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Background Precision in estimating placebo rates is important for clinical trial design. Aim To quantify placebo rates across relevant endpoints in Crohn's disease [CD] trials and identify the factors influencing these rates in a contemporary meta-analysis. Methods We searched MEDLINE, EMBASE, and CENTRAL from inception to March 2021. Eligible studies were placebo-controlled trials of pharmacological interventions for CD. Placebo response and remission rates for induction and maintenance trials were extracted and pooled by random-effects to quantify placebo rates across studies. Mixed-effects meta-regression was used to evaluate the effects of study-level characteristics on placebo rates. Results In 125 studies [91 induction, 46 maintenance], placebo clinical remission and response rates for induction studies were 18% (95% confidence interval [CI] 16, 21%], and 32% [95% CI 29, 35%], respectively, and for maintenance studies were 28% [95% CI 23, 34%] and 30% [95% CI 24, 37%], respectively. Endoscopic remission and response rates in induction studies were 8% [95% CI 4, 18%] and 16% [95% CI 11, 23%], respectively. Trials enrolling patients with prior biologic exposure, longer disease duration, and higher CD activity index scores were associated with lower placebo clinical remission rates. Increased duration of follow-up, more follow-up visits, and a greater proportion of patients with colonic disease distribution were associated with higher clinical placebo rates. Conclusions Placebo remission and response rates in CD trials vary according to the phase of the trial, endpoint assessed, and induction or maintenance design. These contemporary estimates will help to inform future CD trial design. [ABSTRACT FROM AUTHOR]

Background and Aims Quantifying placebo rates and the factors influencing them are essential to inform trial design. We provide a contemporary summary of clinical, endoscopic, histological and safety placebo rates in induction and maintenance clinical trials of ulcerative colitis, and identify factors influencing them. Methods MEDLINE, EMBASE and the Cochrane library were searched from April 2014 to April 2020, updating a prior meta-analysis that searched from inception to April 2014. We included placebo-controlled trials of aminosalicylates, corticosteroids, immunosuppressives, small-molecules and biologics in adults with ulcerative colitis. Placebo rates were pooled using random-effects and mixed-effects meta-regression models to assess the associated study-level. Results In 119 trials [92 induction, 27 maintenance] clinical, endoscopic and histological remission placebo rates for induction trials were 11% (95% confidence interval [CI] 9–13%), 19% [95% CI 15–23%] and 15% [95% CI 11–19%], respectively; for maintenance trials, clinical and endoscopic placebo remission rates were 18% [95% CI 12–25%] and 20% [95% CI 15–25%], respectively. Higher endoscopic subscore and a higher rate of exposure to prior biologic therapy at enrolment were associated with lower clinical and endoscopic placebo remission rates. Absence of central reading was associated with an increase in placebo endoscopic response and remission rates. More follow-up visits and increasing trial duration were associated with higher clinical placebo rates. Conclusions Placebo rates in ulcerative colitis trials vary according to the endpoint assessed, whether it is for assessment of response or remission, and whether the trial is designed for induction or maintenance. These contemporary rates across different endpoints and drug classes will help to inform trial design. [ABSTRACT FROM AUTHOR]

Background: Patient-centred interventions to help patients with multimorbidity have had mixed results.Aim: To assess the effectiveness of a provider-created, patient-centred, multi-provider case conference with follow-up, and understand under what circumstances it worked, and did not work.Design and Setting: Mixed-methods design with a pragmatic randomised trial and qualitative study, involving nine urban primary care sites in Ontario, Canada.Method: Patients aged 18-80 years with ≥3 chronic conditions were referred to the Telemedicine IMPACT Plus intervention; a nurse and patient planned a multi-provider case conference during which a care plan could be created. The patients were randomised into an intervention or control group. Two subgroup analyses and a fidelity assessment were conducted, with the primary outcomes at 4 months being self-management and self-efficacy. Secondary outcomes were mental and physical health status, quality of life, and health behaviours. A thematic analysis explored the patients' experiences of the intervention.Results: A total of 86 patients in the intervention group and 77 in the control group showed no differences, except that the intervention improved mental health status in the subgroup with an annual income of ≥C$50 000 (β-coefficient 11.003, P = 0.006). More providers and follow-up hours were associated with poorer outcomes. Five themes were identified in the qualitative study: valuing the team, patients feeling supported, receiving a follow-up plan, being offered new and helpful additions to their treatment regimen, and experiencing positive outcomes.Conclusion: Overall, the intervention showed improvements only for patients who had an annual income of ≥C$50 000, implying a need to address the costs of intervention components not covered by existing health policies. Findings suggest a need to optimise team composition by revising the number and type of providers according to patient preferences and to enhance the hours of nurse follow-up to better support the patient in carrying out the case conference's recommendations. [ABSTRACT FROM AUTHOR]

