication, critical limb ischemia, or general peripheral arterial disease, and the ICD code(s) applied for case identification mapped.

RESULTS

Ninety studies were identified, of which 36 (40%) did not specify the grade of PAD studied. Forty-nine (54%) articles specified PAD grade studied. Five (6%) articles specified different PAD subgroups in methods and baseline demographics, but not in further analyses. Mapping of the ICD codes applied for case identification for studies that specified the PAD grade studied indicated a remarkable heterogeneity, overlap, and inconsistency.

CONCLUSIONS

A large proportion of registry-based studies on PAD fail to define the study focus. In addition, inconsistent strategies are used for PAD case identification in studies that report a focus. These findings challenge study validity and interfere with inter-study comparison. This scoping review provides a first initiative for a consensus framework for standardized case selection in administrative studies on PAD. It is anticipated that more uniform coding will improve study validity and facilitate inter-study comparisons.

Development and Integration of Machine Learning Algorithm to Identify Peripheral Arterial Disease: Multistakeholder Qualitative Study

BACKGROUND

Machine learning (ML)-driven clinical decision support (CDS) continues to draw wide interest and investment as a means of improving care quality and value, despite mixed real-world implementation outcomes.

OBJECTIVE

This study aimed to explore the factors that influence the integration of a peripheral arterial disease (PAD) identification algorithm to implement timely guideline-based care.

METHODS

A total of 12 semistructured interviews were conducted with individuals from 3 stakeholder groups during the first 4 weeks of integration of an ML-driven CDS. The stakeholder groups included technical, administrative, and clinical members of the team interacting with the ML-driven CDS. The ML-driven CDS identified patients with a high probability of having PAD, and these patients were then reviewed by an interdisciplinary team that developed a recommended action plan and sent recommendations to the patient's primary care provider. Pseudonymized transcripts were coded, and thematic analysis was conducted by a multidisciplinary research team.

RESULTS

Three themes were identified: positive factors translating in silico performance to real-world efficacy, organizational factors and data structure factors affecting clinical impact, and potential challenges to advancing equity. Our study found that the factors that led to successful translation of in silico algorithm performance to real-world impact were largely nontechnical, given adequate efficacy in retrospective validation, including strong clinical leadership, trustworthy workflows, early consideration of end-user needs, and ensuring that the CDS addresses an actionable problem. Negative factors of integration included failure to incorporate the on-the-ground context, the lack of feedback loops, and data silos limiting the ML-driven CDS. The success criteria for each stakeholder group were also characterized to better understand how teams work together to integrate ML-driven CDS and to understand the varying needs across stakeholder groups.

CONCLUSIONS

Longitudinal and multidisciplinary stakeholder engagement in the development and integration of ML-driven CDS underpins its effective translation into real-world care. Although previous studies have focused on the technical elements of ML-driven CDS, our study demonstrates the importance of including administrative and operational leaders as well as an early consideration of clinicians' needs. Seeing how different stakeholder groups have this more holistic perspective also permits more effective detection of context-driven health care inequities, which are uncovered or exacerbated via ML-driven CDS integration through structural and organizational challenges. Many of the solutions to these inequities lie outside the scope of ML and require coordinated systematic solutions for mitigation to help reduce disparities in the care of patients with PAD.

Association of Premature Menopause With Risk of Abdominal Aortic Aneurysm in the Women's Health Initiative

OBJECTIVE

To determine if premature menopause and early menarche are associated with increased risk of AAA, and to explore potential effect modification by smoking history.

SUMMARY OF BACKGROUND DATA

Despite worse outcomes for women with AAA, no studies have prospectively examined sex-specific risk factors, such as premature menopause and early menarche, with risk of AAA in a large, ethnically diverse cohort of women.

METHODS

This was a post-hoc analysis of Women's Health Initiative participants who were beneficiaries of Medicare Parts A&B fee-for-service. AAA cases and interventions were identified from claims data. Follow-up period included Medicare coverage until death, end of follow-up or end of coverage inclusive of 2017.

