Cost-effectiveness analysis of 3-D computerized tomography colonography versus optical colonoscopy for imaging symptomatic gastroenterology patients.

BACKGROUND: When symptomatic gastroenterology patients have an indication for colonic imaging, clinicians have a choice between optical colonoscopy (OC) and computerized tomography colonography with three-dimensional reconstruction (3-D CTC). 3-D CTC provides a minimally invasive and rapid evaluation of the entire colon, and it can be an efficient modality for diagnosing symptoms. It allows for a more targeted use of OC, which is associated with a higher risk of major adverse events and higher procedural costs. A case can be made for 3-D CTC as a primary test for colonic imaging followed if necessary by targeted therapeutic OC; however, the relative long-term costs and benefits of introducing 3-D CTC as a first-line investigation are unknown. AIM: The aim of this study was to assess the cost effectiveness of 3-D CTC versus OC for colonic imaging of symptomatic gastroenterology patients in the UK NHS. METHODS: We used a Markov model to follow a cohort of 100,000 symptomatic gastroenterology patients, aged 50 years or older, and estimate the expected lifetime outcomes, life years (LYs) and quality-adjusted life years (QALYs), and costs (£, 2010-2011) associated with 3-D CTC and OC. Sensitivity analyses were performed to assess the robustness of the base-case cost-effectiveness results to variation in input parameters and methodological assumptions. RESULTS: 3D-CTC provided a similar number of LYs (7.737 vs 7.739) and QALYs (7.013 vs 7.018) per individual compared with OC, and it was associated with substantially lower mean costs per patient (£467 vs £583), leading to a positive incremental net benefit. After accounting for the overall uncertainty, the probability of 3-D CTC being cost effective was around 60 %, at typical willingness-to-pay values of £20,000-£30,000 per QALY gained. CONCLUSION: 3-D CTC is a cost-saving and cost-effective option for colonic imaging of symptomatic gastroenterology patients compared with OC

The clinical effectiveness of different surveillance strategies to prevent colorectal cancer in people with intermediate-grade colorectal adenomas: a retrospective cohort analysis, and psychological and economic evaluations

Background: The UK guideline recommends 3-yearly surveillance for patients with intermediate-risk (IR) adenomas. No study has examined whether or not this group has heterogeneity in surveillance needs. Objectives To examine the effect of surveillance on colorectal cancer (CRC) incidence; assess heterogeneity in risk; and identify the optimum frequency of surveillance, the psychological impact of surveillance, and the cost-effectiveness of alternative follow-up strategies. Design: Retrospective multicentre cohort study. Setting: Routine endoscopy and pathology data from 17 UK hospitals (n = 11,944), and a screening data set comprising three pooled cohorts (n = 2352), followed up using cancer registries. Subjects: Patients with IR adenoma(s) (three or four small adenomas or one or two large adenomas). Primary outcomes: Advanced adenoma (AA) and CRC detected at follow-up visits, and CRC incidence after baseline and first follow-up. Methods: The effects of surveillance on long-term CRC incidence and of interval length on findings at follow-up were examined using proportional hazards and logistic regression, adjusting for patient, procedural and polyp characteristics. Lower-intermediate-risk (LIR) subgroups and higher-intermediate-risk (HIR) subgroups were defined, based on predictors of CRC risk. A model-based cost–utility analysis compared 13 surveillance strategies. Between-group analyses of variance were used to test for differences in bowel cancer worry between screening outcome groups (n = 35,700). A limitation of using routine hospital data is the potential for missed examinations and underestimation of the effect of interval and surveillance. Results: In the hospital data set, 168 CRCs occurred during 81,442 person-years (pys) of follow-up [206 per 100,000 pys, 95% confidence interval (CI) 177 to 240 pys]. One surveillance significantly lowered CRC incidence, both overall [hazard ratio (HR) 0.51, 95% CI 0.34 to 0.77] and in the HIR subgroup (n = 9265; HR 0.50, 95% CI 0.34 to 0.76). In the LIR subgroup (n = 2679) the benefit of surveillance was less clear (HR 0.62, 95% CI 0.16 to 2.43). Additional surveillance lowered CRC risk in the HIR subgroup by a further 15% (HR 0.36, 95% CI 0.20 to 0.62). The odds of detecting AA and CRC at first follow-up (FUV1) increased by 18% [odds ratio (OR) 1.18, 95% CI 1.12 to 1.24] and 32% (OR 1.32, 95% CI 1.20 to 1.46) per year increase in interval, respectively, and the odds of advanced neoplasia at second follow-up increased by 22% (OR 1.22, 95% CI 1.09 to 1.36), after adjustment. Detection rates of AA and CRC remained below 10% and 1%, respectively, with intervals to 3 years. In the screening data set, 32 CRCs occurred during 25,745 pys of follow-up (124 per 100,000 pys, 95% CI 88 to 176 pys). One follow-up conferred a significant 73% reduction in CRC incidence (HR 0.27, 95% CI 0.10 to 0.71). Owing to the small number of end points in this data set, no other outcome was significant. Although post-screening bowel cancer worry was higher in people who were offered surveillance, worry was due to polyp detection rather than surveillance. The economic evaluation, using data from the hospital data set, suggested that 3-yearly colonoscopic surveillance without an age cut-off would produce the greatest health gain. Conclusions: A single surveillance benefited all IR patients by lowering their CRC risk. We identified a higher-risk subgroup that benefited from further surveillance, and a lower-risk subgroup that may require only one follow-up. A surveillance interval of 3 years seems suitable for most IR patients. These findings should be validated in other studies to confirm whether or not one surveillance visit provides adequate protection for the lower-risk subgroup of intermediate-risk patients

