Adrienne Faerber

Fifteen-Year Trends in Lower Limb Amputation, Revascularization, and Preventive Measures Among Medicare Patients

Although severe lower extremity peripheral arterial disease affects more than 12 million people in the United States,1,2 secular trends in the risk of amputation remain unexplored in recent years. Using national billing and survey data sets from the Centers for Medicare and Medicaid Services and the Behavioral Risk Factor Surveillance System, we examined trends in lower extremity amputation rates, diagnostic and therapeutic vascular procedures, and the use of preventive measures aimed at limiting the use of amputation procedures in the United States between 1996 and 2011.

A pilot study for long-term outcome assessment after aortic aneurysm repair using Vascular Quality Initiative data matched to Medicare claims

Objective: Accurate and complete long‐term postoperative outcome data are critical to improving value in health care delivery. The Society for Vascular Surgery Vascular Quality Initiative (VQI) is an important tool to achieve this goal in vascular surgery. To improve on the capture of long‐term outcomes after vascular surgery procedures for patients in the VQI, we sought to match VQI data to Medicare claims for comprehensive capture of major clinical outcomes in the first several years after vascular procedures. Methods: Patient and procedure characteristics for abdominal aortic aneurysm procedures captured in the Society for Vascular Surgery VQI between January 1, 2002, and December 31, 2013, were matched to Medicare claims data using an indirect identifier methodology. Late outcomes captured in the VQI and in Medicare claims were compared. Results: Matching procedures yielded 9895 endovascular aneurysm repair (EVAR) patients (82.4% of eligible VQI patients) and 3405 open aneurysm repair (OAR) patients (74.4% of eligible). Comparison of patients who did and did not match to a Medicare claim demonstrated similar patient and procedure characteristics. Evaluation of late outcomes revealed good patient‐level agreement on mortality for both EVAR (&kgr;, 0.64) and OAR (&kgr;, 0.82). Postoperative reintervention rates demonstrated lower agreement for both EVAR (&kgr;, 0.26) and OAR (&kgr;, 0.16). Conclusions: This work demonstrates the feasibility of an algorithm using indirect identifiers to match VQI patients and procedures to Medicare claims data. The refinement of this strategy will focus on establishing and improving algorithms related to identifying and categorizing late events after EVAR and may serve as a mechanism to ensure that the best quality follow‐up information is achieved within the VQI.

US Food and Drug Administration and Design of Drug Approval Studies

US Food and Drug Administration and Design of Drug Approval Studies To enhance protocol quality, federal regulations encourage but do not require meetings between pharmaceutical companies and the US Food and Drug Administration (FDA) during the design phase of pivotal studies assessing drug efficacy and safety for the proposed indication.1 These meetings often generate FDA recommendations for improving research, although companies are not bound to follow them. Companies can also request special protocol assessments (SPAs) in which the FDA formally reviews the protocol.2 When the FDA endorses an SPA, it agrees not to object to study design, outcomes, or analytic issues when it ultimately reviews the drug for approval, provided the company conducted the trial as planned. We describe interactions between the FDA and pharmaceutical companies to learn how the FDA influences pivotal study design of new drugs.

Consistency of Hemoglobin A1c Testing and Cardiovascular Outcomes in Medicare Patients With Diabetes.

Background Annual hemoglobin A1c testing is recommended for patients with diabetes mellitus. However, it is unknown how consistently patients with diabetes mellitus receive hemoglobin A1c testing over time, or whether testing consistency is associated with adverse cardiovascular outcomes. Methods and Results We identified 1 574 415 Medicare patients (2002–2012) with diabetes mellitus over the age of 65. We followed each patient for a minimum of 3 years to determine their consistency in hemoglobin A1C testing, using 3 categories: low (testing in 0 or 1 of 3 years), medium (testing in 2 of 3 years), and high (testing in all 3 years). In unweighted and inverse propensity‐weighted cohorts, we examined associations between testing consistency and major adverse cardiovascular events, defined as death, myocardial infarction, stroke, amputation, or the need for leg revascularization. Overall, 70.2% of patients received high‐consistency testing, 17.6% of patients received medium‐consistency testing, and 12.2% of patients received low‐consistency testing. When compared to high‐consistency testing, low‐consistency testing was associated with a higher risk of adverse cardiovascular events or death in unweighted analyses (hazard ratio [HR]=1.21; 95% CI, 1.20–1.23; P<0.001), inverse propensity‐weighted analyses (HR=1.16; 95% CI, 1.15–1.17; P<0.001), and weighted analyses limited to patients who had at least 4 physician visits annually (HR=1.15; 95% CI, 1.15–1.16; P<0.001). Less‐consistent testing was associated with worse results for each cardiovascular outcome and in analyses using all years as the exposure. Conclusions Consistent annual hemoglobin A1c testing is associated with fewer adverse cardiovascular outcomes in this observational cohort of Medicare patients of diabetes mellitus.

Does Rapid Diffusion of HbA1c Testing Affect Amputation Rates

Background: The association of speed of diffusion of Hemoglobin A1C (hbA1c) testing with temporal changes in outcomes of primary importance to patients with diabetes, such as amputation, remains an issue of debate. We investigated these correlations. Methods: We performed a retrospective cohort study of diabetics, based on Medicare fee-for-service claims data from 2002 to 2012. We examined the association of the rate of diffusion of HbA1c testing with changes in amputation rates. Our unit of analysis was the hospital referral region (HRR), a definition of tertiary care markets defined in the Dartmouth Atlas of Health Care. Results: From the 11 096 270 diabetics followed in our study for a mean follow-up of 4.1 years, 106 340 (0.96%) underwent lower extremity amputations. The speed of diffusion of HbA1c testing had a moderate association with the speed of diffusion of lower extremity amputations, after adjusting for multiple factors including baseline regional amputation and testing rates (adjusted difference, −0.7%; 95% confidence interval, −1.0% to −0.3%). The risk-adjusted HRR-level speed of diffusion of testing demonstrated significant correlation with the risk-adjusted HRR-level diffusion of amputations (r = .250, P < .001). Conclusions: We observed a moderate association of the speed of diffusion of HbA1c testing with the speed of diffusion of lower extremity amputations among Medicare patients with diabetes. Improvements in performance on quality metrics such as HbA1c testing may not immediately translate into tangible patient outcomes.