RESULTS

Of 101,119 participants included in the analysis, the mean age was 63 years and median follow-up was 11.3 years. Just under 10,000 (9.4%) women experienced premature menopause and 22,240 (22%) experienced early men-arche. Women with premature menopause were more likely to be overweight, Black, have >20 pack years of smoking, history of cardiovascular disease, hypertension, and early menarche. During 1,091,840 person-years of follow-up, 1125 women were diagnosed with AAA, 134 had premature menopause (11.9%), 93 underwent surgical intervention and 45 (48%) required intervention for ruptured AAA. Premature menopause was associated with increased risk of AAA [hazard ratio 1.37 (1.14, 1.66)], but the association was no longer significant after multivariable adjustment for demographics and cardiovascular disease risk factors. Amongst women with ≥20 pack year smoking history (n = 19,286), 2148 (11.1%) had premature menopause, which was associated with greater risk of AAA in all models [hazard ratio 1.63 (1.24, 2.23)]. Early menarche was not associated with increased risk of AAA.

CONCLUSIONS

This study finds that premature menopause may be an important risk factor for AAA in women with significant smoking history. There was no significant association between premature menopause and risk of AAA amongst women who have never smoked. These results suggest an opportunity to develop strategies for better screening, risk reduction and stratification, and outcome improvement in the comprehensive vascular care of women.

Women's Health Initiative Strong and Healthy (WHISH): A pragmatic physical activity intervention trial for cardiovascular disease prevention

BACKGROUND

National guidelines promote physical activity to reduce cardiovascular disease (CVD); yet, no RCT has tested the effectiveness of physical activity as the sole intervention for primary CVD prevention in older adults. The Women's Health Initiative (WHI) Strong and Healthy (WHISH) trial, a pragmatic trial embedded in the WHI-Extension Study (ES), is testing whether increasing physical activity and decreasing sedentary behavior will reduce major CV events in older women.

METHODS

The randomized consent design was used to assign 49,331 women (aged 68-99 years in 2015) who had consented to ongoing WHI-ES follow-up and for whom CV outcomes were available through WHI-ES procedures (N = 18,985) and/or linkage to the Centers for Medicare and Medicaid Services (N = 30,346) to a physical activity (PA) intervention designed to promote national recommendations (N = 24,657) or "usual activity" comparison (N = 24,674). Women assigned to the intervention provided passive consent to receive the intervention and provide data. A multi-component PA intervention is delivered by seasonal (quarterly) newsletters with targeted inserts (lower, middle, higher) based on self-reported levels of physical functioning (PF) and physical activity; monthly motivational telephone messages; monthly emails; a website; and contact with staff, as requested. Major CV events, myocardial infarction (MI), stroke, or CVD death, collected annually through WHI-ES, comprise the primary outcome. Hip fracture and non-CVD death are primary safety outcomes. Intention-to-treat analyses in all randomized participants will include 8 years of follow-up.

CONCLUSION

Determining whether increased physical activity and decreased sedentary behavior reduce major CV events in older women is of major public health significance.

CLINICAL TRIALS REGISTRATION

ClinicalTrials.govidentifier:NCT02425345.

Younger patients with chronic limb threatening ischemia face more frequent amputations

INTRODUCTION

Amputations among younger patients with chronic limb threatening ischemia (CLTI) may carry higher personal and societal costs, but younger patients are often not included in CLTI research because of dataset limitations. We aimed to characterize and compare outcomes between younger (<65 years old) and older patients with CLTI.

METHODS

This retrospective cohort study identified patients with CLTI between July 1, 2014 and December 31, 2017 in the MarketScan commercial claims database, a proprietary set of claims for over 50 million patients with private insurance in the United States. The primary outcome was major adverse limb events (MALE); secondary outcomes included amputations, major adverse cardiovascular events, and statin prescription fills.

RESULTS

The study cohort included 64,663 people with CLTI, of whom 25,595 (39.6%) were <65 years old. Younger patients were more likely to have diabetes mellitus (54.1% versus 49.9%, P<.001) but less likely to have other comorbidities. A higher proportion of younger patients suffered MALE (31.7% versus 30.2%, P=.002), specifically amputation (11.5% versus 9.3%, P<.001). After adjustment, age <65 years old was associated with a 24% increased risk of amputation (HR_adj 1.24, 95%CI 1.18-1.32, P<.001) and a 10% increased risk of MALE (HR_adj 1.10, 95%CI 1.07-1.14, P<.001).

