3,947 research outputs found
Incidence and Risk Factors of Thromboembolism with Multiple Myeloma in the Presence of Death as a Competing Risk: An Empirical Comparison of Statistical Methodologies
Multiple myeloma (MM) has an inherent high risk of thromboembolic events associated with patient as well as disease- and treatment-related factors. Previous studies have assessed the association of MM-related thromboembolism using “traditional” Kaplan–Meier (KM) and/or Cox proportional hazard (PH) regression. In the presence of high incidence of death, as would be the case in cancer patients with advanced age, these statistical models will produce bias estimates. Instead, a competing risk framework should be used. This study assessed the baseline patient demographic and clinical characteristics associated with MM-related thromboembolism and compared the cumulative incidence and the measures of association obtained using each statistical approach. The cumulative incidence of thromboembolism was 9.2% using the competing risk framework and nearly 12% using the KM approach. Bias in the measures of covariate risk associations was highest for factors related to risk of death such as increased age (75% bias) and severe liver disease (50%) for the Cox PH model compared to the competing risk model. These results show that correct specification of statistical techniques can have a large impact on the results obtained
Male body image: testosterone's response to body comparisons
Although there have been only a few etiological studies that have examined the
development and maintenance of body image in males, research fairly consistently
reports that exposure and presumed comparison to images of ideal male bodies increases
body dissatisfaction. Social comparison provides individuals with a mechanism by
which to evaluate their body appearance to those around them. When individuals
compare their bodies to those of others, they are attempting to gauge their standing or
status relative to those around them, the results of which have inherent status
implications. There is increasing empirical evidence that suggests perceived increases in
status result in increased testosterone levels, whereas testosterone decreases when status
is perceived as having been diminished. Thus, the core of the present study: can the
process of comparing the appearance of oneÂ’s body to that of others affect the
testosterone levels, body satisfaction, and mood of males?
To examine the above research questions, a two-part study was designed. A pilot
study was conducted with 117 male undergraduates primarily to examine the
psychometrics of measures to be used in the main study. The measures appeared psychometrically sound and were thus used in the main study. In the main study, 129
male undergraduates were exposed to photographs of one of three male body types (i.e.,
lean/muscular, skinny, average) to determine whether or not exposure to the different
body types differentially affected participantsÂ’ testosterone levels, body satisfaction, and
mood. Results indicate that testosterone levels decreased over the course of the
experiment in each of the three groups; however, the body type to which participants
were exposed did not differentially affect participantsÂ’ testosterone levels. Body
dissatisfaction was greater among participants who viewed lean/muscular bodies than
those who viewed average bodies. Lastly, mood was not differentially affected by
viewing different types of male bodies. Implications and possible explanations for these
results are discussed
Utilization of Free Medication Samples in the United States in a Nationally Representative Sample: 2009-2013
Background—Manufacturers provide free sample medications as a means to increase use of branded medications. Sample use varies year-to-year as branded product patents expire and new products come to market.
Objective—This study sought to describe the use of sample medications during 2009–2013 and assess individual characteristics associated with sample use.
Methods—Data from the 2009–2013 U.S. Medical Expenditure Panel Survey (MEPS) were used. MEPS asks participants whether they received each medication they are taking as a sample. The top 10 medications and medication classes used each year by volume were identified as well as the proportion of people who used at least one sample medication. The proportion of new initiators of medications were also classified as the percent who received a sample for the specific medication. Logistic regression was used to assess individual demographics, insurance, and medication characteristics associated with use.
Results—Prevalence of sample use ranged from 9.3% in 2009 to 6.2% in 2013. The most widely used sample medications included statins during 2009–2011, which changed to inhaled β-agonists in 2012–2013, as atorvastatin became available as a generic. The overall volume of the top 10 free sample medications decreased by one-third over this study period. In 2013, 12.6% of new insulin analog users and 11.0% of new oral contraceptive users receive these medications through samples. Regression analysis showed that U.S. Medicaid- and Medicare-insured persons were less likely to use samples compared to those with private insurance.
