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Purpose: The production and construction of buildings cause significant environmental impacts besides those arising from their operation. Recently, some European countries have started introducing life cycle assessment as a mandatory calculation method for new buildings, and it is foreseen that by 2030 this will be done in every member state, at first without any legal minimum values. Methods: Extensive databases on the embodied impacts of buildings, which would be needed to support setting the baseline impacts, are still missing. This paper proposes an approach for determining bottom-up reference values. A large building sample is generated describing "technically feasible" new buildings. Instead of analysing a few typical buildings, the main parameters describing a building are determined and the ranges are defined that these parameters typically take. With the variation of these parameters, a large building sample is generated, and the surfaces and built-in material quantities are determined for typical construction solutions to assess environmental performance. Results and discussion: The method is demonstrated by calculating the reference embodied benchmark values for new residential buildings in Hungary. The results show a baseline embodied Global Warming Potential of 9.5–15.5 kg CO2-eq/m2/yr for single-family houses and 9.1–14.3 kg CO2-eq/m2/yr for multi-family houses. Conclusions: This method is suitable for estimating the environmental impact of typical new buildings in countries where a large pool of real building data is not yet available. [ABSTRACT FROM AUTHOR]

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Despite immense importance of reference intervals (RIs) for clinical diagnosis, there have been no reliable RIs available for Nepalese. Hence, this nationwide study was organized to establish RIs for 30 common biochemical parameters. This study was conducted following the harmonized protocol provided by IFCC Committee on Reference Interval and Decision Limits (C-RIDL) with recruitment of 617 apparently healthy volunteers (18 − 65 years) by near-equal gender balance from 5 major cities. Fasting blood were collected, serum was separated and measured collectively using Beckman-Coulter/Olympus AU480 chemistry analyzer. The sources of variations of reference values (RVs) were evaluated by multiple regression analysis and nested ANOVA. Latent abnormal values exclusion (LAVE) method was applied to reduce influence of latent diseases. RIs were standardized based on a value-assigned serum panel provided by C-RIDL. By ANOVA, no between-city differences were observed, while sex-related changes were typically noted for urate, creatinine, iron, γ-glutamyl transferase (GGT), immunoglobulin M, and transferrin, but not for high-density lipoprotein cholesterol. Age-related changes were observed for total cholesterol (TC), triglyceride, low-density lipoprotein cholesterol, and C-reactive protein (CRP). RIs were successfully derived all parametrically. The LAVE procedure was effective in lowering upper limits for aspartate aminotransferase, alanine aminotransferase (ALT), and CRP. Compared to other collaborating countries, Nepalese RIs were low for urea, cholesterols, ALT, and high for triglyceride, GGT, CRP, immunoglobulin G, and complements. The RIs for major chemistry analytes were derived and standardized for nationwide use in Nepal. This study distinctly elucidated sources of variation and international features of Nepalese RIs. [ABSTRACT FROM AUTHOR]

Abstract Background Reference values (RVs) for knee function tests have been reported in perioperative patients with knee osteoarthritis (KOA); however, such values for practical use in outpatient setting has yet to be determined. Therefore, we aimed to establish the reference intervals (RIs) for outpatients with mild to moderate KOA. Methods This cross-sectional study enrolled 202 outpatients with KOA from 8 Japanese orthopedic clinics and measured knee extensor/flexor muscle strength (MS) and knee extension/flexion range of motion (ROM). We used multiple regression analysis to evaluate the sources of variation, including sex, age, body mass index, Kellgren–Lawrence (K-L) classification, bilateral KOA, and exercise habits. Magnitude of between-subgroup differences is expressed as standard deviation ratio (SDR) based on a three-level nested analysis of variance, with SDR ≥ 0.4 as the threshold for requiring RIs specific for subgroups. RIs were calculated parametrically using two-parameter Box-Cox formula if Gaussian transformation of RVs was successful, otherwise calculated nonparametrically. Results Partitioning was required by sex for extensor and flexor MS (SDR = 0.65, 0.57, respectively) and by K-L classification for flexion ROM (SDR = 0.54). RIs were determined parametrically for extensor MS as 0.27–2.09 (male) and 0.27–1.54 (female) Nm/kg and for flexor MS 0.18–1.20 (male) and 0.13–0.79 (female) Nm/kg. On the other hand, RIs for extension and flexion ROM were determined nonparametrically due to discrete nature of their RVs. The RIs determined for extension ROM were -15°–0° and for flexion ROM were 105°–150° (for K-L grade I/II) and 95°–140° (for K-L grade III/IV). Conclusions The ranges of RIs determined specifically for patients with mild to moderate KOA were in-between those of age-matched healthy controls and pre-surgical KOA patients, both of which we had reported for use in physiotherapeutic management of KOA patients undergone total knee arthroplasty. The newly derived RIs will provide an objective benchmark for physiotherapy targeting outpatients with mild to moderate KOA.

We present a test of the two most established reciprocity models, an intention factor model and a reference value model. We test characteristic elements of each model in a series of twelve mini-ultimatum games. Results from online experiments show major differences between actual behavior and predictions of both models: the distance of actual offers to the proposed reference value provides a poor measure for the kindness of offers, while a comparison of offers with extreme offers as suggested by the intention factor model makes offers indiscriminable in richer settings. We discuss possible combinations of both models better describing our observations. [ABSTRACT FROM AUTHOR]

Background: Reference values (RVs) for knee function tests have been reported in perioperative patients with knee osteoarthritis (KOA); however, such values for practical use in outpatient setting has yet to be determined. Therefore, we aimed to establish the reference intervals (RIs) for outpatients with mild to moderate KOA. Methods: This cross-sectional study enrolled 202 outpatients with KOA from 8 Japanese orthopedic clinics and measured knee extensor/flexor muscle strength (MS) and knee extension/flexion range of motion (ROM). We used multiple regression analysis to evaluate the sources of variation, including sex, age, body mass index, Kellgren–Lawrence (K-L) classification, bilateral KOA, and exercise habits. Magnitude of between-subgroup differences is expressed as standard deviation ratio (SDR) based on a three-level nested analysis of variance, with SDR ≥ 0.4 as the threshold for requiring RIs specific for subgroups. RIs were calculated parametrically using two-parameter Box-Cox formula if Gaussian transformation of RVs was successful, otherwise calculated nonparametrically. Results: Partitioning was required by sex for extensor and flexor MS (SDR = 0.65, 0.57, respectively) and by K-L classification for flexion ROM (SDR = 0.54). RIs were determined parametrically for extensor MS as 0.27–2.09 (male) and 0.27–1.54 (female) Nm/kg and for flexor MS 0.18–1.20 (male) and 0.13–0.79 (female) Nm/kg. On the other hand, RIs for extension and flexion ROM were determined nonparametrically due to discrete nature of their RVs. The RIs determined for extension ROM were -15°–0° and for flexion ROM were 105°–150° (for K-L grade I/II) and 95°–140° (for K-L grade III/IV). Conclusions: The ranges of RIs determined specifically for patients with mild to moderate KOA were in-between those of age-matched healthy controls and pre-surgical KOA patients, both of which we had reported for use in physiotherapeutic management of KOA patients undergone total knee arthroplasty. The newly derived RIs will provide an objective benchmark for physiotherapy targeting outpatients with mild to moderate KOA. [ABSTRACT FROM AUTHOR]

Background and Aim: The threshold values of two-point discrimination (TPD) provide a numerical measure of tactile acuity. Normal reference values are needed to decide whether sensory variability is within normal sensorial limits. The study aimed to determine the upper extremity and face threshold values in healthy young adults. Materials and Methods: Static TPD thresholds of 67 healthy young adults aged 18-35 years were assessed. Eight skin areas in the face and upper extremity on the dominant side were assessed using a "method of limits" approach with an aesthesiometer. Differences between genders were examined with the Mann-Whitney U test. The Spearman correlation analysis investigated the relationship between age and TPD measurements. Results: TPD values ranged between 4.66 and 19.16 mm and 1.33-68.66 mm in the face and upper extremity, respectively, in the participants with a mean age of 23.83 ± 4.66 years. Fingertips and the area over the lateral mandibula showed the greatest sensitivity. The threshold values of TPD showed both interindividual and intraindividual variability. There was no statistical difference in the TPD values according to gender in any of the measured areas, and there was no relationship between age and TPD test values. Conclusions The threshold values of TPD have clinical applicability in various diseases affecting the sensation of the upper extremity and/or face. These data may help the detection of early sensory loss. [ABSTRACT FROM AUTHOR]

