Development and quality evaluation of lyophilized plasma external quality assessment samples for coagulation testing in resource-limited settings

ABSTRACT Background Accurate coagulation testing is essential for clinical decision-making in emergency, surgical, and obstetric care. External quality assessment (EQA) is an important component of laboratory quality assurance; however, liquid or frozen EQA materials can impose logistical challenges related to temperature-controlled storage and transportation, particularly in low- and middle-income countries (LMICs). Lyophilized plasma may provide a practical alternative by improving material stability and reducing cold-chain dependence. Methods This study aimed to produce three batches of candidate lyophilized human plasma EQA materials representing three coagulation profiles (Levels 1–3) and to evaluate their quality according to ISO 13528:2022. Homogeneity was assessed using one-way analysis of variance, with 10 randomly selected vials per batch analyzed in duplicate on three automated coagulation analyzer platforms: Sysmex CS-2500, Stago Compact Max, and ACL TOP 350. The between-vial standard deviation (S s ) was compared with 0.3σpt. Refrigerated storage stability at 2–8 °C was evaluated over 5 months using the criterion |ȳ t − ȳ 0 | ≤ 0.3σpt, while transport stability was assessed using an equivalence approach with the same acceptance limit. Results All three batches demonstrated acceptable homogeneity for prothrombin time (PT), activated partial thromboplastin time (APTT), and fibrinogen (Fib), with S s ≤ 0.3σpt across the three analyzer platforms. The materials remained stable throughout 4 months of storage at 2–8 °C, and transport stability was demonstrated under ambient shipping conditions. Conclusion These findings indicate that the candidate lyophilized plasma materials possess satisfactory homogeneity, refrigerated storage stability, and transport stability, supporting their potential use as locally produced EQA materials for coagulation testing and reducing cold-chain dependence in resource-limited settings.