Reference Ranges for Arterial Oxygen Saturation, Heart Rate, and Cerebral Oxygen Saturation during Immediate Postnatal Transition in Neonates Born Extremely or Very Preterm.

OBJECTIVE: To define percentile charts for arterial oxygen saturation (SpO2), heart rate (HR), and cerebral oxygen saturation (crSO2) during the first 15 minutes after birth in neonates born very or extremely preterm and with favorable outcome. STUDY DESIGN: We conducted a secondary-outcome analysis of neonates born preterm included in the Cerebral regional tissue Oxygen Saturation to Guide Oxygen Delivery in preterm neonates during immediate transition after birth III (COSGOD III) trial with visible cerebral oximetry measurements and with favorable outcome, defined as survival without cerebral injuries until term age. We excluded infants with inflammatory morbidities within the first week after birth. SpO2 was obtained by pulse oximetry, and electrocardiogram or pulse oximetry were used for measurement of HR. crSO2 was assessed with near-infrared spectroscopy. Measurements were performed during the first 15 minutes after birth. Percentile charts (10th to 90th centile) were defined for each minute. RESULTS: A total of 207 neonates born preterm with a gestational age of 29.7 (23.9-31.9) weeks and a birth weight of 1200 (378-2320) g were eligible for analyses. The 10th percentile of SpO2 at minute 2, 5, 10, and 15 was 32%, 52%, 83%, and 85%, respectively. The 10th percentile of HR at minute 2, 5, 10, and 15 was 70, 109, 126, and 134 beats/min, respectively. The 10th percentile of crSO2 at minute 2, 5, 20, and 15 was 15%, 27%, 59%, and 63%, respectively. CONCLUSIONS: This study provides new centile charts for SpO2, HR, and crSO2 for neonates born extremely or very preterm with favorable outcome. Implementing these centiles in guiding interventions during the stabilization process after birth might help to more accurately target oxygenation during postnatal transition period.

Cohort-Based Reference Values for Serum Ferritin and Transferrin and Longitudinal Determinants of Iron Status in European Children Aged 3-15 Years.

BACKGROUND: Reference values of ferritin and transferrin for European children do not exist. OBJECTIVE: We aimed to provide sex-, age-, and body mass index (BMI)-specific serum ferritin and transferrin reference percentiles of 3-15-y-old children based on cohort data and to investigate determinants of iron status. METHODS: A total of 3390 ferritin and 3416 transferrin measurements from children residing in 8 European countries participating in the IDEFICS/I.Family cohort (https://www.isrctn.com/ISRCTN62310987) at baseline (W0) and 6 y later (W3) were used to estimate percentiles using the generalized additive model for location, scale and shape. Associations of serum ferritin and transferrin concentrations with total iron intake, total iron intake additionally adjusted for vitamin C intake, and iron from heme sources were investigated separately with adjustment for sex, age, country of residence, parental education, usual energy intake and BMI z-score in regression models using cross-sectional and longitudinal data. RESULTS: The age-specific ferritin and transferrin 5th and 95th reference percentiles ranged from 10.9 to 81.1 µg/L and 2.23 to 3.56 g/L, respectively. A deficient iron status was observed in 3% of children at W0 and 7% of children and adolescents at W3, respectively. At both waves, a higher iron intake from heme sources was positively associated with serum ferritin {W0: ß = 3.21 [95% confidence interval (CI): 0.71, 5.71]; W3: ß = 4.48 [95% CI: 2.09, 6.87]}, that is, children consuming one mg more heme iron had a 3.21 and 4.48 µg/L higher ferritin concentration. Adherence to a mainly vegetarian diet was associated with a lower chance for sufficient serum ferritin cross-sectionally at W3 [odds ratio (OR) 0.40 (95% CI: 0.21, 0.81)] and longitudinally [OR 0.35 (95% CI: 0.15, 0.93)]. CONCLUSIONS: Age-, sex-, and BMI-specific reference percentiles of serum ferritin and transferrin concentrations based on cohort data are provided for European children aged 3-15 y and may be used in clinical practice.

Looking beyond the mean: quantile regression for comparative physiologists.

