Development of the 2023 ACR/EULAR Antiphospholipid Syndrome Classification Criteria, Phase III-D Report:...

Area of Science:

• Rheumatology
• Clinical Immunology
• Medical Classification Systems

Background:

• The 2023 American College of Rheumatology/EULAR antiphospholipid syndrome (APS) classification criteria were developed to identify patients with a high likelihood of APS for research purposes.
• Previous phases (I and II) generated 27 candidate criteria, categorized into laboratory and clinical domains.

Purpose of the Study:

• To summarize the final stage (Phase III) of the APS classification criteria development.
• To employ a consensus-based multicriteria decision analysis (MCDA) to determine the relative weights of candidate criteria.
• To establish a threshold score for classifying patients with APS.

Main Methods:

• Evaluation of 192 international patients with suspected APS and diverse manifestations.
• Subcommittee members ranked 20 representative patients and refined candidate criteria definitions.
• An MCDA exercise using 1000Minds software assigned weights based on consensus decisions and pairwise comparisons.
• Patients were rank-ordered using additive scores, and a consensus threshold was set.

Main Results:

• Initial evaluation revealed variability in APS assessment among subcommittee members.
• MCDA facilitated 81 pairwise decisions, establishing a hierarchy of domain items.
• The Steering Committee determined that separate clinical and laboratory scores, not a single aggregate score, are necessary for high specificity in APS classification.

Conclusions:

• Preliminary weights for candidate APS classification criteria were determined using MCDA.
• The new APS classification criteria uniquely incorporate separate thresholds for clinical and laboratory domains, diverging from single-aggregate score systems.