scholarly journals Sample size and sample composition for constructing growth reference centiles

2020 ◽  
pp. 096228022095843
Author(s):  
TJ Cole
Keyword(s):  
Sample Size ◽  
Reference Data ◽  
Simulated Data ◽  
Additive Models ◽  
Z Score ◽  
Cross Sectional ◽  
Growth Reference ◽  
Borrowing Strength ◽  
Sample Composition ◽  
Age Range

Growth reference centile charts are widely used in child health to assess weight, height and other age-varying measurements. The centiles are easy to construct from reference data, using the LMS method or GAMLSS (Generalised Additive Models for Location Scale and Shape). However, there is as yet no clear guidance on how to design such studies, and in particular how many reference data to collect, and this has led to study sizes varying widely. The paper aims to provide a theoretical framework for optimally designing growth reference studies based on cross-sectional data. Centiles for weight, height, body mass index and head circumference, in 6878 boys aged 0–21 years from the Fourth Dutch Growth Study, were fitted using GAMLSS. The effect on precision of varying the sample size and the distribution of measurement ages (sample composition) was explored by fitting a series of GAMLSS models to simulated data. Sample composition was defined as uniform on the age λ scale, where λ was chosen to give constant precision across the age range. Precision was measured on the z-score scale, and was the same for all four measurements, with a standard error of 0.041 z-score units for the median and 0.066 for the 2nd and 98th centiles. Compared to a naïve calculation, the process of smoothing the centiles increased the notional sample size two- to threefold by ‘borrowing strength’. The sample composition for estimating the median curve was optimal for λ=0.4, reflecting considerable over-sampling of infants compared to children. However, for the 2nd and 98th centiles, λ=0.75 was optimal, with less infant over-sampling. The conclusion is that both sample size and sample composition need to be optimised. The paper provides practical advice on design, and concludes that optimally designed studies need 7000–25,000 subjects per sex.

scholarly journals Z-score growth reference data for Saudi preschool children

2017 ◽  
Vol 37 (1) ◽  
pp. 10-15 ◽  
Author(s):  
Mohammad Issa El Mouzan ◽  
Ahamed Shaffi ◽  
Abdullah Al Salloum ◽  
Mansour M. Alqurashi ◽  
Abdullah Al Herbish ◽  
...  
Keyword(s):  
Preschool Children ◽  
Reference Data ◽  
Z Score ◽  
Growth Reference

scholarly journals Telomere length is associated with growth in children in rural Bangladesh

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Audrie Lin ◽  
Andrew N Mertens ◽  
Benjamin F Arnold ◽  
Sophia Tan ◽  
Jue Lin ◽  
...  
Keyword(s):  
Telomere Length ◽  
Generalized Additive Models ◽  
Nutritional Intervention ◽  
Additive Models ◽  
P Value ◽  
Z Score ◽  
Cross Sectional ◽  
Telomere Attrition ◽  
Healthy Growth ◽  
Gates Foundation

Background: Previously, we demonstrated that a water, sanitation, handwashing, and nutritional intervention improved linear growth and was unexpectedly associated with shortened childhood telomere length (TL) (Lin et al., 2017). Here, we assessed the association between TL and growth. Methods: We measured relative TL in whole blood from 713 children. We reported differences between the 10th percentile and 90th percentile of TL or change in TL distribution using generalized additive models, adjusted for potential confounders. Results: In cross-sectional analyses, long TL was associated with a higher length-for-age Z score at age 1 year (0.23 SD adjusted difference in length-for-age Z score (95% CI 0.05, 0.42; FDR-corrected p-value = 0.01)). TL was not associated with other outcomes. Conclusions: Consistent with the metabolic telomere attrition hypothesis, our previous trial findings support an adaptive role for telomere attrition, whereby active TL regulation is employed as a strategy to address 'emergency states' with increased energy requirements such as rapid growth during the first year of life. Although short periods of active telomere attrition may be essential to promote growth, this study suggests that a longer overall initial TL setting in the first two years of life could signal increased resilience against future telomere erosion events and healthy growth trajectories. Funding: Funded by the Bill and Melinda Gates Foundation.

