Nigel J. Hall

Core outcome sets (COSs) provide a mechanism to guide researchers and clinicians when deciding which outcomes to report in research related to a specific clinical condition or intervention. The intention behind creating a COS for a specific condition is to improve the reporting of important and meaningful outcomes, thus enhancing the relevance of research. Additionally, a COS helps facilitate comparison of outcomes between different clinical studies and reduces research waste. In this paper, we discuss the availability of COSs in the field of pediatric general surgery. We provide an overview of the methodologies used to develop a COS, including common pitfalls, and finally, we discuss COS uptake and implementation. An understanding of all these aspects is important for researchers considering developing a new COS and for those reading research where a COS has been developed or used within a study. Failure to adequately appreciate the nuances of COS development, in particular, risks fundamental flaws that may jeopardize COS validity and subsequently hinder COS uptake and implementation.