CONCLUSIONS

A significant proportion of commercially insured patients with CLTI are under the age of 65, and younger patients have worse limb-related outcomes. These findings highlight the importance of aggressively treating risk factors for atherosclerosis and intentionally including younger patients with CLTI in future analyses to better understand their disease patterns and outcomes.

Accuracy of Cardiovascular Trial Outcome Ascertainment and Treatment Effect Estimates from Routine Health Data: A Systematic Review and Meta-Analysis

BACKGROUND

Registry-based randomized controlled trials allow for outcome ascertainment using routine health data (RHD). While this method provides a potential solution to the rising cost and complexity of clinical trials, comparative analyses of outcome ascertainment by clinical end point committee (CEC) adjudication compared with RHD sources are sparse. Among cardiovascular trials, we set out to systematically compare the incidence of cardiovascular events and estimated randomized treatment effects ascertained from RHD versus traditional clinical evaluation and adjudication.

METHODS

We searched MEDLINE (1976 to August 2020) for studies where outcome ascertainment was performed by both RHD and CEC adjudication to compare the incidence of cardiovascular events and treatment effects. We derived ratios of hazard ratios to compare treatment effects from RHD and CEC adjudication. We pooled ratios of hazard ratios using an inverse variance random-effects meta-analysis.

RESULTS

Nine studies (1988-2020; 32 156 patients) involving 10 randomized control trials compared outcome ascertainment with RHD and CEC in patients with or at risk of cardiovascular disease. There was a high degree of agreement and interrater reliability between CEC and RHD outcome determination for all-cause mortality (agreement percentage: 98.4%-100% and κ: 0.95-1.0) and cardiovascular mortality (agreement percentage: 97.8%-99.9% and κ: 0.66-0.99). For myocardial infarction, the κ values ranged from 0.67-0.98, and for stroke the values ranged from 0.52-0.89. In contrast, the κ value for peripheral artery disease was low (κ: 0.27). There was little difference in the randomized treatment effect derived from CEC and RHD ascertainment of events based on the ratios of hazard ratio, with pooled ratios of hazard ratios ranging from 0.93 (95% CI, 0.63-1.39) for cardiovascular mortality to 1.27 (95% CI, 0.67-2.41) for stroke.

CONCLUSIONS

Clinical outcome ascertainment using retrospectively acquired RHD displayed high levels of agreement with CEC adjudication for identifying all-cause mortality and cardiovascular outcomes. Importantly, cardiovascular treatment effects in randomized control trials determined from RHD and CEC resulted in similar point estimates. Overall, our review supports the use of RHD as a potential alternative source for clinical outcome ascertainment in cardiovascular trials. Validation studies with prospectively planned linkage are warranted.

Women's Health Initiative Strong and Healthy Pragmatic Physical Activity Intervention Trial for Cardiovascular Disease Prevention: Design and Baseline Characteristics

BACKGROUND

National guidelines promote physical activity to prevent cardiovascular disease (CVD), yet no randomized controlled trial has tested whether physical activity reduces CVD.

METHODS

The Women's Health Initiative (WHI) Strong and Healthy (WHISH) pragmatic trial used a randomized consent design to assign women for whom cardiovascular outcomes were available through WHI data collection (N = 18 985) or linkage to the Centers for Medicare and Medicaid Services (N30 346), to a physical activity intervention or "usual activity" comparison, stratified by ages 68-99 years (in tertiles), U.S. geographic region, and outcomes data source. Women assigned to the intervention could "opt out" after receiving initial physical activity materials. Intervention materials applied evidence-based behavioral science principles to promote current national recommendations for older Americans. The intervention was adapted to participant input regarding preferences, resources, barriers, and motivational drivers and was targeted for 3 categories of women at lower, middle, or higher levels of self-reported physical functioning and physical activity. Physical activity was assessed in both arms through annual questionnaires. The primary outcome is major cardiovascular events, specifically myocardial infarction, stroke, or CVD death; primary safety outcomes are hip fracture and non-CVD death. The trial is monitored annually by an independent Data Safety and Monitoring Board. Final analyses will be based on intention to treat in all randomized participants, regardless of intervention engagement.