Statistical analyses that physiologists use to test hypotheses predominantly centre on means, but the tail ends of the response distribution can behave quite differently and underpin important scientific phenomena. We demonstrate that quantile regression (QR) offers a way to bypass some limitations of least squares regression (LSR) by building a picture of independent variable effects across the whole distribution of a dependent variable. We used LSR and QR with simulated and real datasets. With simulated data, LSR showed no change in the mean response but missed significant effects in the tails of the distribution found using QR. With real data, LSR showed a significant change in the mean response but missed a lack of response in the upper quantiles which was biologically revealing. Together, this highlights that QR can help to ask and answer more questions about variation in nature.

Does weight influence the course of RSV bronchiolitis in hospitalized infants?

Acute bronchiolitis is among the most common causes of hospitalizations in infants worldwide. Associations between weight and severity of respiratory syncytial virus (RSV) bronchiolitis remain unclear. The aim of this study was to evaluate this association. A single-center, retrospective cohort study of infants aged under 24 months, who were hospitalized between 2018 and 2022 for RSV bronchiolitis. Data from computerized medical records were extracted using the MDclone platform. Participants were divided into three groups according to weight percentiles: underweight (below 5th percentile), normal-weight, and overweight (above 85th percentile). A total of 1936 infants (mean age 6.3 months, 55% males) were included, comprising 274 infants who were underweight, 1470 with normal weight, and 192 with overweight. Underweight infants had a higher rate of admission to the pediatric intensive care unit (PICU) (9.1% vs. 3.5%, P < 0.005) and prolonged length of stay (LOS) in the hospital (3.13 vs. 2.79 days P < 0.001) compared to those with normal weight. Hyponatremia was also more common in the underweight group (23% vs. 15%, P < 0.001). A multivariable model accounting for prematurity and birthweight predicted a relative risk of 2.01 (95% CI 1.13-3.48, P = 0.015) for PICU admission and 1.42 (95% CI 1.17-1.7, P < 0.001) for a prolonged LOS. Being overweight was not associated with a more severe disease.  Conclusion: Underweight infants, hospitalized for RSV bronchiolitis, had a more severe disease course with a higher complication rate, including PICU admission and prolonged LOS. Thus, careful attention and supervision should be given to this subgroup of infants. What is Known: • Established risk factors for severe bronchiolitis include prematurity, BPD, CHD, and compromised immunity. • Abnormal weight status has been associated with an increased risk for morbidity and mortality from infectious diseases, proposedly due to the effects on endocrine and immunologic systems. What is New: • Underweight infants hospitalized with RSV bronchiolitis face an independent risk of PICU admission and prolonged hospital stay. • Conversely, overweight infants did not display associations with severity measures in our study.

Disparities with global standards about growth references of mid-upper arm circumference-for-age for Pakistani children aged 6-60 months.

AIM: Growth reference values about mid-upper arm circumference (MUAC) are vital for assessing children's nutritional status. However, Pakistan lacks these reference values and growth charts. This study aims to develop these for children aged 6-60 months and compare them with global standards. METHODS: The data were acquired from the 2018 National Nutrition Survey of Pakistan, which was conducted by the United Nations Children's Fund (UNICEF) during 2018-2019. The final study cohort comprised 57 285 children, with 51% being boys. Percentile values and charts for MUAC-for-age were developed using generalised additive models for location, scale and shape with the Box-Cox power exponential distribution. RESULTS: The mean MUAC was 14.21 cm (±2.07 cm) and 14.13 cm (±2.12 cm) for the boys and girls, respectively. At 60 months of age, the P3 and P97 percentiles for girls were slightly higher than those for boys. The median percentiles of Pakistani children were smaller than the World Health Organisation 2007 standards and with international references. CONCLUSION: We observed disparities in MUAC-for-age growth references among Pakistani children compared to global standards, highlighting regional, age and gender variations. This underscores the need for developing countries like Pakistan to establish their growth references.

Evaluation of a non-auditory neurocognitive test battery in hearing-impaired according to age.

