The cost-effectiveness of training US primary care physicians to conduct colorectal cancer screening in family medicine residency programs.

BACKGROUND: Demand for a wide array of colorectal cancer screening strategies continues to outpace supply. One strategy to reduce this deficit is to dramatically increase the number of primary care physicians who are trained and supportive of performing office-based colonoscopies or flexible sigmoidoscopies. This study evaluates the clinical and economic implications of training primary care physicians via family medicine residency programs to offer colorectal cancer screening services as an in-office procedure. METHODS: Using previously established clinical and economic assumptions from existing literature and budget data from a local grant (2013), incremental cost-effectiveness ratios are calculated that incorporate the costs of a proposed national training program and subsequent improvements in patient compliance. Sensitivity analyses are also conducted. RESULTS: Baseline assumptions suggest that the intervention would produce 2394 newly trained residents who could perform 71,820 additional colonoscopies or 119,700 additional flexible sigmoidoscopies after ten years. Despite high costs associated with the national training program, incremental cost-effectiveness ratios remain well below standard willingness-to-pay thresholds under base case assumptions. Interestingly, the status quo hierarchy of preferred screening strategies is disrupted by the proposed intervention. CONCLUSIONS: A national overhaul of family medicine residency programs offering training for colorectal cancer screening yields satisfactory incremental cost-effectiveness ratios. However, the model places high expectations on primary care physicians to improve current compliance levels in the US.

Determinants of variations in self-reported barriers to colonoscopy among uninsured patients in a primary care setting.

Colorectal cancer (CRC) is the third most common type of cancer among both males and females in the United States and the second leading cause of cancer-related deaths. Although largely preventable through screening, early detection and removal of polyps, screening rates are considered sub-optimal. Perceived barriers to screening have been reported to influence screening rates. This paper examines variations in the extent to which uninsured patients identified barriers to CRC screening using colonoscopy based on race/ethnicity, educational attainment, age, gender, marital status and prior colonoscopy. Multivariate analyses showed that compared to Caucasians, African Americans had an increased likelihood of identifying lack of transportation as a barrier [odds ratio (OR) 2.68; 95 % confidence interval (CI) 1.35-5.32] while Hispanics were more likely to identify fear of finding cancer as a barrier (OR 2.09; 95 % CI 1.19-3.66). Compared to those with more than a high school education, there was increased likelihood of identifying lack of knowledge as a barrier among individuals with high school education (OR 3.51; 95 % CI 1.94-6.36) or less than a high school education (OR 2.16; 95 % CI 1.04-4.50). Our findings suggest that strategies aimed at increasing colonoscopy screening rates among underserved populations should take into consideration race/ethnicity, educational attainment, age, and prior colonoscopy experience when developing education and outreach plans to reduce barriers to colonoscopy.

Associations of Cerebral Small Vessel Disease and Chronic Kidney Disease in Patients With Acute Intracerebral Hemorrhage: A Cross-Sectional Study.

