A core outcome set for clinical trials in oropharyngeal cancer

Abstract

The impact of randomized controlled trials is frequently diminished by disparate outcome reporting, precluding the comparison of results between trials or synthesis of data in meta-analyses. This is particularly problematic in lower incidence conditions such as oropharyngeal squamous cell carcinoma (OPSCC), where the need to synthesise data from competing trials is greater. Minimum outcome reporting standards, known as Core Outcome Sets (COS) have been shown to increase the consistency of outcome reporting between trials of comparable interventions, thus facilitating the comparison or synthesis of trial data. The objective of the work in this thesis was to identify outcomes of importance to patients, carers and healthcare professionals and define a COS for OPSCC. The methods used comprised a systematic review of OPSCC RCTs to identify the outcomes reported and establish whether there was outcomes heterogeneity as suggested by other studies; semi-structured qualitative interviews with patients and carers to establish their outcomes of importance; a Delphi Study of patients, carers and healthcare professionals, to reach consensus on the outcomes that should be included in a COS for OPSCC. The systematic review described in chapter two identified significant heterogeneity in outcome reporting; 58 outcomes were reported in 43 RCTs, only three outcomes were measured in more than 50% of studies, and only 41% of outcomes were measured in more than one study. The qualitative study identified 136 outcomes. Survival and late adverse effects of treatment are of greatest priority to patients and carers. The Delphi study successfully reached consensus on eight outcomes for inclusion in the COS. There is substantial heterogeneity in the outcomes measured in contemporary RCTs in OPSCC. Yet, there is strong consensus between stakeholder groups in the outcomes of importance. Implementation of the COS will increase the consistency of outcome reporting thus facilitating the comparison of data from competing trials and synthesis of data in meta-analyses. Further consideration must be given to ways in which the uptake of COS can be maximised to have the highest impact. The COS is applicable to trials of interventions used in current clinical practice, however the advent of new treatment strategies may require that this is reviewed and adapted.