Unveiling the Concept of Minimal Clinically Important Difference (MCID) in Cardiac Surgery

Abstract

Objectives: The aim of this review is to describe the different statistical methods used in estimating the Minimal Clinically Important Difference (MCID) for the assessment of quality of life (QOL)-related and clinical improvement interventions, along with its implementation in cardiac surgery.Methods: A thorough literature search was performed in three databases (PubMed/Medline, Scopus, Google scholar) for relevant articles from 1980 to 2021. We included articles that described anchors and statistical methods used to estimate the concept of MCID in the evaluation of clinical improvement interventions in cardiac surgery.Results: MCID has been successfully implemented in several medical specialties. Anchor-based and distribution-based methods are the most common approaches when evaluating the MCID. Nonetheless, we found only three studies investigating the MCID in the context of cardiac surgery. Two of them used anchor-based approaches and one used both anchor-based and distribution-based methods. MCID values were very variable depending on methods applied, as also on clinical context of the study. The variables of interest were the Short Form 36 Health Survey (SF-36) and the European Quality of Life Five Dimension (EQ-5D) questionnaires.Conclusions: Multiple anchors and methods are applied, leading to different estimations of MCID. Given that cardiac surgery is associated with significant morbidity, MCID might be a valuable tool to interpret clinical outcomes. Nonetheless, collaboration between statisticians and cardiac surgeons is necessary to integrate a consensus regarding the appropriate method to determine the appropriate MCID approaches. More studies are needed to validate different MCID methods in the cardiac surgery context.KeywordsCardiac surgeryMinimal clinically important differenceMCIDQuality of lifeQoL