Current Indications for Thrombophilia Testing – A Modified Delphi Consensus Study in Switzerland

Abstract Background Thrombophilia is a hereditary or acquired condition associated with an increased risk of venous thromboembolism (VTE) and VTE recurrence. Existing recommendations on patient selection vary across guidelines, resulting in variability of testing practices. This heterogeneity reflects persistent uncertainty regarding appropriate testing strategies in routine care. This modified Delphi survey was conducted to establish expert consensus on clinical indications for thrombophilia testing in Switzerland. Methods A modified Delphi study was performed with clinical experts managing patients with VTE in Switzerland. A steering committee developed clinical scenarios and statements on thrombophilia testing. These were distributed to the expert panel who rated their agreement and provided written feedback in two rounds. Consensus was defined as ≥70% of experts rating a statement ≥5 on a 7-point Likert scale. Results Forty-two clinical experts completed the survey. Consensus was reached after two rounds on 32 statements addressing indications for thrombophilia testing in various clinical scenarios, including unprovoked VTE, provoked VTE (including hormone-associated events), unusual site VTE, pediatric VTE, and patients without VTE. For example, consensus supported thrombophilia testing in patients aged <60 years with unprovoked VTE or unusual site VTE, and in women with hormone-associated VTE. Conclusion In this modified Delphi process, an expert panel achieved consensus on 32 statements regarding indications for thrombophilia testing in various clinical scenarios. These statements reflect current expert opinion, may help inform clinical decision-making, support consistent testing practices in routine care, and may inform the future development of evidence-based recommendations.