Aspects of economic costs and evaluation of health surveillance systems after a radiation accident with a focus on an ultrasound thyroid screening programme for children.

Health surveillance initiatives targeted at populations evacuated from, and residing in, areas affected by radiation contamination were implemented by international institutions as well as national and local governments after the nuclear accidents of Chernobyl and Fukushima Dai-ichi nuclear power plants. Most of these initiatives included a component of childhood thyroid cancer monitoring, with the more comprehensive schemes corresponding to national programmes of health monitoring for adults and children around general health and wellbeing. This article provides a short overview of available data on the costs and resources associated with surveillance responses to two recent nuclear accidents: Chernobyl and the Fukushima Dai-Ichi nuclear plant accidents.

Practical help for specifying the target difference in sample size calculations for RCTs: the DELTA five-stage study, including a workshop.

Background: The randomised controlled trial is widely considered to be the gold standard study for comparing the effectiveness of health interventions. Central to its design is a calculation of the number of participants needed (the sample size) for the trial. The sample size is typically calculated by specifying the magnitude of the difference in the primary outcome between the intervention effects for the population of interest.

Correction to: Choosing the target difference and undertaking and reporting the sample size calculation for a randomised controlled trial - the development of the DELTA2 guidance.

Following publication of the original article [1], we have been notified of a few mistakes.

DELTA guidance on choosing the target difference and undertaking and reporting the sample size calculation for a randomised controlled trial.

Randomised controlled trials are considered to be the best method to assess comparative clinical efficacy and effectiveness, and can be a key source of data for estimating cost effectiveness. Central to the design of a randomised controlled trial is an a priori sample size calculation, which ensures that the study has a high probability of achieving its prespecified main objective. Beyond pure statistical or scientific concerns, it is ethically imperative that an appropriate number of study participants be recruited, to avoid imposing the burdens of a clinical trial on more patients than necessary.

DELTA guidance on choosing the target difference and undertaking and reporting the sample size calculation for a randomised controlled trial.

Background: A key step in the design of a RCT is the estimation of the number of participants needed in the study. The most common approach is to specify a target difference between the treatments for the primary outcome and then calculate the required sample size. The sample size is chosen to ensure that the trial will have a high probability (adequate statistical power) of detecting a target difference between the treatments should one exist.

Choosing the target difference and undertaking and reporting the sample size calculation for a randomised controlled trial - the development of the DELTA guidance.

Background: A key step in the design of a randomised controlled trial is the estimation of the number of participants needed. The most common approach is to specify a target difference in the primary outcome between the randomised groups and then estimate the corresponding sample size. The sample size is chosen to provide reassurance that the trial will have high statistical power to detect the target difference at the planned statistical significance level.

Choosing the target difference ('effect size') for a randomised controlled trial - DELTA guidance protocol.

Background: A key step in the design of a randomised controlled trial (RCT) is the estimation of the number of participants needed. By far the most common approach is to specify a target difference and then estimate the corresponding sample size; this sample size is chosen to provide reassurance that the trial will have high statistical power to detect such a difference between the randomised groups (at the planned statistical significance level). The sample size has many implications for the conduct of the study, as well as carrying scientific and ethical aspects to its choice.

Specifying the target difference in the primary outcome for a randomised controlled trial: guidance for researchers.

Background: Central to the design of a randomised controlled trial is the calculation of the number of participants needed. This is typically achieved by specifying a target difference and calculating the corresponding sample size, which provides reassurance that the trial will have the required statistical power (at the planned statistical significance level) to identify whether a difference of a particular magnitude exists. Beyond pure statistical or scientific concerns, it is ethically imperative that an appropriate number of participants should be recruited.

Methods for specifying the target difference in a randomised controlled trial: the Difference ELicitation in TriAls (DELTA) systematic review.

Background: Randomised controlled trials (RCTs) are widely accepted as the preferred study design for evaluating healthcare interventions. When the sample size is determined, a (target) difference is typically specified that the RCT is designed to detect. This provides reassurance that the study will be informative, i.

Assessing methods to specify the target difference for a randomised controlled trial: DELTA (Difference ELicitation in TriAls) review.

Background: The randomised controlled trial (RCT) is widely considered to be the gold standard study for comparing the effectiveness of health interventions. Central to the design and validity of a RCT is a calculation of the number of participants needed (the sample size). The value used to determine the sample size can be considered the 'target difference'.

