The problem with composite indicators

Abstract

‘The Problem with…’ series covers controversial topics related to efforts to improve healthcare quality, including widely recommended but deceptively difficult strategies for improvement and pervasive problems that seem to resist solution.

Influence of remoteness of residence on timeliness of diagnosis and treatment of oral cavity and oropharynx cancer: A retrospective cohort study

“…Therefore, a composite measure weighting specific intervals along the diagnostic pathway may be considered. However, larger studies using population‐based data should be performed to determine the appropriate weights given to each individual measure within the composite …”

Composite measures of healthcare quality: sensible in theory, problematic in practice

“…Unless these limitations are addressed, for instance, through improving the transparency around the composite measures’ inherent aims and limitations, or by allowing users to adapt composites to reflect individual preference which could be aided through data visualisation tools,19 their main applications are likely to be about helping patients to decide where to go for care, rather than quality improvement. Producers of performance rankings might be better advised to combine data across multiple years to make impact assessments.…”

Identifying adverse events: reflections on an imperfect gold standard after 20 years of patient safety research

“…Such composites offer two advantages—the simplicity of a single overall measure and increased statistical power from having more eligible events. But, these composites can create problems,34 35 just as with composite outcomes in clinical trials 36 37. Composite outcomes pose particular problems when the components vary substantially in terms of their frequency and/or severity and when an intervention exerts differential effects on the various components.…”