Linked Medicare Claims Data Research Articles

Derivation and Validation of ICD-10 Codes for Identifying Incident Stroke

Claims data with International Statistical Classification of Diseases, Tenth Revision (ICD-10) codes are routinely used in clinical research. However, the use of ICD-10 codes to define incident stroke has not been validated against expert-adjudicated outcomes in the US population. To develop and validate the accuracy of an ICD-10 code list to detect incident stroke events using Medicare inpatient fee-for-service claims data. This cohort study used data from 2 prospective population-based cohort studies, the Atherosclerosis Risk in Communities (ARIC) study and the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study, and included participants aged 65 years or older without prior stroke who had linked Medicare claims data. Stroke events in the ARIC and REGARDS studies were identified via active surveillance and adjudicated by expert review. Medicare-linked ARIC data (2016-2018) were used to develop a list of ICD-10 codes for incident stroke detection. The list was validated using Medicare-linked REGARDS data (2016-2019). Data were analyzed from September 1, 2022, through September 30, 2023. Stroke events detected in Medicare claims vs expert-adjudicated stroke events in the ARIC and REGARDS studies. The main outcomes were sensitivity and specificity of incident stroke detection using ICD-10 codes. In the ARIC study, there were 110 adjudicated incident stroke events among 5194 participants (mean [SD] age, 80.1 [5.3] years) over a median follow-up of 3.0 (range, 0.003-3.0) years. Most ARIC participants were women (3160 [60.8%]); 993 (19.1%) were Black and 4180 (80.5%) were White. Using the primary diagnosis code on a Medicare billing claim, the ICD-10 code list had a sensitivity of 81.8% (95% CI, 73.3%-88.5%) and a specificity of 99.1% (95% CI, 98.8%-99.3%) to detect incident stroke. Using any diagnosis code on a Medicare billing claim, the sensitivity was 94.5% (95% CI, 88.5%-98.0%) and the specificity was 98.4% (95% CI, 98.0%-98.8%). In the REGARDS study, there were 140 adjudicated incident strokes among 6359 participants (mean [SD] age, 75.8 [7.0] years) over a median follow-up of 4.0 (range, 0-4.0) years. More than half of the REGARDS participants were women (3351 [52.7%]); 1774 (27.9%) were Black and 4585 (72.1%) were White. For the primary diagnosis code, the ICD-10 code list had a sensitivity of 70.7% (95% CI, 63.2%-78.3%) and a specificity of 99.1% (95% CI, 98.9%-99.4%). For any diagnosis code, the ICD-10 code list had a sensitivity of 77.9% (95% CI, 71.0%-84.7%) and a specificity of 98.9% (95% CI, 98.6%-99.2%). These findings suggest that ICD-10 codes could be used to identify incident stroke events in Medicare claims with moderate sensitivity and high specificity.

Variability in short-term mortality following repair of ruptured abdominal aortic aneurysms across centers and physicians

BackgroundVariation in the care management of repairs for ruptured infrarenal abdominal aortic aneurysms between centers and physicians, such as procedural volumes, may explain differences in mortality outcomes. First, we quantified the center and physician variability associated with 30- and 90-day mortality risk after ruptured open surgical repair (rOSR) and ruptured endovascular aneurysm repair (rEVAR). Second, we explored wheter part of this variability was attributable to procedural volume at the center and physician levels. MethodsTwo cohorts including rOSR and rEVAR procedures between 2013 and 2019 were analyzed from the Vascular Quality Initiative database. Thirty- and 90-day all-cause mortality rates were derived from linked Medicare claims data. The median odds ratio (MOR) (median mortality risk from low- to high-risk cluster) and intraclass correlation coefficient (ICC) (variability attributable to each cluster) for 30- and 90-day mortality risks associated with center and physician variability were derived using patient-level adjusted multilevel logistic regression models. Procedural volume was calculated at the center and physician levels and stratified by quartiles. The models were sequentially adjusted for volumes, and the difference in ICCs (without vs with accounting for volume) was calculated to describe the center and physician variability in mortality risk attributable to volumes. ResultsWe included 450 rOSRs (mean age, 74.5 ± 7.6 years; 23.5% female) and 752 rEVARs (76.4 ± 8.4 years; 26.1% female). After rOSRs, the 30- and 90-day mortality rates were 32.9% and 38.7%, respectively. No variability across centers and physicians was noted (30- and 90-day MORs ≈1 and ICCs ≈0%). Neither center nor physician volume was associated with 30-day (P = .477 and P = .796) or 90-day mortality (P = .098 and P = .559). After rEVAR, the 30- and 90-day mortality rates were 21.3% and 25.5%, respectively. Significant center variability (30-day MOR, 1.82 [95% confidence interval (CI), 1.33-2.22]; ICC, 11% [95% CI, 2%-36%]; and 90-day MOR, 1.76 [95% CI, 1.37-2.09]; ICC, 10% [95% CI, 3%-30%]), but negligeable variability across physicians (30- and 90-day MORs ≈1 and ICCs ≈0%) were noted. Neither center nor physician volume were associated with 30-day (P = .076 and P = .336) or 90-day mortality risk (P = .066 and P = .584). The center variability attributable to procedural volumes was negligeable (difference in ICCs, 1% for 30-day mortality; 0% for 90-day mortality). ConclusionsVariability in practice from center to center was associated with short-term mortality outcomes in rEVAR, but not for rOSR. Physician variability was not associated with short-term mortality for rOSR or rEVAR. Annualized center and physician volumes did not significantly explain these associations. Further work is needed to identify center-level factors affecting the quality of care and outcomes for ruptured abdominal aortic aneurysms.

