Retrospective Analysis of Prescription Drug Claims, with Applications to Risk Score Construction and Treatment of Heart Failure in End Stage Renal Disease

University of Minnesota Ph.D. dissertation. May 2015. Major: Epidemiology. Advisor: Sue Duval. 1 computer file (PDF); v, 176 pages.There are more than 450,000 patients receiving chronic dialysis in the US. Patients with end stage renal disease are statutorily eligible for Medicare, regardless of age. Due to high prevalence of poverty, many are dually enrolled in Medicare and Medicaid and are automatically enrolled in Part D (prescription drug insurance). This dissertation comprises 3 studies involving prescription drug claims in dialysis patients. In the first study, I constructed and validated risk scores based on Part D claims in incident and prevalent dialysis patients. Comorbidity indices derived from administrative data are typically based on diagnosed diseases, but the middling sensitivity of diagnosis codes limits the accuracy of these indices. In contrast, prescription drug claims are bona fide evidence of medication dispensation. I investigated aspects of newly developed scores and compared their performance in predicting risk with older scores based on diseases. In the second study, I assessed the efficacy and safety of pharmacologic inhibition of the renin-angiotensin system in dialysis patients with congestive heart failure. ACE inhibitors and ARBs are recommended for the treatment of heart failure with reduced ejection fraction. However, pivotal clinical trials all excluded patients on dialysis. I used propensity score matching to identify matched controls for treated patients that were newly dispensed an ACE inhibitor or ARB shortly after discharge from hospitalization for heart failure. I described the relative hazards of mortality and morbidity with treatment. In the third study, I assessed relative hazards of death and hospitalization associated with 4 ACE inhibitors and 2 ARBs in dialysis patients with congestive heart failure. The existence of class effects is generally presumed, but not necessarily supported by evidence regarding clinical outcomes. I showed that the most widely used agent (lisinopril) in this patient population is not necessarily associated with best outcomes

The Effects of Repetitive Drop Jumps on Impact Phase Joint Kinematics and Kinetics

The purpose of the study was to investigate the effects of fatigue on lower extremity joint kinematics, and kinetics during repetitive drop jumps. Twelve recreationally active males (n = 6) and females (n = 6) (nine used for analysis) performed repetitive drop jumps until they could no longer reach 80% of their initial drop jump height. Kinematic and kinetic variables were assessed during the impact phase (100 ms) of all jumps. Fatigued landings were performed with increased knee extension, and ankle plantar flexion at initial contact, as well as increased ankle range of motion during the impact phase. Fatigue also resulted in increased peak ankle power absorption and increased energy absorption at the ankle. This was accompanied by an approximately equal reduction in energy absorption at the knee. While the knee extensors were the muscle group primarily responsible for absorbing the impact, individuals compensated for increased knee extension when fatigued by an increased use of the ankle plantar flexors to help absorb the forces during impact. Thus, as fatigue set in and individuals landed with more extended lower extremities, they adopted a landing strategy that shifted a greater burden to the ankle for absorbing the kinetic energy of the impact

Comparative mortality of hemodialysis patients at for-profit and not-for-profit dialysis facilities in the United States, 1998 to 2003: A retrospective analysis

<p>Abstract</p> <p>Background</p> <p>Concern lingers that dialysis therapy at for-profit (versus not-for-profit) hemodialysis facilities in the United States may be associated with higher mortality, even though 4 of every 5 contemporary dialysis patients receive therapy in such a setting.</p> <p>Methods</p> <p>Our primary objective was to compare the mortality hazards of patients initiating hemodialysis at for-profit and not-for-profit centers in the United States between 1998 and 2003. For-profit status of dialysis facilities was determined after subjects received 6 months of dialysis therapy, and mean follow-up was 1.7 years.</p> <p>Results</p> <p>Of the study population (<it>N </it>= 205,076), 79.9% were dialyzed in for-profit facilities after 6 months of dialysis therapy. Dialysis at for-profit facilities was associated with higher urea reduction ratios, hemoglobin levels (including levels above 12 and 13 g/dL [120 and 130 g/L]), epoetin doses, and use of intravenous iron, and less use of blood transfusions and lower proportions of patients on the transplant waiting-list (<it>P </it>< 0.05). Patients dialyzed at for-profit and at not-for-profit facilities had similar mortality risks (adjusted hazards ratio 1.02, 95% CI 0.99–1.06, <it>P </it>= 0.143).</p> <p>Conclusion</p> <p>While hemodialysis treatment at for-profit and not-for-profit dialysis facilities is associated with different patterns of clinical benchmark achievement, mortality rates are similar.</p

Nocturnal home hemodialysis with low-flow dialysate: Retrospective analysis of the first European patients.