Conclusions—Sample medication use has decreased as generic medications are becoming more used in the U.S
Impact of Time-Varying Treatment Exposures on the Risk of Venous Thromboembolism in Multiple Myeloma
Multiple myeloma (MM) has one of the highest risks of venous thromboembolism (VTE) of all cancers due to pathologic changes and treatment-related exposures. This study assessed the one-year incidence of VTE in newly diagnosed MM and to determine the baseline and time-varying treatment-related factors associated with VTE risk in a U.S.-based cohort. MM patients were identified and age, gender, and baseline comorbidities were determined. Treatment-related exposures included thalidomide derivatives (IMIDs), proteasome inhibitors, cytotoxic chemotherapy, steroids, erythropoietin-stimulating agents (ESAs), stem cell transplants (SCT), hospitalizations, infection, and central venous catheters (CVC). Multiple statistical models were used including a baseline competing risks model, a time-varying exposure Cox proportional hazard (CPH) model, and a case-time-control analysis. The overall incidence of VTE was 107.2 per 1000 person-years with one-half of the VTEs occurring in the first 90 days. The baseline model showed that increasing age, heart failure, and hypertension were associated with one-year incidence of VTE. MM-specific IMID treatment had lower than expected associations with VTE based on prior literature. Instead, exposure to ESAs, SCT, CVC, and infection had higher associations. Based on these results, VTE risk in MM may be less straightforward than considering only chemotherapy exposures, and other treatment-related exposures should be considered to determine patient risk
The Prevalence and Predictors of Low-Cost Generic Program Use in a Nationally Representative Uninsured Population
The uninsured population has much to gain from affordable sources of prescription medications. No prior studies have assessed the prevalence and predictors of low-cost generic drug programs (LCGP) use in the uninsured population in the United States. A cross-sectional study was conducted using data from the Medical Expenditure Panel Survey (MEPS) during 2007–2012 including individuals aged 18 and older who were uninsured for the entire 2-year period they were in MEPS. The proportions of LCGP fills and users was tracked each year and logistic regression was used to assess significant factors associated with LCGP use. A total of 8.3 million uninsured individuals were represented by the sample and 39.9% of these used an LCGP. Differences between users and non-users included higher age, gender, year of participation, and number of medications filled. The proportion of fills and users via LCGPs increased over the 2007–2012 study period. Healthcare providers, especially pharmacists, should make uninsured patients aware of this source of affordable medications
Empirical Assessment of the Impact of Low-Cost Generic Programs on Adherence-Based Quality Measures
In the United States, federally-funded health plans are mandated to measure the quality of care. Adherence-based medication quality metrics depend on completeness of administrative claims data for accurate measurement. Low-cost generic programs (LCGPs) cause medications fills to be missing from claims data as medications are not adjudicated through a patient’s insurance. This study sought to assess the magnitude of the impact of LCGPs on these quality measures. Data from the 2012–2013 Medical Expenditure Panel Survey (MEPS) were used. Medication fills for select medication classes were classified as LCGP fills and individuals were classified as never, sometimes, and always users of LCGPs. Individuals were classified based on insurance type (private, Medicare, Medicaid, dual-eligible). The proportion of days covered (PDC) was calculated for each medication class and the proportion of users with PDC ≥ 0.80 was reported as an observed metric for what would be calculated based on claims data and a true metric which included missing medication fills due to LCGPs. True measures of adherence were higher than the observed measures. The effect’s magnitude was highest for private insurance and for medication classes utilized more often through LCGPs. Thus, medication-based quality measures may be underestimated due to LCGPs
Deitsch, Däätsch, Düütsch and Dietsch: The Varieties of Kansas German Dialects after 150 Years of German Group Settlement in Kansas
This is the published version, made available with permission of the editor
Deciphering structural and magnetic disorder in the chiral skyrmion host materials CoZnMn ()
CoZnMn () compounds crystallizing in the chiral
-Mn crystal structure are known to host skyrmion spin textures even at
elevated temperatures. As in other chiral cubic skyrmion hosts, skyrmion
lattices in these materials are found at equilibrium in a small pocket just
below the magnetic Curie temperature. Remarkably, CoxZnyMnz compounds have also
been found to host metastable non-equilibrium skyrmion lattices in a broad
temperature and field range, including down to zero-field and low temperature.
This behavior is believed to be related to disorder present in the materials.
Here, we use neutron and synchrotron diffraction, density functional theory
calculations, and DC and AC magnetic measurements, to characterize the atomic
and magnetic disorder in these materials. We demonstrate that Co has a strong
site-preference for the diamondoid 8c site in the crystal structure, while Mn
tends to share the geometrically frustrated 12d site with Zn, due to its
ability to develop a large local moment on that site. This magnetism-driven
site specificity leads to distinct magnetic behavior for the Co-rich 8c
sublattice and the Mn on the 12d sublattice. The Co-rich sublattice orders at
high temperatures (compositionally tunable between 100K to 470K) with a moment
around 1 /atom and maintains this order to low temperature. The Mn-rich
sublattice holds larger moments (about 3 which remain fluctuating below
the Co moment ordering temperature. At lower temperature, the fluctuating Mn
moments freeze into a reentrant disordered cluster-glass state with no net
moment, while the Co moments maintain order. This two-sublattice behavior
allows for the observed coexistence of strong magnetic disorder and ordered
magnetic states such as helimagnetism and skyrmion lattices.Comment: 17 pages, 10 figure
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