Self-reported Visual Difficulty, Age-related Eye Disease, and Neuropsychiatric Outcomes in Older Adults

ABSTRACT Purpose Self-reported visual difficulty is consistently associated with dementia and other neuropsychiatric outcomes, but studies of specific age-related eye diseases have yielded conflicting results. Methods We conducted a retrospective cohort study using data from The National Health and Aging Trends Study, an ongoing nationally representative survey of older U.S. adults (n = 10,089). All subjects are screened for self-reported visual difficulty annually. Using linked Medicare claims data, we identified subjects with age-related macular degeneration (AMD), primary open-angle glaucoma (POAG), diabetic retinopathy, and cataract. For each condition, controls with complete Medicare eligibility and at least one eye care encounter were selected. We used semiparametric discrete time proportional hazards models to measure associations with incident dementia, and generalized estimating equations to examine longitudinal associations with depression, anxiety, and hallucinations, adjusting for baseline demographics and time-varying comorbidities. Results Self-reported visual difficulty was associated with dementia (HR 1.16, 95% CI: 1.00–1.34), depression (OR 1.14, 95% CI: 1.04–1.26), anxiety (OR 1.17, 95% CI: 1.06–1.29), and hallucinations (OR 1.54, 95% CI: 1.29–1.84). Diabetic retinopathy was associated with depression (OR 1.31, 95% CI: 1.05–1.64), and cataracts were associated with a lower risk of depression (OR 0.84, 95% CI: 0.74–0.95) and anxiety (OR 0.86, 95% CI: 0.75–0.99). There were no other associations between age-related eye disease and neuropsychiatric outcomes. Conclusion Self-reported visual difficulty is associated with dementia and other neuropsychiatric outcomes to a greater degree than age-related eye disease. These findings highlight the distinction between self-reported vision and clinically diagnosed eye disease with regard to health outcomes in older adults.

Short-term outcomes of prehospital opioid pain management for older adults with fall-related injury.

Opioids are recommended for pain management in patients being cared for and transported by emergency medical services, but no specific guidelines exist for older adults with fall-related injury. Prior research suggests prehospital opioid administration can effectively manage pain in older adults, but less is known about safety in this population. We compared short-term safety outcomes, including delirium, disposition, and length of stay, among older adults with fall-related injury according to whether they received prehospital opioid analgesia. We linked Medicare claims data with prehospital patient care reports for older adults (≥65) with fall-related injury in Illinois between January 1, 2014 and December 31, 2015. We used weighted regression models (logistic, multinomial logistic, and Poisson) to assess the association between prehospital opioid analgesia and incidence of inpatient delirium, hospital disposition, and length of stay. Of 28,150 included older adults, 3% received prehospital opioids. Patients receiving prehospital opioids (vs. no prehospital opioids) were less likely to be discharged home from the emergency department (adjusted probability = 0.30 [95% CI: 0.25, 0.34] vs. 0.47 [95% CI: 0.46, 0.48]), more likely to be discharged to a non-home setting after an inpatient admission (adjusted probability = 0.43 [95% CI: 0.39, 0.48] vs. 0.30 [95% CI: 0.30, 0.31]), had inpatient length of stay 0.4 days shorter (p < 0.001) and ICU length of stay 0.7 days shorter (p = 0.045). Incidence of delirium did not vary between treatment and control groups. Few older adults receive opioid analgesia in the prehospital setting. Prehospital opioid analgesia may be associated with hospital disposition and length of stay for older adults with fall-related injury. However, our findings do not provide evidence of an association with inpatient delirium. These findings should be considered when developing guidelines for prehospital pain management specific to the older adult population.

Improving the accuracy of automated gout flare ascertainment using natural language processing of electronic health records and linked Medicare claims data.

We aimed to determine whether integrating concepts from the notes from the electronic health record (EHR) data using natural language processing (NLP) could improve the identification of gout flares. Using Medicare claims linked with EHR, we selected gout patients who initiated the urate-lowering therapy (ULT). Patients' 12-month baseline period and on-treatment follow-up were segmented into 1-month units. We retrieved EHR notes for months with gout diagnosis codes and processed notes for NLP concepts. We selected a random sample of 500 patients and reviewed each of their notes for the presence of a physician-documented gout flare. Months containing at least 1 note mentioning gout flares were considered months with events. We used 60% of patients to train predictive models with LASSO. We evaluated the models by the area under the curve (AUC) in the validation data and examined positive/negative predictive values (P/NPV). We extracted and labeled 839 months of follow-up (280 with gout flares). The claims-only model selected 20 variables (AUC = 0.69). The NLP concept-only model selected 15 (AUC = 0.69). The combined model selected 32 claims variables and 13 NLP concepts (AUC = 0.73). The claims-only model had a PPV of 0.64 [0.50, 0.77] and an NPV of 0.71 [0.65, 0.76], whereas the combined model had a PPV of 0.76 [0.61, 0.88] and an NPV of 0.71 [0.65, 0.76]. Adding NLP concept variables to claims variables resulted in a small improvement in the identification of gout flares. Our data-driven claims-only model and our combined claims/NLP-concept model outperformed existing rule-based claims algorithms reliant on medication use, diagnosis, and procedure codes.

