Clinical Chemistry Reference Intervals in a Rwandan Population

Abstract Objectives A large number of people undergo annual health checkup but accurate laboratory criterion for evaluating their health status is limited. The present study determined annual biological variation (BV) and derived parameters of common laboratory analytes in order to accurately evaluate the test results of the annual healthcare population. Methods A total of 43 healthy individuals who had regular healthcare once a year for six consecutive years, were enrolled using physical, electrocardiogram, ultrasonography and laboratory. The annual BV data and derived parameters, such as reference change value (RCV) and index of individuality (II) were calculated and compared with weekly data. We used annual BV and homeostatic set point to calculate personalized reference intervals (RIper) which were compared with population-based reference intervals (RIpop). Results We have established the annual within-subject BV (CVI), RCV, II, RIper of 24 commonly used clinical chemistry and hematology analytes for healthy individuals. Among the 18 comparable measurands, CVI estimates of annual data for 11 measurands were significantly higher than the weekly data. Approximately 50% measurands of II were <0.6, the utility of their RIpop were limited. The distribution range of RIper for most measurands only copied small part of RIpop with reference range index for 8 measurands <0.5. Conclusions Compared with weekly BV, for annual healthcare individuals, annual BV and related parameters can provide more accurate evaluation of laboratory results. RIper based on long-term BV data is very valuable for “personalized” diagnosis on annual health assessments.

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Establishment of Reference Intervals of Clinical Chemistry Analytes for the Adult Population in Egypt

10.1101/2020.07.15.204057 ◽

2020 ◽

Author(s):

Heba Baz ◽

Kiyoshi Ichihara ◽

May Selim ◽

Ahmed Awad ◽

Sarah Aglan ◽

...

Keyword(s):

Regional Differences ◽

Clinical Chemistry ◽

Adult Population ◽

Middle Eastern ◽

Low Density Lipoprotein ◽

Parametric Method ◽

Density Lipoprotein ◽

Reference Intervals ◽

Lipoprotein Cholesterol ◽

Multiple Regions

AbstractBackgroundThis is the first Egyptian nationwide study for derivation of reference intervals (RIs) for 34 major chemistry analytes. It was conducted as a part of the global initiative by the IFCC Committee on Reference Intervals and Decision Limits (C-RIDL) for establishing country-specific RIs based on a harmonized protocol.Methods691 apparently healthy volunteers aged ≥18 years were recruited from multiple regions in Egypt. Serum specimens were analyzed in two centers. The harmonization and standardization of test results were achieved by measuring value-assigned serum panel provided by C-RIDL. The RIs were calculated by parametric method. Sources of variation of reference values (RVs) were evaluated by multiple regression analysis. The need for partitioning by sex, age, and region was judged primarily by standard deviation ratio (SDR).ResultsGender-specific RIs were required for six analytes including total bilirubin (TBil), aspartate and alanine aminotransferase (AST, ALT). Seven analytes required age-partitioning including glucose and low-density lipoprotein cholesterol (LDL-C)., Regional differences were observed between northern and southern Egypt for direct bilirubin, glucose, and high-density-lipoprotein cholesterol (HDL-C) with all their RVs lower in southern Egypt. Compared with other collaborating countries, the features of Egyptian RVs were lower HDL-C and TBil and higher TG and C-reactive protein. In addition, BMI showed weak association with most of nutritional markers. These features were shared with two other Middle Eastern countries: Saudi Arabia and Turkey.ConclusionThe standardized RIs established by this study can be used as common Egyptian RI, except for a few analytes that showed regional differences. Despite high prevalence of obesity among Egyptians, their RVs of nutritional markers are less sensitive to increased BMI, compared to other collaborating countries.

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Erratum to “CLSI-based transference of the CALIPER database of pediatric reference intervals from Abbott to Beckman, Ortho, Roche and Siemens Clinical Chemistry Systems: Direct validation using reference samples from the CALIPER cohort” [Clin. Biochem., volume 46 (2013) 1197–1219]

Clinical Biochemistry ◽

10.1016/j.clinbiochem.2013.10.010 ◽

2013 ◽

Vol 46 (18) ◽

pp. 1916

Author(s):

Mathew P. Estey ◽

Ashley H. Cohen ◽

David A. Colantonio ◽

Man Khun Chan ◽

Tina Binesh Marvasti ◽

...

Keyword(s):

Clinical Chemistry ◽

Reference Intervals ◽

Reference Samples

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An update report on the harmonization of adult reference intervals in Australasia

Clinical Chemistry and Laboratory Medicine (CCLM) ◽

10.1515/cclm-2017-0920 ◽

2018 ◽

Vol 0 (0) ◽

Cited By ~ 1

Author(s):

Gus Koerbin ◽

Ken Sikaris ◽

Graham R.D. Jones ◽

Robert Flatman ◽

Jillian R. Tate

Keyword(s):

Royal College ◽

Clinical Chemistry ◽

Metrological Traceability ◽

Reference Intervals ◽

Evidence Based ◽

Blood Gas ◽

Arterial Blood Gas ◽

The Past ◽

Arterial Blood ◽

Blood Gas Parameters

Abstract The Australasian Association of Clinical Biochemists (AACB) has over the past 5 years been actively working to achieve harmonized reference intervals (RIs) for common clinical chemistry analytes using an evidence-based checklist approach where there is sound calibration and metrological traceability. It has now recommended harmonized RIs for 18 common clinical chemistry analytes which are performed in most routine laboratories and these have been endorsed by the Royal College of Pathologists of Australasia (RCPA). In 2017 another group of analytes including urea, albumin and arterial blood gas parameters were considered and suggested harmonized RIs proposed. This report provides an update of those harmonization efforts.