BACKGROUND AND OBJECTIVES: Chronic kidney disease (CKD) may be associated with the pathogenesis and phenotype of cerebral small vessel disease (SVD), which is the commonest cause of intracerebral hemorrhage (ICH). The purpose of this study was to investigate the associations of CKD with ICH neuroimaging phenotype, volume, and location, total burden of small vessel disease, and its individual components. METHODS: In 2 cohorts of consecutive patients with ICH evaluated with MRI, we investigated the frequency and severity of CKD based on established Kidney Disease Improving Global Outcomes criteria, requiring estimated glomerular filtration rate (eGFR) measurements <60 mL/min/1.732 ≥ 3 months apart to define CKD. MRI scans were rated for ICH neuroimaging phenotype (arteriolosclerosis, cerebral amyloid angiopathy, mixed location SVD, or cryptogenic ICH) and the presence of markers of SVD (white matter hyperintensities [WMHs], cerebral microbleeds [CMBs], lacunes, and enlarged perivascular spaces, defined according to the STandards for ReportIng Vascular changes on nEuroimaging criteria). We used multinomial, binomial logistic, and ordinal logistic regression models adjusted for age, sex, hypertension, and diabetes to account for possible confounding caused by shared risk factors of CKD and SVD. RESULTS: Of 875 patients (mean age 66 years, 42% female), 146 (16.7%) had CKD. After adjusting for age, sex, and comorbidities, patients with CKD had higher rates of mixed SVD than those with eGFR >60 (relative risk ratio 2.39, 95% CI 1.16-4.94, p = 0.019). Severe WMHs, deep microbleeds, and lacunes were more frequent in patients with CKD, as was a higher overall SVD burden score (odds ratio 1.83 for each point on the ordinal scale, 95% CI 1.31-2.56, p < 0.001). Patients with eGFR ≤30 had more CMBs (median 7 [interquartile range 1-23] vs 2 [0-8] for those with eGFR >30, p = 0.007). DISCUSSION: In patients with ICH, CKD was associated with SVD burden, a mixed SVD phenotype, and markers of arteriolosclerosis. Our findings indicate that CKD might independently contribute to the pathogenesis of arteriolosclerosis and mixed SVD, although we could not definitively account for the severity of shared risk factors. Longitudinal and experimental studies are, therefore, needed to investigate causal associations. Nevertheless, stroke clinicians should be aware of CKD as a potentially independent and modifiable risk factor of SVD.

Statin Therapy for Secondary Prevention in Ischemic Stroke Patients With Cerebral Microbleeds.

BACKGROUND AND OBJECTIVES: The association between statin use and the risk of intracranial hemorrhage (ICrH) following ischemic stroke (IS) or transient ischemic attack (TIA) in patients with cerebral microbleeds (CMBs) remains uncertain. This study investigated the risk of recurrent IS and ICrH in patients receiving statins based on the presence of CMBs. METHODS: We conducted a pooled analysis of individual patient data from the Microbleeds International Collaborative Network, comprising 32 hospital-based prospective studies fulfilling the following criteria: adult patients with IS or TIA, availability of appropriate baseline MRI for CMB quantification and distribution, registration of statin use after the index stroke, and collection of stroke event data during a follow-up period of ≥3 months. The primary endpoint was the occurrence of recurrent symptomatic stroke (IS or ICrH), while secondary endpoints included IS alone or ICrH alone. We calculated incidence rates and performed Cox regression analyses adjusting for age, sex, hypertension, atrial fibrillation, previous stroke, and use of antiplatelet or anticoagulant drugs to explore the association between statin use and stroke events during follow-up in patients with CMBs. RESULTS: In total, 16,373 patients were included (mean age 70.5 ± 12.8 years; 42.5% female). Among them, 10,812 received statins at discharge, and 4,668 had 1 or more CMBs. The median follow-up duration was 1.34 years (interquartile range: 0.32-2.44). In patients with CMBs, statin users were compared with nonusers. Compared with nonusers, statin therapy was associated with a reduced risk of any stroke (incidence rate [IR] 53 vs 79 per 1,000 patient-years, adjusted hazard ratio [aHR] 0.68 [95% CI 0.56-0.84]), a reduced risk of IS (IR 39 vs 65 per 1,000 patient-years, aHR 0.65 [95% CI 0.51-0.82]), and no association with the risk of ICrH (IR 11 vs 16 per 1,000 patient-years, aHR 0.73 [95% CI 0.46-1.15]). The results in aHR remained consistent when considering anatomical distribution and high burden (≥5) of CMBs. DISCUSSION: These observational data suggest that secondary stroke prevention with statins in patients with IS or TIA and CMBs is associated with a lower risk of any stroke or IS without an increased risk of ICrH. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that for patients with IS or TIA and CMBs, statins lower the risk of any stroke or IS without increasing the risk of ICrH.

Hypertension and small vessel disease: do the drugs work?