Use of methods for specifying the target difference in randomised controlled trial sample size calculations: Two surveys of trialists' practice.

Background: Central to the design of a randomised controlled trial (RCT) is a calculation of the number of participants needed. This is typically achieved by specifying a target difference, which enables the trial to identify a difference of a particular magnitude should one exist. Seven methods have been proposed for formally determining what the target difference should be.

Developing the clinical components of a complex intervention for a glaucoma screening trial: a mixed methods study.

Background: Glaucoma is a leading cause of avoidable blindness worldwide. Open angle glaucoma is the most common type of glaucoma. No randomised controlled trials have been conducted evaluating the effectiveness of glaucoma screening for reducing sight loss.

Randomised trial of glutamine, selenium, or both, to supplement parenteral nutrition for critically ill patients.

Objective: To determine whether inclusion of glutamine, selenium, or both in a standard isonitrogenous, isocaloric preparation of parenteral nutrition influenced new infections and mortality among critically ill patients.

Design: Randomised, double blinded, factorial, controlled trial.

Setting: Level 2 and 3 (or combined) critical care units in Scotland.

Economic evaluation of screening for open-angle glaucoma.

Objectives: The aim of this study was to assess the cost-effectiveness of screening for open-angle glaucoma (OAG) in the United Kingdom, given that OAG is an important cause of blindness worldwide.

Methods: A Markov model was developed to estimate lifetime costs and benefits of a cohort of patients facing, alternatively, screening or current opportunistic case finding strategies. Strategies, varying in how screening would be organized (e.

Early treatment with prednisolone or acyclovir in Bell's palsy.

Background: Corticosteroids and antiviral agents are widely used to treat the early stages of idiopathic facial paralysis (i.e., Bell's palsy), but their effectiveness is uncertain.

Randomised trial of glutamine and selenium supplemented parenteral nutrition for critically ill patients. Protocol Version 9, 19 February 2007 known as SIGNET (Scottish Intensive care Glutamine or seleNium Evaluative Trial).

Background: Mortality rates in the Intensive Care Unit and subsequent hospital mortality rates in the UK remain high. Infections in Intensive Care are associated with a 2-3 times increased risk of death. It is thought that under conditions of severe metabolic stress glutamine becomes "conditionally essential".

Effect of multivitamin and multimineral supplementation on cognitive function in men and women aged 65 years and over: a randomised controlled trial.

Background: Observational studies have frequently reported an association between cognitive function and nutrition in later life but randomised trials of B vitamins and antioxidant supplements have mostly found no beneficial effect. We examined the effect of daily supplementation with 11 vitamins and 5 minerals on cognitive function in older adults to assess the possibility that this could help to prevent cognitive decline.

Methods: The study was carried out as part of a randomised double blind placebo controlled trial of micronutrient supplementation based in six primary care health centres in North East Scotland.

A cost-utility analysis of multivitamin and multimineral supplements in men and women aged 65 years and over.

Background & Aims: As people age there is a progressive dysregulation of the immune system that may lead to an increased risk of infections, which may precipitate hospital admission in people with chronic heart or respiratory diseases. Mineral and vitamin supplementation in older people could therefore influence infections in older people. However, the evidence from the available randomised controlled trials (RCTs) is mixed.

Effect of multivitamin and multimineral supplements on morbidity from infections in older people (MAVIS trial): pragmatic, randomised, double blind, placebo controlled trial.

Objective: To examine whether supplementation with multivitamins and multiminerals influences self reported days of infection, use of health services, and quality of life in people aged 65 or over.

Design: Randomised, placebo controlled trial, with blinding of participants, outcome assessors, and investigators.

Setting: Communities associated with six general practices in Grampian, Scotland.

Low back pain: influence of early MR imaging or CT on treatment and outcome--multicenter randomized trial.

Purpose: To establish whether early use of magnetic resonance (MR) imaging or computed tomography (CT) influences treatment and outcome of patients with low back pain (LBP) and whether it is cost-effective.

Materials And Methods: In a multicenter randomized study, two imaging policies for LBP were compared in 782 participants with symptomatic lumbar spine disorders who were referred to orthopedists or neurosurgeons. Participants were randomly allocated to early (393 participants; mean age, 43.