The analysis of odds ratio curves is a valuable tool in understanding the relationship between continuous predictors and binary outcomes. Traditional parametric regression approaches often assume specific functional forms, limiting their flexibility and applicability to complex data. To address this limitation and introduce more flexibility, several smoothing methods may be applied, and approaches based on splines are the most frequently considered in this context. To better understand the effects that each continuous covariate has on the outcome, results can be expressed in terms of splines-based odds ratio (OR) curves, taking a specific covariate value as reference. In this paper, we introduce an R package, flexOR, which provides a comprehensive framework for pointwise nonparametric estimation of odds ratio curves for continuous predictors. The package can be used to estimate odds ratio curves without imposing rigid assumptions about their underlying functional form while considering a reference value for the continuous covariate. The package offers various options for automatically choosing the degrees of freedom in multivariable models. It also includes visualization functions to aid in the interpretation and presentation of the estimated odds ratio curves. flexOR offers a user-friendly interface, making it accessible to researchers and practitioners without extensive statistical backgrounds. [ABSTRACT FROM AUTHOR]

Introduction Methods Results Conclusion Posterior tibial nerve (PTN) cross‐sectional area (CSA) reference values for the diagnosis of tarsal tunnel syndrome (TTS) using ultrasound imaging exist in several countries but not in South Africa (SA). Therefore, the objective was to measure the CSA reference values for PTN in SA.Ultrasound CSA measurements of PTN in both ankles on 112 participants were performed, the mean measurement was recorded, and the effect of race, age, gender, and body mass index (BMI) were recorded.In this study, the primary variables age and BMI affect the CSA measurement of the PTN. A positive correlation was found between PTN asymptomatic size and age (r = 0.196, P < 0.05), size and BMI (r = 0.200, P < 0.05). Age (categories) had a mean value of 3.17 for the age group 36–45 years (95% confidence interval (CI) 2.9–3.4). The mean BMI was 30.0 kg/m2 (CI 28.57–31.08). As for the asymptomatic PTN, a mean CSA reference value of 0.10 cm2 was obtained.With increase in age and BMI, a greater PTN measurement will occur. Race appears to be a contributing factor, but further research is needed in this regard. The reference CSA value for normal PTN should be set at 0.10 cm2 for all racial groups for a basic musculoskeletal ultrasound exam protocol in South Africa. [ABSTRACT FROM AUTHOR]

Alpha-fetoprotein (AFP) is a serum protein highly produced during the fetal period. It is also known as a biomarker of various pathologies. Commonly, tumors requiring diagnosis and monitoring through AFP determination appear during the first year of life, with poorer outcomes when presenting in fetal life. Due to advancements in imaging technology, the detectability of ovarian masses in infants is higher. However, the use of AFP as a biomarker could improve diagnosis in cases when imaging and histological examinations are not sensitive enough to detect tumors. From the outcome of our investigation, it is possible to conclude that there is evidence of an association between increased AFP levels and ovarian masses. However, previous studies have presented contradictory and unverified results, with the authors emphasizing that future research is needed. In this article, an analysis of the available literature on AFP as a biomarker of ovarian masses in children was performed. Two types of literature were reviewed: guidance and published studies (clinical trials, reviews, and systematic reviews). We searched the Embase, PubMed, ScienceDirect, and Web of Science databases to collect essential data. [ABSTRACT FROM AUTHOR]

Introduction: Cystatin C is considered an early marker of kidney damage. The aim was to determine the reference interval in children since this information was not available from the test manufacturer. Materials and methods: Included were children aged 0 to 18 years undergoing routine check without history of any renal disease. Cystatin C was measured by the immunoturbidimetric method, and creatinine by the enzymatic method on a Cobas c501 analyzer (Roche Diagnostics, Manheim, Germany). Reference intervals were determined according to the CLSI C28-A3 guidelines using a robust method and a nonparametric percentile method, depending on the sample size. The Schwartz's formula was applied to estimate glomerular filtration (eGFR) from cystatin C. Results: The cystatin C reference interval for children aged 1-18 years (N = 204, median 8 years) was from 0.61 mg/L (90% CI: 0.53 to 0.64) to 1.08 mg/L (90% CI: 1.07 to 1.14). Differences according to sex were not found. For children aged 0-1 years (N = 29, median 5 months), the reference interval was from 0.60 mg/L (90% CI: 0.48 to 0.72) to 1.49 mg/L (90% CI: 1.36 to 1.61). The sample size was too small to test the difference according to sex. The eGFR was 76 (70-88) mL/min/1.73m² for males and 83 (74-92) mL/min/1.73m² for females. Conclusion: The cystatin C reference intervals for Croatian pediatric population according to age were determined. The cystatin C concentrations in children reach adulthood values after the first year. The cystatin C Schwartz's formula is applicable for eGFR calculation in children. [ABSTRACT FROM AUTHOR]

Introduction: Trabecular bone score (TBS) is partially independent of fracture risk. Reference values for TBS have not been established in official guidelines, and thus clinicians often have difficulty interpreting TBS results. This study aimed to investigate whether reference values for TBS could be a valid indicator for clinical vertebral fracture (CVF). Materials and methods: This cross-sectional study involved 231 women with CVF and 563 women without CVF aged 60–90 years who underwent dual-energy X-ray absorptiometry during 2019–2023. They were divided into osteoporosis, osteopenia, and normal groups according to bone mineral density of the lumbar spine. Reference values for TBS were defined as low (≤ 1.23), intermediate (1.23–1.31), and high (≥ 1.31). Results: Among patients without anti-osteoporosis treatment (n = 476), the proportion with low TBS was 36.7% in the CVF group and 10.7% in the control group. The proportion with CVF was higher in the low TBS group than in the intermediate and high TBS groups, especially in the osteoporosis group (p < 0.001). The odds ratio for CVF was higher in the low TBS group than in the intermediate and high especially in patients with normal BMD and osteoporosis. The TBS cut-off values for incidence of CVF in the osteoporosis, osteopenia, and normal groups were 1.224, 1.319, and 1.322, respectively. Conclusions: The reference value for low TBS (≤ 1.23) was useful as an indicator for CVF, especially in patients with osteoporosis. It is expected that reference values for TBS will be established in official guidelines in the future. [ABSTRACT FROM AUTHOR]

Hair cortisol concentration (HCC) has shown remarkable promise as a stable, non‐invasive measure of systemic cortisol; however, despite methodological advances, the value that would typically be seen in healthy adults has not been established. Therefore, we sought to review the relevant literature to determine a reference value for HCC in healthy (i.e., non‐clinical) adults. To this end, we conducted a systematic review of the PubMed, Scopus, and CINAHL databases for studies that measured healthy adult HCC using immunoassay methods, given that these are the most widely accessible analytical tools. To be eligible, studies were required to have been published in English, to have provided relevant descriptive statistics (i.e., means and standard deviations), and to have used a healthy adult human sample. We found 17 studies that met our inclusion criteria; the reports involved 1348 participants with a mean age of about 38 years. Since we identified a large amount of between‐study heterogeneity, we completed a random‐effect meta‐regression analysis and found that test kit vendor was the only significant variable of the model. As a result, when using methodologies from traditional finite mixture distributions to determine reference values for mean and elevated HCC in individual healthy adults, we calculated these estimates for each of the major test kit vendors. Future work will need to determine whether our estimated reference values need to be modified, and these efforts will be greatly assisted by studies that account for potential moderating factors, such as age, sex, and ethnicity. Due to ease and cost, immunoassays are widely used for hair cortisol analysis. However, guidelines for typical hair cortisol concentration (HCC) in healthy adults are lacking. Therefore, we completed a systematic review of relevant studies and used methodologies from traditional finite mixture distributions to determine reference values for mean and elevated HCC in individual healthy adults. Given that our random‐effect meta‐regression analysis found test kit vendor to be the only significant variable of the model, we prepared estimates for each of the major test kit vendors. [ABSTRACT FROM AUTHOR]

