Comparing the Centers for Medicare and Medicaid Services (CMS) enrollment data death dates to the National Death Index (NDI).

PURPOSE: In the United States, the National Death Index (NDI) is the most complete source of death information, while epidemiologic studies with mortality outcomes often rely on U.S. Medicare data for outcome ascertainment. The purpose of this study was to assess the agreement of death information between the Centers for Medicare & Medicaid Services (CMS) Medicare enrolment data and NDI. METHODS: Using Medicare and NDI data from 1999 through 2016, we identified Medicare beneficiaries who were reported dead in the CMS Medicare enrolment database (EDB) and Common Medicare Environment (CME), linked these beneficiaries to the NDI using CMS Health Insurance Claim number, and compared death dates between the two data sources. To assess agreement between our data sources, we calculated kappa scores; where a kappa of 1 indicates perfect agreement and a kappa of 0 indicates agreement equivalent to chance. We also examined CMS to NDI linkage and death date matching for stability over time. RESULTS: Of the 36 785 640, Medicare beneficiaries reported dead in CMS enrollment data from 1999 to 2016, 97.5% were linked to the NDI. A kappa score of 0.98 showed a near perfect agreement between NDI and CMS reported deaths. The percentage of linked cases exactly matching on death dates increased from 94.8% in 1999 to 99.4% in 2016. CONCLUSIONS: Our findings suggest strong concordance between death dates as recorded by CMS enrollment data and the NDI in the entire Medicare population.

Recombinant Zoster Vaccine (Shingrix): Real-World Effectiveness in the First 2 Years Post-Licensure.

BACKGROUND: Shingrix (recombinant zoster vaccine) was licensed to prevent herpes zoster, dispensed as 2 doses given 2-6 months apart among adults aged ≥50 years. Clinical trials yielded efficacy of >90% for confirmed herpes zoster, but post-market performance has not been evaluated. Efficacy of a single dose and a delayed second dose and efficacy among persons with autoimmune or immunosuppressive conditions have not been studied. We aimed to assess post-market vaccine effectiveness of Shingrix. METHODS: We conducted a cohort study among Medicare Part D community-dwelling beneficiaries aged >65 years. Herpes zoster was identified using a medical office visit diagnosis with treatment, and postherpetic neuralgia was identified using a validated algorithm. We used inverse probability of treatment weighting to improve cohort balance and marginal structural models to estimate hazard ratios. RESULTS: We found a vaccine effectiveness of 70.1% (95% confidence interval [CI], 68.6-71.5) and 56.9% (95% CI, 55.0-58.8) for 2 and 1 doses, respectively. The 2-dose vaccine effectiveness was not significantly lower for beneficiaries aged >80 years, for second doses received at ≥180 days, or for individuals with autoimmune conditions. The vaccine was also effective among individuals with immunosuppressive conditions. Two-dose vaccine effectiveness against postherpetic neuralgia was 76.0% (95% CI, 68.4-81.8). CONCLUSIONS: This large real-world observational study of the effectiveness of Shingrix demonstrates the benefit of completing the 2-dose regimen. Second doses administered beyond the recommended 6 months did not impair effectiveness. Our effectiveness estimates were lower than the clinical trials estimates, likely due to differences in outcome specificity.

Comparative Effectiveness of Influenza Vaccines Among US Medicare Beneficiaries Ages 65 Years and Older During the 2019-2020 Season.

BACKGROUND: Approximately 50 000 influenza-associated deaths occur annually in the United States, overwhelmingly among individuals aged ≥65 years. Although vaccination is the primary prevention tool, investigations have shown low vaccine effectiveness (VE) in recent years, particularly among the elderly. We analyzed the relative VE (RVE) of all influenza vaccines among Medicare beneficiaries aged ≥65 years to prevent influenza hospital encounters during the 2019-2020 season. METHODS: Retrospective cohort study using Poisson regression and inverse probability of treatment weighting (IPTW). Exposures included egg-based high-dose trivalent (HD-IIV3), egg-based adjuvanted trivalent (aIIV3), egg-based standard dose (SD) quadrivalent (IIV4), cell-based SD quadrivalent (cIIV4), and recombinant quadrivalent (RIV4) influenza vaccines. RESULTS: We studied 12.7 million vaccinated beneficiaries. Following IPTW, cohorts were well balanced for all covariates and health-seeking behavior indicators. In the adjusted analysis, RIV4 (RVE, 13.3%; 95% CI, 7.4-18.9%), aIIV3 (RVE, 8.2%; 95% CI, 4.2-12.0%), and HD-IIV3 (RVE, 6.8%; 95% CI, 3.3-10.1%) were significantly more effective in preventing hospital encounters than the reference egg-based SD IIV4, while cIIV4 was not significantly more effective than IIV4 (RVE, 2.8%; 95% CI, -2.8%, 8.2%). Our results were consistent across all analyses. CONCLUSIONS: In this influenza B-Victoria and A(H1N1)-dominated season, RIV4 was moderately more effective than other vaccines, while HD-IIV3 and aIIV3 were more effective than the IIV4 vaccines, highlighting the contributions of antigen amount and adjuvant use to VE. Egg adaptation likely did not substantially affect our RVE evaluation. Our findings, specific to the 2019-2020 season, should be evaluated in other studies using virological case confirmation.