PURPOSE: Due to the demographic shift, the number of older people suffering from hearing loss and from cognitive impairment increases. Both are closely related and hard to differentiate as most standard cognitive test batteries are auditory-based and hearing-impaired individuals perform worse also in non-auditory test batteries. Therefore, reference data for hearing-impaired are mandatory. METHODS: The computer-based battery ALAcog assesses multiple cognitive domains, such as attention, (delayed) memory, working memory, inhibition, processing speed, mental flexibility and verbal fluency. A data set of 201 bilaterally hearing-impaired subjects aged ≥ 50 (mean 66.6 (SD 9.07)) was analysed. The LMS method, estimated curves for the 10th, 25th, 50th, 75th and 90th percentile were calculated, and classified according to age, starting from the age of 50. RESULTS: Cognitive function shows a decline in all subtests as people age, except for verbal fluency, which remains almost stable over age. The greatest declines were seen in recall and delayed recall and in mental flexibility. Age and hearing ability did not correlate (p = 0.68). However, as people age, inter-subject variability of cognitive test results increases. This was especially the case for inhibition. Cognitive function was not correlated with hearing ability (each p ≥ 0.13). CONCLUSION: The present results make an approach to establish reference data for a comprehensive non-auditory test battery in a large sample of elderly hearing-impaired people which can be used as a simple tool to better contextualise cognitive performance beyond mean and median scores.

Normative Reference Centiles for Sprint Performance in High-Level Youth Soccer Players: The Need to Consider Biological Maturity.

PURPOSE: To compute reference centiles for 5- and 30-m sprint times relative to chronological and skeletal age in youth soccer players. Subsequently, to compare individual's sprint performance scores derived from the chronological and skeletal age reference centiles. METHODS: Sprint times were collected for a sample of male U11 to U19 soccer players (n = 1745 data points). Skeletal age data were available for a subsample (n = 776 data points). Reference centiles were fitted using generalized additive models for location, scale, and shape. Individual z scores relative to chronological and skeletal age reference centiles were computed and compared for each maturity group (late, on-time, early, and very early) using standardized mean differences (SMD). RESULTS: Reference centiles for chronological age increased more rapidly between 10.5 and 15.5 years, while reference centiles for skeletal age increased more rapidly between 13.0 and 16.5 years. Differences in chronological and skeletal z scores for very early (SMD: -0.73 to -0.43) and late (SMD: 0.58 to 1.29) maturing players were small to large, while differences for early (SMD: -0.30 to -0.19) and on-time (SMD: 0.16 to 0.28) were trivial to small. CONCLUSION: Reference centiles provide a valuable tool to assist the evaluation of sprint performance in relation to chronological and skeletal age for talent identification purposes in youth soccer players.

Brief report: ADHD Rating Scale-IV (parent/caregiver-report) norms for young Danish schoolchildren.

OBJECTIVE: The Attention-Deficit/Hyperactivity Disorder Rating Scale-IV (ADHD-RS-IV) assesses ADHD symptoms in children and adolescents. The original United States norms comprise percentiles. Yet, no Nordic percentile norms exist, and only T-scores, which (often falsely) assume normally distributed data, are currently available. Here, we for the first time provide Danish percentile norms for children aged 6-9 based on parent/caregiver-reports, and illustrate the potential consequences of T-scores when derived based on the expected skewed distribution of an ADHD scale in the population. MATERIALS AND METHODS: The sample comprised 1895 Danish schoolchildren (879 girls and 1016 boys) in 1st, 2nd, or 3rd grade from the general population. Their parents/caregivers completed the ADHD-RS-IV. Sex and age differences were investigated, percentiles were derived based on the observed score distributions, and for comparison, T-scores > 70 were estimated, which are expected to identify the top 2.3% under the assumption of normality. RESULTS: Boys were rated to have higher ADHD-RS-IV scores than girls except on the impulsivity score. No age effects were found on the majority of scores. Sex-stratified and unisex percentiles (80, 90, 93, 98) were reported. The distribution of ADHD-RS-IV scores were highly skewed. T-score cutoffs identified a significantly higher proportion of and about twice as many children as having elevated ADHD symptoms than expected (4.3-5.2% vs. 2.3%). CONCLUSIONS: ADHD-RS-IV (parent/caregiver-report) percentile norms for young Danish schoolchildren are now available for future reference. The use of percentiles is considered appropriate given the skewed score distribution and since T-scores appear to over-identify children as having clinically elevated ADHD symptoms.

Body surface area-based kidney length percentiles misdiagnose small kidneys in children with overweight/obesity.

