White Cell Count Tests Research Articles

Clinical and Cost-Effectiveness of Procalcitonin Test for Prodromal Meningococcal Disease-A Meta-Analysis.

BackgroundDespite vaccines and improved medical intensive care, clinicians must continue to be vigilant of possible Meningococcal Disease in children. The objective was to establish if the procalcitonin test was a cost-effective adjunct for prodromal Meningococcal Disease in children presenting at emergency department with fever without source.Methods and FindingsData to evaluate procalcitonin, C-reactive protein and white cell count tests as indicators of Meningococcal Disease were collected from six independent studies identified through a systematic literature search, applying PRISMA guidelines. The data included 881 children with fever without source in developed countries.The optimal cut-off value for the procalcitonin, C-reactive protein and white cell count tests, each as an indicator of Meningococcal Disease, was determined. Summary Receiver Operator Curve analysis determined the overall diagnostic performance of each test with 95% confidence intervals. A decision analytic model was designed to reflect realistic clinical pathways for a child presenting with fever without source by comparing two diagnostic strategies: standard testing using combined C-reactive protein and white cell count tests compared to standard testing plus procalcitonin test. The costs of each of the four diagnosis groups (true positive, false negative, true negative and false positive) were assessed from a National Health Service payer perspective. The procalcitonin test was more accurate (sensitivity=0.89, 95%CI=0.76-0.96; specificity=0.74, 95%CI=0.4-0.92) for early Meningococcal Disease compared to standard testing alone (sensitivity=0.47, 95%CI=0.32-0.62; specificity=0.8, 95% CI=0.64-0.9). Decision analytic model outcomes indicated that the incremental cost effectiveness ratio for the base case was £-8,137.25 (US $ -13,371.94) per correctly treated patient.ConclusionsProcalcitonin plus standard recommended tests, improved the discriminatory ability for fatal Meningococcal Disease and was more cost-effective; it was also a superior biomarker in infants. Further research is recommended for point-of-care procalcitonin testing and Markov modelling to incorporate cost per QALY with a life-time model.

PIH20 - Clinical and Cost-effectiveness of a Procalcitonin Test as a Prompt Indicator of Prodomol Meningococcal Disease in Febrile Children: Cost-effectiveness Analysis

Bell J.M.1, Shields M.1, Angus A.2, Dunlop K.3, Bourke T.1, Kee F.1, Lynn F.A.1 1Queen’s University Belfast, Belfast, UK, 2Belfast Health & Social Care Trust, Belfast, UK, 3South Eastern Health and Social Care Trust, Belfast, UK OBJECTIVES: To establish if the procalcitonin (PCT) test’s diagnostic performance is more clinically and cost-effective than C reactive protein (CRP) and White Cell Count (WCC) tests for suspicion of prodomal stage Meningococcal disease (MD) in children presenting at emergency department (ED) with a fever without source. METHODS: A decision analytic model was designed to reflect realistic clinical pathways for a child presenting with non-specific fever to ED. Test accuracy was evaluated using data from independent studies carried out in developed countries identified through a systematic literature search. Studies were combined to determine the optimal cut-off value for the PCT, CRP and WCC tests, each as an indicator of MD. Summary Receiver Operator Curve (SROC) analysis was used to determine the inter-study and overall diagnostic performance of each test from the areas under the curve (AUC), with 95% confidence intervals (CIs). Components of each clinical pathway were costed in UK sterling using the National Schedule of Reference Costs 2010-2011. Hospital stays were costed using the appropriate Health Resource Group code. RESULTS: Seven studies involving 881 children with non-specific fever provided data for inclusion. The PCT test was more accurate (sensitivity= 89%, 95%CI= 75-96; specificity= 71%, 95%CI= 37-91) for early MD compared to CRP (sensitivity= 84%, 95%CI= 74-90; specificity= 60%, 95%CI= 44-74) and WCC (sensitivity= 50%, 95%CI= 39-60; specificity= 68%, 95%CI= 54-79). PCT had the best PLR (3.0, 95%CI= 1.8-7.8) to be viable as a rule-in test for MD and a borderline NLR as a rule-out test, making it a better option to either CRP (2.1, 95%CI= 1.4-3.1) or WCC (1.5, 95%CI= 1.0-2.3). Outcomes from the decision analytic model indicated that the PCT test was the most cost-effective (£2547 per patient treated), followed by the combined CRP and WCC test (£3069 per patient treated). CONCLUSIONS: The improved sensitivity and specificity of the PCT test provides a more cost-effective test than the currently recommended CRP and WCC tests.