scholarly journals To Determine the Frequency of Pyrexia in Women with Prelaborrupture of Membranes

2017 ◽  
Vol 3 (2) ◽  
pp. 18-22
Author(s):  
Maimoona Qadir ◽  
Sohail Amir
Keyword(s):  
Sample Size ◽  
Sample Size Calculation ◽  
Public Health Problem ◽  
Cross Sectional Study ◽  
Age Group ◽  
Cross Sectional ◽  
Gynecology And Obstetrics ◽  
Margin Of Error ◽  
Prelabor Rupture Of Membranes ◽  
Age Range

OBJECTIVETo determine the frequency of pyrexia in patients with prelabor rupture of membranesMETHODOLOGYThis descriptive (cross sectional) study was conducted in Department of Gynecology and Obstetrics, Khyber Teaching Hospital, Peshawar from 12th January 2016 to 13th July 2016.Sample size was 369,keeping 4% proportion of pyrexia among women with PROM,95% confidence interval and 2%margin of error under WHO sample size calculation. All women with any age or parity who presented with prelabor rupture of membranes were included in the study.RESULTSIn this study, 369 women with PROM were observed.41(11.1%) patients were less than 20 years,139(37.7%) were in 21-30years age range,179(48.5%) were in age group 31-40years and only 10(2.7%) were more than 41 years age. Average age was 29.53+6.3SD.The pyrexia among women with PROM was observed in 39(10.57%)women, being more common in 31-40 years age group where it was noticed in 20(11.2%),followed by 21-30years age where 14(10.1%)patients were pyrexial.CONCLUSIONPyrexia is an enormous public health problem, accounting for the majority of cases of PROM in this part of the country.

scholarly journals Prevalence of Malnutrition in a Rural Residential Sanskrit School in Baglung, Nepal

2017 ◽  
Vol 56 (205) ◽  
pp. 153-157
Author(s):  
Bhawana Amatya ◽  
Nitesh Shrestha
Keyword(s):  
Reference Data ◽  
Child Growth ◽  
Z Score ◽  
Microsoft Excel ◽  
Severe Stunting ◽  
Under Nutrition ◽  
Growth Reference ◽  
Measuring Tape ◽  
Poor Absorption ◽  
Weight For Age

Introduction: Under-nutrition is a condition in which there is inadequate consumption, poor absorption or excessive loss of nutrients. Nepal still faces high chronic as well as acute under‐nutrition in children. The following study was conducted a Sanskrit school in rural Baglung to find the prevalence of malnutrition among the children which could reflect the nutritional status of the community. Methods: Out of 60 students admitted to the school, only 43 were present at the time when we collected our data. Weight was measured with a standard weighing scale and standing height with a measuring tape attached to the wall. Data were filled up in proforma, entered in Microsoft Excel 2013 and were analyzed and indicators calculated with SPSS version 20 using WHO Child Growth Reference data for 5-19 years and macros. Results: Stunting (Z score < -2) was found in 53.5 % of the study group and severe stunting (Z score < -3) was found in 25.6%. 12.5% of the 8 children under 10 years in our study had weight for age < -2 Z score which indicates underweight. No one was severely underweight. In our study, 2.3% had severe thinness (Z-score < -3), 14% had thinness (Z-score < -2). No one was overweight or obese. Conclusions: The prevalence of malnutrition was high among the students of the rural Sanskrit school where the study was conducted.   Keywords: anthropometry; Baglung; malnutrition; Nepal; prevalence.

scholarly journals PFAS Concentrations and Cardiometabolic Traits in Highly Exposed Children and Adolescents

2021 ◽  
Vol 18 (24) ◽  
pp. 12881
Author(s):  
Cristina Canova ◽  
Andrea Di Nisio ◽  
Giulia Barbieri ◽  
Francesca Russo ◽  
Tony Fletcher ◽  
...  
Keyword(s):  
Children And Adolescents ◽  
Generalized Additive Models ◽  
Density Lipoprotein ◽  
Positive Association ◽  
Additive Models ◽  
Lipoprotein Cholesterol ◽  
Surveillance Program ◽  
Z Score ◽  
Large Area ◽  
Cross Sectional