Sepsis Among Medicare Beneficiaries: 4. Precoronavirus Disease 2019 Update January 2012-February 2020.

OBJECTIVES: To provide updated information on the burdens of sepsis during acute inpatient admissions for Medicare beneficiaries. DESIGN: Analysis of paid Medicare claims via the Centers for Medicare and Medicaid Services DataLink Project. SETTING: All U.S. acute-care hospitals, excluding federally operated hospitals (Veterans Administration and Defense Health Agency). PATIENTS: All Medicare beneficiaries, January 2012-February 2020, with an explicit sepsis diagnostic code assigned during an inpatient admission. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The count of Medicare Part A/B (fee-for-service) plus Medicare Advantage inpatient sepsis admissions rose from 981,027 (CY2012) to 1,700,433 (CY 2019). The proportion of total admissions with sepsis in the Medicare Advantage population rose from 21.43% to 35.39%, reflecting the increasing beneficiary proportion enrolled in Medicare Advantage. In CY2019, 6-month mortality rates in Medicare fee-for-service beneficiaries for sepsis continued to decline, but remained high: 59.9% for septic shock, 35.5% for severe sepsis, 30.8% for sepsis attributed to a specific organism, and 26.5% for unspecified sepsis. Total fee-for-service-only inpatient hospital costs rose from $17.79B (CY2012) to $22.98B (CY2019). We estimated that the aggregate cost of sepsis hospital care for the entire U.S. population was at least $57.47B in 2019. Inclusion of 14 months' (January 2019-February 2020) newer data exposed new trends: the cost per patient, number of admissions, and fraction of patients with sepsis labeled as present on admission inflected around November 2015, coincident with the change to International Classification of Diseases, 10th Edition, and introduction of the Severe Sepsis and Septic Shock Management Bundle (SEP-1) metric. CONCLUSIONS: Sepsis among Medicare beneficiaries precoronavirus disease 2019 imposed immense burdens upon patients, their families, and the taxpayers.

Risk of Covid-19-Related Hospitalization and More Severe Outcomes in Medicare Beneficiaries Treated with Renin-Angiotensin-Aldosterone System Inhibitors for Hypertension.

BACKGROUND: There are theoretical concerns that angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) could increase the risk of severe Covid-19. OBJECTIVE: To determine if ACEIs and ARBs are associated with an increased risk of Covid-19 hospitalization overall, or hospitalization involving intensive care unit (ICU) admission, invasive mechanical ventilation, or death. DESIGN: Observational case-control study. PARTICIPANTS: Medicare beneficiaries aged ≥ 66 years with hypertension, treated with ACEIs, ARBs, calcium channel blockers (CCBs), or thiazide diuretics. MAIN MEASURES: Adjusted odds ratios (OR) and 95% confidence intervals (CI) for the outcomes of Covid-19 hospitalization, or hospitalization involving ICU admission, invasive mechanical ventilation, or death. RESULTS: A total of 35,300 cases of hospitalized Covid-19 were matched to 228,228 controls on calendar date and neighborhood of residence. The median age of cases was 79 years, 57.4% were female, and the median duration of hospitalization was 8 days (interquartile range 5-12). ACEIs and ARBs were associated with a slight reduction in Covid-19 hospitalization risk compared with treatment with other first-line antihypertensives (OR for ACEIs 0.95, 95% CI 0.92-0.98; OR for ARBs 0.94, 95% CI 0.90-0.97). Similar results were obtained for hospitalizations involving ICU admission, invasive mechanical ventilation, or death. There were no meaningful differences in risk for ACEIs compared with ARBs. In an analysis restricted to monotherapy with a first-line agent, CCBs were associated with a small increased risk of Covid-19 hospitalization compared with ACEIs (OR 1.09, 95% CI 1.04-1.14), ARBs (OR 1.10, 95% CI 1.05-1.15), or thiazide diuretics (OR 1.11, 95% CI 1.03-1.19). CONCLUSIONS: ACEIs and ARBs were not associated with an increased risk of Covid-19 hospitalization or with hospitalization involving ICU admission, invasive mechanical ventilation, or death. The finding of a small increased risk of Covid-19 hospitalization with CCBs was unexpected and could be due to residual confounding.