BACKGROUND: We evaluated the diagnostic performance of height-, age- and body surface area (BSA)-based kidney length (KL) percentiles in the identification of at least one small kidney (KL < 3rd) and in the prediction of reduced estimated glomerular filtration rate (eGFR) and/or elevated blood pressure (BP) in children with and without overweight (OW)/obesity(OB). METHODS: In this cross-sectional study, 744 apparently healthy children (mean age 8.3 years) were recruited in a primary care setting. Clinical data were collected, and serum creatinine and KL were measured. Height-, age- and BSA-based percentiles of KL were calculated and the association of at least one small kidney per subject with reduced eGFR and/or elevated BP was explored by logistic regression. RESULTS: Two hundred fifty-seven out of seven hundred forty-four (34.5%) subjects were OW/OB and 127 (17.1%) had reduced eGFR or elevated BP. In separate analyses in children with OW/OB, the KL percentiles calculated on the basis of BSA were lower compared with height- and age-based KL percentiles. Consequently, the prevalence of a small kidney was significantly higher when evaluating percentiles of KL based on BSA compared with other percentiles. In logistic regression analysis, a small kidney was significantly associated with reduced eGFR and/or elevated BP only when using height-based KL percentiles. The KL percentiles according to BSA for the ideal weight (iBSA) showed similar performance compared with height-based percentiles. No differences in the diagnostic performance of different percentiles were found in children with normal weight. CONCLUSIONS: BSA-based percentiles underestimate KL in children with OW/OB. In these subjects, the use of height-based or iBSA-based percentiles should be preferred. A higher resolution version of the Graphical abstract is available as Supplementary information.

Sex-specific percentiles for bodyweight and height in children born with esophageal atresia: a registry-based analysis 2001-2021.

BACKGROUND: Esophageal atresia (EA) is a rare malformation with a wide range of co-morbidity and associated malformations impairing weight gain and growth. The aim of this study was to calculate specific percentiles for body weight and height for children born with esophageal atresia according to sex from birth to the age of 6 years, accounting for prematurity and presence of congenital heart disease (CHD). METHODS: Data was extracted from an anonymized voluntary national registry for patients born with esophageal atresia between 2001 and 2021, from birth until the age of six years. Missing values were imputed using a multiple imputation approach. In premature infants, chronological age was corrected for gestational week until the age of one year. The impact of sex and additional congenital heart disease on weight gain and growth was analysed using quartile regression models. RESULTS: In total, 1812 examinations of 485 patients were considered and 1232 examinations of 301 patients were finally included. Most data was available for children at birth and during the first year of life. Body weight was imputed for 3.3% and height for 12.5% of examinations. The mean body weight-for-age and length-for-age at birth according to gestational age was lower in EA patients and median body weight developed along the tenth percentile compared to the general population. Median height-for-age was at the 50th percentile during the first months of life, before crossing to lower percentiles before the age of one year. CHD had an additional negative impact on growth and weight gain, especially during the first year of life. CONCLUSIONS: Children with EA had a reduced bodyweight and -height compared to the general population. Therefore, specific percentile curves are helpful to evaluate growth and development. Especially during the first year of life, particular attention is necessary and complications leading to a reduced calorie intake should be treated without delay to promote timely development and growth. Cardiac co-morbidities may further compromise weight gain in these patients, implying that such patients should be under even closer surveillance.

The 2022 Pakistani references from birth to 60 months for length/height, weight and body mass index.

AIM: The present study aimed to develop age- and sex-specific anthropometric reference growth curves for the Pakistani children, aged 1-60 months. METHODS: The weight and height of 60 595 children including 30 885 (50.96%) boys and 29 710 (49.04%) girls from Pakistan were collected through a cross-sectional study. Growth reference charts about weight-for-age, length/height-for-age, and body BMI-for-age were constructed for boys and girls using the generalised additive model for location, scale and shape (GAMLSS) with the Box-Cox power exponential distribution. RESULTS: The 3rd, 5th, 15th, 25th, 50th, 75th, 85th, 95th and 97th smoothed percentile values with L, M and S for weight, length/height, and BMI for boys and girls from aged 1 to 60 months are presented. The median percentile for all indicators increases as the age increases in both sexes. The median percentiles of the Pakistani children are lower than the WHO 2006 standards for both sexes. CONCLUSION: This study provides the first references for the Pakistani children from 1 to 60 months. The reference values could be taken as a starting point for examining the secular change in the Pakistani population.

Normative-referenced values for health-related fitness among Czech youth: Physical fitness data from the study IPEN Adolescent Czech Republic.