Nickel compounds are classified as group 1 carcinogens by the International Agency for Research on Cancer. However, only a few exposure assessment studies have been conducted on such compounds to date. In this study, we investigated the distribution of nickel in three biological types of samples (blood, serum, and urine) and its temporal variability through repeated measurements. From 2020 to 2021, blood and urine samples were collected for four times from 50 healthy participants. Nickel concentrations were determined using inductively coupled plasma mass spectrometry, and inter-individual correlation was calculated from linear mixed model. The overall geometric mean of nickel was 1.028 μg/L in blood, 0.687 μg/L in serum, and 1.464 μg/L in urine. Blood nickel was the highest in November (blood: 1.197 μg/L), and the geometric mean of nickel concentrations in the serum and urine were the highest in March (serum: 1.146 μg/L; urine: 1.893 μg/L). This matched seasonal trends for fine particulate matter concentrations from 2020 to 2021. Thus, seasonal effects significantly affect nickel levels in blood, serum, and urine. The inter-individual correlations were low as 0.081 for blood and 0.064 for urine. In addition, the correlation of nickel levels between each biological sample was low. It was also found that age, gender, commuting time, and different matrices affect concentrations. Blood and serum nickel levels were high in this study compared to other nationwide data, with urinary nickel ranking the second highest among the six countries examined. Therefore, biomonitoring study in the general population should be conducted, and finding a suitable matrix that can reflect nickel exposure to set exposure guideline levels is imperative. [ABSTRACT FROM AUTHOR]

Background: Total immunoglobulin E (IgE) analysis is a common tool in allergy diagnosis. Suggested reference values for IgE are divergent and sometimes based on outdated assay methods. We aimed to validate the published reference values (geometric mean [GM]: 13.2 kU/L, upper limit of normal [ULN], 114 kU/L) shown in an Uppsala cohort from 1974 using Phadebas IgE PRIST, and the suggested clinical threshold of 100 kU/L (Zetterström and Johansson 1981). Methods: Immunoglobulin E was measured in two Uppsala cohorts from 1997 (Blood bank) and 2011 to 2013 (the European community respiratory health survey part III [ECRHS III]) using ImmunoCAP™ Total IgE. For the reference value calculations, exclusion criteria were atopy (both cohorts), doctor’s diagnosis of asthma and self-reported allergy (hay fever, rhinitis, rash) (only ECRHS III). Upper limit of normal was defined as mean + 2 standard deviations (SD) calculated using log-transformed values and back-transformation of the ULN prior to presentation. Common imputation methods for results below the assay range were evaluated. Results: The average GM was 14.2 kU/L (Blood bank, n = 63; imputation method range: 16.9–17.4 kU/L; ECRHS III, n = 113: 10.7–11.6 kU/L) and the overall mean ULN was 118 kU/L (Blood bank: 113–130 kU/L; ECRHS III: 104–128 kU/L). The clinical sensitivity and specificity of the 100 kU/L IgE threshold were 37.8 and 94.3% for atopy, 34.9 and 89.5% for doctor’s diagnosis of asthma, and 24.5 and 97.3% for any self-reported allergy (ECRHS III). Conclusion: The calculated ULN values were similar between the cohorts. We conclude that the total IgE reference values shown for Uppsala subjects from 1974 are still valid and suitable also for the ImmunoCAP Total IgE assay. The 100 kU/L threshold for total IgE had a low sensitivity but high specificity for atopy, asthma, and allergy.

Background: Reference blood pressure (BP) values for Japanese children based on a large number of measurements by auscultation have not yet been established. Methods: This was a cross-sectional analysis of data from a birth-cohort study. The data from the sub-cohort study conducted for children at the age of 2 years in the Japan Environment and Children's Study from April 2015 to January 2017 were analyzed. BP was measured via auscultation using an aneroid sphygmomanometer. Each participant was measured in triplicate, and the average value of two consecutive measurements with a difference of less than 5 mmHg was recorded. The reference BP values were estimated using the lambda–mu–sigma (LMS) method and compared with those obtained via the polynomial regression model. Results: Data from 3361 participants were analyzed. Although the difference between the estimated BP values by the LMS and the polynomial regression model was small, the LMS model was more valid based on the results of the fit curve of the observed values and regression models for each model. For 2-year-old children with heights in the 50th percentile, the 50th, 90th, 95th, and 99th percentile reference values of systolic BP (mmHg) for boys were 91, 102, 106, and 112, and that for girls were 90, 101, 103, and 109, respectively, and those of diastolic BP for boys were 52, 62, 65, and 71, and that for girls were 52, 62, 65, and 71, respectively. Conclusion: The reference BP values for 2-year-old Japanese children were determined based on auscultation and were made available. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs) are one of the most important environmental pollutants. Urinary concentrations of 1-hydropyren metabolites of PAHs have been used as biomarkers of these chemicals' exposure in humans. This cross-sectional study was conducted on 468 healthy Iranian adults over 25 years old and non-smokers in six provinces who were selected based on the clustering method. Fasting urine sampling and body composition and demographic measurements were performed. Urine samples were analyzed by GC-MS. The analysis included descriptive statistics and analytical statistics using multiple linear regression by Python software. 1-Hydroxypyrene was found in 100% of samples, and the mean (Reference Value 95%) concentration of 1-hydroxypyrene was 6.12 (RV 95%: 20) μg/L and 5.95 (21) μg/gcrt. There was a direct relationship between the amount of body composition (body fat, visceral fat), BMI, and age with the urinary concentrations of 1-hydropyren metabolites, and this relationship was significant for BMI with urinary concentrations of 1-hydropyren metabolites (P = 0.045). The amount of 1-hydroxypyrene in healthy Iranian adults has been higher than in similar studies in other countries. These results provide helpful information regarding the exposure of Iranian adults to 1-hydroxypyrene, and these data can be used to supplement the national reference values of human biomonitoring for the interpretation of biomonitoring results. [ABSTRACT FROM AUTHOR]

Alpha-fetoprotein (AFP) is a serum protein highly produced during the fetal period. It is also known as a biomarker of various pathologies. Commonly, tumors requiring diagnosis and monitoring through AFP determination appear during the first year of life, with poorer outcomes when presenting in fetal life. Due to advancements in imaging technology, the detectability of ovarian masses in infants is higher. However, the use of AFP as a biomarker could improve diagnosis in cases when imaging and histological examinations are not sensitive enough to detect tumors. From the outcome of our investigation, it is possible to conclude that there is evidence of an association between increased AFP levels and ovarian masses. However, previous studies have presented contradictory and unverified results, with the authors emphasizing that future research is needed. In this article, an analysis of the available literature on AFP as a biomarker of ovarian masses in children was performed. Two types of literature were reviewed: guidance and published studies (clinical trials, reviews, and systematic reviews). We searched the Embase, PubMed, ScienceDirect, and Web of Science databases to collect essential data.

The analysis of odds ratio curves is a valuable tool in understanding the relationship between continuous predictors and binary outcomes. Traditional parametric regression approaches often assume specific functional forms, limiting their flexibility and applicability to complex data. To address this limitation and introduce more flexibility, several smoothing methods may be applied, and approaches based on splines are the most frequently considered in this context. To better understand the effects that each continuous covariate has on the outcome, results can be expressed in terms of splines-based odds ratio (OR) curves, taking a specific covariate value as reference. In this paper, we introduce an R package, flexOR, which provides a comprehensive framework for pointwise nonparametric estimation of odds ratio curves for continuous predictors. The package can be used to estimate odds ratio curves without imposing rigid assumptions about their underlying functional form while considering a reference value for the continuous covariate. The package offers various options for automatically choosing the degrees of freedom in multivariable models. It also includes visualization functions to aid in the interpretation and presentation of the estimated odds ratio curves. flexOR offers a user-friendly interface, making it accessible to researchers and practitioners without extensive statistical backgrounds.

The six-minute walk test (6MWT) is a common utility outcome for evaluating exercise capacity in patients with pulmonary diseases. However, there is no existent reference value for Nigerian older adults. This study is therefore aimed at establishing reference values and equations for 45-70 years old Nigerian adults. We consecutively recruited apparently healthy adults into this cross-sectional survey and used standard protocols for 6MWT and anthropometrics. Regression equations were developed based on demographic and anthropomorphic data. These equations were compared to existing prediction equations. One hundred and four participants completed two 6MWT. The average six-minute walk distance (6MWD) was 378 metres; greater in men than women (p<0.001). The 25th and 75th percentiles were 345.10 and 408.18 metres, respectively. The variables that were significantly associated with 6MWD were sex, age and height. We found two explanatory model equations and the model equation for all participants is 6MWD = 297.96 + 47.41 (sex) - 1.001 (age) + 65.214 (height) where female = 0 and male = 1 with explanatory power of 41.3%. Applying other studies' equations to our population resulted in an underestimation or overestimation of the 6MWD. In conclusion, the average 6MWD in this Nigerian population was 378 metres. Age, height and sex were the most significant predictors of 6MWD and the regression equations explained 41% of the variance in the distance walked. These equations will help to improve evaluation of patients with diseases that affect aerobic capacity. [ABSTRACT FROM AUTHOR]

