scholarly journals A global multicenter study on reference values: 1. Assessment of methods for derivation and comparison of reference intervals

2017 ◽  
Vol 467 ◽  
pp. 70-82 ◽  
Author(s):  
Kiyoshi Ichihara ◽  
Yesim Ozarda ◽  
Julian H Barth ◽  
George Klee ◽  
Ling Qiu ◽  
...  
Keyword(s):  
Reference Values ◽  
Multicenter Study ◽  
Reference Intervals

scholarly journals Reference values of plasma homocysteine in Cuban children and adults

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Alina Concepción Alvarez ◽  
Ivette Camayd Viera ◽  
Lisy Vento Buigues ◽  
Yanet Fernández Martínez ◽  
Eraida Hernández ◽  
...  
Keyword(s):  
Reference Values ◽  
High Performance ◽  
Age Groups ◽  
Coffee Consumption ◽  
Reference Interval ◽  
Reference Intervals ◽  
Multifactorial Diseases ◽  
Weak Association ◽  
Different Populations ◽  
Cuban Population

AbstractObjectivesHomocysteine (Hcy) is a nonessential amino acid, produced by the demethylation of methionine. High Hcy levels, or hyperhomocysteinemia, have been associated with genetic and multifactorial diseases. Hcy reference values may vary between different populations, as Hcy levels are affected by factors such as sex, age, diet, smoking, and coffee consumption. The estimation reference interval (RI) allows to establish the normal values of this marker in population. At present, these levels are unknown in Cuba. The aim of this work is to estimate the Hcy reference intervals in Cuban children and adults.MethodsTotal Hcy concentration was quantified by high performance liquid chromatography (HPLC) in plasma. Hcy levels were evaluated in samples from 507 healthy individuals (260 children, 247 adults).ResultsRIs were estimated by nonparametric methods. We found significant differences between both age groups, but we did not find significant differences between sexes, within these groups. The established ranges were 2.56–14.55 µM and 3.63–17.19 µM for children and adults, respectively. Also, we observed a weak association between Hcy levels and age in both sex groups.ConclusionsThis is the first study that assesses Hcy reference values in Cuban population. Our results will allow the introduction of Hcy as a biochemical marker in laboratory testing.

Reference values for jitter recorded by concentric needle electrodes in healthy controls: A multicenter study

2015 ◽  
Vol 53 (3) ◽  
pp. 351-362 ◽  
Author(s):  
Erik Stålberg ◽  
Donald B. Sanders ◽  
Sajjad Ali ◽  
Gerald Cooray ◽  
Lea Leonardis ◽  
...  
Keyword(s):  
Reference Values ◽  
Multicenter Study ◽  
Healthy Controls

Selection of Hormonal Reference Values for Undescended Testicle Case in 8-Year-Old Boy with Abnormal Chromosome

2021 ◽  
Vol 28 (1) ◽  
pp. 91
Author(s):  
Vina Corry ◽  
Merci M. Pasaribu
Keyword(s):  
Reference Values ◽  
Clinical Pathology ◽  
Tanner Stage ◽  
Chromosome Analysis ◽  
Reference Intervals ◽  
Undescended Testicle ◽  
Pediatric Endocrinology ◽  
Pathology Laboratory ◽  
Testosterone Levels ◽  
And Gender

Establishing the diagnosis of undescended testicles requires appropriate hormonal laboratory reference values basedon age and gender. An 8-year-old boy with an undescended testicle, mental retardation, and stunting had a blood test thatwas carried out at the Clinical Pathology Laboratory, dr. Cipto Mangunkusumo (RSCM) Hospital on February 6, 2020, withtestosterone levels of 0.69 nmol/L (N male: 4.94-32.01 nmol/L) indicating decreased testosterone levels. The patient wasconsulted from urological surgery to pediatric endocrinology to determine the presence or rudiment of the patient'stesticles. Using the reference range of testosterone values assists clinicians in determining the diagnosis, monitoringtherapy, and prognosis of a disease. There are some testosterone reference values, which are currently available, includingCanadian Laboratory Initiative on Pediatric Reference Intervals Database (CALIPER) and the Tanner stage reference value.Later is more applicable because it is based on chronological age and secondary sexual development in assessing pubertydevelopment. A case of an 8-year-old boy with a clinical diagnosis of an undescended testicle, the laboratory test resultsshowed normal-low testosterone levels using the CALIPER and Tanner stage ranges according to the patient's age. Noincrease of testosterone levels after the second HCG stimulation test might be due to differences in the HCG administrationprotocol; therefore, the diagnosis of anorchia had not been established, and chromosome abnormalities of 46 XY, +6 Mar,17 dmin on chromosome analysis suggested the suspected syndrome. These findings were consistent with the suspicion ofprimary hypogonadism in children with suspected syndrome caused by bilateral cryptorchidism with a suspectedseminiferous tubular defect.