Trends in Erythropoiesis-stimulating agent use and blood transfusions for chemotherapy-induced anemia throughout FDA's risk evaluation and mitigation strategy lifecycle.

PURPOSE: Erythropoiesis-stimulating agents (ESAs), indicated for treating some patients with chemotherapy-induced anemia (CIA), may increase the risk of tumor progression and mortality. FDA required a Risk Evaluation and Mitigation Strategy (REMS) to mitigate these risks. We assessed REMS impact on ESA administration and red blood cell (RBC) transfusion as surrogate metrics for REMS effectiveness. METHODS: Retrospective cohort study including data from January 1, 2006 to December 31, 2018 for beneficiaries ≥65 years enrolled in Centers for Medicare & Medicaid Services (CMS) Medicare Parts A/B with a cancer diagnosis; patients with other indications for ESA use were excluded. Study time was divided into five periods demarcated by issuance of CMS National Coverage Determination (NCD) (Pre-NCD, Pre-REMS) and REMS milestones (Grace Period, REMS, post-REMS). Study outcomes were monthly proportion of chemotherapy episodes (CTEs) with concomitant ESA administration, with post-CTE ESA administration, and with RBC transfusions. RESULTS: Of 1 778 855 beneficiaries treated with CT, 308742 received concomitant ESA for CIA. The proportion of CTEs with concomitant and post-CTE ESA administration decreased Pre-REMS (9.0 percentage points [pp] and 3.5 pp, respectively). There were no significant post-REMS changes in the proportion of CTEs with concomitant (0.0 pp) and post-CTE ESA administration (0.1 pp). Fluctuation in RBC transfusions was <4 pp throughout the study period. CONCLUSIONS: Medicare beneficiaries showed a substantive decrease in ESA administration after NCD, with minimal impact by the REMS and its removal. Small changes in RBC transfusion over the study period were likely due to a national secular trend.

Sepsis Among Medicare Beneficiaries: 1. The Burdens of Sepsis, 2012-2018.

OBJECTIVES: To provide contemporary estimates of the burdens (costs and mortality) associated with acute inpatient Medicare beneficiary admissions for sepsis. DESIGN: Analysis of paid Medicare claims via the Centers for Medicare & Medicaid Services DataLink Project. SETTING: All U.S. acute care hospitals, excluding federally operated hospitals (Veterans Administration and Defense Health Agency). PATIENTS: All Medicare beneficiaries, 2012-2018, with an inpatient admission including one or more explicit sepsis codes. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Total inpatient hospital and skilled nursing facility admission counts, costs, and mortality over time. From calendar year (CY)2012-CY2018, the total number of Medicare Part A/B (fee-for-service) beneficiaries with an inpatient hospital admission associated with an explicit sepsis code rose from 811,644 to 1,136,889. The total cost of inpatient hospital admission including an explicit sepsis code for those beneficiaries in those calendar years rose from $17,792,657,303 to $22,439,794,212. The total cost of skilled nursing facility care in the 90 days subsequent to an inpatient hospital discharge that included an explicit sepsis code for Medicare Part A/B rose from $3,931,616,160 to $5,623,862,486 over that same interval. Precise costs are not available for Medicare Part C (Medicare Advantage) patients. Using available federal data sources, we estimated the aggregate cost of inpatient admissions and skilled nursing facility admissions for Medicare Advantage patients to have risen from $6.0 to $13.4 billion over the CY2012-CY2018 interval. Combining data for fee-for-service beneficiaries and estimates for Medicare Advantage beneficiaries, we estimate the total inpatient admission sepsis cost and any subsequent skilled nursing facility admission for all (fee-for-service and Medicare Advantage) Medicare patients to have risen from $27.7 to $41.5 billion. Contemporary 6-month mortality rates for Medicare fee-for-service beneficiaries with a sepsis inpatient admission remain high: for septic shock, approximately 60%; for severe sepsis, approximately 36%; for sepsis attributed to a specific organism, approximately 31%; and for unspecified sepsis, approximately 27%. CONCLUSION: Sepsis remains common, costly to treat, and presages significant mortality for Medicare beneficiaries.

Sepsis Among Medicare Beneficiaries: 2. The Trajectories of Sepsis, 2012-2018.