Variation in hospital use of cardiac resynchronization therapy-defibrillator among eligible patients and association with clinical outcomes

Despite strong guideline recommendations for cardiac resynchronization therapy-defibrillator (CRT-D) in select patients, this therapy is underutilized with substantial variation among hospitals, and the association of this variation with outcomes is unknown. The purpose of this study was to assess whether facility variation in CRT-D utilization is associated with differences in hospital-level outcomes. We linked Medicare claims data with the National Cardiovascular Data Registry's ICD Registry from 2010 to 2015. We calculated the intraclass correlation coefficient to quantify the degree of variation in patient-level CRT use that can be explained by interfacility variation on a hospital level. To quantify the degree of hospital variation in patient-level outcomes (all-cause mortality, readmissions, and cardiac readmissions) that can be attributed to variations in CRT-D use, we utilized multilevel modeling. The study included 30,134 patients across 1377 hospitals. The median rate of CRT-D implantation in those meeting guideline indications was 89%, but there was a wide variation across hospitals. After adjustment, most of the variation (74%) in hospital rates of CRT-D utilization was attributable to the hospital in which the patient was treated. Differences in hospital CRT-D utilization was associated with 8.76%, 5.26%, and 4.71% of differences in hospital mortality, readmissions, and cardiac readmission rates, respectively (P < .001 for all outcomes). There is a wide variation in the use of CRT-D across hospitals that was not explained by case mix. Hospital-level variation in CRT-D utilization was associated with clinically significant differences in outcomes. A measure of CRT-D utilization in eligible patients may serve as a useful metric for quality improvement efforts.

Effect of Low-Fat Dietary Modification on Incident Open-Angle Glaucoma

We tested whether dietary modification (DM) altered the risk for incident primary open-angle glaucoma (POAG). Secondary analysis of a randomized intervention trial. We linked Medicare claims data to 45 203 women in the Women's Health Initiative Dietary Modification Trial, of which 23 776 participants were enrolled in fee-for-service Medicare Part B and had physician claims. Women were randomized to follow either DM (a low-fat diet, with increased vegetable, fruit, and grain intake) or their usual diet without modification. Nine thousand three hundred forty women were randomized to the DM intervention, whereas 13 877 women were randomized to the control group. Our analyses were based on an intention-to-treat design, with a follow-up to the end of continuous Medicare coverage, death, or the last claims date (12/31/2018), whichever occurred first. Primary open-angle glaucoma was defined as the first claim with the International Classification of Diseases, Ninth or Tenth Revision, codes. Dietary data were assessed using a food frequency questionnaire. We used Cox proportional hazards models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for risk of POAG. Subgroup analyses were performed with P values for interaction. After exclusion of women with Medicare-derived glaucoma before randomization, the final analysis included 23 217 women (mean age, 64.4 ± 5.8 years). Baseline characteristics were balanced between the intervention and control groups. Primary open-angle glaucoma incidence was 11.1 per 1000 woman-years (mean follow-up, 11.6 ± 7.4 years; mean DM duration, 5.2 ± 3.2 years). We found no overall benefit of DM in reducing incident POAG (HR, 1.04; 95% CI, 0.96-1.12). Race and participant age did not modify this relation (P = 0.08 and P = 0.24 for interaction, respectively). In further analysis of baseline nutrient and food intake stratified by quartile groups, risk of open-angle glaucoma (OAG) in DM participants in the lowest quartile group for percentage calories (kilocalories) from total fat (33.8 or lower) was increased (HR, 1.22; 95% CI, 1.05-1.41; P = 0.007 for interaction). Analysis suggests that DM in participants in the lowest quartile group for percentage calories from total fat at baseline increased the risk of incident OAG among women regardless of age or race. Proprietary or commercial disclosure may be found after the references.

Neighborhood Socioeconomic Disadvantage and Disability After Critical Illness.

