Calculation of unconditional and conditional reference intervals for foetal size and growth from longitudinal measurements.
Methods for estimating unconditional and conditional reference intervals for foetal size and growth based on longitudinal observations are presented. The methods are based on simple random-effects regression models and involve transforming both the response and the covariate (timepoint). A dataset from a designed longitudinal study of foetal size is analysed in detail as a motivating example.
D000886:Anthropometry; D003627:Data Interpretation, Statistical; D005314:Embryonic and Fetal Development; D005260:Female; D005865:Gestational Age; D006801:Humans; D008137:Longitudinal Studies; D015233:Models, Statistical; D015999:Multivariate Analysis; D011247:Pregnancy; D012016:Reference Values; D012044:Regression Analysis; D012107:Research Design; D016216:Ultrasonography, Prenatal