OBJECTIVES: The aim of this study was to developed sex- and age-specific normative-referenced percentile values for health-related fitness among 12 to 18 years old Czech youth. METHODS: This study included cross-sectional data from 1,173 participants (50.7% boys) collected between 2013 and 2016. Participants were recruited from 32 elementary or secondary schools across eight cities located in the Czech Republic. Health-related fitness was objectively measured using both anthropometric (height, body mass, and sum of skinfolds) and performance (20-m shuttle run for cardiorespiratory endurance, modified push-ups for muscular strength/endurance, and V sit-and-reach for flexibility) tests. Sex- and age-specific normative values were calculated using the Lambda Mu Sigma method. Sex- and age-related differences in means were expressed as standardized effect sizes. RESULTS: Normative percentiles were tabulated and displayed as smoothed curves. Among boys, measures of health-related fitness generally increased with age, except for an age-related decline in the sum of skinfolds and a plateau in V sit-and-reach. Among girls, most measures of health-related fitness increased from age 12 to 16 years before stabilizing, except for the sum of skinfolds, which remained stable from age 12 to 18 years. The sex-related differences were large with boys having higher cardiorespiratory endurance and muscular strength/endurance than girls. Girls compared to boys had higher flexibility. CONCLUSIONS: This study presents the most up-to-date sex- and age-specific normative-referenced percentile values for health-related fitness among Czech youth. Normative values may be useful for fitness and public health screening and surveillance, for example, by helping to identify youth with low fitness who might benefit from a fitness-enhancing intervention.

Body Fat Distribution in Children and Adolescents With Cerebral Palsy.

To evaluate the body fat distribution in children with cerebral palsy (CP). The present study focusses on a monocentric retrospective analysis of body fat distribution from children diagnosed with CP. The children participated in a rehabilitation program. Reference centiles were calculated based on data from the National Health and Nutrition Examination Survey (NHANES, 1999-2004). Z-scores for trunk-to-leg fat ratio were calculated. Further, fat mass index (FMI) was evaluated based on percentiles that have already been published. 237 males and 194 females with CP were considered (mean age: 11 years and 11 months [SD 3 years]). These were compared to 1059 males and 796 females from the NHANES (mean age: 14 years and 7 months [SD 3 years and 4 months]). The z-scores for trunk-to-leg fat ratio showed the following values: mean -0.47 (SD 1.50) for males, -0.49 (SD 1.11), for females, -0.48 (SD 1.34) for all. The z-scores for FMI showed the following values: mean -0.29 (SD 0.70) for males, -0.88 (SD 2.0) for females, -0.55 (SD 1.46) for all. The results showed rather a gynoid fat distribution and a lower FMI in children with CP than in the reference population (NHANES 1999-2004).

Detection of ocular hypertelorism among Indian children.

Background & objectives: Ocular hypertelorism constitutes an important component of many clinical syndromes. It is typically recommended to use inter-pupillary distance (IPD) for objective evaluation of ocular hypo/hypertelorism. Barring infancy, there is a scarcity of data on this anthropometric parameter relating to the ocular apparatus. This study aims to study auxological dynamics of IPD in children of Indian origin. Methods: A total of 3622 ( 2239 males and, 1383 females) normal, healthy Indian children of North-western origin, aged one month to 14 yr comprised the sample for this study. Inner and outer-canthal distance were measured using standardized anthropometric techniques. None of the children who participated in this study had craniofacial dysmorphism or any body deformity. Mean (standard deviation SD) and percentiles were calculated for IPD in male and female subjects at different age levels. Results: IPD increased from 4.68±0.21 to 6.19±0.36 cm in males and from 4.59±0.26 to 6.08±0.25 cm in females between one month and 14 yr of age. Boys in general, possessed larger IPD than girls, however, the gender differences became significant (P≤0.05) at 10, 11, 16-18 and 22-24 months, respectively, and five and 10 yr of age, respectively. Interpretation & conclusions: The results of this study suggest that the patients having IPD less than the 3rd percentile should be treated as cases of hypotelorism while, those exceeding 97th percentile as cases of hypertelorism. The use of percentile grids presented for IPD may be used to detect ocular hypotelorism and hypertelorism in male and female children to corroborate diagnosis of different syndromes.

Age-Dependent Reference Values for hs-Troponin T and NT-proBNP and Determining Factors in a Cohort of Healthy Children (The LIFE Child Study).