OBJECTIVES: To distinguish characteristics of Medicare beneficiaries who will have an acute inpatient admission for sepsis from those who have an inpatient admission without sepsis, and to describe their further trajectories during and subsequent to those inpatient admissions. DESIGN: Analysis of paid Medicare claims via the Centers for Medicare and Medicaid Services DataLink Project. SETTING: All U.S. acute care hospitals, excepting federal hospitals (Veterans Administration and Defense Health Agency). PATIENTS: Medicare beneficiaries, 2012-2018, with an inpatient hospital admission including one or more explicit sepsis codes. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Prevalent diagnoses in the year prior to the inpatient admission; healthcare contacts in the week prior to the inpatient admission; discharges, transfers, readmissions, and deaths (trajectories) for 6 months following discharge from the inpatient admission. Beneficiaries with no sepsis inpatient hospital admission for a year prior to an index hospital admission for sepsis were nearly indistinguishable by accumulated diagnostic codes from beneficiaries who had an index hospital admission without sepsis. Although the timing of healthcare services in the week prior to inpatient hospital admission was similar among beneficiaries who would be admitted for sepsis versus those whose inpatient admission did not include a sepsis code, the setting differed: beneficiaries destined for a sepsis admission were more likely to have received skilled nursing or unskilled nursing (e.g., nursing aide for activities of daily living) care. In contrast, comparing beneficiaries who had been free of any inpatient admission for an entire year and then required an inpatient admission, acute inpatient stays that included a sepsis code led to more than three times as many deaths within 1 week of discharge, with more admissions to skilled nursing facilities and fewer discharges to home. Comparing all beneficiaries who were admitted to a skilled nursing facility after an inpatient hospital admission, those who had sepsis coded during the index admission were more likely to die in the skilled nursing facility; more likely to be readmitted to an acute inpatient hospital and subsequently die in that setting; or if they survive to discharge from the skilled nursing facility, they are more likely to go next to a custodial nursing home. CONCLUSIONS: Although Medicare beneficiaries destined for an inpatient hospital admission with a sepsis code are nearly indistinguishable by other diagnostic codes from those whose admissions will not have a sepsis code, their healthcare trajectories following the admission are worse. This suggests that an inpatient stay that included a sepsis code not only identifies beneficiaries who were less resilient to infection but also signals increased risk for worsening health, for mortality, and for increased use of advanced healthcare services during and postdischarge along with an increased likelihood of an inpatient hospital readmission.

Sepsis Among Medicare Beneficiaries: 3. The Methods, Models, and Forecasts of Sepsis, 2012-2018.

OBJECTIVE: To evaluate the impact of sepsis, age, and comorbidities on death following an acute inpatient admission and to model and forecast inpatient and skilled nursing facility costs for Medicare beneficiaries during and subsequent to an acute inpatient sepsis admission. DESIGN: Analysis of paid Medicare claims via the Centers for Medicare & Medicaid Services DataLink Project (CMS) and leveraging the CMS-Hierarchical Condition Category risk adjustment model. SETTING: All U.S. acute care hospitals, excepting federal hospitals (Veterans Administration and Defense Health Agency). PATIENTS: All Part A/B (fee-for-service) Medicare beneficiaries with an acute inpatient admission in 2017 and who had no inpatient sepsis admission in the prior year. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Logistic regression models to determine covariate risk contribution to death following an acute inpatient admission; conventional regression to predict Medicare beneficiary sepsis costs. Using the Hierarchical Condition Category risk adjustment model to illuminate influence of illness on outcome of inpatient admissions, representative odds ratios (with 95% CIs) for death within 6 months of an admission (referenced to beneficiaries admitted but without the characteristic) are as follows: septic shock, 7.27 (7.19-7.35); metastatic cancer and acute leukemia (Hierarchical Condition Category 8), 6.76 (6.71-6.82); all sepsis, 2.63 (2.62-2.65); respiratory arrest (Hierarchical Condition Category 83), 2.55 (2.35-2.77); end-stage liver disease (Hierarchical Condition Category 27), 2.53 (2.49-2.56); and severe sepsis without shock, 2.48 (2.45-2.51). Models of the cost of sepsis care for Medicare beneficiaries forecast arise approximately 13% over 2 years owing the rising enrollments in Medicare offset by the cost of care per admission. CONCLUSIONS: A sepsis inpatient admission is associated with marked increase in risk of death that is comparable to the risks associated with inpatient admissions for other common and serious chronic illnesses. The aggregate costs of sepsis care for Medicare beneficiaries will continue to increase.

Comparison of propensity score methods for pre-specified subgroup analysis with survival data.