Time from first presentation in primary care to treatment of symptomatic colorectal cancer:effect on disease stage and survival

BACKGROUND: British 5-year survival from colorectal cancer (CRC) is below the European average, but the reasons are unclear. This study explored if longer provider delays (time from presentation to treatment) were associated with more advanced stage disease at diagnosis and poorer survival. METHODS: Data on 958 people with CRC were linked with the Scottish Cancer Registry, the Scottish Death Registry and the acute hospital discharge (SMR01) dataset. Time from first presentation in primary care to first treatment, disease stage at diagnosis and survival time from date of first presentation in primary care were determined. Logistic regression and Cox survival analyses, both with a restricted cubic spline, were used to model stage and survival, respectively, following sequential adjustment of patient and tumour factors. RESULTS: On univariate analysis, those with <4 weeks from first presentation in primary care to treatment had more advanced disease at diagnosis and the poorest prognosis. Treatment delays between 4 and 34 weeks were associated with earlier stage (with the lowest odds ratio occurring at 20 weeks) and better survival (with the lowest hazard ratio occurring at 16 weeks). Provider delays beyond 34 weeks were associated with more advanced disease at diagnosis, but not increased mortality. Following adjustment for patient, tumour factors, emergency admissions and symptoms and signs, no significant relationship between provider delay and stage at diagnosis or survival from CRC was found. CONCLUSIONS: Although allowing for a nonlinear relationship and important confounders, moderately long provider delays did not impact adversely on cancer outcomes. Delays are undesirable because they cause anxiety; this may be fuelled by government targets and health campaigns stressing the importance of very prompt cancer diagnosis. Our findings should reassure patients. They suggest that a health service's primary emphasis should be on quality and outcomes rather than on time to treatment

The changing association between socioeconomic circumstances and the incidence of colorectal cancer: a population-based study

Background:There is emerging evidence to suggest that the association between socioeconomic circumstances and colorectal cancer incidence has changed over recent decades.Methods:We conducted a descriptive population-based study to describe the relationship between socioeconomic circumstances and the incidence of colorectal cancer in a pre-screened population. Incident cases of colorectal cancer from the West of Scotland were identified from the Scottish Cancer Registry and European age-standardised incidence rates (EASR) were calculated. Socioeconomic circumstances were measured using the area-based Scottish Index of Multiple Deprivation (SIMD).Results:In total, 14?051 incident cases of colorectal cancer were recorded from 1999 to 2007. Incidence of colorectal cancer was associated with increased deprivation in men but not among women; an association that became evident from 2005 onwards. From 2005 to 2007, the deprivation gap in incidence among men was 13.3 per 100?000 (95% confidence interval 3.2-23.4), with rates 19.5% lower among the least deprived compared with the most deprived. This deprivation gap now accounts for an estimated 75 excess cases per year of male colorectal cancer in the West of Scotland.Conclusion:Deprivation was associated with higher incidence rates of male, but not female, colorectal cancer before the implementation of a national bowel screening programme

Polyp measurement based on CT colonography and colonoscopy: variability and systematic differences

To assess the variability and systematic differences in polyp measurements on optical colonoscopy and CT colonography. Gastroenterologists measured 51 polyps by visual estimation, forceps comparison and linear probe. CT colonography observers randomly assessed polyp size two-dimensionally (abdominal and intermediate window) and three-dimensionally (manually and semi-automatically). Linear mixed models were used to assess the variability and systematic differences between CT colonography and optical colonoscopy techniques. The variability of forceps and linear probe measurements was comparable and both showed less variability than measurement by visual assessment. Measurements by linear probe were 0.7 mm smaller than measurements by visual assessment or by forceps. The variability of all CT colonography techniques was lower than for measurements by forceps or visual assessment and sometimes lower (only 2D intermediate window and manual 3D) compared with measurements by linear probe. All CT colonography measurements judged polyps to be larger than optical colonoscopy, with differences ranging from 0.7 to 2.3 mm. A linear probe does not reduce the measurement variability of endoscopists compared with the forceps. Measurement differences between observers on CT colonography were usually smaller than at optical colonoscopy. Polyps appeared larger when using various CT colonography techniques than when measured during optical colonoscop

