Publications by authors named "Diana R Elbourne"
Background: The theory of human functioning and school organisation proposes that schools with rigid 'boundaries' (weaker relationships), for example, between staff and students, or learning and broader development, engender weaker student school commitment and sense of belonging, particularly among disadvantaged students, leading to greater involvement in risk-behaviours. Existing studies provide some support but rely on a proxy exposure of 'value-added education' and have not explored effects by disadvantage.
Methods: We used longitudinal data from English secondary schools from the control arm of a trial, assessing school-level measures of rigid boundaries, and student commitment and belonging at age 11/12, and student risk-behaviours at age 14/15.
Background: Interventions to modify school environments are effective in promoting young people's health across outcomes, but mechanisms are poorly understood. We assessed mediation in a trial of the Learning Together intervention, building on the recent publication of results of effectiveness for reducing bullying and benefits across secondary outcomes and generally good implementation fidelity.
Methods: Within a cluster-randomised trial involving 40 English schools, we examined student-reported and staff-reported school climate and student-reported involvement with delinquent peers at 24-month and 36-month follow-up, assessing the reliability of measures and whether these mediated health outcomes at a final follow-up.
Objectives: This study aims to (1) elucidate whether the Hawthorne effect exists, (2) explore under what conditions, and (3) estimate the size of any such effect.
Study Design And Setting: This systematic review summarizes and evaluates the strength of available evidence on the Hawthorne effect. An inclusive definition of any form of research artifact on behavior using this label, and without cointerventions, was adopted.
Background: The use of restricted randomisation methods such as minimisation is increasing. This paper investigates under what conditions it is preferable to use restricted randomisation in order to achieve balance between treatment groups at baseline with regard to important prognostic factors and whether trialists should be concerned that minimisation may be considered deterministic.
Methods: Using minimisation as the randomisation algorithm, treatment allocation was simulated for hypothetical patients entering a theoretical study having values for prognostic factors randomly assigned with a stipulated probability.
The CONSORT (Consolidated Standards of Reporting Trials) Statement, which includes a checklist and a flow diagram, is a guideline developed to help authors improve the reporting of the findings from randomized controlled trials. It was updated most recently in 2010. Its primary focus is on individually randomized trials with 2 parallel groups that assess the possible superiority of one treatment compared with another.
View Article and Find Full Text PDFBackground: In healthcare research the randomised controlled trial is seen as the gold standard because it ensures selection bias is minimised. However, there is uncertainty as to which is the most preferred method of randomisation in any given setting and to what extent more complex methods are actually being implemented in the field.
Methods: In this paper we describe the results of a survey of UK academics and publicly funded researchers to examine the extent of the use of various methods of randomisation in clinical trials.
Background: Extracorporeal Membrane Oxygenation (ECMO) is a technology used in treatment of patients with severe but potentially reversible respiratory failure. A multi-centre randomised controlled trial (CESAR) was funded in the UK to compare care including ECMO with conventional intensive care management. The protocol and funding for the CESAR trial included plans for economic data collection and analysis.
View Article and Find Full Text PDFBackground: Publicly funded clinical trials require a substantial commitment of time and money. To ensure that sufficient numbers of patients are recruited it is essential that they address important questions in a rigorous manner and are managed well, adopting effective marketing strategies.
Methods: Using methods of analysis drawn from management studies, this paper presents a structured assessment framework or reference model, derived from a case analysis of the MRC's CRASH trial, of 12 factors that may affect the success of the marketing and sales activities associated with clinical trials.
Background: Securing and managing finances for multicentre randomised controlled trials is a highly complex activity which is rarely considered in the research literature. This paper describes the process of financial negotiation and the impact of financial considerations in four UK multicentre trials. These trials had met, or were on schedule to meet, recruitment targets agreed with their public-sector funders.
View Article and Find Full Text PDFBackground: A commonly reported problem with the conduct of multicentre randomised controlled trials (RCTs) is that recruitment is often slower or more difficult than expected, with many trials failing to reach their planned sample size within the timescale and funding originally envisaged. The aim of this study was to explore factors that may have been associated with good and poor recruitment in a cohort of multicentre trials funded by two public bodies: the UK Medical Research Council (MRC) and the Health Technology Assessment (HTA) Programme.
Methods: The cohort of trials was identified from the administrative databases held by the two funding bodies.
The CONSORT (Consolidated Standards of Reporting Trials) Statement, including a checklist and a flow diagram, was developed to help authors improve their reporting of randomized controlled trials. Its primary focus was on individually randomized trials with 2 parallel groups that assess the possible superiority of one treatment compared with another but is now being extended to other trial designs. Noninferiority and equivalence trials have methodological features that differ from superiority trials and present particular difficulties in design, conduct, analysis, and interpretation.
View Article and Find Full Text PDFWith the publication of the CONSORT statement there is now increased awareness of the need to adequately report the findings of randomised controlled trials. The CONSORT statement includes a checklist of items that should be addressed in the trial report. The original CONSORT statement was developed to ensure the appropriate reporting of parallel group randomised controlled trials in which individual participants are allocated to different intervention groups.
View Article and Find Full Text PDFBackground: Increasingly, researchers are recognizing that there are many situations where the use of a cluster randomized trial may be more appropriate than an individually randomized trial. Similarly, the need for appropriate standards of reporting of cluster trials is more widely acknowledged.
Methods: In this paper, we describe the results of a survey to inform the appropriate reporting of the intracluster correlation coefficient (ICC)--the statistical measure of the clustering effect associated with a cluster randomized trial.
Background: Meta-analysis of randomized controlled trials (RCTs) is usually based on trials where patients are randomized individually into two different, parallel, treatment groups. This paper concentrates on RCTs of a different design-two-period, two-treatment cross-over trials.
Methods: The characteristics of these trials are outlined, with detailed examples of methods for analysis for both continuous and binary data.