Search

Importance: In an effort to regulate physician conflicts of interest, some US academic medical centers (AMCs) enacted policies restricting pharmaceutical representative sales visits to physicians (known as detailing) between 2006 and 2012. Little is known about the effect of these policies on physician prescribing.Objective: To analyze the association between detailing policies enacted at AMCs and physician prescribing of actively detailed and not detailed drugs.Design, Setting, and Participants: The study used a difference-in-differences multivariable regression analysis to compare changes in prescribing by physicians before and after implementation of detailing policies at AMCs in 5 states (California, Illinois, Massachusetts, Pennsylvania, and New York) that made up the intervention group with changes in prescribing by a matched control group of similar physicians not subject to a detailing policy.Exposures: Academic medical center implementation of policies regulating pharmaceutical salesperson visits to attending physicians.Main Outcomes and Measures: The monthly within-drug class market share of prescriptions written by an individual physician for detailed and nondetailed drugs in 8 drug classes (lipid-lowering drugs, gastroesophageal reflux disease drugs, diabetes drugs, antihypertensive drugs, hypnotic drugs approved for the treatment of insomnia [sleep aids], attention-deficit/hyperactivity disorder drugs, antidepressant drugs, and antipsychotic drugs) comparing the 10- to 36-month period before implementation of the detailing policies with the 12- to 36-month period after implementation, depending on data availability.Results: The analysis included 16 121 483 prescriptions written between January 2006 and June 2012 by 2126 attending physicians at the 19 intervention group AMCs and by 24 593 matched control group physicians. The sample mean market share at the physician-drug-month level for detailed and nondetailed drugs prior to enactment of policies was 19.3% and 14.2%, respectively. Exposure to an AMC detailing policy was associated with a decrease in the market share of detailed drugs of 1.67 percentage points (95% CI, -2.18 to -1.18 percentage points; P < .001) and an increase in the market share of nondetailed drugs of 0.84 percentage points (95% CI, 0.54 to 1.14 percentage points; P < .001). Associations were statistically significant for 6 of 8 study drug classes for detailed drugs (lipid-lowering drugs, gastroesophageal reflux disease drugs, antihypertensive drugs, sleep aids, attention-deficit/hyperactivity disorder drugs, and antidepressant drugs) and for 9 of the 19 AMCs that implemented policies. Eleven of the 19 AMCs regulated salesperson gifts to physicians, restricted salesperson access to facilities, and incorporated explicit enforcement mechanisms. For 8 of these 11 AMCs, there was a significant change in prescribing. In contrast, there was a significant change at only 1 of 8 AMCs that did not enact policies in all 3 areas.Conclusions and Relevance: Implementation of policies at AMCs that restricted pharmaceutical detailing between 2006 and 2012 was associated with modest but significant reductions in prescribing of detailed drugs across 6 of 8 major drug classes; however, changes were not seen in all of the AMCs that enacted policies. [ABSTRACT FROM AUTHOR]

Objectives To ascertain predictors of initiation of brand-name versus generic narrow therapeutic index ( NTI) drugs. Design Retrospective cohort study. Setting Data from CVS Caremark were linked to Medicare claims and to U.S. census data. Participants Individuals aged 65 and older who initiated an NTI drug in 2006 and 2007 (N = 36,832). Measurements Demographic, health service utilization, and geographic predictors of whether participants initiated a generic or brand-name version of their NTI drug were identified using logistic regression. Results Overall, 30,014 (81.5%) participants started on a generic version of their NTI drug. The most commonly initiated NTI drugs were warfarin (n = 17,790; 48%), levothyroxine (n = 10,779; 29%), and digoxin (n = 6,414; 17%). Older age (odds ratio ( OR) = 1.12, 95% confidence interval ( CI) = 1.02-1.22 comparing aged ≥85 with 65-74), higher burden of comorbidity ( OR = 1.05, 95% CI = 1.04-1.07 for each 1-point increase in comorbidity score), and prior use of any generic drug ( OR = 1.55, 95% CI = 1.29-1.87) were positively associated with generic drug initiation. Independent of other predictors, residing in the census block group with the highest generic use was positively associated with greater odds of generic NTI drug initiation ( OR = 1.24, 95% CI = 1.14-1.35 compared with the lowest quintile). Conclusion Demographic, health service utilization, and geographic characteristics are important determinants of whether individuals initiate treatment with a brand-name or generic NTI drug. These factors may contribute to disparities in care and highlight potential targets for educational campaigns. [ABSTRACT FROM AUTHOR]