Factors common to socioeconomically disadvantaged neighborhoods, such as low availability of transportation, may limit access to restorative care services for critical illness survivors. Our primary objective was to evaluate whether neighborhood socioeconomic disadvantage was associated with an increased disability burden after critical illness. Our secondary objective was to determine if the effect differed for those discharged to the community compared with those discharged to a facility. Longitudinal cohort study with linked Medicare claims data. United States. One hundred ninety-nine older adults, contributing to 239 ICU admissions, who underwent monthly assessments of disability for 12 months following hospital discharge in 13 different functional tasks from 1998 to 2017. Neighborhood disadvantage was assessed using the area deprivation index, a 1-100 ranking evaluating poverty, housing, and employment metrics. Those living in disadvantaged neighborhoods (top quartile of scores) were less likely to self-identify as non-Hispanic White compared with those in more advantaged neighborhoods. In adjusted models, older adults living in disadvantaged neighborhoods had a 9% higher disability burden over the 12 months following ICU discharge compared with those in more advantaged areas (rate ratio, 1.09; 95% Bayesian credible interval, 1.02-1.16). In the secondary analysis adjusting for discharge destination, neighborhood disadvantage was associated with a 14% increase in disability burden over 12 months of follow-up (rate ratio, 1.14; 95% credible interval, 1.07-1.21). Disability burden was 10% higher for those living in disadvantaged neighborhoods and discharged home as compared with those discharged to a facility, but this difference was not statistically significant (interaction rate ratio, 1.10; 95% credible interval, 0.98-1.25). Neighborhood socioeconomic disadvantage is associated with a higher disability burden in the 12 months after a critical illness. Future studies should evaluate barriers to functional recovery for ICU survivors living in disadvantaged neighborhoods.

Risk of Hospitalization and Death Associated With Pimavanserin Use in Older Adults With Parkinson Disease.

To determine the risk of hospitalization and death associated with pimavanserin use. We conducted a retrospective cohort study of adults 65 years and older with Parkinson disease between November 1, 2015, and December 31, 2018, using an administrative dataset on residents of Medicare-certified long-term care facilities and linked Medicare claims data. Propensity score-based inverse probability of treatment weighting (IPTW) was used to balance pimavanserin users and nonusers on 24 baseline characteristics. Fine-Gray competing risk and Cox proportional hazards regression models were used to estimate the risk of hospitalization and death up to 1 year, respectively. The study cohort included 2,186 pimavanserin users and 18,212 nonusers. There was a higher risk of 30-day hospitalization with pimavanserin use vs nonuse (IPTW-adjusted hazard ratio [aHR] 1.24, 95% confidence intervals [CI] 1.06-1.43). There was no association of pimavanserin use with 90-day hospitalization (aHR 1.10, CI 0.99-1.24) or with 30-day mortality (aHR 0.76, CI 0.56-1.03). Pimavanserin use vs nonuse was associated with increased 90-day mortality (aHR 1.20, CI 1.02-1.41) that persisted after 180 days (aHR 1.28, CI 1.13-1.45) and 1 year (aHR 1.56, CI 1.42-1.72). Pimavanserin use vs nonuse in older adults was associated with an increased risk of hospitalization at 1 month of initiation and a higher risk of death for up to 1 year following initiation. These findings, in a large real-world cohort within long-term care facilities, may help to inform decisions regarding its risk/benefit balance among patients with Parkinson disease. This study provides Class II evidence that in patients with Parkinson disease who are 65 or older and residing in Medicare-certified long-term care facilities, pimavanserin is associated with an increased risk of 30-day hospitalization and higher 90-, 180-, and 365-day mortality.

Using a Simple Prescription Gap to Determine Warfarin Discontinuation Can Lead to Substantial Misclassification.

Warfarin remains widely used and a key comparator in studies of other direct oral anticoagulants. As longer-than-needed warfarin prescriptions are often provided to allow for dosing adjustments according to international normalized ratios (INRs), the common practice of using a short allowable gap between dispensings to define warfarin discontinuation may lead to substantial misclassification of warfarin exposure. We aimed to quantify such misclassification and determine the optimal algorithm to define warfarin discontinuation. We linked Medicare claims data from 2007 to 2014 with a multicenter electronic health records system. The study cohort comprised patients ≥65 years with atrial fibrillation and venous thromboembolism initiating warfarin. We compared results when defining warfarin discontinuation by (1) different gaps (3, 7, 14, 30, and 60 days) between dispensings and (2) having a gap ≤60 days or bridging larger gaps if there was INR ordering at least every 42 days (60_INR). Discontinuation was considered misclassified if there was an INR ≥2 within 7 days after the discontinuation date. Among 3,229 patients, a shorter gap resulted in a shorter mean follow-up time (82, 95, 117, 159, 196, and 259 days for gaps of 3, 7, 14, 30, 60, and 60_INR, respectively; p < 0.001). Incorporating INR (60_INR) can reduce misclassification of warfarin discontinuation from 68 to 4% (p < 0.001). The on-treatment risk estimation of clinical endpoints varied significantly by discontinuation definitions. Using a short gap between warfarin dispensings to define discontinuation may lead to substantial misclassification, which can be improved by incorporating intervening INR codes.

Epilepsy and Neurodegeneration: A Bidirectional Relationship.