RESULTS

The 49 331 randomized participants had a mean baseline age of 79.7 years; 84.3% were White, 9.2% Black, 3.3% Hispanic, 1.9% Asian/Pacific Islander, 0.3% Native American, and 1% were of unknown race/ethnicity. The mean baseline RAND-36 physical function score was 71.6 (± 25.2 SD). There were no differences between Intervention (N = 24 657) and Control (N = 24 674) at baseline for age, race/ethnicity, current smoking (2.5%), use of blood pressure or lipid-lowering medications, body mass index, physical function, physical activity, or prior CVD (10.1%).

CONCLUSION

The WHISH trial is rigorously testing whether a physical activity intervention reduces major CV events in a large, diverse cohort of older women. Clinical Trials Registration Number: NCT02425345.

Lipoprotein(a) levels and risk of abdominal aortic aneurysm in the Women's Health Initiative

OBJECTIVE

Few studies have prospectively examined the associations of lipoprotein(a) [Lp(a)] levels with the risk of abdominal aortic aneurysm (AAA), especially in women. Accounting for commonly recognized risk factors, we investigated the baseline Lp(a) levels and the risk of AAA among postmenopausal women participating in the ongoing national Women's Health Initiative.

METHODS

Women's Health Initiative participants with baseline Lp(a) levels available who were beneficiaries of Medicare parts A and B fee-for-service at study enrollment or who had aged into Medicare at any point were included. Participants with missing covariate data or known AAA at baseline were excluded. Thoracic aneurysms were excluded owing to the different pathophysiology. The AAA cases and interventions were identified using the International Classification of Diseases, 9th and 10th revision, codes and Current Procedural Terminology codes from claims data. Hazard ratios were computed using Cox proportional hazard models according to the quintiles of Lp(a).

RESULTS

The mean age of the 6615 participants included in the analysis was 65.3 years. Of the 6615 participants, 66.6% were non-Hispanic white, 18.9% were black, 7% were Hispanic and 4.7% were Asian/Pacific Islander. Compared with the participants in the lowest Lp(a) quintile, those in higher quintiles were more likely to be overweight, black, and former or current smokers, to have hypertension, hyperlipidemia, and a history of cardiovascular disease, and to use menopausal hormone therapy and statins. During 65,476 person-years of follow-up, with a median of 10.4 years, 415 women had been diagnosed with an AAA and 36 had required intervention. More than one half had required intervention for a ruptured AAA. We failed to find a statistically significant association between Lp(a) levels and incident AAA. Additional sensitivity analyses stratified by race, with exclusion of statin users and alternative categorizations of Lp(a) using log-transformed levels, tertiles, and a cutoff of >50 mg/dL, were conducted, which did not reveal any significant associations.

CONCLUSIONS

We found no statistically significant association between Lp(a) levels and the risk of AAA in a large and well-phenotyped sample of postmenopausal women. Women with high Lp(a) levels were more likely to be overweight, black, and former or current smokers, and to have hypertension, hyperlipidemia, and a history of cardiovascular disease, or to use hormone therapy and statins compared with those with lower Lp(a) levels. These findings differ from previous prospective, case-control, and meta-analysis studies that had supported a significant relationship between higher Lp(a) levels and an increased risk of AAA. Differences in the association could have resulted from study limitations or sex differences.

Model-Based Algorithms for Detecting Peripheral Artery Disease Using Administrative Data From an Electronic Health Record Data System: Algorithm Development Study

Background

Peripheral artery disease (PAD) affects 8 to 10 million Americans, who face significantly elevated risks of both mortality and major limb events such as amputation. Unfortunately, PAD is relatively underdiagnosed, undertreated, and underresearched, leading to wide variations in treatment patterns and outcomes. Efforts to improve PAD care and outcomes have been hampered by persistent difficulties identifying patients with PAD for clinical and investigatory purposes.

Objective

The aim of this study is to develop and validate a model-based algorithm to detect patients with peripheral artery disease (PAD) using data from an electronic health record (EHR) system.