Background: Thromboelastography is a viscoelastic test of whole blood hemostasis. Currently, no reference value exists for native whole blood and recalcified citrated blood without activators. The aim of this study was to compare the results of ROTEM® tests using fresh native blood without decalcification "TRUE-NATEM" with those using decalcified citrated blood "NATEM" and provide reference values for each. Methods: Inclusion criteria were healthy adult volunteers (18–65 years). Exclusion criteria were any medical condition or medication affecting coagulation. Native whole blood testing was defined as "TRUE-NATEM-test." For recalcified citrated blood testing, the NATEM function was used on ROTEM®. Result: The reference value for TRUE-NATEM was CT: 872-1595s, A10: 14-34 mm, A20: 26-48 mm, CFT: 314-839s, MCF: 34-55 mm, and alpha angle: 17-40°. The reference value for NATEM was CT: 757-1327s, A10: 19-43 mm, A20: 33-55 mm, CFT: 219-615s, MCF: 37-61 mm, alpha angle: 24-51°, and ML: 0-3%. When comparing the reference value of NATEM to TRUE-NATEM, the CT and CFT values are decreased and the MCF and alpha angle are increased. The recalcification process of citrated blood in NATEM shows significant activation of coagulation. Female healthy volunteers had enhanced coagulation when activators were used. Age-related statistical difference was seen when activators were used. Ethnicity did not show any difference on the ROTEM values. Conclusion: We determined the reference value for native whole blood and recalcified whole blood using ROTEM®. A significant discrepancy in native whole blood and recalcified citrated blood coagulation was found. Our study underlines the importance of native whole blood as the gold standard reference value in coagulation. [ABSTRACT FROM AUTHOR]

To determine and compare pelvic and lumbosacral reference parameters with computed tomography in patients with low back pain (LBP) and a control group of asymptomatic patients to provide quantification data and morphological correlations for L5S1 transforaminal endoscopic approach (L5S1TEA). We prospectively evaluated 100 patients with LBP and a control group of 100 individuals, with spinopelvic computed tomography. We measured lumbopelvic and L5S1 transforaminal approach parameters: maximum approach angle (maxAA) and minimum approach angle (minAA) and skin incision (maxSI and minSI), iliac crest (IC) projection at intersection point (ICPi), distance between the projected intersection of maxAA with the ilium (ICi) and the posterior limit of the IC (ΔICi-ICpost), and distance between ICi and spinous process (ΔICi-SP). Females and ICPi were increased in the LBP group: maxAA: 48.38° ± 5.09°; minAA:32.5° ± 3.90°; maxSI: 11.39 ± 1.86 cm; and minSI: 8.30 ± 1.48 cm. Ilium intersection was increased in males; IC projection at the highest point (ICPh) was higher than ICPi; maxAA intersected the ilium in 28% and minAA in 1.5% of cases; ICi was positively correlated with facet angle, ICPh, and ICPi and negatively with ΔICi-SP. Our results set preliminary reference values for L5S1TEA surgical planning. Besides higher ICPi, there were no differences between groups in measured parameters. Traditional IC height (ICPh) does not correspond to the point of intersection of the approach and is significantly higher than ICPi. ICi correlated to higher facet angle values, ICPh and ICPi grades, and lower ΔICi-SP. Potential conflict with the ilium is increased in the male population. IC is not impeditive of L5S1TEA in most cases. [ABSTRACT FROM AUTHOR]

Background: Optimal vitamin D levels for an effective role in immune function and rickets prevention are thought to vary, but have not yet been definitively determined. Reports on reference values of 25-hydroxyvitamin D (25(OH)D) in cats are limited. Aims: The study provides information about serum 25(OH)D values in cats with different age, gender, breed, diet type, reproductive status, housing condition, and also the relationship between these levels and various hematological and biochemical parameters. Methods: Clinically healthy cats (88) were included in the study. Physical examination and assessment of hematological and biochemical parameters were performed on cats in order to confirm their health status. Reference value of serum 25(OH)D was assayed by ELISA method and the effects of age (under six months and above six months), gender, breed, diet (only commercial diet, only homemade food, mixture of commercial and homemade food), reproduction status, and housing conditions on serum 25(OH)D was determined. Results: The median, 2.5% and 97.5% of 25(OH)D in sampled cats were 19.74 ng/ml, 3.12 ng/ml, and 92.1 ng/ml, respectively. Serum 25(OH)D concentration was lower when homemade diet was used compared to commercial and mixed diets as well as in cats under six months of age compared to older cats. Conclusion: Diet type and age can affect serum 25(OH)D levels in healthy cats while other parameters had no significant effects. [ABSTRACT FROM AUTHOR]

Context: The Balance Error Scoring System (BESS), originally designed to diagnose and assess athletes with concussion syndrome, is now widely used to evaluate postural stability. To inteipret balance status, a normative database can be a reliable source. However, different anthropometric characteristics and sociocultural backgrounds across populations hinder the application of previously developed databases in different populations. Objective: The present study was designed to develop a normative data set for the general population of healthy Iranian adults according to their age groups and to study the correlation between BESS scores and the participants' sex, height, weight, and body mass index. Design: A cross-sectional study. Participants: A total of 1051 community-dwelling adults aged 20-69 years not suffering from balance disorders, dizziness, or other neurological or musculoskeletal diseases were recruited and stratified into 5 different age groups by decade. Main Outcome Measures: The BESS tests were composed of single-leg, double-leg, and tandem stances, each on a rigid surface and a foam pad. The individuals maintained each position for 20 seconds with eyes closed. The assessor recorded the total number of errors as the individuals' BESS score (range: 0-60). Results: Significant but weak correlations were found between BESS score and height (r = -.13, P<.001) and between BESS score and body mass index (r=.11, P<.001), and the difference between sexes in BESS score was statistically significant in the 50- to 59-year-old (P = .021) and 60- to 69-year-old (P<.001) groups. The BESS scores were significantly different between all age groups (P < .05), except between the 20- to 29-year-old and 30- to 39-year-old groups (P - 1.000) and between the 40- to 49-year-old and 50- to 59-year-old groups (P = .086). Conclusions: This study provided a normative database for different age groups of asymptomatic Iranian adults. The BESS score had weak correlations with height and body mass index and no correlation with weight, and significant differences were found between sexes in 50- to 69-year-old individuals. This study emphasizes the importance of obtaining specific normative data for different populations. [ABSTRACT FROM AUTHOR]

This study proposes a spirometry reference equation suitable for Asian migrant workers undergoing special health examinations. The study participants were divided according to their region: Central Asia, Northeast Asia, and South Asia Pacific. We confirmed results of the spirometry analysis of migrant workers and the interpretation consistency between the prediction equations. Based on this data, we propose a reference equation suitable for domestic migrant workers and suggest a scaling factor applicable to the spirometer wherein the reference equation is not easily applicable. The kappa-values obtained for men and women, respectively, between the global lung function initiative 2012 (GLI2012)-Southeast Asian and the Southeast Asian equations were 0.819 and 0.770, between the GLI2012-Southeast Asian and the South Asian equations were 0.881 and 0.866, and between the GLI2012-Northeast Asian and the Central Asian equations were 0.831 and 0.833. We propose applying the GLI2012-Northeast Asian equation for Northeast Asian and Central Asian countries, whereas the GLI2012-Southeast Asian equation was found to be more suitable for predicting Southeast Asian and South Asian populations. For spirometry, we recommend applying a scaling factor of 0.87 to the Dr. Choi equation, wherein the GLI2012-Southeast Asian equation is not applicable.

Questions: What are comfortable gait speed values for apparently healthy adults? How do these differ by age group, sex and geographical region? Design: Systematic review of observational studies with meta-analysis. Participants: Apparently healthy, community-dwelling adults who have undergone measurement of comfortable gait speed. Search method: Potentially relevant studies were identified in four databases. Extracted data from studies that satisfied the eligibility criteria were added to a database containing the same information from a meta-analysis published a decade ago. Outcome measures: The weighted mean comfortable gait speed was calculated along with the 95% confidence interval for each stratum of age/sex using a random-effects model. Mean gait speeds were further stratified by the continent where the study took place. Tests of homogeneity included I2 and prediction intervals. Results: Meta-analysis of data from 51,248 apparently healthy adults was stratified by age (in decades) and sex. Male gait speed slowed beyond age 50 years whereas female gait speed slowed beyond age 30 years. The weighted mean gait speed ranged from 97 cm/s (females aged ≥ 80 years) to 140 cm/s (males aged 40 to 49 years). The I2 values ranged from 0 to 34.07; prediction interval ranges varied from a low of 30 (125 to 155 cm/s; males aged 40 to 49 years) to a high of 77 (83 to 160 cm/s; females aged 60 to 69 years). There was considerable overlap in confidence intervals between continents for each sex/age group. Conclusions: Comfortable gait speed slowed through the adult years, but males maintained a faster walking speed than females. Further stratification of comfortable gait speed by geographical region is not warranted.

