Paediatric reference intervals are heterogeneous and differ considerably in the classification of healthy paediatric blood samples

Insulin reference intervals in Brazilian adolescents by direct and indirect approaches: validation of a data mining method from laboratory data

OBJECTIVE

To determine reference intervals (RI) for fasting blood insulin (FBI) in Brazilian adolescents, 12 to 17 years old, by direct and indirect approaches, and to validate indirectly determined RI.

METHODS

Two databases were used for RI determination. Database 1 (DB1), used to obtain RI through a posteriori direct method, consisted of prospectively selected healthy individuals. Database 2 (DB2) was retrospectively mined from an outpatient laboratory information system (LIS) used for the indirect method (Bhattacharya method).

RESULTS

From DB1, 29345 individuals were enrolled (57.65 % female) and seven age ranges and sex partitions were statistically determined according to mean FBI values: females: 12 and 13 years-old, 14 years-old, 15 years-old, 16 and 17 years-old; and males: 12, 13 and 14 years-old, 15 years-old, 16 and 17 years-old. From DB2, 5465 adolescents (67.5 % female) were selected and grouped according to DB1 partitions. The mean FBI level was significantly higher in DB2, on all groups. The RI upper limit (URL) determined by Bhattacharya method was slightly lower than the 90 % CI URL directly obtained on DB1, except for group female 12 and 13 years old. High agreement rates for diagnosing elevated FBI in all groups on DB1 validated indirect RI presented.

CONCLUSION

The present study demonstrates that Bhattacharya indirect method to determine FBI RI in adolescents can overcome some of the difficulties and challenges of the direct approach.

When Positive is Negative: Health Literacy Barriers to Patient Access to Clinical Laboratory Test Results

BACKGROUND

Health literacy is a multidimensional set of skills (e.g., narrative, numeracy, digital, medication) that patients need to access and understand health information timely and accurately to make evidence-based informed decisions.

CONTENT

Multiple barriers prevent patients from effectively interacting with health information. The most salient barriers are poor overall health literacy skills and linguistic proficiency in English. As patients prefer direct access to laboratory test results, especially those of routine tests, contextualization and provider-directed interpretation of results are required to foster shared decision-making to address their healthcare issues and improve health outcomes.

SUMMARY

The use of systematic approaches that account for poor health literacy skills and include culturally and linguistically appropriate planning and availability of resources is warranted at individual and population health levels (e.g., human-centered design of patient portals).

Epidemiology, risk factors, and applicability of CDC definitions for healthcare-associated bloodstream infections at a level IV neonatal ICU

OBJECTIVES

We studied the epidemiology of primary bloodstream infections (BSIs), secondary BSIs, and central line-associated BSIs (CLABSIs) and applicability of CDC definitions for primary sources of infection causing secondary BSIs in patients in the neonatal ICU.

STUDY DESIGN

We classified healthcare-associated BSIs (HABSIs) as primary BSIs, secondary BSIs, and CLABSIs using CDC surveillance definitions and determined their overall incidence and incidence among different gestational age strata. We assessed the applicability of CDC definitions for infection sources causing secondary BSIs.

RESULTS

From 2010 to 2019, 141 (32.7%), 202 (46.9%), and 88 (20.4%) HABSIs were classified as primary BSIs, secondary BSIs, and CLABSIs, respectively; all declined during the study period (all p < 0.001). Gestational age <28 weeks was associated with increased incidence of all HABSI types. CDC criteria for site-specific primary sources were met in 137/202 (68%) secondary BSIs.

CONCLUSIONS

Primary and secondary BSIs were more common than CLABSIs and should be prioritized for prevention.

Current State of Pediatric Reference Intervals and the Importance of Correctly Describing the Biochemistry of Child Development: A Review

Importance

Appropriately established pediatric reference intervals are critical to the clinical decision-making process and should reflect the physiologic changes that occur during healthy child development. Reference intervals used in pediatric care today remain highly inconsistent across a broad range of common clinical biomarkers.

Observations

This narrative review assesses biomarker-specific pediatric reference intervals and their clinical utility with respect to the underlying biological changes occurring during development. Pediatric reference intervals from PubMed-indexed articles published from January 2015 to April 2021, commercial laboratory websites, study cohorts, and pediatric reference interval books were all examined. Although large numbers of pediatric reference intervals are published for some biomarkers, very few are used by clinical and commercial laboratories. The patterns, extent, and timing of biomarker changes are highly variable, particularly during developmental stages with rapid physiologic changes. However, many pediatric reference intervals do not capture these changes and thus do not accurately reflect the underlying biochemistry of development, resulting in significant inconsistencies between reference intervals.

Conclusions and Relevance

There is a need to correctly describe the biochemistry of child development as well as to identify strategies to develop accurate and consistent pediatric reference intervals for improved pediatric care.

Status of folate in healthy children in Almeria

The objective of this study is to establish reference values for folic acid in a healthy population of children aged 4-11 years and to examine related epidemiological, dietary and analytical factors. A cross-sectional study of 658 healthy children aged 4-11 years was made. Epidemiological, socioeconomic and dietary variables were analysed, the BMI Z-score was obtained, levels of serum folate and serum vitamin B₁₂ were determined and haematological, iron status and erythropoietic activity parameters were examined. The study data were analysed by non-parametric tests and linear multiple regression. The mean folate value was 8.6 ± 4.6 ng/mL (95% reference interval: 2.8-20 ng/mL). A level < 3 ng/mL (5th percentile) was considered as folate deficiency (4.6% of subjects). No child reported symptoms related to this deficiency. Folate values were significantly lower with age (p < 0.01), low NSE and low parental educational level (p: 0.0001). No relationship was found between folates and the analytical variables. According to multivariate linear regression, the variables significantly associated with serum folate were age, socioeconomic level and vitamin B₁₂.Conclusions: Serum folate levels in healthy school children are described. Age, socioeconomic level and serum vitamin B₁₂ are factors associated with folate status. Specific cut-off values for a paediatric population should be defined. What is Known: • Folic acid is an essential micronutrient for optimal growth and development; its deficit is associated with adverse health effects. • The studies on their status and deficit are not comparable due to a lack of agreement on appropriate indicators and reference values. What is New: • This study reports the levels of serum folate in a large population of healthy schoolchildren, with strict inclusion criteria in a developed country and identifies the associated sociodemographic, dietary and analytical (vitamin B12, iron parameters and erythropoietic activity) factors, avoiding potential confusion.