Methods

An initial query of the EHR in a large health system identified all patients with PAD-related diagnosis codes for any encounter during the study period. Clinical adjudication of PAD diagnosis was performed by chart review on a random subgroup. A binary logistic regression to predict PAD was built and validated using a least absolute shrinkage and selection operator (LASSO) approach in the adjudicated patients. The algorithm was then applied to the nonsampled records to further evaluate its performance.

Results

The initial EHR data query using 406 diagnostic codes yielded 15,406 patients. Overall, 2500 patients were randomly selected for ground truth PAD status adjudication. In the end, 108 code flags remained after removing rarely- and never-used codes. We entered these code flags plus administrative encounter, imaging, procedure, and specialist flags into a LASSO model. The area under the curve for this model was 0.862.

Conclusions

The algorithm we constructed has two main advantages over other approaches to the identification of patients with PAD. First, it was derived from a broad population of patients with many different PAD manifestations and treatment pathways across a large health system. Second, our model does not rely on clinical notes and can be applied in situations in which only administrative billing data (eg, large administrative data sets) are available. A combination of diagnosis codes and administrative flags can accurately identify patients with PAD in large cohorts.

Trends in the Medical Complexity and Outcomes of Medicare-insured Patients Undergoing Kidney Transplant in the Years 1998-2014

BACKGROUND

Graft and patient survival following kidney transplant are improving. However, the drivers of this trend are unclear. To gain further insight, we set out to examine concurrent changes in pretransplant patient complexity, posttransplant survival, and cause-specific hospitalization.

METHODS

We identified 101 332 Medicare-insured patients who underwent their first kidney transplant in the United States between the years 1998 and 2014. We analyzed secular trends in (1) posttransplant patient and graft survival and (2) posttransplant hospitalization for cardiovascular disease, infection, and cancer using Cox models with year of kidney transplant as the primary exposure of interest.

RESULTS

Age, dialysis vintage, body mass index, and the prevalence of a number of baseline medical comorbidities increased during the study period. Despite these adverse changes in case mix, patient survival improved: the unadjusted and multivariable-adjusted hazard ratios (HRs) for death in 2014 (versus 1998) were 0.61 (confidence interval [CI], 0.52-0.73) and 0.46 (CI, 0.39-0.55), respectively. For graft failure excluding death with a functioning graft, the unadjusted and multivariable adjusted subdistribution HRs in 2014 versus 1998 were 0.4 (CI, 0.25-0.55) and 0.45 (CI, 0.3-0.6), respectively. There was a marked decrease in hospitalizations for cardiovascular disease following transplant between 1998 and 2011, subdistribution HR 0.51 (CI, 0.43-0.6). Hospitalization for infection remained unchanged, while cancer hospitalization increased modestly.

CONCLUSIONS

Medicare-insured patients undergoing kidney transplant became increasingly medically complex between 1998 and 2014. Despite this, both patient and graft survival improved during this period. A marked decrease in serious cardiovascular events likely contributed to this positive trend.

Regional Variation in Rates of Total Knee Arthroplasty Among Medicare Beneficiaries

IMPORTANCE

Rates of total knee arthroplasty vary widely across the United States. Whether this variation is associated with differences in patient characteristics or physician practice is unknown.

OBJECTIVES

To determine regional variations in rates of total knee arthroplasty after accounting for the prevalence of knee arthritis and other potentially associated patient risk factors and to assess the correlation of these variations with measures of access to care and surgical indications.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective national cohort study used Medicare data on more than 24 million deidentified beneficiaries annually from 2011 to 2015. Individuals included had fee-for-service coverage, were 65 to 89 years of age, and resided in 1 of 306 health referral regions. Data were analyzed from September 13, 2018, to August 15, 2019.

MAIN OUTCOMES AND MEASURES

Rate of primary total knee arthroplasty indexed to the national rate using observed to expected ratios. The expected numbers of arthroplasty procedures were derived from estimates based on beneficiaries' demographic and clinical characteristics. Observed to expected ratios were confounded by race/ethnicity; thus race/ethnicity-stratified analyses were conducted.

