Search

Showing total 6 results
Start Over Topic randomized controlled trials Publication Type Reviews
6 results

1. GOST: A generic ordinal sequential trial design for a treatment trial in an emerging pandemic.

Author

Whitehead, John and Horby, Peter

Subjects
*MEDICAL software, *COMMUNICABLE disease treatment, *PANDEMICS
Abstract

Background: Conducting clinical trials to assess experimental treatments for potentially pandemic infectious diseases is challenging. Since many outbreaks of infectious diseases last only six to eight weeks, there is a need for trial designs that can be implemented rapidly in the face of uncertainty. Outbreaks are sudden and unpredictable and so it is essential that as much planning as possible takes place in advance. Statistical aspects of such trial designs should be evaluated and discussed in readiness for implementation. Methodology/Principal findings: This paper proposes a generic ordinal sequential trial design (GOST) for a randomised clinical trial comparing an experimental treatment for an emerging infectious disease with standard care. The design is intended as an off-the-shelf, ready-to-use robust and flexible option. The primary endpoint is a categorisation of patient outcome according to an ordinal scale. A sequential approach is adopted, stopping as soon as it is clear that the experimental treatment has an advantage or that sufficient advantage is unlikely to be detected. The properties of the design are evaluated using large-sample theory and verified for moderate sized samples using simulation. The trial is powered to detect a generic clinically relevant difference: namely an odds ratio of 2 for better rather than worse outcomes. Total sample sizes (across both treatments) of between 150 and 300 patients prove to be adequate in many cases, but the precise value depends on both the magnitude of the treatment advantage and the nature of the ordinal scale. An advantage of the approach is that any erroneous assumptions made at the design stage about the proportion of patients falling into each outcome category have little effect on the error probabilities of the study, although they can lead to inaccurate forecasts of sample size. Conclusions/Significance: It is important and feasible to pre-determine many of the statistical aspects of an efficient trial design in advance of a disease outbreak. The design can then be tailored to the specific disease under study once its nature is better understood. [ABSTRACT FROM AUTHOR]

Published
2017
Full Text
View/download PDF

3. Review of: Interpreting and Reporting Clinical Trials -- A guide to the CONSORT statement and the principles of randomised controlled trials by Anthony Keech, Val Gebski and Rhana Pike.

Author

Evans, Stephen J. W.

Subjects
RANDOMIZED controlled trials, NONFICTION
Abstract

The article reviews the book "Interpreting and Reporting Clinical Trials: A Guide to the CONSORT Statement and the Principles of Randomised Controlled Trials," Anthony Keech, Val Gebski and Rhana Pike.

Published
2008
Full Text
View/download PDF

6. School dental screening does not increase dental attendance rates or reduce disease levels.

Author

Rodgers, Jennifer

Subjects
SCHOOL children's dental care, RANDOMIZED controlled trials, DENTAL caries in children, ORAL sepsis, DENTAL plaque, DENTISTS, PREVENTION
Abstract

DesignThis was a cluster randomised controlled trial, in which the unit of randomisation was the school.InterventionThree models of screening were tested against a control. A ‘new’ model of school dental screening incorporated a consensus view, from clinicians in the northwest of England, on a set of clinical criteria that would prompt a referral following a screening examination. A ‘traditional’ model involved the delivery of the existing school dental screening programme according to the principle that a child is referred if, in the opinion of the screening dentist, dental care is required. The third intervention tested was a dental information leaflet, distributed via the schools, which encouraged parents to examine their child's mouth and to take their child to a dentist if any problems were noted. Children a ttending the control schools received no intervention during the study period.Outcome measureThe main outcome measures were prevalence of teeth with active caries and mean number of teeth with active caries in the permanent or primary dentition. Secondary outcome measures were prevalence of oral sepsis, gross plaque or calculus, and dental trauma to incisor teeth.ResultsSeventeen thousand and ninety-eight children in 169 clusters (schools) were eligible for inclusion in the study. One school was withdrawn from the study because of failure to agree to follow the trial protocol. Of the total, 15 004 children were available for baseline examination in 168 schools and 13 570 children received a baseline and outcome examination, representing 80.5% of the eligible population. After adjustment for clustering of children in schools, there was no significant difference in the reduction from baseline in untreated caries between the study groups in either the primary or permanent dentition. Similarly there were no significant differences across the four arms of the study in the secondary outcome measures of prevalence of sepsis, presence of gross plaque or calculus, and trauma to the permanent incisor teeth. In the traditional arms, 42% of children attended a dentist during the study period, with 41% in the new-model arm, 37% in the information-leaflet arm and 38% in the control arm. Although more children in the traditional and new-model arms of the study attended a dental appointment these differences were not statistically significant.ConclusionsSchool dental screening delivered according to three different models was not effective at reducing levels of active caries and increasing dental attendance in the population under study.Evidence-Based Dentistry (2007) 8, 5–6. doi:10.1038/sj.ebd.6400460 [ABSTRACT FROM AUTHOR]

Published
2007
Full Text
View/download PDF