Summary. Background: Very premature infants are at high risk of bleeding complications; however, few data exist on ranges for standard coagulation tests. Objectives: The primary objective of this study was to measure standard plasma coagulation tests and thrombin generation in very premature infants compared with term infants. The secondary objective was to evaluate whether an association existed between coagulation indices and intraventricular hemorrhage (IVH). Patients/Methods: Cord and peripheral blood of neonates < 30 weeks gestational age (GA) was drawn at birth, on days 1 and 3 and fortnightly until 30 weeks corrected gestational age. Prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen and coagulation factor levels were measured and tissue factor-stimulated thrombin generation was characterized. Control plasma was obtained from cord blood of term neonates. Results: One hundred and sixteen infants were recruited. Median (range) GA was 27.7 (23.7-29.9) weeks and mean (SD) birth weight was 1020 (255) g. Median (5th-95th percentile) day 1 PT, APTT and fibrinogen were 17.5 (12.7-26.6) s, 78.7 (48.7-134.3) s and 1.4 (0.72-3.8) g L À1, respectively. No difference in endogenous thrombin potential between preterm and term plasma was observed, where samples were available. Levels of coagulation factors II, VII, IX and X, protein C, protein S and antithrombin were reduced in preterm compared with term plasma. Day 1 APTT and PT were not associated with IVH. Conclusion: In the largest cross-sectional study to date of very preterm infants, typical ranges for standard coagulation tests were determined. Despite long clotting times, thrombin generation was observed to be similar in very preterm and term infants.

Background: Few published data exist to guide interpretation of coagulation times in extremely premature infants. Objective: To determine coagulation reference ranges on day 1 of life in extremely premature infants. Methods: A retrospective review of day 1 coagulation tests was performed in 144 infants <27 weeks' gestation between 2004 and 2010 in a tertiary neonatal unit. Samples were drawn through a non-heparinized umbilical or peripheral venous catheter as part of routine clinical care. Results: Mean (SD) and median (range) prothrombin times (PT) of 21.5 (5.3) and 20.2 (13.3-39) s, respectively, activated partial thromboplastin times (APTT) of 75.2 (27.8) and 67.4 (34.9-191.6) s, respectively, and plasma fibrinogen levels of 1.9 (1.1) and 1.4 (0.5-4.8) g/l, respectively, were reported. Using reference intervals derived from the 2.5th to 97.5th centiles, ranges of 14.4-36.7 s, 40.5-158.5 s and 0.7-4.8 g/l were determined for PT, APTT and plasma fibrinogen levels, respectively. In a subcohort with grade 0-2 intraventricular haemorrhage (n = 92), mean PT and APTT were 20.9 and 71.3 s, respectively, versus mean PT and APTT of 23.1 and 88.4 s (p = 0.06 and p = 0.03), respectively for those with grade 3-4 intraventricular haemorrhage. Mean PT and APTT in a cohort of infants defined to be small for gestational age were 22 and 76.8 s. These results did not differ significantly from non-small for gestational age infants, with a mean PT and APTT of 19.5 and 73.4 s (p = 0.09 and p = 0.7). Conclusions: Reference ranges based on retrospective data were determined for PT, APTT and fibrinogen in a large cohort of extremely preterm infants.

The range of supplementary tests available for diagnosing malaria has continued to expand. Despite this, carefully examined thick and thin blood films remain an essential part of the process. This guideline updates the previous 2013 British Society for Haematology Guideline for the Laboratory Diagnosis of Malaria. M ETHODOLOGYThis guideline was compiled according to the British Society for Haematology (BSH) process at https://b-s-h.org.uk/media/ 16732/ bsh-guida nce-devel opmen t-proce ss-dec-5-18.pdf. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) nomenclature was used to evaluate levels of evidence and to assess the strength of recommendations, although there are some challenges with applying these to laboratory diagnostic methods. The GRADE criteria can be found at http://www.grade worki nggro up.org. R EV IEW OF TH E M A N USCR IP TReview of the manuscript was performed by the BSH General Haematology Task Force, the BSH Guidelines Committee and the sounding board of BSH. It was also on the members section of the BSH website for comment.

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Background Early COVID-19 diagnosis prior to laboratory testing results is crucial for infection control in hospitals. Models exist predicting COVID-19 diagnosis, but significant concerns exist regarding methodology and generalisability. Aim To generate the first COVID-19 diagnosis risk score for use at the time of hospital admission using the TRIPOD (transparent reporting of a multivariable prediction model for individual prognosis or diagnosis) checklist. Design A multivariable diagnostic prediction model for COVID-19 using the TRIPOD checklist applied to a large single-centre retrospective observational study of patients with suspected COVID-19. Methods 581 individuals were admitted with suspected COVID-19; the majority had laboratory-confirmed COVID-19 (420/581, 72.2%). Retrospective collection was performed of electronic clinical records and pathology data. Results The final multivariable model demonstrated AUC 0.8535 (95% confidence interval (0.8121–0.8950). The final model used 6 clinical variables that are routinely available in most low and high resource settings. Using a cut-off of 2, the derived risk score has a sensitivity of 78.1% and specificity of 86.8%. At COVID-19 prevalence of 10% the model has a negative predictive value (NPV) of 96.5%. Conclusions Our risk score is intended for diagnosis of COVID-19 in individuals admitted to hospital with suspected COVID-19. The score is the first developed for COVID-19 diagnosis using the TRIPOD checklist. It may be effective as a tool to rule out COVID-19 and function at different pandemic phases of variable COVID-19 prevalence. The simple score could be used by any healthcare worker to support hospital infection control prior to laboratory testing results.