The Euro-Growth Study: why, who, and how.
BACKGROUND
Assessment of growth is important in health management of infants and children. Evaluation of growth performance requires anthropometric measurements, with proper interpretation depending on the use of appropriate references. Europe-specific growth references have not been available. The purpose of the present study was to generate such references for infants and children from birth to 3 years of age. The study was further intended to assess the influence of nutrition and lifestyle factors on growth.


METHODS
The Euro-Growth Study was designed as a multicenter longitudinal cohort study. This report describes the study design, the sample (cohort), and the methods used. Quality control measures included standardized measurement techniques with ongoing cross-sectional and longitudinal consistency checks. Selectivity in participation and discontinuation and reproducibility of data over time were evaluated.


RESULTS
Of 2,245 infants who were enrolled in the study at 22 study sites in 11 countries, 1,746 (78%) provided longitudinal data until 12 months of age, 1,205 (57%) until 24 months of age, and 1071 (48%) until 36 months of age. Anthropometric measurements were performed on 21,773 occasions. As a result of cross-sectional and longitudinal data checks, 209 data points (0.09% of all data points) were rejected. Comparison of participants's demographic data with those of nonparticipating local subjects indicated that the cohort was selective in maternal age (higher), maternal education level (higher), household location, and family structure. The withdrawal rate during the study was low (24%), and withdrawals occurred at random. Analysis of reproducibility over time resulted in the elimination of the data from one study site.


CONCLUSIONS
The Euro-Growth Study provided longitudinal growth data from a large cohort of normal European children. Because of the chosen sampling method, the study cohort ws somewhat selective relative to the local background population. Internal validity was satisfactory in that the reproducibility of anthropometric measurements was high in 21 sites and the withdrawal rate was low and random.
van't Hof
M A
MA
Department of Medical Statistics, Nijmegen University, The Netherlands.
Haschke
F
F
D000886:Anthropometry; D002657:Child Development; D002664:Child Nutritional Physiological Phenomena; D002675:Child, Preschool; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005060:Europe; D005260:Female; D006128:Growth; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008137:Longitudinal Studies; D008297:Male; D018579:Patient Selection; D011786:Quality Control; D012016:Reference Values; D015203:Reproducibility of Results; D012107:Research Design / Q000592:standards