Outcomes of periodontal therapy: Strengthening the relevance of research to patients. A co-created review.

Periodontitis is a long-term condition affecting up to half of the population globally and causing significant impacts on life quality. Successful management depends on taking life-long ownership of the condition by those affected. There is a wealth of research to inform on management options. However, most of the research has been designed by professional experts with outcomes to gauge benefits and harms based on parameters that inform on the disease process but which might not be informative to support decision-making in people with lived experience (PWLE) of periodontal ill-health (including both patients and carers). The importance of relevant outcomes is highlighted in the concept of the "expert patient" which aims to strengthen the capacity of PWLE to make health-care choices that are important for them, elements of which are likely to be already familiar to many clinicians delivering periodontal health care. Therefore, the voice and collaboration of PWLE in research are recognised as crucial to developing high quality, relevant evidence especially for long-term conditions. In this paper, we review what is known about the relevance of treatment outcomes to PWLE. We also examine the degree to which PWLE have been involved in identifying outcomes that are important to them as well as the diversity and therefore representativeness of PWLE recruited for studies. We consider why having more relevant outcomes could enhance the expertise of PWLE in managing their periodontitis. We then conclude with key learnings from our review which we hope will encourage more rapid development of these initiatives in periodontology for the benefit of global health and wellbeing.