Background: Residents of a large area of north-eastern Italy were exposed for decades to high concentrations of perfluoroalkyl and polyfluoroalkyl substances (PFAS) via drinking water. Despite the large amount of evidence in adults of a positive association between serum PFAS and metabolic outcomes, studies focusing on children and adolescents are limited. We evaluated the associations between serum PFAS concentrations that were quantifiable in at least 40% of samples and lipid profile, blood pressure (BP) and body mass index (BMI) in highly exposed adolescents and children. Methods: A cross-sectional analysis was conducted in 6669 adolescents (14–19 years) and 2693 children (8–11 years) enrolled in the health surveillance program of the Veneto Region. Non-fasting blood samples were obtained and analyzed for perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), perfluorohexanesulfonic acid (PFHxS), perfluorononanoic acid (PFNA), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and triglycerides. Low-density lipoprotein cholesterol (LDL-C) was calculated. Systolic and diastolic BP were measured, and BMI z-score accounting for age and sex was estimated. The associations between ln-transformed PFAS (and categorized into quartiles) and continuous outcomes were assessed using generalized additive models. The weighted quantile sum regression approach was used to assess PFAS-mixture effects for each outcome. Analyses were stratified by gender and adjusted for potential confounders. Results: Among adolescents, significant associations were detected between all investigated PFAS and TC, LDL-C, and to a lesser extent HDL-C. Among children, PFOS and PFNA had significant associations with TC, LDL-C and HDL-C, while PFOA and PFHxS had significant associations with HDL-C only. Higher serum concentrations of PFAS, particularly PFOS, were associated with lower BMI z-score. No statistically significant associations were observed between PFAS concentrations and BP. These results were confirmed by the multi-pollutant analysis. Conclusions: Our study supports a consistent association between PFAS concentration and serum lipids, stronger for PFOS and PFNA and with a greater magnitude among children compared to adolescents, and a negative association of PFAS with BMI.

scholarly journals PFAS Concentrations and Cardiometabolic Traits in Highly Exposed Children and Adolescents

2021 ◽  
Author(s):  
Cristina Canova ◽  
Andrea Di Nisio ◽  
Giulia Barbieri ◽  
Francesca Russo ◽  
Tony Fletcher ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Children And Adolescents ◽  
Density Lipoprotein ◽  
Positive Association ◽  
Additive Models ◽  
Lipoprotein Cholesterol ◽  
Surveillance Program ◽  
Z Score ◽  
Large Area ◽  
Cross Sectional

Background: Residents of a large area of North-Eastern Italy were exposed for decades to high concentrations of perfluoroalkyl and polyfluoroalkyl substances (PFAS) via drinking water. Despite the large amount of evidence in adults of a positive association between serum PFAS and metabolic outcomes, studies focusing on children and adolescents are limited. We evaluated the associations between serum PFAS concentrations and lipid profile, blood pressure and body mass index (BMI) in highly exposed adolescents and children. Methods: A cross-sectional analysis was conducted in 6669 adolescents (14-19 years) and 2693 children (8-11 years) enrolled in the health surveillance program of the Veneto Region. Non-fasting blood samples were obtained and analyzed for perfluorooctanoic acid (PFOA) perfluorooctane sulfonate (PFOS), perfluorohexanesulfonic acid (PFHxS), perfluorononanoic acid (PFNA), total cholesterol (TC) high-density lipoprotein cholesterol (HDL-C) and triglycerides. Low-density lipoprotein cholesterol (LDL-C) was calculated. Systolic and diastolic blood pressure (BP) were measured and BMI z-score accounting for age and sex was estimated. The associations between ln-transformed PFAS (and categorized into quartiles) and continuous outcomes were assessed using generalized additive models. Analyses were stratified by gender and adjusted for potential confounders. Results: Among adolescents, significant associations were detected between all investigated PFAS and TC, LDL-C, and to a fewer extent HDL-C. Among children, PFOS and PFNA had significant associations with TC, LDL-C and HDL-C, while PFOA and PFHxS had significant associations with HDL-C only. Increased serum concentrations of PFAS, particularly PFOS, were associated with decreased BMI z-score. No statistically significant associations were observed between PFAS concentrations and BP. Conclusions: Our study supports a consistent association between PFAS concentration and serum lipids, stronger for PFOS and PFNA and with a greater magnitude among children compared to adolescents, and a negative association of PFAS with BMI.

