Annals of clinical biochemistry
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Ann. Clin. Biochem. · Sep 2018
Valid analytical performance specifications for combined analytical bias and imprecision for the use of common reference intervals.
Background Many clinical decisions are based on comparison of patient results with reference intervals. Therefore, an estimation of the analytical performance specifications for the quality that would be required to allow sharing common reference intervals is needed. The International Federation of Clinical Chemistry (IFCC) recommended a minimum of 120 reference individuals to establish reference intervals. ⋯ The formulae are identical for Gaussian and log-Gaussian distributions. Results Method 2 gives the correct results with a constant percentage of 4.4% for all combinations of bias and imprecision. Conclusion The Microsoft Excel formula NORMINV is useful for the estimation of analytical performance specifications for both Gaussian and log-Gaussian distributions of reference intervals.
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Ann. Clin. Biochem. · Mar 2018
Comparative Study Observational StudyNeutrophil gelatinase-associated lipocalin is a better biomarker than cystatin C for the prediction of imminent acute kidney injury in critically ill patients.
Aims The prevention of acute kidney injury can be lifesaving for the intensive care unit patients. However, conventional methods are not sufficient for the prediction of the risk of future acute kidney injury. In this study, the promising biomarker, neutrophil gelatinase-associated lipocalin, was compared with cystatin C as an indicator for the risk of future acute kidney injury. ⋯ The mean serum creatinine on admission did not significantly differ between this and control groups (0.72 ± 0.20 and 0.83 ± 0.21; P = 0.060); however, the serum and urinary neutrophil gelatinase-associated lipocalin concentrations on the second day were significantly different (median: 75.69 [54.18-91.18] and 123.68 [90.89-166.31], P = 0.001; and median: 17.60 [8.56-34.04] and 61.37 [24.59-96.63], P = 0.001). Notably, the 48-h serum cystatin C concentration did not differ. Conclusion Neutrophil gelatinase-associated lipocalin concentrations in the urine and serum on the second day of intensive care unit admission could be used to predict the development of acute kidney injury in the following three to seven days in the intensive care unit; however, the cystatin C concentration did not have predictive value.
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Ann. Clin. Biochem. · Jan 2018
Review Comparative StudyComparison of method-related reference intervals for thyroid hormones: studies from a prospective reference population and a literature review.
Introduction Reference intervals are dependent on the reference population, the analytical methods and the way the data are handled statistically. Individual method-related differences have been studied but the comparative differences in reference intervals have not. Methods We studied a reference population of healthy adult subjects and measured free thyroxine and thyroid-stimulating hormone by the four most commonly used analytical platforms used in the UK. ⋯ Discussion Our study demonstrates clearly that there are marked variations in the reference intervals for thyroid hormones between analytical platforms. There is an urgent need for standardization of thyroid hormone assays to permit transferability of results. Until then, guidelines will need to reflect this method-related difference.
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Ann. Clin. Biochem. · Jan 2018
Application of NICE guideline NG12 to the initial assessment of patients with lower gastrointestinal symptoms: not FIT for purpose?
Background The National Institute for Health and Care Excellence (NICE) published NG12 in 2015. The referral criteria for suspected colorectal cancer (CRC) caused controversy, because tests for occult blood in faeces were recommended. Faecal immunochemical tests for haemoglobin (FIT), which estimate faecal haemoglobin concentrations (f-Hb), might more than fulfil the intentions. ⋯ The AUC for CRC was 0.85 (95% CI: 0.87-0.90) for f-Hb versus 0.65 (95%CI: 0.58-0.73) for NG12 ( P < 0.005). For SCD, the AUC was 0.73 (95%CI: 0.69-0.77) for f-Hb versus 0.56 (95%CI: 0.52-0.60) for NG12 ( P < 0.0005). Conclusion f-Hb provides a good rule-out test for SCD and has significantly higher overall diagnostic accuracy than NG12.
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Ann. Clin. Biochem. · Nov 2017
Red blood cell distribution width and neutrophil to lymphocyte ratio are associated with outcomes of adult subarachnoid haemorrhage patients admitted to intensive care unit.
Background Red blood cell distribution width (RDW) and neutrophil to lymphocyte ratio (NLR) have been reported to be associated with outcomes of acute cerebral infarction. However, their prognostic value in patients with subarachnoid haemorrhage (SAH) remains largely unknown. The aim of this study was to investigate the prognostic value of RDW and NLR in SAH patients. ⋯ RDW and NLR were significantly associated with hospital death, with adjusted odds ratios of 1.39 (95% CI, 1.06-1.82) and 1.04 (95% CI, 1.00-1.08), respectively. Furthermore, increased RDW and NLR were associated with higher one-year mortality, with an adjusted hazard ratio of 1.20 (95% CI, 1.02-1.41) for per 1% increased RDW and 1.03 (95% CI, 1.00-1.05) for per 1 increased NLR. Conclusion RDW and NLR are useful indices to evaluate the outcomes of ICU admitted patients with SAH.