Optimizing antiphospholipid antibody testing: a real-world analysis of appropriateness and resource utilization

Efficient utilization of healthcare resources, including laboratory testing, is crucial for environmental sustainability and cost-effectiveness. The diagnosis of APS requires the presence of at least one clinical event (either an objectively confirmed thrombotic event and/or pregnancy complication) and detection of one or more aPL (lupus anticoagulant [LA], IgG/IgM anticardiolipin [aCL], and/or IgG/IgM anti-β2 glycoprotein-1 [aβ2GPI]). However, inappropriate requests for aPL tests contribute to unnecessary healthcare expenses and environmental impact. This study evaluates the appropriateness of aPL testing in a clinical setting. A retrospective analysis was conducted on 642 patients attending the San Giovanni Di Dio Hospital, Florence (11/2023-02/2024). Diagnostic suspicion underlying aPL test requests were classified as appropriate, inappropriate, or unevaluable using a scoring system based on clinical recommendations. Appropriateness assessment was performed independently by two researchers and reconciled with a third expert. Patient demographics, test results, and the specialty of the physicians ordering aPL were recorded and analyzed. Of the 642 queries, 36% were deemed appropriate, 42% inappropriate, and 22% unevaluable. Family physicians accounted for 53% of all test requests but exhibited the highest rate of inappropriate requests (44%). Rheumatologists, internal medicine physicians, and gynecologists demonstrated better adherence to recommendations (with 34%, 30%, and 18% of inappropriate requests, respectively). Only 4.9% of patients underwent comprehensive aPL testing per international standards (Sidney criteria). Among the 115 aPL-positive cases, multiple antibody positivity was more common in appropriate test requests. Inappropriate requests often stemmed from conditions without established links to APS, such as alopecia, hypercholesterolemia, and dysmenorrhea. A considerable proportion of aPL testing in routine practice lacks clinical justification, reflecting variability in guideline adherence across specialties. Inappropriate testing increases healthcare costs, specialist referrals, and environmental burdens. Improved education, adherence to diagnostic recommendations, and sustainable practices are critical to optimizing APS testing and resource utilization.