The Bi-Directional Association Between Epilepsy and Dementia. The Framingham Heart Study Stefanidou M, Beiser AS, Himali JJ, et al. Neurology. 2020. doi:10.1212/WNL.0000000000011077.Objectives:To assess the risk of incident epilepsy among participants with prevalent dementia, and the risk of incident dementia among participants with prevalent epilepsy in the Framingham Heart Study (FHS).Methods:We analyzed prospectively collected data in the Original and Offspring FHS cohorts. To determine the risk of developing epilepsy among participants with dementia and the risk of developing dementia among participants with epilepsy we used separate, nested, case–control designs, and matched each case to 3 age-, sex-, and FHS cohort-matched controls. We used Cox proportional hazards regression analysis, adjusting for sex and age. In secondary analysis, we investigated the role of education level and apolipoprotein ε4 allele status in modifying the association between epilepsy and dementia.Results:A total of 4906 participants had information on epilepsy and dementia and dementia follow-up after age 65. Among 660 participants with dementia and 1980 dementia-free controls there were 58 incident epilepsy cases during follow-up. Analysis comparing epilepsy risk among dementia cases versus controls yielded (hazards ratio [HR] = 1.82 [95% CI:1.05-3.16], P = .034). Among 43 participants with epilepsy and 129 epilepsy-free controls, there were 51 incident dementia cases. Analysis comparing dementia risk among epilepsy cases versus controls yielded (HR = 1.99 [1.11-3.57], P = .021). In this group, among participants with any post-high school education, prevalent epilepsy was associated with a nearly 5-fold risk for developing dementia (HR = 4.67 [1.82-12.01], P = .001) compared to controls of the same educational attainment.Conclusions:There is a bidirectional association between epilepsy and dementia with either condition carrying a nearly 2-fold risk of developing the other when compared with controls. Dementia in Late Onset Epilepsy: The Atherosclerosis Risk in Communities Study Johnson EL, Krauss GL, Kucharska-Newton A, et al. Neurology. 2020.Objective:To determine the risk of dementia after the development of late-onset epilepsy (LOE).Methods:We used data from the Atherosclerosis Risk in Communities (ARIC) cohort study, which started in 1987 to 1989 with 15 792 mostly black and white men and women from 4 US communities. We identified LOE (seizures starting at age 67 or later) from linked Medicare claims data. We used a Cox proportional hazards regression model to evaluate associations between LOE and dementia through 2017 as ascertained from neuropsychological testing, interviews, and hospital discharge surveillance; and we used multinomial logistic regression to assess the risk of dementia and mild cognitive impairment in the subset with full neuropsychological assessments available. We adjusted for demographics, and vascular and Alzheimer disease risk factors.Results:Of 9033 ARIC participants with sufficient Medicare coverage data (4980 [55.1%] female, 1993 [22.1%] black), 671 met the definition of LOE. 279 (41.6%) participants with LOE and 1408 (16.8%) without LOE developed dementia (P < .001). After a diagnosis of LOE, the adjusted hazard ratio for developing subsequent dementia was 3.05 (95% CI: 2.65-3.51). The median time to dementia ascertainment after the onset of LOE was 3.66 years (Q1-Q3 1.28-8.28 years).Interpretation:The risk of incident dementia is substantially elevated in individuals with LOE. Further work is needed to explore causes for the increased risk of dementia in this growing population.

Physical Frailty, Cognitive Impairment, and Healthcare Utilization in Linked Cohort and Claims Data

Accurate prediction of healthcare utilization is an important issue for Medicare managed care organizations. We hypothesized that physical frailty and cognitive impairment increase the risk of healthcare utilization in older adults receiving Medicare coverage, independent of age and multimorbidity. We used the marginal means/rates model to investigate the association between baseline cognitive impairment with/without frailty (using the physical frailty phenotype), vs. frailty alone, in NHATS and the number of incident non-ER-related hospitalizations and emergency room (ER) visits within 12 months in linked Medicare claims data (N=3,915). After covariate adjustment, physical frailty alone was predictive of both non-ER-related hospitalizations (HR=1.77; p=0.012) and ER visits (HR=1.75; p<0.001). Cognitive impairment with or without frailty was only associated with ER visits (HR=1.53, p=0.002; HR=1.30, p=0.001). Our findings support the value of physical frailty and cognitive impairment assessment above and beyond multimorbidity to improve the prediction of care utilization for vulnerable subgroups of Medicare beneficiaries.

The Financial Presentation of Alzheimer’s Disease and Related Dementias

Dementia, a currently incurable degenerative cognitive disease, represents a major threat to financial stability. Early signs of dementia can include difficulties managing money and forgetting to pay bills, raising concerns about the implications of pre-clinical disease for financial well-being. We linked Medicare claims data to 20 years of consumer credit data for more than 80,000 older Americans living in single households to study the financial presentation of Alzheimer’s Disease and Related Dementias. Using non-parametric regression models, we find elevated rates of payment delinquency, subprime credit, and withdrawal from use of credit products up to 6 years before dementia is clinically diagnosed. Similar patterns did not appear with a number of placebo acute and chronic health conditions, suggesting that the adverse financial events are unique to dementia and do not occur with other acute or chronic illnesses. Part of a symposium sponsored by the Economics of Aging Interest Group.