Associations of hypertension with ischaemic stroke and intracerebral haemorrhage, particularly when attributed to cerebral small vessel disease, are well established. While it seems plausible that treating hypertension should prevent small vessel disease from developing or progressing, there is limited evidence demonstrating this. This article critically appraises the evidence answering this clinical question. Hypertension is also closely associated with chronic kidney disease, with anatomical and functional similarities between the vasculature of the brain and kidneys leading to the hypothesis that shared multi-system pathophysiological processes may be involved. Therefore, the article also summarises data on prevention of progression of chronic kidney disease. Evidence supports a target blood pressure of <130/80 mmHg to optimally prevent progression of both small vessel disease and chronic kidney disease. However, future studies are needed to determine long-term effects of more intensive blood pressure treatment targets on small vessel disease progression and incident dementia.

Association of the Presence and Pattern of MRI Markers of Cerebral Small Vessel Disease With Recurrent Intracerebral Hemorrhage.

BACKGROUND AND OBJECTIVES: Assessing the risk of recurrent intracerebral hemorrhage (ICH) is of high clinical importance. MRI-based cerebral small vessel disease (SVD) markers may help establish ICH etiologic subtypes (including cryptogenic ICH) relevant for recurrence risk. METHODS: We investigated the risk of recurrent ICH in a large cohort of consecutive ICH survivors with available MRI at baseline. Patients with macrovascular, structural, or other identified secondary causes (other than SVD) were excluded. Based on MRI findings, ICH etiology was defined as probable cerebral amyloid angiopathy (CAA) according to the Boston 2.0 criteria, arteriolosclerosis (nonlobar ICH and additional markers of arteriolosclerosis, absent lobar hemorrhagic lesions), mixed SVD (mixed deep and lobar hemorrhagic changes), or cryptogenic ICH (no MRI markers of SVD). Recurrent ICH was determined using electronic health records and confirmed by neuroimaging. Data from an independent multicenter cohort (CROMIS-2 ICH) were used to confirm core findings. RESULTS: Of 443 patients with ICH (mean age 67 ± 13 years, 41% female), ICH etiology was mixed SVD in 36.7%, arteriolosclerosis in 23.6%, CAA in 23.0%, and cryptogenic ICH in 16.7%. During a median follow-up period of 5.7 years (interquartile range 2.9-10.0, 2,682 patient-years), recurrent ICH was found in 59 individual patients (13.3%). The highest recurrence rate per 100 person-years was detected in patients with CAA (8.5, 95% CI 6.1-11.7), followed by that in those with mixed SVD (1.8, 95% CI 1.1-2.9) and arteriolosclerosis (0.6, 95% CI 0.3-1.5). No recurrent ICH occurred in patients with cryptogenic ICH during 510 person-years follow-up (97.5% CI 0-0.7); this finding was confirmed in an independent cohort (CROMIS-2 ICH, n = 216), in which also there was no recurrence in patients with cryptogenic ICH. In patients with CAA, cortical superficial siderosis was the imaging feature strongest related to ICH recurrence (hazard ratio 5.7, 95% CI 2.4-13.6). DISCUSSION: MRI-based etiologic subtypes are helpful in determining the recurrence risk of ICH; while the highest recurrence risk was found in CAA, recurrence risk was low for arteriolosclerosis and negligible for cryptogenic ICH.

Associations of renal function with cerebral small vessel disease and functional outcome in acute intracerebral haemorrhage: A hospital-based prospective cohort study.

