Solid C.A.,Minneapolis Medical Research Foundation |
Carlin C.,Medica Research Institute |
Carlin C.,University of Minnesota
American Journal of Nephrology | Year: 2012
Background/Aims: Arteriovenous fistulas (AVFs) appear to be clinically superior to catheters as vascular access for maintenance hemodialysis, but higher insertion costs and high disease burden and mortality obscure the issue of whether AVF placement before hemodialysis initiation represents a net cost savings. We aimed to investigate Medicare costs for patients beginning maintenance hemodialysis, as related to timing of AVF placement. Methods: Data were from Medicare claims for incident hemodialysis patients aged ≥67 years in 2006. The study period extended from 2 years before to 1 year after dialysis initiation. Patients identified as having AVFs were categorized by timing of placement (mature AVF at dialysis initiation, maturing AVF at initiation, postinitiation AVF placement). Because timing may be influenced by factors that also influence overall costs, the model accounted for this nonrandom treatment assignment. An ordered probit extension of the classic Heckman correction was employed after identifying an appropriate instrumental variable. A cohort with Medicare coverage before and after dialysis initiation was identified, and Medicare claims were used to identify comorbid conditions and treatment costs. Results: Principal findings are that earlier AVF placement leads to lower costs, with the potential for about USD 500 million in savings. Additionally, the effect of nonrandom treatment assignment is real and significant. In our data, the impact of AVF placement timing was understated when treatment selection was ignored. Conclusions: For appropriate AVF candidates, having a mature AVF in place at the time of dialysis initiation appears to confer cost savings. Copyright © 2012 S. Karger AG, Basel.
Grebenstein P.E.,University of Florida |
Grebenstein P.E.,Minneapolis Medical Research Foundation |
Thompson I.E.,University of Florida |
Rowland N.E.,University of Florida
Psychopharmacology | Year: 2013
Rationale: Increased appetite and weight gain after cessation is a deterrent for quitting smoking. Attempts to understand the mechanism for these effects using animals have been hampered by the difficulty or inconsistency of modeling the effects seen in humans. Objective: To examine the effects of extended daily access to intravenous nicotine, via programmed infusions, on body weight and meal patterns in rats. Methods: Intravenous (IV) nicotine infusions (0.06 mg/kg/inf) were administered noncontingently, every 30 min throughout the dark cycle and the last 3 h of the light cycle, to emulate self-administration. The effect of these infusions on food intake, meal patterns, and weight change were examined relative to a control group during treatment and in a post-nicotine phase. Results: Nicotine-treated rats gained half the weight that vehicle treated animals gained and ate approximately 20 % less food overall than vehicle-treated rats. Whereas a compensatory increase in meal frequency occurred during the dark period to account for smaller meals, no compensation was observed throughout the light period. In a post-nicotine phase, the nicotine group maintained a lower weight for 1 week and then gained weight back to control levels. The rate of weight gain post-cessation was faster in animals that had received nicotine compared to controls. Conclusion: Compared to previous studies examining the effects of minipump or intraperitoneal injections of nicotine on food intake, the present study was able to detect previously unknown circadian differences in meal patterns which will be important in the development of smoking cessation and weight gain prevention drugs. © 2013 Springer-Verlag Berlin Heidelberg.
Robinson-O'Brien R.,Minneapolis Medical Research Foundation |
Gerald B.L.,Gerald Consulting LLC
Journal of the Academy of Nutrition and Dietetics | Year: 2013
Registered dietitians (RDs) and dietetic technicians, registered (DTRs) can implement environmentally responsible practices in their workplace and personal lives. RDs and DTRs who conserve natural resources while minimizing environmental degradation will help maintain sustainability of the food system, which requires knowledge of the external costs of operational and personal decisions. These external costs include energy to produce, transport, and process food; water for food production, preparation, and sanitation; removal of air pollutants; and waste management. As client and public educators, RDs and DTRs are uniquely positioned to meet the growing needs of those seeking guidance on food choices as they relate to ecological sustainability. In an effort to promote ecologically sustainable diets, it is important to consider natural resources as they relate to food production, transformation, distribution, access, and consumption. It is essential that the dietetics community takes a more active leadership role in support of ecological sustainability and social responsibility. RDs and DTRs can influence policy at the institutional, community, local, state, and national levels by presenting results of operational practices and science-based natural resource information. RDs and DTRs are encouraged to become educated and active in implementing sustainable practices and shaping policy in an effort to promote healthier individuals, communities, and the nation as a whole. © 2013 Academy of Nutrition and Dietetics.
Minneapolis Medical Research Foundation and University of Minnesota | Date: 2013-09-17
The present invention relates to conjugates and vaccine compositions for treatment of opioid addiction, and methods of use of these conjugates and compositions.
Liu J.,Minneapolis Medical Research Foundation |
Weinhandl E.D.,Minneapolis Medical Research Foundation |
Gilbertson D.T.,Minneapolis Medical Research Foundation |
Collins A.J.,Minneapolis Medical Research Foundation |
And 2 more authors.
Kidney International | Year: 2012
In observational studies, treatment is often time dependent. Mishandling the time from the beginning of follow-up to treatment initiation can result in bias known as immortal time bias. Nephrology researchers who conduct observational research must be aware of how immortal time bias can be introduced into analyses. We review immortal time bias issues in time-to-event analyses in the biomedical literature and give examples from the nephrology literature. We also use simulations to quantify the bias in different methods of mishandling immortal time; intuitively explain how bias is introduced when immortal time is mishandled; raise issues regarding unadjusted treatment comparison, patient characteristics comparison, and confounder adjustment; and, using data from DaVita Inc., linked with the Centers for Medicare Medicaid Services end-stage renal disease database, show that the severity of bias and the issues described can occur in actual data analyses of patients with end-stage renal disease. In the simulation examples, mishandling immortal time led to an underestimated hazard ratio (treatment vs. control), thus an overestimated treatment effect, by as much as 96%, and an overestimated hazard ratio by as much as 138%, depending on the distribution of survival time and the method used. Results from the DaVita data were consistent with the simulation. Careful consideration of methodology is needed in observational analyses with time-dependent treatment. © 2012 International Society of Nephrology.