Comparative study of medical common data models for FAIR data sharing / 中华流行病学杂志

The common data model (CDM) is an important tool to facilitate the standardized integration of multi-source heterogeneous healthcare big data, enhance the consistency of data semantic understanding, and promote multi-party collaborative analysis. The data collections standardized by CDM can provide powerful support for observational studies, such as large-scale population cohort study. This paper provides an in-depth comparative analysis of the data storage structure, term mapping pattern, and auxiliary tools development of the three international typical CDMs, then analyzes the advantages and limitations of each CDM and summarizes the challenges and opportunities faced in the CDM application in China. It is expected that exploring the advanced technical concepts and practical patterns of foreign countries in data management and sharing will provide references for promoting FAIR (findable, accessible, interoperable, reusable) construction of healthcare big data in China and solving the current practical problems, such as the poor quality of data resources, the low degree of semantization, and the inabilities of data sharing and reuse.

Association of Breastfeeding Duration with Body Composition in Children Aged 3-5 Years / 生物医学与环境科学（英文）

OBJECTIVE@#This study aimed to assess the relationship between the body composition of children aged 3-5 years and breastfeeding status and duration.@*METHODS@#The study was conducted using data from the National Nutrition and Health Systematic Survey for children 0-17 years of age in China (CNHSC), a nationwide cross-sectional study. Breastfeeding information and potential confounders were collected using standardized questionnaires administered through face-to-face interviews. The body composition of preschool children was measured using bioelectrical impedance analysis. A multivariate linear regression model was used to assess the relationship between breastfeeding duration and body composition after adjusting for potential confounders.@*RESULTS@#In total, 2,008 participants were included in the study. Of these, 89.2% were ever breastfed and the median duration of breastfeeding was 12 months (IQR 7-15 months). Among children aged 3 years, the height-for-age Z-score (HAZ) for the ever breastfed group was lower than that for never breastfed group (0.12 vs. 0.42, P = 0.043). In addition, the weight-for-age Z-score (WAZ) of the ever breastfed group was lower than that of the never breastfed group (0.31 vs. 0.65, P = 0.026), and the WAZ was lower in children aged 4 years who breastfed between 12 and 23 months than in those who never breastfed. Compared to the formula-fed children, the fat-free mass of breastfed infants was higher for children aged 3 years (12.84 kg vs. 12.52 kg, P = 0.015) and lower for those aged 4 years (14.31 kg vs. 14.64 kg, P = 0.048), but no difference was detected for children aged 5 years (16.40 kg vs. 16.42 kg, P = 0.910) after adjusting for potential confounders. No significant difference was detected in the weight-for-height Z-score (WHZ), body mass index (BMI)-for-age Z-score (BAZ), fat-free mass index, and body fat indicators in the ever breastfed and never breastfed groups and among various breastfeeding duration groups for children aged 3-5 years.@*CONCLUSION@#No obvious associations were detected between breastfeeding duration, BMI, and fat mass indicators. Future prospective studies should explore the relationship between breastfeeding status and fat-free mass.

The association between vitamin D and bone mineral density of urban postmenopausal women in Beijing / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study the association between vitamin D status and bone mineral density(BMD) in urban postmenopausal women in Beijing.</p><p><b>METHODS</b>A total of 400 community-dwelling women older than 60 (median age 67.8 years) were selected randomly from 17 community of 3 districts in Beijing by cluster sampling method from May to July, 2008. Serum 25(OH)D concentrations were measured by radioimmunoassay, using the DiaSorin kit, America. The objects were assigned into four groups: vitamin D deficient group (group A, 25(OH)D < 25 nmol/L), insufficient group(group B, 25 nmol/L < 25(OH)D < or = 50 nmol/L), normal group (group C, 50 nmol/L < 25(OH)D < or = 75 nmol/L) and enough group (group D, 25(OH)D > 75 nmol/L). The BMD at total, lumbar spine (L(2-4)) and proximal femur were measured by dual-energy X-ray absorptiometry (DEXA).</p><p><b>RESULTS</b>The mean concentration of serum 25(OH)D concentration was (36.0 +/- 14.6) nmol/L, BMD at total and proximal femur were respectively (0.829 +/- 0.090) and (0.679 +/- 0.106) g/cm(2). The mean BMD at total of group A, B, C + D were respectively (0.811 +/- 0.077), (0.825 +/- 0.088) and (0.864 +/- 0.112) g/cm(2)(F = 16.93, P < 0.01), and BMD at proximal femur of group A, B, C + D were respectively (0.666 +/- 0.107), (0.673 +/- 0.099) and (0.725 +/- 0.117) g/cm(2)(F = 18.36, P < 0.01). The 25(OH)D level was positively correlated with BMD at total body and proximal femur (r values were 0.17 and 0.18, both P values < 0.05).</p><p><b>CONCLUSION</b>Vitamin D status was highly correlated with BMD at lumbar spine (L(2-4)), proximal femur, pelvis and limbs for the postmenopausal older women.</p>