Examining medical products' benefits and risks in different population subsets is often necessary for informing public health decisions. In observational cohort studies, safety analyses by pre-specified subgroup can be powered, and are informative about different population subsets' risks if the study designs or analyses adequately control for confounding. However, few guidelines exist on how to simultaneously control for confounding and conduct subgroup analyses. In this simulation study, we evaluated the performance, in terms of bias, efficiency and coverage, of six propensity score methods in 24 scenarios by estimating subgroup-specific hazard ratios of average treatment effect in the treated with Cox regression models. The subgroup analysis methods control for confounding either by propensity score matching or by inverse probability treatment weighting. These methods vary as to whether they subset information or borrow it across subgroups to estimate the propensity score. Simulation scenarios varied by size of subgroup, strength of association of subgroup with exposure, strength of association of subgroup with outcome (simulated survival), and outcome incidence. Results indicated that subsetting the data by the subgrouping variable, to estimate the propensity score and hazard ratio, has the smallest bias, far exceeding any penalty in precision. Moreover, weighting methods pay a heavier price in bias than do matching methods when the propensity score model is misspecified and the subgrouping variable is a strong confounder.

Zostavax vaccine effectiveness among US elderly using real-world evidence: Addressing unmeasured confounders by using multiple imputation after linking beneficiary surveys with Medicare claims.

PURPOSE: Medicare claims can provide real-world evidence (RWE) to support the Food and Drug Administration's ability to conduct postapproval studies to validate products' safety and effectiveness. However, Medicare claims do not contain comprehensive information on some important sources of bias. Thus, we piloted an approach using the Medicare Current Beneficiary Survey (MCBS), a nationally representative survey of the Medicare population, to (a) assess cohort balance with respect to unmeasured confounders in a herpes zoster vaccine (HZV) effectiveness claims-based study and (b) augment Medicare claims with MCBS data to include unmeasured covariates. METHODS: We reanalyzed data from our published HZV effectiveness Medicare analysis, using linkages to MCBS to obtain information on impaired mobility, education, and health-seeking behavior. We assessed survey variable balance between the matched cohorts and selected imbalanced variables for model adjustment, applying multiple imputation by chained equations (MICE) to impute these potential unmeasured confounders. RESULTS: The original HZV effectiveness study cohorts appeared well balanced with respect to variables we selected from the MCBS. Our imputed results showed slight shifts in HZV effectiveness point estimates with wider confidence intervals, but indicated no statistically significant differences from the original study estimates. CONCLUSIONS: Our innovative use of linked survey data to assess cohort balance and our imputation approach to augment Medicare claims with MCBS data to include unmeasured covariates provide potential solutions for addressing bias related to unmeasured confounding in large database studies, thus adding new tools for RWE studies.

Cardiovascular, bleeding, and mortality risks in elderly Medicare patients treated with dabigatran or warfarin for nonvalvular atrial fibrillation.

BACKGROUND: The comparative safety of dabigatran versus warfarin for treatment of nonvalvular atrial fibrillation in general practice settings has not been established. METHODS AND RESULTS: We formed new-user cohorts of propensity score-matched elderly patients enrolled in Medicare who initiated dabigatran or warfarin for treatment of nonvalvular atrial fibrillation between October 2010 and December 2012. Among 134 414 patients with 37 587 person-years of follow-up, there were 2715 primary outcome events. The hazard ratios (95% confidence intervals) comparing dabigatran with warfarin (reference) were as follows: ischemic stroke, 0.80 (0.67-0.96); intracranial hemorrhage, 0.34 (0.26-0.46); major gastrointestinal bleeding, 1.28 (1.14-1.44); acute myocardial infarction, 0.92 (0.78-1.08); and death, 0.86 (0.77-0.96). In the subgroup treated with dabigatran 75 mg twice daily, there was no difference in risk compared with warfarin for any outcome except intracranial hemorrhage, in which case dabigatran risk was reduced. Most patients treated with dabigatran 75 mg twice daily appeared not to have severe renal impairment, the intended population for this dose. In the dabigatran 150-mg twice daily subgroup, the magnitude of effect for each outcome was greater than in the combined-dose analysis. CONCLUSIONS: In general practice settings, dabigatran was associated with reduced risk of ischemic stroke, intracranial hemorrhage, and death and increased risk of major gastrointestinal hemorrhage compared with warfarin in elderly patients with nonvalvular atrial fibrillation. These associations were most pronounced in patients treated with dabigatran 150 mg twice daily, whereas the association of 75 mg twice daily with study outcomes was indistinguishable from warfarin except for a lower risk of intracranial hemorrhage with dabigatran.

Dialysis care and death following Hurricane Sandy.