BACKGROUND: Intracerebral haemorrhage (ICH) is a severe clinical consequence of cerebral small vessel disease (SVD), but associations between renal impairment and SVD in patients with ICH have not been fully characterised. METHODS: Using data from the CROMIS-2 ICH observational study, we compared SVD neuroimaging markers and total burden (score 0-3) identified using CT brain imaging in patients with and without renal impairment (estimated glomerular filtration rate, eGFR<60). We assessed functional outcome at 6-month follow-up using the modified Rankin scale. RESULTS: 1027 participants were included (mean age 72.8, 57.1% male); 274 with and 753 without renal impairment. 18.7% of the eGFR<60 group had moderate-to-severe SVD burden (score 2-3), compared with 14.0% of those with eGFR>60 (p = 0.039). SVD burden was associated with renal impairment after adjusting for hypertension (OR 1.36, 95% CI 1.04-1.77, p = 0.023), but not after adjusting for age. Cerebral atrophy was more prevalent in patients with eGFR<60 (81.2% vs. 72.0%, p = 0.002), as were WMH (45.6% vs. 36.6%, p = 0.026). Neither was associated with renal function after adjusting for age and vascular risk factors. Renal impairment was associated with functional outcome (OR 0.65, 95% CI 0.47-0.89, p = 0.007), but not after adjusting for age, pre-morbid function and comorbidities (OR 0.95, 95% CI 0.65-1.38, p = 0.774). CONCLUSION: In acute ICH, renal impairment is associated with a higher cerebral SVD burden independent of hypertension, but not age. Reduced eGFR is associated with worse functional outcome, but not independent of age and comorbidities. Since CT has limited sensitivity to detect SVD severity and distribution, further studies including MRI are needed.

Achieving highly dispersed nanofibres at high loading in carbon nanofibre-metal composites.

In order to tap into the advantages of the properties of carbon nanotubes (CNTs) or carbon nanofibres (CNFs) in composites, the high dispersion of CNTs (or CNFs) and strong interfacial bonding are the key issues which are still challenging. In the current work, a novel approach, consisting of in situ synthesis of CNFs within the Cu powders and mixing Cu ions with the in situ CNF(Ni/Y)-Cu composite powders in a solvent, was developed to highly disperse CNFs in a Cu matrix. The composite, produced by vacuum hot pressing, shows extremely high strength, 3.6 times more than that of the matrix material alone. It is worth mentioning that this method can disperse CNFs at high loading in a metal matrix, inferring good potential for applications, such as electronic packaging materials.

Experimental formation enthalpies for intermetallic phases and other inorganic compounds.

The standard enthalpy of formation of a compound is the energy associated with the reaction to form the compound from its component elements. The standard enthalpy of formation is a fundamental thermodynamic property that determines its phase stability, which can be coupled with other thermodynamic data to calculate phase diagrams. Calorimetry provides the only direct method by which the standard enthalpy of formation is experimentally measured. However, the measurement is often a time and energy intensive process. We present a dataset of enthalpies of formation measured by high-temperature calorimetry. The phases measured in this dataset include intermetallic compounds with transition metal and rare-earth elements, metal borides, metal carbides, and metallic silicides. These measurements were collected from over 50 years of calorimetric experiments. The dataset contains 1,276 entries on experimental enthalpy of formation values and structural information. Most of the entries are for binary compounds but ternary and quaternary compounds are being added as they become available. The dataset also contains predictions of enthalpy of formation from first-principles calculations for comparison.

Impact of intrapatient variability (IPV) in tacrolimus trough levels on long-term renal transplant function: multicentre collaborative retrospective cohort study protocol.

INTRODUCTION: High intrapatient variability (IPV) in tacrolimus trough levels has been shown to be associated with higher rates of renal transplant failure. There is no consensus on what level of IPV constitutes a risk of graft loss. The establishment of such a threshold could help to guide clinicians in identifying at-risk patients to receive targeted interventions to improve IPV and thus outcomes. METHODS AND ANALYSIS: A multicentre Transplant Audit Collaborative has been established to conduct a retrospective study examining tacrolimus IPV and renal transplant outcomes. Patients in receipt of a renal transplant at participating centres between 2009 and 2014 and fulfilling the inclusion criteria will be included in the study. The aim is to recruit a minimum of 1600 patients with follow-up spanning at least 2 years in order to determine a threshold IPV above which a renal transplant recipient would be considered at increased risk of graft loss. The study also aims to determine any national or regional trends in IPV and any demographic associations. ETHICS AND DISSEMINATION: Consent will not be sought from patients whose data are used in this study as no additional procedures or information will be required from participants beyond that which would normally take place as part of clinical care. The study will be registered locally in each participating centre in line with local research and development protocols. It is anticipated that the results of this audit will be disseminated locally, in participating NHS Trusts, through national and international meetings and publications in peer-reviewed journals.