FAKTOR PENGETAHUAN YANG MEMPENGARUHI KETERATURAN IBU BALITA DALAM MENGUNJUNGI POSYANDU DI DESA CIPANGERAN KECAMATAN SAGULING KABUPATEN BANDUNG BARAT TAHUN 2017

2018 ◽  
Vol 5 (2) ◽  
pp. 13-20
Author(s):  
Lia Kamila ◽  
Liawati . ◽  
Suci Lailani Alipah
Keyword(s):  
Public Health ◽  
Data Collection ◽  
Sample Size ◽  
Health Center ◽  
Analytical Method ◽  
Random Sampling ◽  
Research Method ◽  
Cross Sectional ◽  
Public Health Center ◽  
Level Of Knowledge

ABSTRAK Indikator D/S di wilayah kerja Puskesmas Saguling Desa Cipangeran pada tahun 2016 menunjukkan masih rendahnya kunjungan balita dalam kegiatan posyandu dengan rata-rata hanya memcapai 41,5%, sedangkan target standar palayanan kota jumlah D/S yaitu 85%. Tujuan penelitian ini adalah untuk mengetahui keteraturan ibu dalam mengunjungi Posyandu dari faktor pengetahuan di Desa Cipangeran Kecamatan Saguling Kabupaten Bandung Barat tahun 2017. Metode penelitian ini menggunakan metode analitik dengan pendekatan cross sectional. Data yang digunakan adalah data primer. Populasi seluruh balita di wilayah kerja Puskesmas Saguling tahun 2016 sebanyak 424 ibu balita, besar sampel yang diambil 81 ibu balita, pengambilan sampel dengan menggunakan Sampel Random Sampling, pengumpulan data dengan hasil kuesioner berisi pertanyaan untuk mendapatkan data yang berkaitan dengan variabel yang diteliti. Hasil penelitian pengetahuan ibu balita didapatkan hampir setengah berada dikategori cukup yaitu 47 ibu balita (58%), namun masih ada ibu balita yang memiliki pengetahuan baik yaitu 18 ibu balita (22%), dan ibu balita yang memiliki pengetahuan kurang yaitu 16 ibu balita (20%). Kesimpulan dari penelitian didapatkan tingkat pengetahuan ibu balita yang tidak teratur dalam mengunjungi Posyandu di Desa Cipangeran Kecamatan Saguling Kabupaten Bandug Barat hampir setengah ibu balita berpengetahuan cukup. ABSTRACT The D / S indicator in the working area of ​​Saguling Public Health Center of Cipangeran Village in 2016 indicates that the low number of toddler visits in posyandu activities reaches an average of 41.5%, while the standard target for city / city is 85%. The purpose of this study is to determine the regularity of mothers in visiting Posyandu from knowledge factor in Cipangeran Village, Saguling District, West Bandung regency in 2017. This research method using analytical method with cross sectional approach. The data used is primary data.The population of all toddlers in the working area of Saguling Publich Health Center in 2016 were 424 mother, the sample size was 81 mother, using Random Sampling , data collection with questionnaires containing questions to obtain data related to the variables studied. The result of the research of the knowledge of the mother of the toddler is almost sufficient, namely 47 mothers (58%),but there are still mother who have good knowledge that is 18 mother of toddler (22%) and mother with less knowledge that is 16 mother of balita (20%). The conclusion of the research is the level of knowledge of irregular mother in visiting Posyandu in Cipangeran Village, Saguling, of West Bandung district, almost half of the toddler are knowledgeable enough.