BACKGROUND: Hurricane Sandy affected access to critical health care infrastructure. Patients with end-stage renal disease (ESRD) historically have experienced problems accessing care and adverse outcomes during disasters. STUDY DESIGN: Retrospective cohort study with 2 comparison groups. SETTING & PARTICIPANTS: Using Centers for Medicare & Medicaid Services claims data, we assessed the frequency of early dialysis, emergency department (ED) visits, hospitalizations, and 30-day mortality for patients with ESRD in Sandy-affected areas (study group) and 2 comparison groups: (1) patients with ESRD living in states unaffected by Sandy during the same period and (2) patients with ESRD living in the Sandy-affected region a year prior to the hurricane (October 1, 2011, through October 30, 2011). FACTOR: Regional variation in dialysis care patterns and mortality for patients with ESRD in New York City and the State of New Jersey. MEASUREMENTS: Frequency of early dialysis, ED visits, hospitalizations, and 30-day mortality. RESULTS: Of 13,264 study patients, 59% received early dialysis in 70% of the New York City and New Jersey dialysis facilities. The ED visit rate was 4.1% for the study group compared with 2.6% and 1.7%, respectively, for comparison groups 1 and 2 (both P<0.001). The hospitalization rate for the study group also was significantly higher than that in either comparison group (4.5% vs 3.2% and 3.8%, respectively; P<0.001 and P<0.003). 23% of study group patients who visited the ED received dialysis in the ED compared with 9.3% and 6.3% in comparison groups 1 and 2, respectively (both P<0.001). The 30-day mortality rate for the study group was slightly higher than that for either comparison group (1.83% vs 1.47% and 1.60%, respectively; P<0.001 and P=0.1). LIMITATIONS: Lack of facility level damage and disaster-induced power outage severity data. CONCLUSIONS: Nearly half the study group patients received early dialysis prior to Sandy's landfall. Poststorm increases in ED visits, hospitalizations, and 30-day mortality were found in the study group, but not in the comparison groups.

Comparative Risk of Anaphylactic Reactions Associated With Intravenous Iron Products.

IMPORTANCE: All intravenous (IV) iron products are associated with anaphylaxis, but the comparative safety of each product has not been well established. OBJECTIVE: To compare the risk of anaphylaxis among marketed IV iron products. DESIGN, SETTING, AND PARTICIPANTS: Retrospective new user cohort study of IV iron recipients (n = 688,183) enrolled in the US fee-for-service Medicare program from January 2003 to December 2013. Analyses involving ferumoxytol were limited to the period January 2010 to December 2013. EXPOSURES: Administrations of IV iron dextran, gluconate, sucrose, or ferumoxytol as reported in outpatient Medicare claims data. MAIN OUTCOMES AND MEASURES: Anaphylaxis was identified using a prespecified and validated algorithm defined with standard diagnosis and procedure codes and applied to both inpatient and outpatient Medicare claims. The absolute and relative risks of anaphylaxis were estimated, adjusting for imbalances among treatment groups. RESULTS: A total of 274 anaphylaxis cases were identified at first exposure, with an additional 170 incident anaphylaxis cases identified during subsequent IV iron administrations. The risk for anaphylaxis at first exposure was 68 per 100,000 persons for iron dextran (95% CI, 57.8-78.7 per 100,000) and 24 per 100,000 persons for all nondextran IV iron products combined (iron sucrose, gluconate, and ferumoxytol) (95% CI, 20.0-29.5 per 100,000) , with an adjusted odds ratio (OR) of 2.6 (95% CI, 2.0-3.3; P < .001). At first exposure, when compared with iron sucrose, the adjusted OR of anaphylaxis for iron dextran was 3.6 (95% CI, 2.4-5.4); for iron gluconate, 2.0 (95% CI 1.2, 3.5); and for ferumoxytol, 2.2 (95% CI, 1.1-4.3). The estimated cumulative anaphylaxis risk following total iron repletion of 1000 mg administered within a 12-week period was highest with iron dextran (82 per 100,000 persons, 95% CI, 70.5- 93.1) and lowest with iron sucrose (21 per 100,000 persons, 95% CI, 15.3- 26.4). CONCLUSIONS AND RELEVANCE: Among patients in the US Medicare nondialysis population with first exposure to IV iron, the risk of anaphylaxis was highest for iron dextran and lowest for iron sucrose.

Incidence of endophthalmitis after corneal transplant or cataract surgery in a medicare population.