Background and purpose: For correction of leg-length discrepancy or angular deformity of the lower limb in skeletally immature patients temporary or permanent (hemi-)epiphysiodesis can be employed. These are reliable treatments with few complications. Recently, radiographic analysis of treatment-related alterations of the central knee anatomy gained interest among pediatric orthopedic surgeons. To date the comparison and adequate interpretation of potential changes of the central knee anatomy is limited due to the lack of defined standardized radiographic references. We aimed to establish new reference values of the central knee anatomy. Patients and methods: A retrospective analysis of calibrated longstanding anteroposterior radiographs of 254 skeletally immature patients with a chronological age ranging from 8 to 16 years was conducted. The following radiographic parameters were assessed: (1) femoral floor angle, (2) tibial roof angle, (3) width at femoral physis, and (4) femoral notch–intercondylar distance. Results: All observed radiographic parameters were normally distributed with a mean age of 12.4 years (standard deviation [SD] 2, 95% confidence interval [CI] 12.2–12.6). Mean femoral floor angle was 142° (SD 6, CI 141.8–142.9), mean tibial roof angle was 144° (SD 5, CI 143.7–144.1), mean width at femoral physis was 73 mm (SD 6, CI 72.8–73.9), and mean femoral notch–intercondylar distance was 8 mm (SD 1, CI 7.5–7.7). The estimated intraclass correlation coefficient values were excellent for all measurements. Conclusion: This study provides new radiographic reference values of the central knee anatomy for children between 8 and 16 years and we suggest considering values within the range of 2 SD as the physiological range.

PurposeOur aim was to investigate the normal reference value and to establish an estimation formulae for renal structural parameters (RSPs) based on large-sample CT data of Chinese children, which can provide a data reference for the clinical assessment of kidney development and diseases in Chinese children.Materials and MethodsA total of 438 children aged 0–17 years with normal renal CT images and basic indices were continuously collected. The bilateral RSP, including renal length (RL), renal width (RW), renal thickness (RT), renal volume (RV), renal cortical thickness (RCT), renal artery diameter (RAD) and renal CT value, were measured. Kendall's rank correlation was used to analyze the correlation between RSP and sex. Pearson's correlation was used to analyze the correlation between RSP and age, height and weight. Differences in the RSP of bilateral kidneys were analyzed via a paired samples t-test. Multiple linear regression was used to analyze the multivariate relationships between RSP and basic indices and establish the estimation formula of RSP.ResultsThe RSP of normal kidneys showed a dynamic increasing trend with age, except for the CT values. The reference value ranges (95% confidence interval) of normal RSP for each age group were determined. Pearson correlation analysis demonstrated strong correlations between RSP (RL, RW, RT, RV, RCT and, RAD) and basic indices (age, height and, weight), with height exhibiting the greatest correlation coefficient, followed by age or weight. Kendall's analysis showed that none of the RSPs were correlated with sex. The RL, RW, RV and RAD of the left kidney were larger than those of the right kidney, and the RT and RCT of the right kidney exhibited opposite results. Multiple linear regression analysis demonstrated a significant linear relationship between the RSP (RL, RW, RT, RV and, RCT) and the variables of the basic indices. The estimation formulae for calculating the RSP were established.ConclusionThis is the first Chinese study to report of the trends, normal reference values and estimation formulae of normal RSP based on large-sample CT data. These results can provide data references for assessing adequate kidney growth or disease damage in Chinese children.

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There is a lack of data regarding the single heel-rise test (SHRT) among children. Hence, we aimed to establish reliability and reference norms of SHRT among children aged 8 to 12 years. About 500 healthy children were randomly selected from the recognized school and community settings. After demographic measurements, SHRT was conducted to evaluate the strength of each plantar flexors. SHRT repetitions were assessed by the same rater on 2 occasions for intrarater (on the same day) and test-retest reliability (on different days) and by 2 raters for inter-rater reliability. Relative reliability was described in terms of the intraclass correlation coefficient (ICC) and Pearson correlation coefficient (r). Absolute reliability was indicated by the standard error of measurement (SEm), minimal detectable change (MDC), and Bland-Altman graph. The mean of the number of repetitions of SHRT was calculated to derive the reference norm of SHRT. The anthropometric parameters were correlated with SHRT for multiple regression analysis. Intrarater, test-retest, and inter-rater reliability of SHRT were, ICC = 0.81, ICC = 0.70, and ICC = 0.57, respectively. The Bland-Altman graph confirmed limits of agreement for intrarater, test-retest, and inter-rater reliability. The reference norm of SHRT is documented to be 20.6 ± 4.8. SEm and MDC are found to be 2 and 3, respectively. Multiple regression analysis predicted a correlation of age, weight, and calf muscle girth with SHRT. SHRT is moderate to good reliable in assessing the strength of plantar flexors. The reference norms of SHRT have been derived for healthy children aged 8 to 12 years. [ABSTRACT FROM AUTHOR]

This study was to investigate blood lead (Pb) and cadmium (Cd) levels and time trend in rural Chinese children derived from the China Nutrition and Health Survey 2002 and 2012 (CNHS 2002, CNHS 2012). In total, 1698 and 1581 of rural Chinese children were selected from the CNHS 2002 and the CNHS 2012 databases, respectively. The blood Pb and Cd levels were determined by inductively coupled plasma mass spectrometer (ICP-MS), whilst the prevalence of blood Pb levels >5 µg/dL and blood Cd levels >0.5 µg/L and the corresponding reference values (RV95s: the upper limit of 95% confidence interval of 95th percentile) were together calculated. From the CNHS 2002 to the CNHS 2012, median concentrations in blood were severally decreased from 6.3 to 3.1 µg/dL for Pb and from 0.64 to 0.39 µg/L for Cd. The prevalence of blood Pb levels >5 µg/dL had decreased from 63.6 to 14.2%, together with blood Cd levels >0.5 µg/L prevalence from 62.7 to 33.5%, respectively. The RV95s of blood Pb and Cd levels were 15.2 µg/dL and 1.54 µg/L in the CNHS 2002, as well as 6.3 µg/dL and 1.12 µg/L in the CNHS 2012. In conclusion, blood Pb and Cd levels had been obviously improved in rural Chinese children during the past 10 years. However, the risks of Pb and Cd exposure are still serious and required to have continuous health monitoring and evaluation, even call for greater collaboration of the government and society. [ABSTRACT FROM AUTHOR]

Abstract Background As a noninvasive tool, myocardial deformation imaging may facilitate the early detection of cardiac dysfunction. However, normal reference ranges of myocardial strain and strain rate (SR) based on large-scale East Asian populations are still lacking. This study aimed to provide reference values of left ventricular (LV) and right ventricular (RV) strain and SR based on a large cohort of healthy Chinese adults using cardiovascular magnetic resonance (CMR) feature tracking (FT). Methods Five hundred and sixty-six healthy Chinese adults (55.1% men) free of hypertension, diabetes, and obesity were included. On cine CMR, biventricular global radial, circumferential, and longitudinal strain (GRS, GCS, and GLS), and the peak radial, circumferential, and longitudinal systolic, and diastolic SRs (PSSRR, PSSRC, PSSRL, PDSRR, PDSRC, and PDSRL), and regional radial and circumferential strain at the basal, mid-cavity, and apical levels were measured. Associations of global and regional biventricular deformation indices with age and sex were investigated. Results Women demonstrated greater magnitudes of LV GRS (37.6 ± 6.1% vs. 32.1 ± 5.3%), GCS (− 20.7 ± 1.9% vs. − 18.8 ± 1.9%), GLS (− 17.8 ± 1.8% vs. − 15.6 ± 1.8%), RV GRS (25.1 ± 7.8% vs. 22.1 ± 6.7%), GCS (− 14.4 ± 3.6% vs. − 13.2 ± 3.2%), GLS (− 22.4 ± 5.2% vs. − 20.2 ± 4.6%), and biventricular peak systolic and diastolic SR in all three coordinate directions (all P