Analysis of the association between serum PFAS levels measured in NHANES and subsequent development of stroke or myocardial infarction as assessed through linked Medicare claims data

Background/Aim: Per- and polyfluoroalkyl substances (PFAS) are persistent chemicals used in many products and manufacturing processes. Human exposure to some PFAS has been associated with serum cholesterol concentrations, but observed cardiovascular disease (CVD) associations have been inconsistent. Previous cross-sectional analyses of PFAS-CVD associations used U.S. National Health and Nutrition Examination Survey (NHANES) data. We prospectively examined associations between NHANES serum PFAS concentrations and subsequent myocardial infarction (MI), ischemic stroke (IS) or any stroke (AS), using linked National Death Index and Medicare claims data, for participants aged ≥65 years with PFAS measurements and Medicare fee-for-service enrollment (study population).Methods: NHANES (1999-2000, 2003-2012) serum PFAS concentrations [perfluorooctane sulfonate, perfluorooctanoic acid (PFOA), perfluorononanoic acid, perfluorohexane sulfonate] were analyzed using quartile (among cases) indicator variables and the natural log of quartile geometric means (continuous variable, trend test). CVD outcomes occurring after serum collection were identified, among participants reporting no prior history of the outcome, using linked (through 2013) Medicare claims ICD-9-CM codes and underlying cause-of-death ICD-10 codes. Survival analysis models with an age time scale; weighted to account for survey design and Medicare matching; and stratified on body mass index; controlled for survey cycle, age, gender, race/ethnicity, smoking, alcohol consumption, physical activity, education, and income-to-poverty ratio.Results: Among 1248 in the study population, 1078 reported no prior MI (72 developed MI) and 1102 reported no prior stroke (67 developed IS; 78 developed AS). Quartile-specific hazard ratios (HRs) and trends for all PFAS-outcome combinations were not statistically significant, but some elevated HRs were observed [e.g., IS HRs (95% confidence intervals) for PFOA quartiles 2-4 vs. 1: 2.04 (0.79-5.28), 1.98 (0.75-5.19), 1.63 (0.61-4.36)].Conclusions: This analysis did not provide clear evidence of an association between serum PFAS concentrations and MI, IS, or AS. Results should be interpreted considering study limitations (e.g., limited power, single exposure measurement).

Dementia in late-onset epilepsy: The Atherosclerosis Risk in Communities study.

To determine the risk of dementia after the development of late-onset epilepsy. We used data from the Atherosclerosis Risk in Communities (ARIC) cohort study, which started in 1987 to 1989 with 15,792 mostly Black and White men and women from 4 US communities. We identified late-onset epilepsy (LOE; seizures starting at age 67 or later) from linked Medicare claims data. We used a Cox proportional hazards regression model to evaluate associations between LOE and dementia through 2017 as ascertained from neuropsychological testing, interviews, and hospital discharge surveillance, and we used multinomial logistic regression to assess the risk of dementia and mild cognitive impairment in the subset with full neuropsychological assessments available. We adjusted for demographics and vascular and Alzheimer disease risk factors. Of 9,033 ARIC participants with sufficient Medicare coverage data (4,980 [55.1%] female, 1993 [22.1%] Black), 671 met the definition of LOE. Two hundred seventy-nine (41.6%) participants with and 1,408 (16.8%) without LOE developed dementia (p < 0.001). After a diagnosis of LOE, the adjusted hazard ratio for developing subsequent dementia was 3.05 (95% confidence interval 2.65-3.51). The median time to dementia ascertainment after the onset of LOE was 3.66 years (quartile 1-3, 1.28-8.28 years). The risk of incident dementia is substantially elevated in individuals with LOE. Further work is needed to explore causes for the increased risk of dementia in this growing population.

Assessment of Rural-Urban Differences in Health Care Use and Survival Among Medicare Beneficiaries With Alzheimer Disease and Related Dementia

