69 research outputs found
Trends in Pharmacotherapy for Bladder Dysfunction among Children in the United States, 2000 to 2013
Bladder-related issues such as nocturnal enuresis and incontinence have long been a part of general pediatric practice. Increasingly, clinicians are prescribing medications directed at a variety of types of bladder dysfunction, but no prior population-based data exist. We used MarketScan health care claims data on 32 074 638 insured children to estimate utilization patterns by age, sex, year, and geographic region in the United States from 2000 to 2013, and to assess related diagnosis codes. Approximately 1 in 500 children filled an antimuscarinic prescription. The most common prescriptions were for oxybutynin (78%) and tolterodine (17%). Rates were highest at ages 6 to 10 years (65/100 000 person-months), 31% higher for girls versus boys, peaked in 2011 (44/100 000 person-months), and were highest in the Midwest (59/100 000 person-months). Seventy-three percent of children with prescriptions had diagnosis codes for genitourinary symptoms, and 13% had codes for congenital anomalies. Research is needed regarding the comparative effectiveness and safety of these drugs in children
Classifying medical histories in US medicare beneficiaries using fixed vs allâavailable lookâback approaches
Purpose: Evaluate use of fixed and allâavailable lookâbacks to identify eligibility criteria and confounders among Medicare beneficiaries. Methods: We identified outpatient visits (2007â2012) with recently documented (â€180 days) cardiovascular risk and classified patients according to whether the exposure (statin) was initiated within 14 days. We selected each beneficiary's first eligible visit (in each treatment group) that met criteria during the respective lookâbacks: continuous enrollment (1 or 3 years for fixed lookâback; 180 days for allâavailable), no cancer history, and no statin claims. We estimated crude and standardized mortality ratio weighted hazard ratios (HRs) for the effect of statin initiation on incident 6âmonth cancer (a known null effect) and 2âyear mortality, separately, adjusting for covariates assessed by using each lookâback. Results: Analyzing shortâterm cancer, the estimated HR from the allâavailable approach (HR = 0.90, 95% CI: 0.83, 0.98) was less biased than the 1âyear lookâback (HR = 0.79, 95% CI: 0.73, 0.84), which included beneficiaries with prevalent cancer. The 3âyear lookâback (HR = 1.05, 95% CI: 0.90, 1.21) was somewhat less biased than the allâavailable estimate but less precise due the exclusion of a large proportion of observations without sufficient continuous enrollment (62.0% and 59.9% of initiators and nonâinitiators, respectively). All approaches produced similar estimates of the effect on allâcause mortality. Alternative lookâbacks did not differ in their ability to control confounding. Conclusions: The allâavailable lookâback performed nearly as well as the 3âyear fixed, which produced the least biased point estimate. If 3âyear lookâbacks are infeasible (eg, due to power/sample), allâavailable lookâbacks may be preferable to short (1âyear) fixed lookâbacks
Giant magnetothermopower of magnon-assisted transport in ferromagnetic tunnel junctions
We present a theoretical description of the thermopower due to
magnon-assisted tunneling in a mesoscopic tunnel junction between two
ferromagnetic metals. The thermopower is generated in the course of thermal
equilibration between two baths of magnons, mediated by electrons. For a
junction between two ferromagnets with antiparallel polarizations, the ability
of magnon-assisted tunneling to create thermopower depends on the
difference between the size of the majority and
minority band Fermi surfaces and it is proportional to a temperature dependent
factor where is the magnon Debye
energy. The latter factor reflects the fractional change in the net
magnetization of the reservoirs due to thermal magnons at temperature
(Bloch's law). In contrast, the contribution of magnon-assisted
tunneling to the thermopower of a junction with parallel polarizations is
negligible. As the relative polarizations of ferromagnetic layers can be
manipulated by an external magnetic field, a large difference results in a magnetothermopower effect. This
magnetothermopower effect becomes giant in the extreme case of a junction
between two half-metallic ferromagnets, .Comment: 9 pages, 4 eps figure
Womenâs beliefs about medicines and adherence to pharmacotherapy in pregnancy: Opportunities for community pharmacists?