This study aimed to provide reliable pediatric reference values for N-terminal pro-brain natriuretic peptide (NT-proBNP) and high-sensitive Troponin T (hsTnT) obtained from a population of well children and investigate for associations with sex, pubertal status, body mass index (BMI), and serum lipid levels. We analyzed hsTnT and NT-proBNP values obtained from 4826 samples provided by 2522 children aged 0.25-18 years participating in a prospective longitudinal population-based cohort study, "LIFE child" in Leipzig, Germany (Poulain et al., Eur J Epidemiol 32:145-158, 2017). NT-proBNP values decreased throughout childhood from values over 400 ng/L at 3 months to 138 ng/L in females and 65 ng/L in males by 18 years of age. Values dropped rapidly with advancing pubertal stage. We found a strong association between lower NT-proBNP values and higher BMI or elevated serum lipids, the latter effect being more pronounced in males. For hsTnT levels, approximately half of the measurements were below the detection limit. However, 76% of those aged 3 months and 21% of those aged 6 months had values exceeding the adult cut-off limit. Females had slightly higher levels in the first 2 years of life but this was reversed during puberty. In males, there was an upward trend from pubertal stage 2 onward. We identified a positive association between hsTnT and BMI but a negative association with low-density lipoprotein (LDL) cholesterol and triglyceride levels in boys but not in girls. Based on a large number of healthy children, we have established reliable reference values for NT-proBNP and hsTnT for use in everyday clinical practice. We have also identified important associations between certain metabolic and cardiac markers.Clinical Trial Registration ClinicalTrial.gov (NCT02550236).

Modeling sparse longitudinal data in early neurodevelopment.

Early childhood is a period marked by rapid brain growth accompanied by cognitive and motor development. However, it remains unclear how early developmental skills relate to neuroanatomical growth across time with no growth quantile trajectories of typical brain development currently available to place and compare individual neuroanatomical development. Even though longitudinal neuroimaging data have become more common, they are often sparse, making dynamic analyses at subject level a challenging task. Using the Principal Analysis through Conditional Expectation (PACE) approach geared towards sparse longitudinal data, we investigate the evolution of gray matter, white matter and cerebrospinal fluid volumes in a cohort of 446 children between the ages of 1 and 120 months. For each child, we calculate their dynamic age-varying association between the growing brain and scores that assess cognitive functioning, applying the functional varying coefficient model. Using local Fréchet regression, we construct age-varying growth percentiles to reveal the evolution of brain development across the population. To further demonstrate its utility, we apply PACE to predict individual trajectories of brain development.

Longitudinal Reference Values for Cerebral Ventricular Size in Preterm Infants Born at 23-27 Weeks of Gestation.

OBJECTIVE: To establish longitudinal reference values for cerebral ventricular size in the most vulnerable patients at risk for intraventricular hemorrhage (IVH) and posthemorrhagic ventricular dilatation (PHVD). STUDY DESIGN: This retrospective study included neurologically healthy preterm neonates born at 230/7-266/7 weeks of gestational age between September 2011 and April 2019. Patients were treated at 2 Austrian tertiary centers, Medical University of Vienna and Medical University of Innsbruck. All available cerebral ultrasound scans until 30 weeks corrected age were analyzed. Ventricular measurements included ventricular index, anterior horn width (AHW), and thalamo-occipital distance (TOD) and longitudinal percentiles were created. RESULTS: The study cohort consisted of 244 preterm neonates, with a median gestational age of 253/7 weeks (IQR, 244/7-260/7 weeks) and a median birth weight of 735 g (IQR, 644-849 g). A total of 993 ultrasound scans were available for analysis, resulting in >1800 measurements of ventricular index, AHW, and TOD. Special attention was given to the 97th percentile as well as 2 mm and 4 mm above the 97th percentile, which are used internationally as cutoffs for intervention in the presence of PHVD. CONCLUSIONS: We present percentile charts based on a cohort of extremely premature infants including neonates born at the border of viability suited to follow-up the most vulnerable patients at risk for IVH and PHVD. Furthermore, we provide an extensive literature research and comparison of all available reference values, focusing on ventricular index, AHW, and TOD.

Using nationally representative percentiles to interpret PROMIS pediatric measures.