OBJECTIVE: To estimate the incidence of infectious endophthalmitis after corneal transplant or cataract surgery, to evaluate the trend of endophthalmitis during the study period, and to assess demographic risk factors for endophthalmitis after surgeries. DESIGN: A retrospective population-based cohort study. PARTICIPANTS AND CONTROLS: Study cohorts were derived from the Medicare claims databases, 2006 to 2011. Patients were continuously enrolled in Medicare Part A, Part B, and Part D. Patients undergoing corneal transplant or cataract surgery were identified using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) procedure codes. METHODS: Endophthalmitis was defined in 3 different ways: (1) using ICD-9-CM codes (sensitive definition), (2) combining ICD-9-CM codes with Current Procedural Terminology, Fourth Edition (CPT-4) codes (specific definition), or (3) combining ICD-9-CM codes with antifungal prescriptions for endophthalmitis caused by fungal infection. Demographic risk factors for endophthalmitis were examined using multivariate Cox models. MAIN OUTCOME MEASURES: Incidence rates of endophthalmitis were calculated and compared for each definition of endophthalmitis at 6-week and 6-month intervals after corneal transplant or cataract surgery. RESULTS: The infectious endophthalmitis incidence rates ranged from 0.11% to 1.05% in the corneal transplant cohort, 0.06% to 0.20% in the cataract surgery cohort, and 0.16% to 0.68% in the concurrent surgery cohort, depending on the definition and time interval after surgery. Compared with the cataract surgery cohort, the corneal transplant cohort had a higher adjusted hazard ratio (HR) of endophthalmitis within the 6-week postoperative interval (HR, 2.744; 95% confidence interval [CI], 1.544-4.880 in the sensitive definition and HR, 2.792; 95% CI, 1.146-6.802 in the specific definition) and within the 6-month postoperative interval (HR, 4.607; 95% CI, 3.144-6.752 for the sensitive definition and HR, 4.385; 95% CI, 2.245-8.566 for the specific definition). CONCLUSIONS: It is possible to monitor the trend of infectious endophthalmitis after corneal transplant or cataract surgery through examining Medicare claims databases as long as a consistent definition of endophthalmitis is used. The annual incidence of endophthalmitis was stable over time during the study period for both corneal transplant and cataract surgery procedures; however, there was a wider year-to-year variation for the corneal transplant cohort.

Cardiovascular and mortality risk in elderly Medicare beneficiaries treated with olmesartan versus other angiotensin receptor blockers.

PURPOSE: In the randomized trial, Randomized Olmesartan and Diabetes Microalbuminuria Prevention, acute cardiovascular death was increased nearly fivefold in diabetic patients treated with high-dose olmesartan, an angiotensin receptor blocker (ARB), compared with placebo. METHODS: Medicare beneficiaries were entered into new-user cohorts of olmesartan or other ARBs and followed on therapy for occurrence of acute myocardial infarction, stroke, or death. Analyses focused on specific subgroups defined by diabetes status, ARB dose, and duration of therapy. Hazard ratios (HR) with 95% confidence intervals (CIs) were estimated using Cox proportional hazards regression, with other ARBs as reference. RESULTS: A total of 158,054 olmesartan and 724,673 other ARB users were followed for 54,285 and 260,390 person-years, respectively, during which 9237 endpoint events occurred. Lower-dose olmesartan was not associated with increased risk for any endpoint, regardless of duration of use. High-dose olmesartan for 6 months or longer was associated with increased risk of death in patients with diabetes (HR 2.03, 95%CI 1.09-3.75, p = 0.02) and with reduced risk in nondiabetic patients (HR 0.46, 95%CI 0.24-0.86, p = 0.01). Some, but not all, sensitivity analyses suggested that selective prescribing of olmesartan to healthier patients (channeling bias) may have accounted for the reduced risk in nondiabetic patients. CONCLUSIONS: High-dose olmesartan was associated with an increased risk of death in diabetic patients treated for 6 months or longer and with a reduced risk of death in nondiabetic patients, when compared with use of other ARBs. This latter effect was probably because of selective prescribing of olmesartan to healthier patients, although effect modification cannot be excluded. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

Cardiovascular and mortality risks in older Medicare patients treated with varenicline or bupropion for smoking cessation: an observational cohort study.