There is poor understanding as to how survival and health care use varies among older adults living with Alzheimer disease and related dementia (ADRD) in rural vs urban areas of the United States. To describe survival and trajectories of hospital, hospice, nursing home, and home health care use among rural and urban Medicare beneficiaries with ADRD in the 6 years after diagnosis. This retrospective cohort study linked Medicare claims data from January 1, 2009, to December 31, 2016, with nursing home and home health assessment data from all US counties. A total of 555 333 Medicare fee-for-service beneficiaries newly diagnosed with ADRD in 2010 were included. A total of 424 561 individuals (76.5%) resided in metropolitan counties, 75 001 (13.5%) in micropolitan counties, and 55 771 (10.0%) in rural counties. Rurality of beneficiary's county of residence. Number of days survived after initial ADRD diagnosis; percent of survived days per month spent in the hospital, hospice nursing home, community with home health care services, and community without home health care services. A total of 555 333 Medicare beneficiaries (mean [SD] age, 82.0 [7.5] years; 345 294 women [62.2%]; 480 286 White [86.5%]) were evaluated. Compared with metropolitan county residents, rural beneficiaries were younger (mean [SD] age, 81.6 [7.6] vs 82.1 [7.5] years), were less likely to be women (34 100 [61.1%] vs 264 688 [62.3%]), were more likely to be White (50 886 [91.2%] vs 361 205 [85.1%]) and Medicaid-eligible (14 264 [25.6%] vs 71 656 [16.9%]), and had fewer preexisting chronic conditions (mean [SD], 6.9 [2.8] vs 7.4 [2.9]). Medicare beneficiaries residing in metropolitan counties survived a mean (SD) of 1183.5 (826.0) days after diagnosis. Adjusting for individual demographic and clinical characteristics, rural and micropolitan county residents survived approximately 1.5 months less than metropolitan residents. The adjusted share of survived days spent in nursing homes was 5.7 (95% CI, 4.0-7.5) percentage points higher for rural vs metropolitan residents. The adjusted share of days in hospitals was 0.7 (95% CI, -0.9 to -0.4) percentage points lower, and the share of days in community without home health care was 4.6 (95% CI, -6.1 to -3.1) percentage points lower for rural vs metropolitan county residents. There were no statistically significant differences in home health or hospice use. Similar patterns were found for micropolitan vs metropolitan residents as for rural vs metropolitan residents, although the magnitude of the differences were smaller. Differences in time spent in community and nursing homes between rural vs metropolitan beneficiaries became more pronounced with further time from diagnosis. Study results suggest that, after diagnosis, rural Medicare beneficiaries with ADRD spend more time in nursing homes and less time in the community, receive less home health care, and have shorter survival than their urban counterparts.

Prompt Outpatient Care For Older Adults Discharged From The Emergency Department Reduces Recidivism.

IntroductionOlder adults present unique challenges to both emergency clinicians and health systems. These challenges are especially evident with respect to discharge after an emergency department (ED) visit as older adults are at risk for short-term, negative outcomes including repeat ED visits. The aim of this study was to evaluate characteristics and risk factors associated with repeat ED utilization by older adults.MethodsED visits among participants in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study between 2003–2016 were examined using linked Medicare claims data to identify such visits and resulting disposition. Multilevel proportional hazards models examined associations of age, comorbidity status, race, gender, Medicaid dual eligibility status, social support characteristics (living alone or caregiver support), and use of ambulatory primary and subspecialty care with repeat ED utilization.ResultsOlder adults discharged from the ED seen by a primary care provider (hazard ratio [HR] = 0.93, confidence interval [CI], 0.87–0.98, p = 0.01) or subspecialist (HR = 0.91, CI 0.86–0.97, P <0.01) after the ED visit were less likely to return to the ED within 30 days compared to those who did not have such post-ED ambulatory visits. Additionally, comorbidity (HR =1.14, 95% CI, 1.13–1.16, P <0.01) and dual eligibility for Medicare and Medicaid (HR = 1.34, 95% CI, 1.20–1.50, p<0.01) were associated with return to the ED within 30 days. Those who were older (HR = 1.10, 95% CI, 1.05–1.15), had more comorbidities (HR = 1.17, 95% CI 1.15–1.18), Black (HR = 1.23, 95% CI, 1.14–1.33,P <0.01), and dually eligible (HR =1.23, 95% CI, 1.14–1.33, P <0.01) were more likely to return within 31–90 days after their initial presentation. The association of outpatient visits with repeat ED visits was no longer seen beyond 30 days. Patients without a caregiver or who lived alone were no more likely to return to the ED in the time periods evaluated in our study.ConclusionBoth primary care and subspecialty care visits among older adults who are seen in the ED and discharged are associated with less frequent repeat ED visits within 30 days.

Racial/Ethnic Disparities in Physical Function Before and After Total Knee Arthroplasty Among Women in the United States

Although racial/ethnic differences in functional outcomes after total knee arthroplasty (TKA) exist, whether such differences are associated with differences in presurgical physical function (PF) has not been thoroughly investigated. To examine trajectories of PF by race/ethnicity before and after TKA among older women. This cohort study was conducted among the prospective Women's Health Initiative with linked Medicare claims data. A total of 10 325 community-dwelling women throughout the United States with Medicare fee-for-service underwent primary TKA between October 1, 1993, and December 31, 2014, and were followed up through March 31, 2017. Race/ethnicity comparisons between Hispanic or Latina women, non-Hispanic black or African American women, and non-Hispanic white women (hereafter referred to as Hispanic, black, and white women, respectively). Physical functioning scale scores and self-reported activity limitations with walking 1 block, walking several blocks, and climbing 1 flight of stairs were measured by the RAND 36-Item Health Survey during the decade before and after TKA, with a median of 9 PF measurements collected per participant over time. In total, 9528 white women (mean [SD] age at surgery, 74.6 [5.5] years), 622 black women (mean [SD] age at surgery, 73.1 [5.3] years), and 175 Hispanic women (mean [SD] age at surgery, 73.1 [5.2] years) underwent TKA. During the decade prior to TKA, black women had lower PF scores than white women (mean difference, -5.8 [95% CI, -8.0 to -3.6]) and higher odds of experiencing difficulty walking a single block (5 years before TKA: odds ratio, 1.86 [95% CI, 1.57-2.21]), walking multiple blocks (odds ratio, 2.14 [95% CI, 1.83-2.50]), and climbing 1 flight of stairs (odds ratio, 1.81 [95% CI, 1.55-2.12]). After TKA, black women continued to have lower PF scores throughout the decade (mean difference 1 year after TKA, -7.8 [95% CI, -10.8 to -4.9]). After adjusting for preoperative PF scores, PF scores after TKA were attenuated (mean difference 1 year after TKA, -3.0 [95% CI, -5.3 to -0.7]), with no statistically significant differences in long-term follow-up. Hispanic women had similar PF scores to white women during the pre-TKA and post-TKA periods. This study suggests that black women had significantly poorer PF than white women during the decades before and after TKA. Poorer PF after surgery was associated with poorer preoperative PF. Reducing disparities in post-TKA functional outcomes should target maintenance of function preoperatively in the early stages of arthritic disease and/or reduction of delays to receiving TKA once need arises.