PURPOSE: This study's aim was to use a representative sample of the US pediatric population to estimate percentiles for several PROMIS pediatric measures: Anger, Anxiety, Depressive Symptoms, Family Relationships, Fatigue, Global Health, Life Satisfaction, Meaning and Purpose, Pain Behavior, Pain Interference, Physical Activity, Physical Function Mobility, Physical Function Upper Extremity, Physical Stress Experiences, Positive Affect, Psychological Stress Experiences, Sleep Disturbance, Sleep Impairment, and Peer Relationships. METHODS: We used two separate, nationally representative samples of parents and children aged 5-17 years drawn in different years from the GfK Knowledge Panel, a dual-frame online probability panel. RESULTS: All measures that were developed using a representative sample had a median at or near the expected value of 50. For the other measures, the 50th percentile was often 10 points or more from 50. Several domains had high floors or low ceilings. No domain's percentiles completely corresponded to the percentiles associated with a normal distribution with a mean of 50 and standard deviation of 10. CONCLUSIONS: This work allows users to interpret a child's self-reported quality of life relative to children in the US general population. When attempting to evaluate whether a child falls above or below other children in the US, one should use the values presented in this study. In addition, we recommend that users should focus on whether a child's score falls into one of a few broad severity groups rather than on specific percentile scores.

Should singleton birth weight standards be applied to identify small-for-gestational age twins?: analysis of a retrospective cohort study.

BACKGROUND: Twin birth weight percentiles are less popular in clinical management among twin pregnancies compared with singleton ones in China. This study aimed to compare the incidence and neonatal outcomes of small for gestational age (SGA) twins between the use of singleton and twin birth weight percentiles. METHODS: This was a retrospective cohort study of 3,027 pregnancies with liveborn twin pairs at gestational age of > 28 weeks. The newborns were categorized as SGA when a birthweight was less than the 10th percentile based on the singleton and twin references derived from Chinese population. Logistic regression models with generalized estimated equation (GEE) were utilized to evaluate the association between SGA twins and neonatal outcomes including neonatal unit admission, neonatal jaundice, neonatal respiratory distress (NRDS), neonatal asphyxia, ventilator support, hypoxic ischemic encephalopathy (HIE), bronchopulmonary dysplasia (BPD), necrotizing enterocolitis (NEC), intracranial hemorrhage (ICH), culture-proven sepsis, neonatal death within 28 days after birth as well as the composite outcome. RESULTS: The incidence of SGA was 33.1 % based on the singleton reference and 7.3 % based on the twin reference. Both of SGA newborns defined by the singleton and twin references were associated with increases in neonatal unit admission, neonatal jaundice and ventilator support. In addition, SGA newborns defined by the twin reference were associated with increased rates of BPD (aOR, 2.61; 95 % CI: 1.18-5.78) as well as the severe composite outcome (aOR, 1.93; 95 % CI: 1.07-3.47). CONCLUSIONS: The use of singleton birth weight percentiles may result in misdiagnosed SGA newborns in twin gestations and the twin birth weight percentiles would be more useful to identify those who are at risk of adverse outcomes.

Establishing percentiles for blood pressure based on absolute height for children and adolescents.

BACKGROUND: Evaluating blood pressure (BP) is one element for diagnosing and preventing disease in student populations. The objectives of this research were to (a) identify the range of height for measuring BP adjusted for student populations and (b) propose percentiles for evaluating BP based on height. METHODS: A cross-sectional study was carried out with 3,013 students. Weight, height, and diastolic (DBP) and systolic (SBP) blood pressure were evaluated. Body Mass Index (BMI) was calculated. Height ranges of 5 and 10 cm were generated. RESULTS: R2 values for height ranges of 5 cm consisted of [normotensive: DBP (R2 = 10 to 13%) and SBP (R2 = 14 to 20%), and for hypertensive: DBP (R2 = 0.07 to 15%) and for SBP (R2 = 29 to 32%)]. For height ranges of 10 cm, values included: [normotensive: DBP (R2 = 10 to 15%), and SBP (R2 = 15 to 21%) and for hypertensive: DBP (R2 = 0.07 to 16%) and SBP (R2 = 29 to 35%)]. For 5 cm height ranges, diferences occurred between both sexes for DBP (in 5 height ranges from 123 to 148 cm and 158 to 168 cm) and for the SBP (in 6 height ranges from 128 to 148 cm and from 158 to 168 cm). In the 10 cm categories, diferences appeared in DBP (from 138 to 148 cm) and in the SBP (from 158 to 168 cm). CONCLUSIONS: Height is a determinant for evaluating blood pressure, and height ranges of 10 cm are more suitable for children and adolescents. The proposed percentiles based on height ranges allowed assessment of the DBP and SBP suggest their use in epidemiological and educational contexts.