PURPOSE: To compare cardiovascular and mortality risks in elderly patients treated with varenicline or bupropion for smoking cessation. METHODS: Elderly Medicare beneficiaries were entered into new-user cohorts of varenicline or bupropion for smoking cessation and followed on therapy for primary outcomes of acute myocardial infarction (AMI), stroke, mortality, and a composite of any of these events. Secondary outcomes were unstable angina, coronary revascularization, and a composite of any primary or secondary outcome event. Propensity score stratification was used to adjust for baseline differences in potential confounding factors. Hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated using Cox proportional hazards, with bupropion as reference. RESULTS: In cohorts of 74 824 varenicline and 14 133 bupropion users, there were 164 AMI, 96 stroke, 87 death, 317 primary composite, and 814 secondary composite events while on therapy. The HRs (95%CI) were 0.79 (0.50-1.24) for AMI, 1.27 (0.63-2.55) for stroke, 0.58 (0.30-1.13) for death, 0.84 (0.58-1.23) for the primary composite, and 0.92 (0.73-1.14) for the secondary composite. The risk of AMI or the primary composite outcome did not differ in subgroups defined by age, diabetes status, or presence of underlying ischemic heart disease. Only 30% of patients remained on either study drug beyond their first prescription. CONCLUSION: Cardiovascular and mortality risks were not increased in older patients treated with varenicline compared with bupropion for smoking cessation. A potential increase in the risk of stroke with varenicline could not be excluded. Treatment persistence with either drug was low. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

Use of an active surveillance system by the FDA to observe patterns of quinine sulfate use and adverse hematologic outcomes in CMS Medicare data.

PURPOSE: In 2005, the Food and Drug Administration approved Qualaquin (quinine) for treatment of malaria and later ordered unapproved quinine formulations off the market. In 2009, labeling for Qualaquin added a warning for use for leg cramps, as serious hematologic reactions could occur. We examined quinine use trends among Medicare beneficiaries focusing on indications for use and associations with adverse hematologic outcomes. METHODS: Medicare beneficiaries, aged 65 years and older, in 2006-2012, were included in incident quinine or comparator, diltiazem, cohorts if 183 days prior to dispensing, they were enrolled in Medicare, had no dispensing of quinine, diltiazem, ticlodipine, clopidogrel, and sulfonamide drugs, and had no diagnoses of thrombocytopenia, immune thrombocytopenic purpura (ITP), thrombotic microangiopathy (TMA), or hemolytic-uremic syndrome (HUS). Diagnoses of malaria or leg cramps were observed during 183 days prior to index dispensing. Outcomes of ITP, TMA, or HUS in inpatient or emergency room settings were then observed during drug use. RESULTS: Prevalent use of quinine decreased by 99%, from 419 675 to 6036 users during 2006-2012. Of 88 066 quinine users, 9 had diagnoses of malaria and 36 218 had leg cramps. Incidence rates (per 1000 person-years) for ITP were quinine 1.67 and diltiazem 0.40 [incidence rate ratio 4.2 (95% confidence interval 2.5, 6.5)], for TMA were quinine 0.23 and diltiazem 0.03 [incidence rate ratio 6.9 (95% confidence interval 1.3, 24.0)], and for HUS were quinine 0 and diltiazem 0.01. CONCLUSIONS: Use of quinine decreased substantially, although diagnoses of leg cramps persist. To our knowledge, this is the first demonstration of an association for quinine and ITP and TMA in claims data.

Candidate metrics for evaluating the impact of prescriber education on the safe use of extended-release/long-acting (ER/LA) opioid analgesics.

OBJECTIVE: The objective of this study was to develop metrics to assess opioid prescribing behavior as part of the evaluation of the Extended-Release/Long-Acting (ER/LA) Opioid Analgesic Risk Evaluation and Mitigation Strategies (REMS). DESIGN: Candidate metrics were selected using published guidelines, examined using sensitivity analyses, and applied to cross-sectional rolling cohorts of Medicare patients prescribed with extended-release oxycodone (ERO) between July 2, 2006 and July 1, 2011. Potential metrics included prescribing opioid-tolerant-only ER/LA opioid analgesics to non-opioid-tolerant patients, prescribing early fills to patients, and ordering drug screens. RESULTS: Proposed definitions for opioid tolerance were seven continuous days of opioid usage of at least 30 mg oxycodone equivalents, within the 7 days (primary) or 30 days (secondary) prior to first opioid-tolerant-only ERO prescription. Forty-four percent of opioid-tolerant-only ERO episodes met the primary opioid tolerance definition; 56% met the secondary definition. Fills were deemed "early" if a prescription was filled before 70% (primary) or 50% (secondary) of the prior prescription's days' supply was to be consumed. Five percent (primary) and 2% (secondary) of episodes had more than or equal to two early fills during treatment. At least one drug screen was billed in 14% of episodes. Stratified analyses indicated that older patients were less likely to be opioid tolerant at the time of the first opioid-tolerant-only ERO prescription. CONCLUSIONS: Investigators propose three metrics to monitor changes in prescribing behaviors for opioid analgesics that might be used to evaluate the ER/LA Opioid Analgesics REMS. Low frequencies of patients, particularly those >85 years, were likely to be opioid tolerant prior to receiving prescriptions for opioid-tolerant-only ERO.