Abstract Background Optimal amount of vitamin D for the proper functioning of the immune system is different from the required vitamin D amount for bones to prevent rickets. However, reports on vitamin D reference values in dogs are minimal, and there is still not enough information regarding the relationship between vitamin D and various variables such as disease, age, breed, diet type, and so on, as well as its relationship with haematological and serum biochemical parameters. Obgectives The present study aimed to determine reference values of 25(OH) Vit D in dogs and its concentration in different groups, categorized based on age, sex, breed, housing conditions, and diet, as well as 25(OH) Vit D relationship with hematology and serum biochemistry parameters. Methods In this study, 90 healthy dogs were selected to determine the reference value of 25 (OH) Vit D of serum after evaluating of their haematological and biochemical parameters to assess their general health. Dogs were divided into different groups according to above‐mentioned variables. Serum 25 (OH) Vit D was subsequently measured by the ELISA method. Results The median concentration of 25 (OH) Vit D was 52.50 ng/ml with minimum and maximum amounts of 14.00 and 155.57 ng/ml, respectively. No significant difference was observed between 25 (OH) Vit D levels in the studied dogs regarding their different age, sex, breed, diet, housing condition, and reproductive status. Serum 25 (OH) Vit D concentration is directly correlated with the number of band neutrophils (p

Abstract Background The oldest old, defined as those aged 90 or over, is now the fastest-growing population sector. This study aimed to determine reference values for several physical performance measures (PPMs) among 90-year-olds using internationally standardized measurements and to clarify the characteristics of these indices by comparing their results for 90-year-olds with those for older people 70 and 80. Methods We used the Septuagenarians, Octogenarians, and Nonagenarians Investigation with Centenarians (SONIC) study data from 2010 to 2018. The study subjects were 70, 80, and 90-year-olds in the target area eligible to participate in the venue. Excluding those certified for long-term care, the final number of eligible persons is 70s cohort 1000 (2010), 80s cohort 973 (2011), and 90s cohort 690. 90s cohort only consisted of three survey waves: 2012, 2015, and 2018. We used hand grip strength and score on the Short Physical Performance Battery (SPPB) for our physical performance measurements. In addition, we statistically analyzed sex and age differences. Result The simple mean ± standard deviation (SD) for the 90-year-old respondents were in men, 24.1 ± 5.4 kg in hand grip strength, 0.80 ± 0.22 m/s in usual gait speed, 17.2 ± 6.73 s in 5times chair stand, 5.89 ± 4.42 s in tandem balance, and 8.3 ± 2.2 in SPPB respectively and in women, 14.4 ± 4.0 kg in hand grip strength, 0.72 ± 0.20 m/s in usual gait speed, 17.8 ± 7.89 s in 5times chair stand, 4.72 ± 4.35 s in tandem balance, and 7.5 ± 2.4 in SPPB, respectively. For all PPMs, the age 90 cohort was statistically significantly different from the age 70 and 80 cohorts (all trends P

The assessment of attention in neuropsychological patients could be performed with visual search tests. The Broken Rings enVision Search test (BReViS) here proposed represents a novel open access paper-and-pencil tool in which layout and crowding are varied among four cards. These manipulations allow the assessment of different components of attention: a selective component, the visuo-spatial orientation of attention, and the focal attention, involved in a crowding phenomenon. Our purpose was to determine the characteristics of the BReViS test, provide specific normative data, and assess these components across the lifespan. The test was administered to a sample of 550 participants aged between 20 and 79 years old and to a series of patients. Three indexes targeting different components of visuo-spatial attention (selective attention, strategic orientation of visual attention, focal attention) were obtained by combining execution times and accuracy together with the total errors. The results showed that age, education and gender influenced, in different combinations, the four indexes, for which specific norms were developed. Regression-based norms were provided in percentiles and equivalent scores. All patients showed pathological scores and specific patterns of attentional deficits. The BreViS test proved to be a free and easy valuable tool which can be used in the clinical environment to assess attentional deficits in neuropsychological patients. [ABSTRACT FROM AUTHOR]

Renal impairment is concurrent with adverse outcomes such as heart disease in humans and dogs. Intrarenal Doppler ultrasonography (IRD) is used to assess intrarenal hemodynamics, and resistance index (RI) and venous impedance index (VII) are used to evaluate intrarenal hemodynamics in humans with heart failure. However, only a few studies have assessed the efficacy of IRD, especially VII, in dogs, and the methods differ between studies. Additionally, repeatability, reproducibility, and factors influencing IRD values have not been validated in dogs. This prospective, analytical study aimed to assess repeatability and reproducibility of IRD, and to clarify influencing factors of IRD in dogs without heart disease. We enrolled 78 dogs without heart disease. The RI and VII were highly reproducible, and the reference intervals for VII were 0.13–0.37. Differences in transducer (sector and convex) and posture (right lateral and supine decubitus position) had no effect on the IRD values. In contrast, RI and VII were higher in the renal vessels than in interlobar vessels. Age affected RI values (r = 0.39, P < 0.001), but there was no correlation between age, body weight, and VII. In conclusion, IRD is a repeatable and reproducible method to assess intrarenal hemodynamics in dogs. The findings also suggest that age should be considered while interpreting RI. [ABSTRACT FROM AUTHOR]

Background: This study aims to investigate the serum fat-soluble vitamins A, D, and E levels of children in Zhejiang Province, and to provide a reference range of fat-soluble vitamins for children in Zhejiang Province. Methods: Between May 2019 and December 2019, 871 children who sent peripheral blood samples to Hangzhou Biozon Medical Institute Co., Ltd. for fat-soluble vitamin A, D, and E analysis were selected, including 432 boys and 439 girls. After the peripheral blood was collected, the serum A, D, and E levels were measured, and the differences in age, gender, season, and region were compared. Results: With age, the level of vitamin A gradually increased (p < 0.01), and vitamin D2, D3, and total vitamin D all increased first and then decreased. Vitamin A (131.79 ± 47.05 ng/mL vs. 121.96 ± 41.01 ng/mL) and E (5.87 ± 2.23 μg/mL vs. 5.56 ± 2.13 μg/mL) levels of girls were higher than boys (p < 0.01), and vitamin D3 (15.25 ± 6.16 ng/mL vs.15.17 ± 7.26 ng/mL) and total vitamin D (18.09 ± 7.01 ng/mL vs. 17.03 ± 8.79 ng/mL) levels of boys were higher than girls (p < 0.01). From the perspective of regional distribution, the levels of vitamin A, D2, and E in Ningbo were higher than those in Hangzhou and other regions. The seasonal distribution of vitamin A and E levels were highest in summer, while vitamin D3 and D levels were highest in fall. The average vitamin concentrations were as follows: vitamin A was (126.81 ± 44.42) ng/mL; vitamin D2 was (1.84 ± 3.16) ng/mL, vitamin D3 was (15.71 ± 6.75) ng/mL, total vitamin D was (17.55 ± 7.91) ng/mL, and vitamin E was (5.72 ± 2.19) μg/mL. The reference value ranges of vitamin A, D2, D3, D, and E were (52.44 - 222.27) ng/mL, (0.01 - 11.66) ng/mL, (4.92 - 30.96) ng/mL, (4.92 - 30.96) ng/mL, and (2.66 - 10.92) μg/mL, respectively. Conclusions: The childrens' fat soluble vitamin levels in Zhejiang province show significant differences in age, gender, season, and regional distribution. Corresponding reference standards should be formulated as soon as possible, and vitamin supplements should be targeted and reasonable to ensure the healthy development of children. [ABSTRACT FROM AUTHOR]

This paper reviews some proficiency testing (PT) programmes operated under the auspices of Asia Pacific Metrology Programme and Asia Pacific Laboratory Accreditation Cooperation Joint Proficiency Testing Working Group. The assigned values of these joint PTs are traceable to the SI. Provision of PTs based on reference values (PTRVs) with metrological traceability enables meaningful performance evaluation and assessment of metrological comparability of the participants' results. Special focus will be given to those joint PTs related to analysis of inorganic elements in various sample matrices organized or co-organized by Government Laboratory of Hong Kong, China. Comparison based on different evaluation criteria (i.e. consensus value vs reference value) is carried out. Comprehensive evaluation and review of some performance indicators revealed several crucial findings such as the performance of different analytical conditions, recent analytical trends and areas of improvements. The organization of a series of these joint PTs could be regarded as a strong support of the concept that PTRV with metrological traceable reference values is an effective way to promote the concept of metrological traceability to the field laboratories and provide a meaningful performance evaluation tool for assessment of PT performance. [ABSTRACT FROM AUTHOR]

