Specialty Content

Coagulation specialty

Coagulation often sits within a broader Haematology service but is its own specialist area with its own Specialist Portfolio and interview track.

Where the content lives

• The Coagulation Laboratory — /coagulation-lims — the full laboratory simulation: Worklist, Bench, Interpret, Learn. Sample acceptance and the citrate ratio, autoverification and what a laboratory may release, the analyser and its quality control, choosing the assay that answers the question asked, and the HIT, TTP, DIC and major haemorrhage pathways
• Specialty page — /coagulation-interviews — guides, simulators and case studies, with the link into the Interview Explorer question bank (Bands 2 to 8)
• Result Interpretation (coagulation) — open /result-interpretation and click the Coagulation card — PT/APTT patterns, mixing studies, factor assays, anti-Xa
• Specialist Portfolio (Coagulation) — /portfolio → choose the Haematology & Transfusion Science discipline card, then select Specialist Diploma in the AI Assistant tab
• Cross-references — coagulation overlaps with Haematology (FBC + clotting screens) and Transfusion (TACO/TRALI workup, MHP coagulopathy)

Key competencies covered

• Routine clotting screen — PT, APTT, fibrinogen, D-dimer
• Mixing studies — 1:1, inhibitor screen, factor deficiency vs inhibitor
• Factor assays — single-factor activity (FVIII, FIX, etc.), chromogenic vs clotting-based
• Thrombophilia screening — antithrombin, protein C/S, factor V Leiden, prothrombin gene, lupus anticoagulant
• Anticoagulant monitoring — INR for warfarin, anti-Xa for LMWH and rivaroxaban/apixaban, dilute thrombin time for dabigatran
• DIC investigation — D-dimer, fibrinogen, platelet trend, schistocytes (link to morphology)
• Lupus anticoagulant — DRVVT, mixing, confirmatory
• Platelet function — light-transmission aggregometry (LTA), PFA

Bands progression

• Band 5 (£32,073-£39,043) — qualified BMS authorising routine coagulation, recognising flagged samples
• Band 6 (£39,959-£48,117) — specialist mixing studies, factor assays, complex case review, training, validation; usually requires Specialist Portfolio in Coagulation
• Band 7 (£49,387-£56,515) — section lead, advanced thrombophilia workup sign-off, on-call cover, clinical advice

Standards alignment

• BSH, Measurement of heparin, direct oral anti-coagulants and other non-coumarin anti-coagulants and their effects on haemostasis assays (2 September 2024) — the laboratory-facing guideline for every anticoagulant below. It uses expected range rather than therapeutic range for a DOAC concentration, because neither the concentration nor a dose adjustment based on it has been shown to affect efficacy or safety
• BSH, Diagnosis and management of heparin-induced thrombocytopenia, third edition (2023) — the 4Ts score and the PF4 pathway
• BSH, Thrombophilia testing (2022) — heritable and acquired
• BSH, Guidelines on oral anticoagulation with warfarin, fourth edition (2011) — still the standing warfarin guideline. The British Committee for Standards in Haematology became the BSH Guidelines Committee in 2016, so older references to BCSH are the same body
• UK NEQAS Blood Coagulation
• CLSI H21, 6th edition (2024) — collection, transport and processing: 3.2% citrate, a 9:1 blood-to-citrate ratio, a fill of at least 90%, and citrate adjustment above a haematocrit of 55%
• ISO 15189:2022 — the quality framework, which since this edition also covers point-of-care testing. ISO 22870, the separate POCT standard, was withdrawn on its publication
• NICE NG158 — venous thromboembolic diseases, which replaced CG144 in March 2020; NG89 for prophylaxis; NG196 for atrial fibrillation; HTG348 (formerly DG13) for viscoelastometric point-of-care testing
• NICE TA697 — andexanet alfa, recommended only where the bleed is in the gastrointestinal tract
• ISTH — the 2025 update to the definition and scoring of disseminated intravascular coagulation

Common interview question themes (Band 5-7)

• "Walk me through your approach to a prolonged APTT"
• "How do you differentiate factor deficiency from an inhibitor?"
• "What is your thrombophilia screen workflow, and when is it appropriate?"
• "How would you investigate a sudden drop in fibrinogen post-partum?"
• "Describe how you would respond to an unexpectedly high INR"

A good preparation order: Result Interpretation → Practice Tests filtered to Coagulation + your Band → AI Interview Coach → mock interview with peers.

Note on terminology

• APTT vs aPTT — both refer to Activated Partial Thromboplastin Time; APTT is the more common UK usage
• DRVVT — Dilute Russell's Viper Venom Time (lupus anticoagulant test)
• LTA — Light Transmission Aggregometry (platelet function)
• TEG / ROTEM — viscoelastic point-of-care coagulation devices