We describe interactive effects of total phosphorus (total P = 0.1-4.0 µmol L-1; added as H2NaPO4), irradiance (40 and 150 µmol quanta m-2 s-1), and the partial pressure of carbon dioxide (PCO2 19 and 81 Pa, i.e., 190 and 800 ppm) on growth and CO2- and dinitrogen (N2)-fixation rates of the unicellular N2-fixing cyanobacterium Crocosphaera watsonii (WH0003) isolated from the Pacific Ocean near Hawaii. In semicontinuous cultures of C. watsonii, elevated positively affected growth and CO2- and N2-fixation rates under high light. Under low light, elevated positively affected growth rates at all concentrations of P, but CO2- and N2-fixation rates were affected by elevated only when P was low. In both high-light and low-light cultures, the total P requirements for growth and CO2- and N2-fixation declined as increased. The minimum concentration (Cmin) of total P and half-saturation constant (K1/2) for growth and CO2- and N2-fixation rates with respect to total P were reduced by 0.05 µmol L-1 as a function of elevated . We speculate that low P requirements under high resulted from a lower energy demand associated with carbon-concentrating mechanisms in comparison with low-cultures. There was also a 0.10 µmol L-1 increase in Cmin and K1/2 for growth and N2 fixation with respect to total P as a function of increasing light regardless of concentration. We speculate that cellular P concentrations are responsible for this shift through biodilution of cellular P and possibly cellular P uptake systems as a function of increasing light. Changing concentrations of P, CO2, and light have both positive and negative interactive effects on growth and CO2-, and N2-fixation rates of unicellular oxygenic diazotrophs like C. watsonii. [ABSTRACT FROM AUTHOR]

Dilution experiments were performed to examine the growth and grazing mortality rates of picophytoplankton (<2 μm), nanophytoplankton (2–20 μm), and microphytoplankton (>20 μm) at stations in the Chesapeake Bay (CB), the Delaware Inland Bays (DIB) and the Delaware Bay (DB), in early spring 2005. At station CB microphytoplankton, including chain-forming diatoms were dominant, and the microzooplankton assemblage was mainly composed of the tintinnid Tintinnopsis beroidea. At station DIB, the dominant species were microphytoplanktonic dinoflagellates, while the microzooplankton community was mainly composed of copepod nauplii and the oligotrich ciliate Strombidium sp. At station DB, nanophytoplankton were dominant components, and Strombidium and Tintinnopsis beroidea were the co-dominant microzooplankton. The growth rate and grazing mortality rate were 0.13–3.43 and 0.09–1.92 d−1 for the different size fractionated phytoplankton. The microzooplankton ingested 73, 171, and 49% of standing stocks, and 95, 70, and 48% of potential primary productivity for total phytoplankton at station CB, DIB, and DB respectively. The carbon flux for total phytoplankton consumed by microzooplankton was 1224.11, 100.76, and 85.85 μg C l−1 d−1 at station CB, DIB, and DB, respectively. According to the grazing mortality rate, carbon consumption rate and carbon flux turn over rates, microzooplankton in study area mostly preferred to graze on picophytoplankton, which was faster growing but was lowest biomass component of the phytoplankton. The faster grazing on Fast-Growing-Low-Biomass (FGLB) phenomenon in coastal regions is explained as a resource partitioning strategy. This quite likely argues that although microzooplankton grazes strongly on phytoplankton in these regions, these microzooplankton grazers are passive. [ABSTRACT FROM AUTHOR]

Presents research which demonstrated that phytoplankton are iron-limited in parts of the California coastal upwelling region. Phytoplankton growth limited by iron availability; Addition of iron to high-nitrate, low-chlorophyll (HNLC) regimes; Silicic acid:nitrate (Si:N) uptake ratios; Diatoms stressed by lack of iron; Si:cell, Si:C and Si:pigment ratios in diatoms; Implications of research.

• Growth rates were near equivalent under upwelling and marine heatwave conditions. • This strain of Pseudo-nitzschia Australis was more toxic under upwelling conditions. • Nitrogen limited toxicity in heatwave and extreme heatwave treatments. • Multivariate scenario experiments can provide a holistic view of bloom dynamics. • Single-factor experiments provide mechanistic understandings of observed responses. Along the west coast of the United States, highly toxic Pseudo-nitzschia blooms have been associated with two contrasting regional phenomena: seasonal upwelling and marine heatwaves. While upwelling delivers cool water rich in pCO 2 and an abundance of macronutrients to the upper water column, marine heatwaves instead lead to warmer surface waters, low pCO 2 , and reduced nutrient availability. Understanding Pseudo-nitzschia dynamics under these two conditions is important for bloom forecasting and coastal management, yet the mechanisms driving toxic bloom formation during contrasting upwelling vs. heatwave conditions remain poorly understood. To gain a better understanding of what drives Pseudo-nitzschia australis growth and toxicity during these events, multiple-driver scenario or 'cluster' experiments were conducted using temperature, pCO 2 , and nutrient levels reflecting conditions during upwelling (13 °C, 900 ppm pCO 2 , replete nutrients) and two intensities of marine heatwaves (19 °C or 20.5 °C, 250 ppm pCO 2 , reduced macronutrients). While P. australis grew equally well under both heatwave and upwelling conditions, similar to what has been observed in the natural environment, cells were only toxic in the upwelling treatment. We also conducted single-driver experiments to gain a mechanistic understanding of which drivers most impact P. australis growth and toxicity. These experiments indicated that nitrogen concentration and N:P ratio were likely the drivers that most influenced domoic acid production, while the impacts of temperature or pCO 2 concentration were less pronounced. Together, these experiments may help to provide both mechanistic and holistic perspectives on toxic P. australis blooms in the dynamic and changing coastal ocean, where cells interact simultaneously with multiple altered environmental variables. [ABSTRACT FROM AUTHOR]