Considering the influence of body's growth and development on thyroid volume (TVOL), whether five existed corrected methods could be applied to correct TVOL remains unclear, in terms of Chinese children's increased growth and development trends. This study aimed to compare the applicability of five correction methods: Body Surface Area corrected Volume (BSAV), Body Mass Indicator corrected Volume (BMIV), Weight and Height corrected Volume Indicator (WHVI), Height corrected Volume Indicator 1 (HVI1) and Height corrected Volume Indicator 2 (HVI2) and to establish the reference values for correction methods. The data of Iodine Nutrition and Thyroid Function Survey were used to analyse the differences in TVOL between normal and abnormal thyroid function children. Data of National Iodine Deficiency Disorders Survey were used to compare five correction methods and to establish their reference values. The median urinary iodine concentrations of children surveyed were 256·1 μg/l in 2009 and 192·6 μg/l in 2019. No significant difference was found in TVOL and thyroid goitre rate between children with normal and abnormal thyroid function. In the determination of goitre, HVI1, HVI2, BSAV and BMIV all showed high agreement with TVOL, while the area under the receiver operating characteristic curve (AUC) of WHVI was relatively low for children aged 8 (AUC = 0·8993) and 9 (AUC = 0·8866) years. Most differences of TVOL between light and heavy weight, short and tall height children can be eliminated by BSAV. BSAV was the best corrected method in this research. Reference values were established for corrected TVOL in Chinese children aged 8–10 years by sex. [ABSTRACT FROM AUTHOR]

Invasive assessments of microvascular function are rapidly becoming an integral part of physiological assessment in chronic coronary syndromes. We aimed to establish a reference range for Doppler flow velocity-derived hyperaemic microvascular resistance index (HMR) in a cohort of angina with no significant epicardial coronary obstruction (ANOCA) patients with no structural pathophysiological alterations in the coronary circulation. The reference population consisted of ANOCA patients undergoing invasive coronary vasomotor function assessment who had a coronary flow reserve (CFR) >2.5, and had either (1) tested negatively for spasm provocation (n = 12) or (2) tested positively with only angina at rest (n = 29). A reference range for HMR was established using a non-parametric method and correlations with clinical characteristics were determined using a spearman rank correlation analysis. In 41 patients median HMR amounted to 1.6 mmHg/cm/s [Q1, Q3: 1.3, 2.2 mmHg/cm/s]. The reference range for HMR that is applicable to 95% of the population was 0.8 mmHg/cm/s (90% CI: 0.8–1.0 mmHg/cm/s) to 2.7 mmHg/cm/s (90% CI: 2.6–2.7 mmHg/cm/s). No significant correlations were found between HMR and clinical characteristics. In this reference population undergoing invasive coronary vasomotor function testing, the 90% confidence interval of the HMR upper limit of normal ranges from 2.6 to 2.7 mmHg/cm/s. A > 2.5 mmHg/cm/s HMR threshold can be used to identify abnormal microvascular resistance in daily clinical practice. [Display omitted] • Increased HMR in the absence of epicardial stenoses is considered a surrogate marker of coronary microvascular pathology. • There was excellent correlation between HMR measurements obtained with or without a microcatheter. • A >2.5 mmHg/cm/s HMR threshold can be used to identify abnormal microvascular resistance in daily clinical practice. [ABSTRACT FROM AUTHOR]

Introduction: There is no global reference value for the 6-minute walking distance (6MWD) in paediatric populations, as it can vary greatly depending on local characteristics and anthropometric measures. This study aimed to identify a 6MWD reference value that could be applied in both local and regional settings. Methods: This cross-sectional multicentre study investigated a healthy paediatric population aged 4–18 years in Indonesia. The 6-minute walk test (6MWT) was conducted in accordance with the American Thoracic Society guidelines. Data were presented as the 6MWD according to age and sex per year. Univariate and multivariate analyses were conducted on the basis of the 6MWDpred Rizky formula. Results: A total of 634 participants were included in this study. Age, sex, weight, leg length and height affected the 6MWD (P<0.001). In the regression model, sex and height were the predictors of 6MWD, with height as the best single predictor. Conclusion: The reference charts and 6MWDpred Rizky formula are applicable in multi-ethnic paediatric Indonesian populations but in limited settings. [ABSTRACT FROM AUTHOR]

Background: Total immunoglobulin E (IgE) analysis is a common tool in allergy diagnosis. Suggested reference values for IgE are divergent and sometimes based on outdated assay methods. We aimed to validate the published reference values (geometric mean [GM]: 13.2 kU/L, upper limit of normal [ULN], 114 kU/L) shown in an Uppsala cohort from 1974 using Phadebas IgE PRIST, and the suggested clinical threshold of 100 kU/L (Zetterström and Johansson 1981). Methods: Immunoglobulin E was measured in two Uppsala cohorts from 1997 (Blood bank) and 2011 to 2013 (the European community respiratory health survey part III [ECRHS III]) using ImmunoCAP™ Total IgE. For the reference value calculations, exclusion criteria were atopy (both cohorts), doctor's diagnosis of asthma and self-reported allergy (hay fever, rhinitis, rash) (only ECRHS III). Upper limit of normal was defined as mean + 2 standard deviations (SD) calculated using log-transformed values and back-transformation of the ULN prior to presentation. Common imputation methods for results below the assay range were evaluated. Results: The average GM was 14.2 kU/L (Blood bank, n = 63; imputation method range: 16.9-17.4 kU/L; ECRHS III, n = 113: 10.7-11.6 kU/L) and the overall mean ULN was 118 kU/L (Blood bank: 113-130 kU/L; ECRHS III: 104-128 kU/L). The clinical sensitivity and specificity of the 100 kU/L IgE threshold were 37.8 and 94.3% for atopy, 34.9 and 89.5% for doctor's diagnosis of asthma, and 24.5 and 97.3% for any self-reported allergy (ECRHS III). Conclusion: The calculated ULN values were similar between the cohorts. We conclude that the total IgE reference values shown for Uppsala subjects from 1974 are still valid and suitable also for the ImmunoCAP Total IgE assay. The 100 kU/L threshold for total IgE had a low sensitivity but high specificity for atopy, asthma, and allergy. [ABSTRACT FROM AUTHOR]

Introduction: The presence of macroenzymes in blood can cause diagnostic confusion. Therefore, confirming the presence of macroenzymes is important to reduce unnecessary (non-)invasive investigations. Polyethylene glycol (PEG) precipitation is a simple and fast first-line method for the detection of macroenzymes. However, there is no consensus on the upper reference limit for the PEG-precipitable activity (%PPA) of monomeric enzymes. The aim of this study was to verify a PEG precipitation protocol for the detection of macroenzymes in our laboratory by establishing upper reference limits (URLs) and determining imprecision for eight enzymes after PEG precipitation. In addition, we aimed to clinically verify the URLs using samples containing macroenzymes as identified by electrophoresis. Materials and methods: Per enzyme, at least 40 leftover blood samples from adult patients with either normal or increased enzyme activities were diluted 1:1 with 25% PEG 6000 and 1:1 with 0.9% NaCl. Mixtures were incubated for 10 min at 37°C and centrifuged. Supernatant enzyme activity was measured on Cobas c702 and the %PPA was calculated. Results: The following URLs were obtained: 26% PPA for amylase, 29% PPA for alkaline phosphatase (ALP), 61% PPA for alanine aminotransferase, 48% PPA for aspartate aminotransferase, 24% PPA for creatine kinase (CK), 55% PPA for gamma-glutamyltransferase, 65% PPA for lactate dehydrogenase, and 56% PPA for lipase. The within-lab imprecision was < 15%. Regarding the clinical verification, the two historical samples with proven macroCK showed a %PPA of 69% and 43%, respectively, and a sample with proven macroALP had a %PPA of 52%. Conclusion: In this study, URLs for monomeric enzyme activities after PEG precipitation for eight different enzymes were established. The URLs are suitable for clinical use, but are only partially in line with other studies. Therefore, our data highlight the importance of establishing laboratory-specific upper reference limits for %PPA to allow a correct interpretation. [ABSTRACT FROM AUTHOR]

