Outcomes in clinical trials in children with asthma

Sinha, Ian
Outcomes in clinical trials in children with asthma. Doctor of Philosophy thesis, University of Liverpool.

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The selection of outcomes is a critically important decision when designing randomised controlled trials (RCTs). Informed clinical decisions can only be based on the results of RCTs that have measured outcomes of importance to both clinicians and patients. It can be difficult to know which outcomes should be measured in RCTs. Some groups advocate core outcome sets, which are a minimum set of outcomes that should be measured, and reported, in all clinical trials in a given condition. These increase the likelihood that important outcomes are measured, reduce nonuniformity between studies, and reduce the risk of outcome reporting bias. We systematically reviewed studies that determined which outcomes to measure in clinical trials in children, and found that such work had been conducted in only few conditions, and the quality of existing work was variable. Few studies used structured consensus techniques to reach agreement about which outcomes to measure in trials, and parents were seldom involved. No studies included children. One condition in which there were no robust recommendations about which outcomes to measurein RCTs was childhood asthma, which is a condition of considerable global importance. We subsequently aimed to assess whether the absence of a core outcome set for RCTs of children with asthma meant that certain outcome domains were measured less frequently than others, and whether there was nonuniformity between studies in terms of outcomes selected. We conducted a systematic review of RCTs of children with asthma, published between January 1988 and December 2007, and found that the included studies focussed on short-term disease activity, but quality of life, functional status, and long-term outcomes were infrequently measured. Certain outcomes were measured and reported in various ways. We recommended that a core outcome set should be developed for childhood asthma, using structured consensus techniques, such as the Delphi process. In order to aid the development of such a core set, we first systematically reviewed studies that used the Delphi process to determine which outcomes to measure in clinical trials. We observed variations in the methodology used, identified potential sources of bias, and provided recommendations about how such studies could be conducted and reported. In order to develop a core outcome set for childhood asthma, we used a Delphi process to ascertain the views of 46 clinicians, and around 100 parents and young people, about which outcomes are most important and relevant from their perspective, when making shared decisions about regular therapies which control asthma. The most important outcomes were symptoms, exacerbations, and quality of life. Although consensus still needs to be reached amongst other groups of individuals involved in clinical trials, we conclude that these outcomes should be measured, and reported, in all RCTs that aim to evaluate the effectiveness of regular therapies for children and young people with asthma.

Item Type: Thesis (Doctor of Philosophy)
Additional Information: Date: 2011-04 (completed)
Subjects: ?? RC ??
?? RJ ??
Divisions: Faculty of Health and Life Sciences
Depositing User: Symplectic Admin
Date Deposited: 25 Aug 2011 14:55
Last Modified: 16 Dec 2022 04:35
DOI: 10.17638/00003193
  • Smyth, RL
URI: https://livrepository.liverpool.ac.uk/id/eprint/3193