The Large Scale Synthesis of Aligned Plate Nanostructures.

We propose a novel technique for the large-scale synthesis of aligned-plate nanostructures that are self-assembled and self-supporting. The synthesis technique involves developing nanoscale two-phase microstructures through discontinuous precipitation followed by selective etching to remove one of the phases. The method may be applied to any alloy system in which the discontinuous precipitation transformation goes to completion. The resulting structure may have many applications in catalysis, filtering and thermal management depending on the phase selection and added functionality through chemical reaction with the retained phase. The synthesis technique is demonstrated using the discontinuous precipitation of a γ' phase, (Ni, Co)3Al, followed by selective dissolution of the γ matrix phase. The production of the nanostructure requires heat treatments on the order of minutes and can be performed on a large scale making this synthesis technique of great economic potential.

Fabrication of in-situ grown graphene reinforced Cu matrix composites.

Graphene/Cu composites were fabricated through a graphene in-situ grown approach, which involved ball-milling of Cu powders with PMMA as solid carbon source, in-situ growth of graphene on flaky Cu powders and vacuum hot-press sintering. SEM and TEM characterization results indicated that graphene in-situ grown on Cu powders guaranteed a homogeneous dispersion and a good combination between graphene and Cu matrix, as well as the intact structure of graphene, which was beneficial to its strengthening effect. The yield strength of 244 MPa and tensile strength of 274 MPa were achieved in the composite with 0.95 wt.% graphene, which were separately 177% and 27.4% enhancement over pure Cu. Strengthening effect of in-situ grown graphene in the matrix was contributed to load transfer and dislocation strengthening.

Ultralight metal foams.

Ultralight (<10 mg/cm3) cellular materials are desirable for thermal insulation; battery electrodes; catalyst supports; and acoustic, vibration, or shock energy damping. However, most of these ultralight materials, especially ultralight metal foams, are fabricated using either expensive materials or complicated procedures, which greatly limit their large-scale production and practical applications. Here we report a simple and versatile method to obtain ultralight monolithic metal foams. These materials are fabricated with a low-cost polymeric template and the method is based on the traditional silver mirror reaction and electroless plating. We have produced ultralight monolithic metal foams, such as silver, nickel, cobalt, and copper via this method. The resultant ultralight monolithic metal foams have remarkably low densities down to 7.4 mg/cm3 or 99.9% porosity. The metal foams have a long flat stress-train curve in compression tests and the densification strain εD of the Ni/Ag foam with a porosity of 99.8% can reach 82%. The plateau stress σpl was measured and found to be in agreement with the value predicted by the cellular solids theory.

The role of health literacy and communication habits on previous colorectal cancer screening among low-income and uninsured patients.

OBJECTIVE: To determine the association between health literacy, communication habits and colorectal cancer (CRC) screening among low-income patients. METHODS: Survey responses of patients who received financial assistance for colonoscopy between 2011 and 2014 at a family medicine residency clinic were analyzed using multivariate logistic regression (n = 456). There were two dependent variables: (1) previous CRC screening and (2) CRC screening adherence. Our independent variables of interest were health literacy and communication habits. RESULTS: Over two-thirds (67.13%) of respondents had not been previously screened for CRC. Multivariate analysis showed a decreased likelihood of previous CRC screening among those who had marginal (OR = 0.52; 95% CI = 0.29-0.92) or inadequate health literacy (OR = 0.49; 95% CI = 0.27-0.87) compared to those with adequate health literacy. Controlling for health literacy, the significant association between educational attainment and previous CRC screening was eliminated. Thus, health literacy mediated the relationship between educational attainment and previous CRC screening. There was no significant association between communication habits and previous CRC screening. There was no significant association between screening guideline adherence, and health literacy or communication. CONCLUSION: Limited health literacy is a potential barrier to CRC screening. Suboptimal CRC screening rates reported among those with lower educational attainment may be mediated by limited health literacy.