Vitamin D-binding protein (VDBP), a serum transport protein for 25-hydroxyvitamin D [25(OH)D], has three common proteoforms which have co-localized amino acid variations and glycosylation. A monoclonal immunoassay was found to differentially detect VDBP proteoforms and methods using liquid chromatography-tandem mass spectrometry (LC-MS/MS) might be able to overcome this limitation. Previously developed multiple reaction monitoring LC-MS/MS methods for total VDBP quantification represent an opportunity to probe the potential effects of proteoforms on proteolysis, instrument response and quantification accuracy. VDBP was purified from homozygous human donors and quantified using proteolysis or acid hydrolysis and LC-MS/MS. An interlaboratory comparison was performed using pooled human plasma [Standard Reference Material® 1950 (SRM 1950) Metabolites in Frozen Human Plasma] and analyses with different LC-MS/MS methods in two laboratories. Several shared peptides from purified proteoforms were found to give reproducible concentrations [≤2.7% coefficient of variation (CV)] and linear instrument responses (R2≥0.9971) when added to human serum. Total VDBP concentrations from proteolysis or amino acid analysis (AAA) of purified proteoforms had ≤1.92% CV. SRM 1950, containing multiple proteoforms, quantified in two laboratories resulted in total VDBP concentrations with 7.05% CV. VDBP proteoforms were not found to cause bias during quantification by LC-MS/MS, thus demonstrating that a family of proteins can be accurately quantified using shared peptides. A reference value was assigned for total VDBP in SRM 1950, which may be used to standardize methods and improve the accuracy of VDBP quantification in research and clinical samples. [ABSTRACT FROM AUTHOR]

What are comfortable gait speed values for apparently healthy adults? How do these differ by age group, sex and geographical region? Systematic review of observational studies with meta-analysis. Apparently healthy, community-dwelling adults who have undergone measurement of comfortable gait speed. Potentially relevant studies were identified in four databases. Extracted data from studies that satisfied the eligibility criteria were added to a database containing the same information from a meta-analysis published a decade ago. The weighted mean comfortable gait speed was calculated along with the 95% confidence interval for each stratum of age/sex using a random-effects model. Mean gait speeds were further stratified by the continent where the study took place. Tests of homogeneity included I 2 and prediction intervals. Meta-analysis of data from 51,248 apparently healthy adults was stratified by age (in decades) and sex. Male gait speed slowed beyond age 50 years whereas female gait speed slowed beyond age 30 years. The weighted mean gait speed ranged from 97 cm/s (females aged ≥ 80 years) to 140 cm/s (males aged 40 to 49 years). The I 2 values ranged from 0 to 34.07; prediction interval ranges varied from a low of 30 (125 to 155 cm/s; males aged 40 to 49 years) to a high of 77 (83 to 160 cm/s; females aged 60 to 69 years). There was considerable overlap in confidence intervals between continents for each sex/age group. Comfortable gait speed slowed through the adult years, but males maintained a faster walking speed than females. Further stratification of comfortable gait speed by geographical region is not warranted. [ABSTRACT FROM AUTHOR]

Aim Noninvasive blood oxygen level-dependent magnetic resonance imaging (BOLD-MRI) has recently been used to evaluate placental oxygenation. However, this method still has unresolved problems, such as long testing times and lack of normal values set. In the present study, we used a shorter protocol in BOLD-MRI and established normal values for placental oxygenation in late pregnancy. Methods We recruited 18 healthy singleton pregnant women (>32 weeks of gestation) who had a normal body size before pregnancy and a normal course of pregnancy. They underwent BOLD-MRI with three consecutive 4-min periods of different oxygenation: normoxia (21% O2), hyperoxia (10 L O2/min), and then normoxia. Placental time–activity curves were presented as signal intensity change relative to baseline (ΔR2*). The time from starting maternal oxygen administration to peak ΔR2*. To assess the relationship between peak ΔR2* values and placenta-related parameters and fetal development, the correlation between peak ΔR2*, placental weight, and neonatal birth weight was evaluated using Spearman’s rank correlation test. Results In all cases, the BOLD signal was elevated by maternal oxygen administration, with the peak resolving within 4 min after the end of oxygen administration. Peak ΔR2* and time to peak ΔR2* during oxygenation were 7.99 ± 2.58, and 458.1 ± 73.9 s, respectively. There was a significant correlation between peak ΔR2* and neonatal birth weight (percentile) (r = 0.537, p = .022), and between placental weight and neonatal birth weight (r = 0.769, p < .01). Conclusions In all cases, the BOLD signal increased with maternal hyperoxia using this protocol. So, 4 min observation following maternal oxygen administration is sufficient for peak ΔR2* evaluation. These reference values set in this study may be one of the indicators of BOLD signal changes in normal pregnancies after 32 weeks of gestation. [ABSTRACT FROM AUTHOR]

This article examines the performance of the adaptive cumulative sum (CUSUM) plans and three simultaneous CUSUM statistics with different levels of temporal memory for monitoring changes in dispersion in the steady state situation. This article demonstrates that taking a larger rational subgroup has early out-of-control detection advantages for all monitoring plans considered. The article illustrates that the CUSUM plan that seems to have the most convincing robust early detection advantages is the three CUSUM statistic with different levels of temporal memory rather than the adaptive CUSUM plans for steady state situations. [ABSTRACT FROM AUTHOR]

Background: Since symptomatology is a major predictor of quality of life and an endpoint for the management of atrial fibrillation (AF), practical approaches for objectively interpreting symptom burden and functional impairment are needed. Aims: We aimed to provide cut-off values for two frequently used field tests to be able to objectively interpret symptom burden in atrial fibrillation. Methods: One hundred twenty-five patients with AF were evaluated with European Heart Rhythm Association (EHRA) score, 6-min walk test (6MWT), 30 s sit-to-stand test (30 s-STST), Short-Form 36 (SF-36), International Physical Activity Questionnaire-Short Form (IPAQ-SF), and spirometry. Patients with EHRA 1 were classified as "asymptomatic", and those with EHRA 2–4 as "symptomatic". Cut-off values of 6MWT and 30 s-STST for discriminating between these patients were calculated. Results: The optimal cut-off value was "450 m" for 6MWT (sensitivity: 0.71; specificity of 0.79) and "11 repetitions" for 30 s-STST (sensitivity 0.77; specificity of 0.70). Area under ROC curve was 0.75 for both tests (p < 0.001). Discriminative properties of the two tests were similar, and they were significantly correlated (r = 0.58; p < 0.001). Subgroup analysis revealed patients below cut-off values also had worse outcomes in SF-36, IPAQ-SF, and spirometry. Conclusions: In patients with AF, walking < 450 m in 6MWT or performing < 11 repetitions in 30 s-STST indicates increased symptom burden, as well as impaired exercise capacity, quality of life, physical activity participation, and pulmonary function. These cut-off values may help identifying patients who may require adjustments in their routine treatment or who may benefit from additional rehabilitative approaches. [ABSTRACT FROM AUTHOR]

Background: As a noninvasive tool, myocardial deformation imaging may facilitate the early detection of cardiac dysfunction. However, normal reference ranges of myocardial strain and strain rate (SR) based on large-scale East Asian populations are still lacking. This study aimed to provide reference values of left ventricular (LV) and right ventricular (RV) strain and SR based on a large cohort of healthy Chinese adults using cardiovascular magnetic resonance (CMR) feature tracking (FT). Methods: Five hundred and sixty-six healthy Chinese adults (55.1% men) free of hypertension, diabetes, and obesity were included. On cine CMR, biventricular global radial, circumferential, and longitudinal strain (GRS, GCS, and GLS), and the peak radial, circumferential, and longitudinal systolic, and diastolic SRs (PSSRR, PSSRC, PSSRL, PDSRR, PDSRC, and PDSRL), and regional radial and circumferential strain at the basal, mid-cavity, and apical levels were measured. Associations of global and regional biventricular deformation indices with age and sex were investigated. Results: Women demonstrated greater magnitudes of LV GRS (37.6 ± 6.1% vs. 32.1 ± 5.3%), GCS (− 20.7 ± 1.9% vs. − 18.8 ± 1.9%), GLS (− 17.8 ± 1.8% vs. − 15.6 ± 1.8%), RV GRS (25.1 ± 7.8% vs. 22.1 ± 6.7%), GCS (− 14.4 ± 3.6% vs. − 13.2 ± 3.2%), GLS (− 22.4 ± 5.2% vs. − 20.2 ± 4.6%), and biventricular peak systolic and diastolic SR in all three coordinate directions (all P < 0.05). For the LV, aging was associated with increasing amplitudes of GRS, GCS, and decreasing amplitudes of PDSRR, PDSRC, PDSRL (all P < 0.05). For the RV, aging was associated with an increase in the magnitudes of GRS, GCS, GLS, PSSRR, PSSRC, PSSRL, and a decrease in the magnitude of PDSRR, PDSRC (all P < 0.05). Biventricular radial and circumferential strain measurements at the basal, mid-cavity, and apical levels were all significantly related to age and sex in both sexes (all P < 0.05). Conclusions: We provide age- and sex-specific normal values of biventricular strain and SR based on a large sample of healthy Chinese adults with a broad age range. These results may be served as a reference standard for cardiac function assessment, especially for the Chinese population. [ABSTRACT FROM AUTHOR]