Despite mounting evidence that increased frequency and duration of hemodialysis (HD) improves outcomes, less than 1% of HD patients worldwide receive nocturnal hemodialysis (NHD). Many perceived barriers exist to providing NHD and increasing its provision. A retrospective analysis of nocturnal therapy using a low-flow dialysate system in 4 European centers for a minimum of 12 months, with data collected on patient demographics, training times, safety features, medications, and biochemical parameters at baseline and at 6 and 12 months. Data were collected on 21 patients, with 12-month analysis available for 20 patients. Mean dialysis duration was 28 hours per week, with most dialysis on an alternate night regimen using 50-60 L of dialysate per session. All vascular access types were represented, and low molecular weight heparin was used as a bolus. All biochemical parameters met European standards, with a trend for improvement in standardized Kt/V, phosphate, hemoglobin, and albumin. There was a significant reduction in phosphate binder usage and a reduction in blood pressure medication. Training time was 9.6 sessions for independence at home, with 2 additional sessions to transition to NHD. Additional safety features included an alarmed drip tray under the cycler and moisture sensors under the venous needle (all patients used dual-cannulation technique). No patient safety events were reported. These data support the use of a low-flow dialysate system for provision of NHD at home. Biochemical parameters were good, medication burden was reduced at 12 months, and all patients received more than double the duration of HD provided in standard in-center units. While patient numbers were small, low-flow dialysis in this cohort was both effective and safe. Use of this alternative HD system could reduce some of the barriers to NHD, increasing the uptake of therapy in Europe, and improving long-term patient outcomes

Disparities in SGLT2 Inhibitor or Glucagon-Like Peptide 1 Receptor Agonist Initiation Among Medicare-Insured Adults With CKD in the United StatesPlain-Language Summary

Rationale &amp; Objective: Information regarding disparities in initiating sodium/glucose cotransporter 2 inhibitors (SGLT2i) and glucagon-like peptide 1 receptor agonists (GLP-1RA) in patients with chronic kidney disease (CKD) is limited. We examined sociodemographic and clinical factors associated with the initiation of SGLT2i, GLP-1RA, or second-generation sulfonylureas in a Medicare Fee-For-Service patient population with CKD and type 2 diabetes. Study Design: Retrospective cohort study. Setting &amp; Participants: The 20% random sample of Medicare Fee-For-Service claims, 2012-2018. Exposures: Patients’ sociodemographic and clinical factors. Outcomes: Use of SGLT2i, GLP-1RA, or sulfonylureas. Analytical Approach: Patients with a newly initiated prescription of SGLT2i, GLP-1RA, or second-generation sulfonylureas from January 1, 2013, to December 31, 2018, were identified. Multinomial logistic regression model was used to evaluate demographic and clinical factors associated with the initiation of SGLT2i, GLP-1RA, or second-generation sulfonylureas. Results: The study cohort comprised 53,029 adults (aged greater than or equal to 18 years) with CKD and type 2 diabetes, of whom 10.0%, 17.4%, and 72.6% had a first prescription for SGLT2i, GLP-1RA, and sulfonylurea, respectively. Patients aged greater than or equal to 75 years versus those aged 65-74 years had lower odds to start SGLT2i or GLP-1RA compared with sulfonylureas. Black patients were associated with lower odds of initiation of SGLT2i (OR, 0.67; 95% CI, 0.61-0.74) and GLP-1RA (OR, 0.73; 95% CI, 0.68-0.79), compared with White patients. Hispanic and Asian patients had lower odds of initiation of GLP-1RA. Patients with cardiovascular disease or hyperlipidemia had higher odds to start SGLT2i or GLP-1RA. Limitations: CKD and type 2 diabetes diagnosis; CKD stage; and patient clinical status were identified with diagnosis or procedure codes. There is potential for residual confounding with the use of retrospective data. Conclusions: The results of this study identified disparities in the use of SGLT2i and GLP-1RA in patients with CKD. Black and older patients were significantly less likely to be initiated on SGLT2i or GLP-1RA than on second-generation sulfonylureas