Background and purpose: Cognitive enhancers are commonly prescribed to people with Alzheimer's disease and related dementias to improve cognition and function. However, their effectiveness for individuals in the pre‐stages of dementia, particularly in functional motor outcomes, remains unknown. We aimed to determine the efficacy of donepezil, a cognitive enhancer that improves cholinergic neurotransmission, on gait performance in mild cognitive impairment (MCI). Methods: This was a double‐blind, placebo‐controlled trial including 60 older adults with MCI, randomized to receive donepezil (10 mg/daily, maximal dose) or placebo. Primary outcome was gait speed (cm/s) under single and three dual‐task conditions (counting backwards by 1 or 7 and naming animals) measured using an electronic walkway. Dual‐task gait cost (DTC), a valid measure of motor–cognitive interaction, was calculated as the percentage change between single (S) and dual‐task (D) gait speeds: [(S − D)/S] × 100. Secondary outcomes included attention, executive function, balance and falls. Results: After 6 months, the donepezil group experienced an improvement in dual‐task gait speed (range 4–11 cm/s), although this was not statistically significant. The donepezil group showed a significant reduction in DTC (improvement) by counting backwards by 1 and 7 compared with placebo (10.25% vs. 1.75%, P = 0.048; 21.38% vs. 14.64%, P = 0.037, intention‐to‐treat analysis). Per‐protocol analyses showed that all three DTCs improved in the donepezil group, along with a non‐significant reduction of rate of falls. Conclusions: Donepezil treatment improved dual‐task gait speed and DTC in elderly patients with MCI. Our results support the concept of reducing falls in MCI by targeting the motor–cognitive interface. [ABSTRACT FROM AUTHOR]

Double-sampling schemes using one classifier assessing the whole sample and another classifier assessing a subset of the sample have been introduced for reducing classification errors when an infallible or gold standard classifier is unavailable or impractical. Inference procedures have previously been proposed for situations where an infallible classifier is available for validating a subset of the sample that has already been classified by a fallible classifier. Here, we consider the case where both classifiers are fallible, proposing and evaluating several confidence interval procedures for a proportion under two models, distinguished by the assumption regarding ascertainment of two classifiers. Simulation results suggest that the modified Wald-based confidence interval, Score-based confidence interval, two Bayesian credible intervals, and the percentile Bootstrap confidence interval performed reasonably well even for small binomial proportions and small validated sample under the model with the conditional independent assumption, and the confidence interval derived from the Wald test with nuisance parameters appropriately evaluated, likelihood ratio-based confidence interval, Score-based confidence interval, and the percentile Bootstrap confidence interval performed satisfactory in terms of coverage under the model without the conditional independent assumption. Moreover, confidence intervals based on log- and logit-transformations also performed well when the binomial proportion and the ratio of the validated sample are not very small under two models. Two examples were used to illustrate the procedures. [ABSTRACT FROM AUTHOR]

