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Growth Charts Of Children's Height Based On Allowing For Parental Height By GAMLSS

Posted on:2021-01-03Degree:MasterType:Thesis
Country:ChinaCandidate:Q ChenFull Text:PDF
GTID:2404330623982492Subject:Applied statistics
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ObjectThis study hopes to develop age-specific height percentile curves for children with different parent height groups,and use dynamic and individualized growth standard curves to evaluate and monitor the growth and development of children under different genetic factors.Children with the same genetic factors have a specific growth standard,so that the diagnosis is more reliable,more conducive to early individuals to identify growth deviations,in order to timely take effective measures such as etiological research,nutrition guidance and other effective measures to enable children to receive timely diagnosis and intervention treatment,promote child growth and health services.MethodOn the basis of the GAMLSS model in the first chapter,we try to establish the age percentile curve of the height(length)of Chongqing boys and girls by fitting the parameters ?,?,?,?,pb and cs smoothing functions,respectively.The distribution is fitted with a variety ofcommonly used link functions,and the optimal model is selected according to the principle of minimum Akaike information and Schwarz Bayesian standard.finally,the accuracy of the model is judged by using worm diagram(worm plot)and residual test(Q-Q diagram)to test the fitting effect.The standard deviation unit values generated by the model were compared with the standards published by the Health and Health Commission in 2009.In the second chapter,we first construct the standard growth curve and get the percentile of the standard age category of the case.Then,according to the father height,mother height of different levels of combination.The growth curves of each group were constructed to obtain the percentile of parent height group.Then the correlation analysis was carried out on father height,mother height,mean parent height,child height,standard age group percentile and parent height group percentile.Finally,a modified model of father height and mother height was constructed by regression equation.ResultPart ?: the optimal model of height(long)growth curve of boys and girls is M7 model according to AIC ? SBC minimum principle: BCT distribution,the combination of smoothing parameters ??CS smoothing parameters ? ? PB smoothing parameters is the optimal model.The standard difference values of height(length)for boys and girls wereobtained,and the percentile curves of height(length)for boys and girls were obtained.The range of reference values is suitable for children aged0-7 years,and the range of positive values of height of boys and girls at birth is more concentrated,which gradually diverges with age.Both boys and girls had peak growth during 0-3 years of age,and the curve showed exponential distribution;after 3 years of age,the height growth was more stable,and the curve showed linear growth.The results of this study compared with the 2009 standard,the distribution and growth rate of all age groups are roughly the same as the 2009 standard,and the height curve is also at the inflection point of 3 years old.In comparison,the curve of this study is more convergent,and the range of percentile is larger under standard age categories in 2009.Therefore,the height level of normal children aged 0-7 in Chongqing is generally lower than the national average standard investigated in 2005.Part ?: the general standard growth curve model of male and female children's height(length)is BCT distribution,CS the combination of smoothing parameters ??CS smoothing parameters ??? constant and ? constant is the optimal model.According to the different levels of height of parents,two combinations were carried out to obtain 16 groups of data for boys and girls.for each set of data,the same function as the fitting model of the height(length)growth curve of the standard male and female children was used to model.the consistency ratebetween the group quantile and the standard quantile was 58.36% for boys and 56.28% for girls.The correlation coefficient passed the significance test,and the correlation between the variables and the percentile was the most high is the standard age category percentile of0.8792 and 0.8757,respectively.The regression model of parent height group quantile was established by stepwise method,and the multivariate linear model of independent variables including father height,mother height and standard quantile was obtained.ConclusionWhen the parents' height is unknown,use the standard child growth curve obtained in the first part as the reference value for children's height.When the parent height is known,the parent height correction model obtained in the second part is used as the height reference value for children.DiscussionChild growth and development is a continuous and complex dynamic process.With the deepening of the research on the growth law of children and the progress of statistics and computer applications,the method of making growth curve is more advanced and standardized.Because the biological data normality is not very good,the estimated percentile of LMS method may be different,GAMLSS more consideration is given to the simulation of kurtosis,which is moresuitable foress distribution data,so that the model residuals are further modified and the curve shape tends to smooth.GAMLSS can obtain population-based reference curves and tables for correcting biology upper age-specific statistical models with skewness,adaptability to the use of percentiles or Z scores,and accuracy in evaluating extreme percentiles by calculation of 95% confidence intervals.In conclusion,the method used is suitable for drawing the height(long)weight reference curve of children.As of the date of publication,this is the first study GAMLSS the development of reference values for children's growth and development in China.This study supplemented the reference range of height and weight of children in Chongqing to provide a basis for the rational diagnosis of short stature and malnutrition.the results of this study are suitable for children aged 0-14 years.when using,we should first find in figure 2.1 and figure 2.2 which decimal section of a child's height is in the standard growth curve,replace it with grade number value,and then substitute it into the modified regression equation.the obtained numbers represent the percentile section of the child based on the height correction of parents.One of the important functions of the growth curve table is to predict the percentile of the child's height in adulthood based on the percentile of the height of the child.but under different genetic conditions,children may have completely different range of adult height expectations.And there'senough evidence that there's affinities gene influence should be different in the sub-combination relationship,so this study considered the correlation between father and mother and the height of boys and girls respectively,which was more comprehensive than the previous study of the same type only studied the correlation between the mean height of parents and the height SDS of children.
Keywords/Search Tags:GAMLSS method, Growth charts, parental height, Modified model
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