Representativeness of the PIONEER-HF Clinical Trial Population in Patients Hospitalized With Heart Failure and Reduced Ejection Fraction.

In PIONEER-HF (Comparison of Sacubitril/Valsartan Versus Enalapril on Effect on NT-pro BNP in Patients Stabilized From an Acute Heart Failure Episode), the in-hospital initiation of sacubitril/valsartan in patients hospitalized for acute decompensated heart failure (ADHF) was well-tolerated and led to improved outcomes. We aim to determine the representativeness of the PIONEER-HF trial among patients hospitalized for ADHF using real-world data. The study population was derived from all patients discharged alive for ADHF in the Get With The Guidelines-HF registry from 2006 to 2018 with HF with reduced ejection fraction (HFrEF; all HFrEF with ADHF). We then determined the proportion of patients meeting PIONEER-HF eligibility criteria (PIONEER-HF eligible) and those meeting a set of limited eligibility criteria (actionable cohort). Rates of HF readmissions and all-cause mortality were then compared between the all HFrEF with ADHF, PIONEER-HF eligible, and actionable cohorts using linked Medicare claims data. A total of 99 767 patients with HFrEF in Get With The Guidelines-HF were hospitalized for ADHF. PIONEER-HF inclusion criteria were met by 71 633 (71.8%) patients, and both inclusion and exclusion criteria were met by 20 704 (20.8%) patients. Further, 68 739 (68.9%) patients met the criteria for the actionable cohort. Among the Centers for Medicare and Medicaid-linked patients, the HF rehospitalization rate at 1 year was 35.1% (95% CI, 34.5-35.8) for all HFrEF with ADHF patients, 32.6% (95% CI, 31.3-33.9) for the PIONEER-HF eligible cohort, and 33.1% (95% CI, 32.3-33.9) for the actionable cohort. The 1-year all-cause mortality was 36.7% (95% CI, 36.1-7.4) for all HFrEF with ADHF patients, 31.6% (95% CI, 30.3-32.9) for the PIONEER-HF eligible cohort, and 32.2% (95% CI, 31.4-33.0) for the actionable cohort. Patient characteristics and clinical outcomes for patients eligible for PIONEER-HF only modestly differ when compared with those encountered in routine practice, suggesting that the in-hospital initiation of sacubitril/valsartan should be routinely considered for patients with HFrEF hospitalized for ADHF.

Multimorbidity in Medicare Beneficiaries: Performance of an ICD-Coded Multimorbidity-Weighted Index.

Most older adults have multimorbidity that impairs physical functioning, but it is difficult to quantify using claims data. We previously developed and validated a multimorbidity-weighted index (MWI) that embeds physical functioning through disease weightings. We mapped these conditions to International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes and compared them with existing indices. Population-based prospective cohort. Respondents to the 2006-2016 waves of the Health and Retirement Study (HRS) with linked Medicare claims data and continuous enrollment in 2006. Community-dwelling Medicare-eligible HRS participants (N = 9923; mean age = 75.5 ± 8.5 y). Individuals were followed for future physical functioning (2006-2014) and mortality (2007-2016). MWI conditions were mapped to ICD-9-CM codes to produce an ICD-coded MWI (MWI-ICD). We compared MWI-ICD, simple disease count, Charlson, Elixhauser, and the health-related quality of life comorbidity index (HRQOL-CI) through distributions, hazard ratios for mortality, and relationships with future physical functioning. MWI-ICD exhibited the broadest distribution and most unique values (5891). Left censoring was most pronounced for Charlson (34.3% score = 0) and Elixhauser (13.1% score = 0) vs MWI (5.0% score = 0). Hazard ratios and concordance (C)-statistics for mortality across extreme quartiles were similar for MWI-ICD, Elixhauser, and Charlson but lower for disease count and the HRQOL-CI. For physical functioning, MWI-ICD yielded the greatest contrast across extreme quartiles and overall coefficient of determination (R2 ). MWI-ICD was significantly associated with mortality and future physical functioning and comparable with established metrics for mortality prediction although not weighted to mortality. MWI-ICD successfully captures diseases accumulation and functioning in claims data. J Am Geriatr Soc 68:999-1006, 2020.