Background During pregnancy women might weigh benefits of treatment against potential risks to the unborn child. However, non-adherence to necessary treatment can adversely affect both mother and child. To optimize pregnant womenâs beliefs and medication adherence, community pharmacists are ideally positioned to play an important role in primary care. Objective This narrative review aimed to summarize the evidence on 1) pregnant womenâs beliefs, 2) medication adherence in pregnancy, and 3) community pharmacistsâ counselling during pregnancy. Method Three search strategies were used in Medline and Embase to find original studies evaluating womenâs beliefs, medication adherence and community pharmacistsâ counselling during pregnancy. All original descriptive and analytic epidemiological studies performed in Europe, North America and Australia, written in English and published from 2000 onwards were included. Results We included 14 studies reporting on womenâs beliefs, 11 studies on medication adherence and 9 on community pharmacistsâ counselling during pregnancy. Women are more reluctant to use medicines during pregnancy and tend to overestimate the teratogenic risk of medicines. Risk perception varies with type of medicine, level of health literacy, education level and occupation. Furthermore, low medication adherence during pregnancy is common. Finally, limited evidence showed current community pharmacistsâ counselling is insufficient. Barriers hindering pharmacists are insufficient knowledge and limited access to reliable information. Conclusion Concerns about medication use and non-adherence are widespread among pregnant women. Community pharmacistsâ counselling during pregnancy is insufficient. Further education, training and research are required to support community pharmacists in fulfilling all the opportunities they have when counselling pregnant women
Marine diatoms grown in chemostats under silicate or ammonium limitation. III. Cellular chemical composition and morphology of Chaetoceros debilis, Skeletonema costatum , and Thalassiosira gravida
Three marine diatoms, Skeletonema costatum, Chaetoceros debilis , and Thalassiosira gravida were grown under no limitation and ammonium or silicate limitation or starvation. Changes in cell morphology were documented with photomicrographs of ammonium and silicate-limited and non-limited cells, and correlated with observed changes in chemical composition. Cultures grown under silicate starvation or limitation showed an increase in particulate carbon, nitrogen and phosporus and chlorophyll a per unit cell volume compared to non-limited cells; particulate silica per cell volume decreased. Si-starved cells were different from Si-limited cells in that the former contained more particulate carbon and silica per cell volume. The most sensitive indicator of silicate limitation or starvation was the ratio C:Si, being 3 to 5 times higher than the values for non-limited cells. The ratios Si:chlorophyll a and S:P were lower and N:Si was higher than non-limited cells by a factor of 2 to 3. The other ratios, C:N, C:P, C:chlorophyll a , N:chlorophyll a , P:chlorophyll a and N:P were considered not to be sensitive indicators of silicate limitation or starvation. Chlorophyll a , and particulate nitrogen per unit cell volume decreased under ammonium limitation and starvation. NH 4 -starved cells contained more chlorophyll a , carbon, nitrogen, silica, and phosphorus per cell volume than NH 4 -limited cells. N:Si was the most sensitive ratio to ammonium limitation or starvation, being 2 to 3 times lower than non-limited cells. Si:chlorophyll a , P:chlorophyll a and N:P were less sensitive, while the ratios C:N, C:chlorophyll a , N:chlorophyll a , C:Si, C:P and Si:P were the least sensitive. Limited cells had less of the limiting nutrient per unit cell volume than starved cells and more of the non-limiting nutrients (i.e., silica and phosphorus for NH 4 -limited cells). This suggests that nutrient-limited cells rather than nutrient-starved cells should be used along with non-limited cells to measure the full range of potential change in cellular chemical composition for one species under nutrient limitation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46631/1/227_2004_Article_BF00392568.pd
A review of techniques for parameter sensitivity analysis of environmental models
Mathematical models are utilized to approximate various highly complex engineering, physical, environmental, social, and economic phenomena. Model parameters exerting the most influence on model results are identified through a âsensitivity analysisâ. A comprehensive review is presented of more than a dozen sensitivity analysis methods. This review is intended for those not intimately familiar with statistics or the techniques utilized for sensitivity analysis of computer models. The most fundamental of sensitivity techniques utilizes partial differentiation whereas the simplest approach requires varying parameter values one-at-a-time. Correlation analysis is used to determine relationships between independent and dependent variables. Regression analysis provides the most comprehensive sensitivity measure and is commonly utilized to build response surfaces that approximate complex models.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42691/1/10661_2004_Article_BF00547132.pd
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