Composite measures are increasingly being used to assess the quality of health care. Recent examples include English star ratings, the quality and outcomes framework points score in the United Kingdom, and national and state scorecards in the United States.1 2 3 4 Composites summarise data from many quality indicators in one more easily understood number or rating.

This is particularly important for patients and the public.5 Ease of interpretation is also important for policymakers, who need broad overviews of a system’s performance.1 Composites may therefore improve communication with the public (although the evidence that the public uses such data is weak, irrespective of how it is presented), increase accountability to payers, and help ensure that quality of care remains a priority in policy.

In the linked study (doi: 10.1136/bmj.a957), Steel and colleagues report findings from a rigorously designed and implemented representative survey of older people in England, and they present various composites based …