scholarly journals Exploring Why Adult Mexican Males Do Not Get Vaccinated: Implications for COVID-19 Preventive Actions

2020 ◽  
Vol 42 (4) ◽  
pp. 515-527
Author(s):  
V. Nelly Salgado de Snyder ◽  
Deliana Garcia ◽  
Roxana Pineda ◽  
Jessica Calderon ◽  
Dania Diaz ◽  
...  
Keyword(s):  
Preventive Medicine ◽  
Age Groups ◽  
Adult Males ◽  
Cross Sectional ◽  
Administrative Services ◽  
Minority Males ◽  
Socially Disadvantaged ◽  
Preventive Actions ◽  
Socially Excluded ◽  
Age Range

Vaccination is the single most important preventive medicine action worldwide. However, there are inequalities in the procurement of vaccines particularly among US ethnic and racial minority males when compared to the rest of the US population. This study explored the reasons given by adult Mexican-origin males residing in Texas, for obtaining or not, immunizations. This was a cross-sectional, exploratory study with a sample of convenience of 401 adult males (age range 18–79) who were invited to participate in the study while waiting their turn to receive administrative services at the Mexican Consulate in Austin Texas. Data was collected in Spanish with a seven-item multiple choice questionnaire, using electronic tablets. The majority of respondents received their last vaccination longer than 5 years earlier. A higher percentage of individuals in the older age groups received a vaccine in the last year, as opposed to their younger counterparts who obtained their last immunization 3 to 5 years earlier. Among the reasons given for not getting vaccinated were lack of time or money, feared injections and side effects, insufficient information, interest or motivation. Others did not get vaccines because they perceived themselves to be healthy and did not feel sick. Findings from this study have important implications for future preventive medicine and vaccination practices that reach socially excluded groups in times of COVID-19. Recommendations are made to facilitate access to vaccines to the target group of this study and other socially disadvantaged populations in the global health context.

scholarly journals Cognitive Performance and Its Associations with Dental Caries: Results from the Dental, Oral, Medical Epidemiological (DOME) Records-Based Nationwide Study

Biology ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 178
Author(s):  
Itzhak Abramovitz ◽  
Avraham Zini ◽  
Matan Atzmoni ◽  
Ron Kedem ◽  
Dorit Zur ◽  
...  
Keyword(s):  
Dental Caries ◽  
Cognitive Performance ◽  
Odds Ratio ◽  
Allocation Of Resources ◽  
Cross Sectional ◽  
Intelligence Score ◽  
Health Related ◽  
The Mean ◽  
Nationally Representative ◽  
Age Range

Relatively few studies have analyzed the association between cognitive performance and dental status. This study aimed to analyze the association between cognitive performance and dental caries. Included were data from the dental, oral, medical epidemiological (DOME) study; cross-sectional records-based research, which integrated large socio-demographic, medical, and dental databases of a nationally representative sample of young to middle-aged military personnel (N = 131,927, mean age: 21.8 ± 5.9 years, age range: 18–50). The cognitive function of draftees is routinely measured at age 17 years using a battery of psychometric tests termed general intelligence score (GIS). The mean number of decayed teeth exhibited a gradient trend from the lowest (3.14 ± 3.58) to the highest GIS category (1.45 ± 2.19) (odds ratio (OR) lowest versus highest = 5.36 (5.06–5.68), p < 0.001). A similar trend was noted for the other dental parameters. The associations between GIS and decayed teeth persisted even after adjusting for socio-demographic parameters and health-related habits. The adjustments attenuated the OR but did not eliminate it (OR lowest versus highest = 3.75 (3.38–4.16)). The study demonstrates an association between cognitive performance and caries, independent of the socio-demographic and health-related habits that were analyzed. Better allocation of resources is recommended, focusing on populations with impaired cognitive performance in need of dental care.

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