Are reference intervals for carboxyhemoglobin appropriate? A survey of Boston area laboratories

1995 ◽  
Vol 41 (10) ◽  
pp. 1434-1438 ◽  
Author(s):  
M D Marshall ◽  
S N Kales ◽  
D C Christiani ◽  
R H Goldman
Keyword(s):  
Reference Values ◽  
Current Literature ◽  
Telephone Survey ◽  
Reference Intervals ◽  
Diagnosis And Treatment ◽  
Aggressive Treatment ◽  
The Us ◽  
Co Intoxication ◽  
Use Values ◽  
Poisoning Deaths

Abstract CO is a leading cause of poisoning deaths in the US today. Treating physicians use the carboxyhemoglobin (COHb) % saturation to guide the diagnosis and treatment of CO intoxication. We conducted a telephone survey of hospitals and laboratories in the Boston area, focusing on methodology for COHb determination and accompanying COHb reference intervals. Among 130 facilities, 23 (18%) provide COHb analysis. All facilities that perform the COHb test utilize dedicated multiwave-length photometry. Reference intervals for COHb varied widely among facilities. Eight of 21 (38%) facilities give unacceptably high "normal intervals" for nonsmokers when compared with values available in the literature. Thirteen of 20 (65%) use reference intervals for smokers that are too low, and 3 of 20 (15%) use values that are too high. These reference values provided by the testing facilities may be misleading to the ordering physicians unfamiliar with background COHb saturations. This may lead to misdiagnoses, false reassurances, and perhaps less aggressive treatment than might be warranted. The results of this study argue for wider adoption of COHb reference intervals supported by the current literature.

scholarly journals Reference Intervals (RIs) of Lipid Parameters for Nepalese Population

2018 ◽  
Vol 6 (4) ◽  
pp. 366-372
Author(s):  
R.V. Mahato ◽  
R.K. Singh ◽  
A. M. Dutta ◽  
K. Ichihara ◽  
M. Lamsal
Keyword(s):  
Total Cholesterol ◽  
Reference Values ◽  
Clinical Laboratory ◽  
Local Population ◽  
Density Lipoprotein ◽  
Physical Exertion ◽  
Hdl Cholesterol ◽  
Reference Interval ◽  
Reference Intervals ◽  
Lipoprotein Cholesterol

Introduction: Reference interval (RIs) is the range of values provided by laboratory scientists in a convenient and practical form to support clinician in interpreting observed values for diagnosis, treatment and monitoring of a disease. Laboratories in Nepal uses RIs, provided in the kit inserts by the manufacturers or from the scientific literature, established for western/European population. It is well known that population across the globe differs physiologically, genetically; race, ethnically, lifestyle, food habits and diet which have great impact on the reference values. Thus, it is inappropriate to use RIs that do not represent the local population. This approach highlights for establishing reference values in Nepalese population using the IFCC-CRIDL guidelines published in (C28-A3). Objectives: The objective of this study is to analyze blood lipids concentration in apparently healthy Nepalese population to set up reference values for total cholesterol (TC), triglycerides (TG), High Density Lipoprotein-cholesterol (HDL-C) and Low Density Lipoprotein-cholesterol (LDL-C) and compare with the internationally recommended values. Methods: Reference individuals selected from healthy volunteers according to the IFCC/C-RIDL protocol in (C28 –A3). Volunteers were requested to avoid excessive physical exertion/exercise/excessive eating and drinking and fast overnight for 10-12 hour. Blood samples were collected from 120 subjects from each five centers of the country between 7:00-10:00 am, serum were separated and refrigerated at -20 in a cryo-vials. Finally, 617 samples were transported to Yamaguchi University, Graduate School of Medicine, Ube, Japan for analysis in dry Ice and 30 parameters were measured by fully automated biochemistry analyzer, Beckman Coulter (BC480) in the clinical laboratory. Results: A reference interval for each parameter was calculated from the 95% reference intervals ranging from 2.5% and 97.5% percentiles and, arithmetic mean + 2 SD were also calculated. The 95% reference range for total cholesterol (2.53-6.14), triglyceride was(0.42-3.32),for HDL Cholesterol was (0.28-1.46), for LDL was(1.05-4.00) and for VLDL was (0.054-0.92) for Nepalese population. Conclusion: Nepalese clinicians can take into consideration of reference lipid values of this study for diagnosis, treatment and monitoring of disease. Int. J. Appl. Sci. Biotechnol. Vol 6(4): 366-372

scholarly journals Reference Interval for Renal Profile parameters in North Indian Population from Rajasthan

2015 ◽  
Vol 1 (5) ◽  
pp. 233
Author(s):  
Dharmveer Yadav ◽  
Monika Gupta ◽  
Sandhya Mishra ◽  
Praveen Sharma
Keyword(s):  
Uric Acid ◽  
Reference Values ◽  
Indian Population ◽  
Reference Interval ◽  
Progressive Increase ◽  
Reference Intervals ◽  
North Indian Population ◽  
The North ◽  
Indian Origin ◽  
Objective Reference