RESULTS

In 2011, there were 218 282 total knee arthroplasty procedures among 24 583 706 white Medicare beneficiaries (mean [SD] age 74.2 [6.9] years; 54.6% women). The rate of arthroplasty during the study period (5 years) was 9.3 per 1000 person-years. Adjustment for clinical characteristics reduced the spread in observed to expected ratios among regions by 29% compared with adjustment for age and sex alone. However, substantial variation remained, with observed to expected ratios that ranged from 0.61 in Newark, New Jersey, to 1.82 in Idaho Falls, Idaho. High ratios were primarily present in the upper Midwest, Great Plains, and Mountain West regions. Higher ratios were associated with regions where beneficiaries had fewer outpatient visits (Spearman correlation [r], -0.64; 95% CI, -0.70 to -0.56) and with regions having more surgeons per capita who performed knee arthroplasty (r = 0.27; 95% CI, 0.16-0.37). Higher ratios were associated with higher rates of arthroplasty procedures among beneficiaries with dementia (r = 0.36; 95% CI, 0.25-0.46), peripheral vascular disease (r = 0.52; 95% CI, 0.42-0.61), and skin ulcers (r = 0.43; 95% CI, 0.32-0.53), which are relative contraindications to arthroplasty.

CONCLUSIONS AND RELEVANCE

Substantial regional variation in rates of total knee arthroplasty remained after adjustment for patient characteristics. Coexistence of high observed to expected ratios and high rates among patients at greater surgical risk suggested overuse of knee arthroplasty in some regions.

Administrative claims data to support pragmatic clinical trial outcome ascertainment on cardiovascular health

BACKGROUND/AIMS

Health plan administrative claims data present a cost-effective complement to traditional trial-specific ascertainment of clinical events typically conducted through patient report or a single health system electronic health record. We aim to demonstrate the value of health plan claims data in improving the capture of endpoints in longitudinal pragmatic clinical trials.

METHODS

This retrospective cohort study paralleled the design of the ADAPTABLE (Aspirin Dosing: A Patient-centric Trial Assessing Benefits and Long-Term Effectiveness) trial designed to compare the effectiveness of two doses of aspirin. We applied the ADAPTABLE identification query in claims data from Anthem, an American health insurance company, and identified health plan members who met the ADAPTABLE trial criteria. Among the ADAPTABLE eligible members, we selected overlapping members with PCORnet Clinical Data Research Networks in the 2 years prior to the index date (1 April 2014). PCORnet Clinical Data Research Networks consist of network partners (or healthcare systems) that store their electronic health record data in the same format to support multi-institutional research. ADAPTABLE outcome events-cardiovascular hospitalizations including admissions for myocardial infarction, stroke, or cardiac procedures; hospitalizations for major bleeding; and in-hospital deaths-were evaluated for a 2-year follow-up period. Events were classified as within or outside PCORnet Clinical Data Research Networks using facility identifiers affiliated with each hospital stay. Patient characteristics were examined with descriptive statistics, and incidence rates were reported for available Clinical Data Research Networks and claims data.

RESULTS

Among 884,311 ADAPTABLE eligible health plan members, 11,101 patients overlapped with PCORnet Clinical Data Research Networks. Average age was 70 years, 71% were male, and average follow-up was 20.7 months. Patients had 1521 cardiovascular hospitalizations (571 (37.5%) occurred outside PCORnet Clinical Data Research Networks), 710 for major bleeding (296 (41.7%) outside PCORnet Clinical Data Research Networks), and 196 in-hospital deaths (67 (34.2%) outside PCORnet Clinical Data Research Networks). Incidence rates (events per1000 patient-months) differed between available network partners and claims data: cardiovascular hospitalizations, 4.1 (95% confidence interval: 3.9, 4.4) versus 6.6 (95% confidence interval: 6.3, 7.0), major bleeding, 1.8 (95% confidence interval: 1.6, 2.0) versus 3.1 (95% confidence interval: 2.9, 3.3), and in-hospital death, 0.56 (95% confidence interval: 0.47, 0.67) versus 0.85 (95% confidence interval: 0.74, 0.98), respectively.