This study was conducted to determine effects of dietary Fe levels on growth performance, hepatic lipid metabolism and antioxidant response for juvenile yellow catfish Pelteobagrus fulvidraco. Yellow catfish were fed six isonitrogenous and isolipidic diets containing Fe levels of 16.20, 34.80, 54.50, 76.44, 100.42 and 118.25 mg/kg for 8 weeks. Weight gain ( WG) and specific growth rate ( SGR) increased with dietary Fe levels from 16.20 to 54.50 mg/kg diet and then plateaued over the level. Feed conversion rate ( FCR) was highest and protein efficiency rate ( PER) was lowest for fish fed the lowest Fe levels of diet. Fe contents in whole body and liver increased with increasing dietary Fe levels. Hepatic lipid content was lowest, but mRNA levels of carnitine palmitoyltransferase ( CPT-1) and peroxisome proliferator-activated receptor α ( PPARα) were highest for fish fed 54.50 mg Fe/kg diet. Fish fed adequate dietary Fe levels reduced hepatic malondialdehyde ( MDA) level and increased activities of antioxidant enzymes Superoxide dismutase ( SOD), Catalase ( CAT) and GS. Based on the broken-line regression analysis of WG against dietary Fe levels, optimal dietary Fe requirement for yellow catfish was 55.73 mg Fe/kg diets. Fe-induced changes in MDA levels and antioxidant enzymatic activities paralleled with the change in hepatic lipid content, suggesting the potential relationship between oxidative stress and hepatic lipid accumulation in yellow catfish. [ABSTRACT FROM AUTHOR]

Cluster randomization trials, in which intact social units are randomized to different interventions, have become popular in the last 25 years. Outcomes from these trials in many cases are positively skewed, following approximately lognormal distributions. When inference is focused on the difference between treatment arm arithmetic means, existent confidence interval procedures either make restricting assumptions or are complex to implement. We approach this problem by assuming log-transformed outcomes from each treatment arm follow a one-way random effects model. The treatment arm means are functions of multiple parameters for which separate confidence intervals are readily available, suggesting that the method of variance estimates recovery may be applied to obtain closed-form confidence intervals. A simulation study showed that this simple approach performs well in small sample sizes in terms of empirical coverage, relatively balanced tail errors, and interval widths as compared to existing methods. The methods are illustrated using data arising from a cluster randomization trial investigating a critical pathway for the treatment of community acquired pneumonia. [ABSTRACT FROM AUTHOR]

Objective: Although low infliximab trough concentrations and antibodies to infliximab (ATI) are associated with poor outcomes in patients with Crohn's disease (CD), the clinical relevance of ATI in patients with adequate infliximab concentrations is uncertain. We evaluated this question using an assay sensitive for identification of ATI in the presence of infliximab. Design: In an observational study, 1487 trough serum samples from 483 patients with CD who participated in four clinical studies of maintenance infliximab therapy were analysed using a fluid phase mobility shift assay. Infliximab and ATI concentrations most discriminant for remission, defined as a C-reactive protein concentration of ≤5 mg/L, were determined by receiver operating characteristic curves. A multivariable regression model evaluated these factors as independent predictors of remission. Results: Based upon analysis of 1487 samples, 77.1% of patients had detectable and 22.9% had undetectable infliximab concentrations, of which 9.5% and 71.8%, respectively, were positive for ATI. An infliximab concentration of >2.79 µg/mL (area under the curve (AUC)=0.681; 95% CI 0.632 to 0.731) and ATI concentration of <3.15 U/mL (AUC=0.632; 95% CI 0.589 to 0.676) were associated with remission. Multivariable analysis showed that concentrations of both infliximab trough (OR 1.8; 95% CI 1.3 to 2.5; p<0.001) and ATI (OR 0.57; 95% CI 0.39 to 0.81; p=0.002) were independent predictors of remission. Conclusions: The development of ATI increases the probability of active disease even at low concentrations and in the presence of a therapeutic concentration of drug during infliximab maintenance therapy. Evaluation of strategies to prevent ATI formation, including therapeutic drug monitoring with selective infliximab dose intensification, is needed. [ABSTRACT FROM AUTHOR]

It is widely accepted that confidence interval construction has important advantages over significance testing for the presentation of research results, as now facilitated by readily available software. However, for a number of effect measures, procedures are either not available or not satisfactory in samples of small to moderate size. In this paper, we describe a general approach for estimating a difference between effect measures, which can also be used to obtain confidence limits for a risk ratio and a lognormal mean. Numerical evaluation shows that this closed-form procedure outperforms existing methods, including the bootstrap. Copyright © 2007 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]