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Personalized Reference Intervals in Laboratory Medicine: A New Model Based on Within-Subject Biological Variation

Clinical Chemistry ◽

10.1093/clinchem/hvaa233 ◽

2020 ◽

Author(s):

Abdurrahman Coşkun ◽

Sverre Sandberg ◽

Ibrahim Unsal ◽

Coskun Cavusoglu ◽

Mustafa Serteser ◽

...

Keyword(s):

Steady State ◽

Personalized Medicine ◽

Clinical Chemistry ◽

Reference Interval ◽

Reference Intervals ◽

Biological Variation ◽

Test Results ◽

Steady State Condition ◽

Laboratory Test Results ◽

Measurement Results

Abstract Background The concept of personalized medicine has received widespread attention in the last decade. However, personalized medicine depends on correct diagnosis and monitoring of patients, for which personalized reference intervals for laboratory tests may be beneficial. In this study, we propose a simple model to generate personalized reference intervals based on historical, previously analyzed results, and data on analytical and within-subject biological variation. Methods A model using estimates of analytical and within-subject biological variation and previous test results was developed. We modeled the effect of adding an increasing number of measurement results on the estimation of the personal reference interval. We then used laboratory test results from 784 adult patients (>18 years) considered to be in a steady-state condition to calculate personalized reference intervals for 27 commonly requested clinical chemistry and hematology measurands. Results Increasing the number of measurements had little impact on the total variation around the true homeostatic set point and using ≥3 previous measurement results delivered robust personalized reference intervals. The personalized reference intervals of the study participants were different from one another and, as expected, located within the common reference interval. However, in general they made up only a small proportion of the population-based reference interval. Conclusions Our study shows that, if using results from patients in steady state, only a few previous test results and reliable estimates of within-subject biological variation are required to calculate personalized reference intervals. This may be highly valuable for diagnosing patients as well as for follow-up and treatment.

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Early pregnancy reference intervals; 29 serum analytes from 4 to 12 weeks’ gestation in naturally conceived and uncomplicated pregnancies resulting in live births

Clinical Chemistry and Laboratory Medicine (CCLM) ◽

10.1515/cclm-2019-0495 ◽

2019 ◽

Vol 57 (12) ◽

pp. 1956-1967 ◽

Cited By ~ 3

Author(s):

Jesper Friis Petersen ◽

Lennart J. Friis-Hansen ◽

Andreas Kryger Jensen ◽

Anders Nyboe Andersen ◽

Ellen C.L. Løkkegaard

Keyword(s):

Pregnant Women ◽

Early Pregnancy ◽

Clinical Chemistry ◽

Clinical Care ◽

Local Population ◽

First Trimester ◽

Reference Intervals ◽

Specific Reference ◽

Cancer Antigen 125 ◽

Serum Samples

Abstract Background Pregnancy introduces major physiological changes that also alter biochemical analytes. Maternal and perinatal health can be optimized by early intervention and therefore, pregnancy-specific reference intervals (RIs) for the local population are warranted. While the second and third trimester-specific changes are well described, the first trimester is less well characterized. We therefore wanted to facilitate early detection of abnormalities by generating first trimester reference values for 29 common analytes. Methods In a prospective early pregnancy (PEP) cohort (2016–2017), 203 pregnant women were recruited from 4 to 8 weeks’ gestation. Consecutive blood samples were drawn every 2 weeks until an ongoing second trimester pregnancy (n = 164) or a miscarriage (n = 39) occurred. After exclusion of women with complicated pregnancies or deliveries (n = 42), 122 women were included. The serum samples collected at <6, 6–8, 8–10, 10–12 and >12 weeks’ gestation were analyzed for 29 common analytes. Subsequently the RIs were calculated according to the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) recommendations (2.5–97.5th percentiles) and compared with the conventional RIs for non-pregnant women. Results Human chorionic gonadotropin (hCG), progesterone (P4), estradiol (E2), pregnancy-associated plasma protein A (PAPP-A), cancer antigen 125 (CA125), thyroid stimulating hormone (TSH), creatinine (CREA) and albumin (ALB) showed an early pregnancy-dependent change compared with conventional limits. For ALB the change was seen at 5.5 weeks’ gestation. Conclusions We report gestational age-specific RIs available from the early part of the first trimester applicable to everyday clinical care of pregnant women. Well-known alterations of RIs seen in later trimesters are also observed in the first.

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