CONCLUSION

This study demonstrated the value of supplementing longitudinal site-based clinical studies with administrative claims data. Our results suggest that claims data together with network partner electronic health record data constitute an effective vehicle to capture patient outcomes since >30% of patients have non-fatal and fatal events outside of enrolling sites.

Impact of hormone therapy on Medicare spending in the Women's Health Initiative randomized clinical trials

BACKGROUND

Randomized trials can compare economic as well as clinical outcomes, but economic data are difficult to collect. Linking clinical trial data with Medicare claims could provide novel information on health care utilization and cost.

METHODS

We linked data from Medicare claims of women ≥65 years old who had Medicare fee-for-service coverage with their clinical data from the Women's Health Initiative trials of conjugated equine estrogens plus medroxyprogesterone acetate (CEE+MPA) versus placebo and of CEE-alone versus placebo. The primary outcome was total Medicare spending during the intervention phase of the trial, and the secondary outcomes were spending on diseases hypothesized a priori to be sensitive to the effects of hormone therapy.

RESULTS

In the CEE+MPA trial, 4,557 participants ≥65 years old were included. Women randomly assigned to CEE+MPA had 4% higher mean Medicare spending overall ($45,690 vs $43,920, P = .08) but 0.5% lower spending for hormone-sensitive diseases ($3,526 vs $3,547, P = .07), with 73% higher spending for coronary heart disease (P = .045) and 122% higher spending for pulmonary embolism (P = .026). In the CEE-alone trial, 3,107 participants were included. Total spending among women randomly assigned to CEE was 3.3% higher ($75,411 vs $72,997, P = .16), and 1.7% higher spending for hormone-sensitive diseases ($5,213 vs $5,127, P = .57), but with 39% lower spending for hip fracture (p<0.03).

CONCLUSIONS

Menopausal hormone therapy increased spending for some diseases, but decreased spending for others. These offsetting effects led to modest (3%-4%), nonsignificant increases in overall spending among women aged 65 years and older.

Sustained Posttransplantation Diabetes Is Associated With Long-Term Major Cardiovascular Events Following Liver Transplantation

Cardiovascular disease is a leading cause of death among liver transplant (LT) recipients. With a rising burden of posttransplantation metabolic disease, increases in cardiovascular-related morbidity and mortality may reduce life expectancy after LT. It is unknown if the risk of long-term major cardiovascular events (MCEs) differs among LT recipients with varying diabetic states. We performed a retrospective cohort study of LT recipients from 2003 through 2013 to compare the incidence of MCEs among patients (1) without diabetes, (2) with pretransplantation diabetes, (3) with de novo transient posttransplantation diabetes, and (4) with de novo sustained posttransplantation diabetes. We analyzed 994 eligible patients (39% without diabetes, 24% with pretransplantation diabetes, 16% with transient posttransplantation diabetes, and 20% with sustained posttransplantation diabetes). Median follow-up was 54.7 months. Overall, 12% of patients experienced a MCE. After adjustment for demographic and clinical variables, sustained posttransplantation diabetes was the only state associated with a significantly increased risk of MCEs (subdistribution hazard ratio 1.95, 95% confidence interval 1.20-3.18). Patients with sustained posttransplantation diabetes mellitus had a 13% and 27% cumulative incidence of MCEs at 5 and 10 years, respectively. While pretransplantation diabetes has traditionally been associated with cardiovascular disease, the long-term risk of MCEs is greatest in LT recipients with sustained posttransplantation diabetes mellitus.

Smartphone-Based Geofencing to Ascertain Hospitalizations

BACKGROUND

Ascertainment of hospitalizations is critical to assess quality of care and the effectiveness and adverse effects of various therapies. Smartphones, mobile geolocators that are ubiquitous, have not been leveraged to ascertain hospitalizations. Therefore, we evaluated the use of smartphone-based geofencing to track hospitalizations.

