Reasons for exclusion at stage 2 (assessment of full text reports).

*Although these studies are relevant to the development of a core outcome set (and therefore suitable for inclusion in the COMET database), they did not meet the review inclusion criteria.*1These studies included qualitative studies describing the impact of a treatment or condition on a patient's quality of life, studies to determine particular domains of quality of life, and single patient narratives of the impact of a condition or treatment on their quality of life. The focus of these studies was on quality of life only.*2Although the ICF is widely comprehensive [13], it is not all inclusive. For example, the ICF does not include outcomes such as death, an outcome that is often relevant to measure in clinical trials. Furthermore, as the ICF focuses on the individual only, caregiver outcomes would not be included. While for many health areas this may not be relevant, for some (e.g. dementia), caregiver outcomes may be core to measure.*3These studies assessed quality or efficiency of care (clinical practice), or the performance of an individual institution. Indicators were often specific to that scenario/environment of care only.*4These studies described the development of registries, each with its own purpose, often to evaluate management of patients, identify best practices or to describe therapeutic strategies.*5599 of these (90%) had no abstract to assess (title only), so had to be reviewed at full paper due to potential eligibility based on the title alone.