TRY plant trait database - enhanced coverage and open access

Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

Effective Inhibition of Xenografts of Hepatocellular Carcinoma (HepG2) by Rapamycin and Bevacizumab in an Intrahepatic Model

10.1007/s11307-009-0213-4Molecular Imaging and Biology115334-342CPIM

Relationship between visual field loss and contrast threshold elevation in glaucoma

BACKGROUND: There is a considerable body of literature which indicates that contrast thresholds for the detection of sinusoidal grating patterns are abnormally high in glaucoma, though just how these elevations are related to the location of visual field loss remains unknown. Our aim, therefore, has been to determine the relationship between contrast threshold elevation and visual field loss in corresponding regions of the peripheral visual field in glaucoma patients. METHODS: Contrast thresholds were measured in arcuate regions of the superior, inferior, nasal and temporal visual field in response to laser interference fringes presented in the Maxwellian view. The display consisted of vertical green stationary laser interference fringes of spatial frequency 1.0 c deg(-1 )which appeared in a rotatable viewing area in the form of a truncated quadrant extending from 10 to 20° from fixation which was marked with a central fixation light. Results were obtained from 36 normal control subjects in order to provide a normal reference for 21 glaucoma patients and 5 OHT (ocular hypertensive) patients for whom full clinical data, including Friedmann visual fields, had been obtained. RESULTS: Abnormally high contrast thresholds were identified in 20 out of 21 glaucoma patients and in 2 out of 5 OHT patients when compared with the 95% upper prediction limit for normal values from one eye of the 36 normal age-matched control subjects. Additionally, inter-ocular differences in contrast threshold were also abnormally high in 18 out of 20 glaucoma patients who had vision in both eyes compared with the 95% upper prediction limit. Correspondence between abnormally high contrast thresholds and visual field loss in the truncated quadrants was significant in 5 patients, borderline in 4 patients and absent in 9 patients. CONCLUSION: While the glaucoma patients tested in our study invariably had abnormally high contrast thresholds in one or more of the truncated quadrants in at least one eye, reasonable correspondence with the location of the visual field loss only occurred in half the patients studied. Hence, while contrast threshold elevations are indicative of glaucomatous damage to vision, they are providing a different assessment of visual function from conventional visual field tests

The effect of alcohol advertising, marketing and portrayal on drinking behaviour in young people: systematic review of prospective cohort studies

<p>Abstract</p> <p>Background</p> <p>The effect of alcohol portrayals and advertising on the drinking behaviour of young people is a matter of much debate. We evaluated the relationship between exposure to alcohol advertising, marketing and portrayal on subsequent drinking behaviour in young people by systematic review of cohort (longitudinal) studies.</p> <p>Methods</p> <p>studies were identified in October 2006 by searches of electronic databases, with no date restriction, supplemented with hand searches of reference lists of retrieved articles. Cohort studies that evaluated exposure to advertising or marketing or alcohol portrayals and drinking at baseline and assessed drinking behaviour at follow-up in young people were selected and reviewed.</p> <p>Results</p> <p>seven cohort studies that followed up more than 13,000 young people aged 10 to 26 years old were reviewed. The studies evaluated a range of different alcohol advertisement and marketing exposures including print and broadcast media. Two studies measured the hours of TV and music video viewing. All measured drinking behaviour using a variety of outcome measures. Two studies evaluated drinkers and non-drinkers separately. Baseline non-drinkers were significantly more likely to have become a drinker at follow-up with greater exposure to alcohol advertisements. There was little difference in drinking frequency at follow-up in baseline drinkers. In studies that included drinkers and non-drinkers, increased exposure at baseline led to significant increased risk of drinking at follow-up. The strength of the relationship varied between studies but effect sizes were generally modest. All studies controlled for age and gender, however potential confounding factors adjusted for in analyses varied from study to study. Important risk factors such as peer drinking and parental attitudes and behaviour were not adequately accounted for in some studies.</p> <p>Conclusion</p> <p>data from prospective cohort studies suggest there is an association between exposure to alcohol advertising or promotional activity and subsequent alcohol consumption in young people. Inferences about the modest effect sizes found are limited by the potential influence of residual or unmeasured confounding.</p