Objective: Reference intervals are an essential part of laboratory medicine. Current study was planned to evaluate renal parameters in the healthy defined group of individuals which would serve as reference values of renal parameters for the North Indian population from Rajasthan.Design & Methods: Present study was conducted on 2021 apparently healthy individuals of North Indian origin ranging in age from 15-60 years, were selected randomly using defined criteria. Fasting samples were analyzed for Urea, Creatinine, Uric Acid, Sodium, Potassium and Chloride. Data were analyzed for middle 95 percentile (2.5th-97.5th percentile), median and 95% confidence interval using SPSS software package version 10.0.Result: RI for Urea, Creatinine and uric acid were lower in female (16-42mg/dl, 0.6-1.2mg/dl, 2.4-6.8mg/dl) as compared to male (17.00-44.35mg/dl, 0.7-1.5mg/dl, 2.8-7.2mg/dl). There was a progressive increase in urea, uric acid and Creatinine with increase in age. Though no appreciable differences could be observed in respect to most of renal parameters in rural versus urban, a wider range for uric acid was observed in urban population (2.50-7.20mg/dl). Except for Na+, K+ and Cl-, rest of parameters i.e. urea, creatinine, uric acid were higher range in obese as compared to non obese (17-45 Vs 17-44, 0.66-1.5 Vs 0.60-1.40, 2.5-7.4 Vs 2.5-7.0). Uric acid level was also found to be higher in non vegetarian population (2.6-7.5mg/dl).Conclusion: Findings of this study provide sex, age, BMI, habitat and diet specific renal function reference values to be used for North Indian population.

Analytical performance, reference values and decision limits. A need to differentiate between reference intervals and decision limits and to define analytical quality specifications

2012 ◽  
Vol 50 (5) ◽  
Author(s):  
Per Hyltoft Petersen ◽  
Esther A. Jensen ◽  
Ivan Brandslund
Keyword(s):  
Reference Values ◽  
Clinical Guidelines ◽  
Reference Intervals ◽  
Analytical Performance ◽  
International Expert ◽  
Analytical Quality ◽  
Quality Specifications ◽  
Reference Samples ◽  
Critical Situations

AbstractWith the increasing use of decision limits (action limits, cut-off points) specified for a number of analytical components in diagnosis and for action in critical situations, formulated in national or international recommendations, the traditional interpretation of reference intervals has been uncertain, and sometimes the two concepts are being mixed up by incorporating risk calculations in the reference intervals. There is, therefore, a need to clarify the two concepts and to keep them definitely separated. Reference intervals are the 95% limits for the descriptions of the distributions of the values of analytical components measured on reference samples from reference individuals. Decision limits are based on guidelines from national and international expert groups defining specific concentrations of certain components as limits for decision about diagnosis or well-defined specific actions. Analytical quality specifications for reference intervals have been defined for bias since the 1990s, but in the recommendations specified in the clinical guidelines analytical quality specifications are only scarcely defined. The demands for negligible biases are, however, even more essential for decision limits, as the choice is no longer left to the clinician, but emerge directly from the concentration. Even a small bias will change the number of diseased individuals, so the demands for negligible biases are obvious. A view over the analytical quality as published gives a variable picture of bias for many components, but with many examples of considerable bias which must be critical – yet no specifications have been stipulated until now.

Obtaining reference intervals traceable to reference measurement systems: is it possible, who is responsible, what is the strategy?

2012 ◽  
Vol 50 (5) ◽  
Author(s):  
Mauro Panteghini ◽  
Ferruccio Ceriotti
Keyword(s):  
Reference Values ◽  
Reference System ◽  
Laboratory Medicine ◽  
Reference Intervals ◽  
Multicenter Studies ◽  
Reference Measurement ◽  
Measurement Systems ◽  
Experimental Protocols ◽  
Definition Of ◽  
Result Interpretation

AbstractAn issue associated with standardization efforts is the need to develop useful reference intervals (RI). Lack of proper RI may hamper the implementation of standardization in Laboratory Medicine as standardization can modify analyte results and, without adequate RI, this can impair the result interpretation. Once defined, RI obtained with analytical procedures that produce results traceable to the corresponding reference system can be transferred among laboratories, providing that they use commercial assays that produce results traceable to the same reference system and populations have the same characteristics. Multicenter studies are needed for a robust definition of traceable RI, using experimental protocols that include well defined prerequisites. Particularly, employed methods must produce results that are traceable to the reference system for that specific analyte. Thus, the trueness of laboratories producing reference values should be verified and, if necessary, experimental results corrected in accordance with correlation results with the selected reference. If requirements in the adoption of traceable RI are fulfilled, the possibility of providing RI that are applicable to any laboratory, able to produce results traceable to the reference system, is realistic. The definition of traceable RI should hopefully cause the disappearance of different RI employed for the same analyte, providing more effective information to clinicians.

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