METHODS AND RESULTS

Participants aged ≥18 years installed a mobile application programmed to geofence all hospitals using global positioning systems and cell phone tower triangulation and to trigger a smartphone-based questionnaire when located in a hospital for ≥4 hours. An in-person study included consecutive consenting patients scheduled for electrophysiology and cardiac catheterization procedures. A remote arm invited Health eHeart Study participants who consented and engaged with the study via the internet only. The accuracy of application-detected hospitalizations was confirmed by medical record review as the reference standard. Of 22 eligible in-person patients, 17 hospitalizations were detected (sensitivity 77%; 95% confidence interval, 55%-92%). The length of stay according to the application was positively correlated with the length of stay ascertained via the electronic medical record (r=0.53; P=0.03). In the remote arm, the application was downloaded by 3443 participants residing in all 50 US states; 243 hospital visits at 119 different hospitals were detected through the application. The positive predictive value for an application-reported hospitalization was 65% (95% confidence interval, 57%-72%).

CONCLUSIONS

Mobile application-based ascertainment of hospitalizations can be achieved with modest accuracy. This first proof of concept may ultimately be applicable to geofencing other types of prespecified locations to facilitate healthcare research and patient care.

Long-term metabolic risk for the metabolically healthy overweight/obese phenotype

BACKGROUND/OBJECTIVES

The clinical relevance of the metabolically healthy overweight/obese (MHO) phenotype is controversial and the relationships between weight change and the development of cardiometabolic risk factors is unknown. Therefore, we aim to: (1) Assess the long-term risk of developing one or more components of the metabolic syndrome in MHO adults compared with metabolically healthy normal weight (MHNW); (2) Evaluate risk of a composite of death, cardiovascular disease (CVD), and risk of developing type 2 diabetes between adults defined according to baseline body mass index and metabolic health.

SUBJECTS/METHODS

Retrospective cohort study of adults 18-65 years of age seen at our institution between 1998 and 2000 who lived in Olmsted County. Metabolically healthy was defined as the absence of all components of the metabolic syndrome (except for waist circumference). Main outcome was the development of metabolic risk factors. The secondary outcome was a composite of mortality, CVD and heart failure.

RESULTS

Of the 18 070 individuals with complete data at baseline, 1805 (10%) were MHO (mean age 38±11 years) and 3047 were MHNW (mean age 35±11 years). After a median follow-up of 15 years, interquartile range 10-17, 80% of MHO vs 68% of MHNW developed at least one cardiometabolic risk factor (P<0.001). In multivariate analysis, MHO individuals who gained ⩾10% of their body weight were more likely to have developed metabolic complications compared to MHO individuals that did not gain weight (P=0.001 for 10-15%, P<0.001 for >15% weight gain). The risk for the secondary composite end point was similar between MHO and MHNW, number of events 218/1805 vs 217/3048 for MHO and MHNW, respectively, (hazard ratio: 1.16, 95% confidence interval: 0.96-1.40).

CONCLUSIONS

MHO are more likely to develop metabolic complications than MHNW, especially if they gain weight.

Use of administrative data to increase the practicality of clinical trials: Insights from the Women's Health Initiative

BACKGROUND

To reduce research costs in the context of pragmatic trials, consideration is given to using administrative data (Medicare claims) to ascertain clinical outcomes.

METHODS

In the historical context of the Women's Health Initiative, the correspondence between selected cardiovascular events derived from Medicare claims was compared to those documented and adjudicated in this large-scale prevention trial.

RESULTS

Classification performance varies somewhat by type of outcome, but hazard ratios and confidence intervals derived from the two data sources were quite comparable.

CONCLUSION

These encouraging results provided the needed support to launch a new embedded pragmatic trial of physical activity that will rely heavily on Medicare claims to ascertain cardiovascular disease incidence in the majority of those randomized.

Ongoing Use of Data and Specimens From National Cancer Institute-Sponsored Cancer Prevention Clinical Trials in the Community Clinical Oncology Program

Large cancer prevention trials provide opportunities to collect a wide array of data and biospecimens at study entry and longitudinally, for a healthy, aging population without cancer. This provides an opportunity to use pre-diagnostic data and specimens to evaluate hypotheses about the initial development of cancer. We report on strides made by, and future possibilities for, the use of accessible biorepositories developed from precisely annotated samples obtained through large-scale National Cancer Institute (NCI)-sponsored cancer prevention clinical trials conducted by the NCI Cooperative Groups. These large cancer prevention studies, which have enrolled more than 80,000 volunteers, continue to contribute to our understanding of cancer development more than 10 years after they were closed.