Which indicator is misclassified as a process measure but should be considered an outcome indicator in the European Society of Cardiology quality‑indicator set for cardiovascular disease prevention?

Which Indicator is Misclassified in ESC Quality Indicators for CVD Prevention

The assessment of patient health-related quality of life (HRQoL) is misclassified as a process measure when it should be considered an outcome indicator in the European Society of Cardiology quality indicator framework for cardiovascular disease prevention. 1

The Misclassification Issue

The ESC Heart Failure Quality Indicators document explicitly acknowledges this misclassification problem. Secondary indicator 5.1, which measures the assessment of patients' health-related quality of life using validated tools, has been deliberately designed as a process QI rather than an outcome measure, despite HRQoL fundamentally representing a patient outcome. 1

Why This Represents a Misclassification

According to ESC methodology, quality indicators should be categorized into three types 1:

• Process QIs: Capture actions taken by healthcare providers or patients, such as adherence to guidelines or prescribed therapies 1
• Outcome QIs: Concern the effects of healthcare on patients, populations, or societies, including patient-reported outcome measures (PROMs) like health-related quality of life 1
• Structural QIs: Describe organizational aspects of care 1

Health-related quality of life clearly falls under the definition of an outcome indicator because it represents the effect of healthcare on patients' well-being and functional status. 1 The ESC explicitly states that outcome QIs "may also include patient-reported outcome measures (PROMs), such as health-related quality of life." 1

The Rationale Behind the Misclassification

The Working Group made a pragmatic decision to classify HRQoL assessment as a process measure due to concerns about feasibility of data collection in clinical practice. 1 By designing this as a process QI, the mere act of assessing the patient's health-related quality of life constitutes accomplishment of the indicator, without setting specific scores as targets for therapy. 1

Clinical Implications

This misclassification has important practical consequences:

• It shifts the focus from achieving actual improvements in patient quality of life (the true outcome) to simply documenting that an assessment was performed (a process). 1
• The approach acknowledges the burden of implementing PROMs in routine clinical practice while still encouraging their use 1
• It represents a compromise between methodological rigor and real-world feasibility 1

Broader Context of Indicator Misclassification

This is not an isolated issue. Research on quality indicator development shows that misclassification occurs across guideline organizations. In one systematic comparison, reviewers disagreed with the categorization made by authors of international clinical practice guidelines for 12 of 64 (19%) quality indicators and changed their category assignments. 1

The ESC methodology document emphasizes that high-quality evidence tends to be available to support process QIs rather than structural or outcome indicators, which may contribute to the tendency to classify indicators as process measures even when they conceptually represent outcomes. 1