Capillary blood reference intervals for platelet parameters in healthy full-term neonates in China

Background

No consensus has been reached on capillary blood reference intervals for platelet parameters in full-term neonates. We aimed to establish neonatal capillary blood reference intervals for platelet parameters and evaluate influences of sex, gestational age and postnatal age on platelet parameters.

Methods

This study was a prospective investigation and implemented in 594 healthy full-term neonates from 12 to 84 h of age, using SYSMEX XN-9000 haematology automatic analyser by means of capillary blood. Reference intervals for platelet parameters were defined by an interval of 2.5th − 97.5th percentiles.

Results

Capillary reference interval for platelet count was (152–464) × 10⁹/L. No significance was found between sex-divided reference intervals for platelet parameters. The values of platelet count changed minimally across gestational age (37–41 weeks) and postnatal age (12–84 h). Reference intervals for other platelet parameters were affected by these factors to a different extent.

Conclusions

We established capillary blood reference intervals for platelet parameters in the first days after birth of full-term neonates in China.

Complex biological patterns of hematology parameters in childhood necessitating age- and sex-specific reference intervals for evidence-based clinical interpretation

INTRODUCTION

Hematology laboratory parameters are among the most routinely ordered tests in support of adult and pediatric care. However, appropriate interpretation of test results has been a challenge in pediatrics since accurate and up-to-date reference intervals that reflect the dynamic physiological changes associated with growth and development have not been available. Critical gaps continue to exist in pediatric hematology reference intervals for modern laboratory platforms. To address this gap, this study establishes age- and sex-specific reference intervals for 25 hematology parameters in the CALIPER cohort of healthy children and adolescents using a common platform, the Sysmex XN-3000 analytical system.

METHODS

Fresh whole blood samples collected from a total of 641 healthy children and adolescents (birth to <21 years) with informed consent were analyzed for 25 hematological parameters on the Sysmex XN-3000 Hematology Analyzer. Age- and sex-specific reference standards were calculated based on Clinical and Laboratory Standards Institute guidelines.

RESULTS

Of the 25 analytes assessed, 19 required age-partitioning and seven required sex-partitioning (ie, red blood cell count, hemoglobin, hematocrit, mean corpuscular volume, red blood cell distribution width-SD, red blood cell distribution width-CV, and monocyte percentage). Age- and sex-specific differences mostly coincided with the onset of puberty.

CONCLUSION

This study establishes a comprehensive database of pediatric reference intervals for hematology parameters in the CALIPER cohort using the widely used Sysmex XN-3000 analytical platform. These data highlight the dynamic hematological profile observed in healthy children and adolescents and the need for reference interval stratification by age and sex.

Application of adult reference intervals in children

The aim of this study was to evaluate to which extend adult reference intervals (RIs) could be applied in children. A local paediatric population (aged 1 to < 20 years), based on first draw samples from general practitioners (GPs), was established. Children with samples taken at a hospital or > 3 samples from GPs were excluded. Analytes evaluated included haematological, liver and pancreatic function, kidney function, electrolytes, and metabolism parameters. Applicability of adult RIs in children aged 1-17 years was evaluated using individuals aged 18-19 years as reference groups for the adult RIs. The local population consisted of 31,024 children with 282,721 analyses in total. For each analyte, 17 age strata and two gender strata were established. Partitioning was not warranted in 51% of the male strata and in 69% of the female strata. Adult RIs could be applied in 42% for children aged 1-< 10 years, 57% for children aged 10-< 15 years, and 85% for children aged 15-<18 years.Conclusion: for certain analytes, there is no need to partition between adult and paediatric RIs, but a need for age- and gender-specific RIs remains for several clinical laboratory tests.What is Known:• Establishing paediatric reference intervals (RIs) is time consuming, costly, and not feasible for many laboratories. Transference of RIs established elsewhere often leads to misclassification of paediatric laboratory results.• Adult RIs are often more easily established and validated.What is New:• Adult RIs can be applied to children as young as 2 years for some analytes. Conversely, for some analytes, adult RIs cannot be applied in children aged 1-17 years.• Laboratory data can be applied in evaluating the need for partitioning in reference intervals.

Medical Diagnostic Tests: A Review of Test Anatomy, Phases, and Statistical Treatment of Data

Diagnostic tests are approaches used in clinical practice to identify with high accuracy the disease of a particular patient and thus to provide early and proper treatment. Reporting high-quality results of diagnostic tests, for both basic and advanced methods, is solely the responsibility of the authors. Despite the existence of recommendation and standards regarding the content or format of statistical aspects, the quality of what and how the statistic is reported when a diagnostic test is assessed varied from excellent to very poor. This article briefly reviews the steps in the evaluation of a diagnostic test from the anatomy, to the role in clinical practice, and to the statistical methods used to show their performances. The statistical approaches are linked with the phase, clinical question, and objective and are accompanied by examples. More details are provided for phase I and II studies while the statistical treatment of phase III and IV is just briefly presented. Several free online resources useful in the calculation of some statistics are also given.