Hospitalization expenses of adult leukemia patients with relapse based on quantile regression / 公共卫生与预防医学

Objective Based on quantile regression analysis, the influencing factors of relapse hospitalization expenses of adult leukemia patients were analyzed. Methods Analyze the composition and influencing factors of hospitalization expenses for leukemia recurrence patients in our hospital. Results From 2017 to 2022 , the per capita hospitalization cost for leukemia patients with recurrence showed an increasing trend year by year. The results of quantile regression model showed that age, payment method , length of stay, times of stay, operation and complications had an impact on the hospitalization expenses of patients at different quantiles, and the difference between different quantiles was statistically significant (P<0.05). Conclusions The quantile regression method can more clearly reflect the distribution of the variables of each factor , we can reduce the hospitalization expenses of patients by improving the coverage rate of medical insurance and controlling the length of stay.

Association between leukocyte telomere length and sex by quantile regression analysis

ABSTRACT Introduction: Telomere length (TL) is a biomarker of cellular proliferative history. In healthy individuals, leukocyte TL shortens with age and associates with the lifespan of men and women. However, most of studies had used linear regression models to address the association of the TL attrition, aging and sex. Methods: We evaluated the association between the TL, aging and sex in a cohort of 180 healthy subjects by quantile regression. The TL of nucleated blood cells was measured by fluorescent in situ hypridization (flow-FISH) in a cohort of 89 men, 81 women, and 10 umbilical cord samples. The results were validated by quantitative polymerase chain reaction (qPCR) and compared to a linear regression analysis. Results: By quantile regression, telomere dynamics slightly differed between sexes with aging: women had longer telomeres at birth and slower attrition rate than men until the sixth decade of life; after that, TL eroded faster and became shorter than that in men. These differences were not observed by linear regression analysis, as the overall telomere attrition rates in women and men were similar (42 pb per year, p < 0.0001 vs. 45 pb kb per year, p < 0.0001). Also, qPCR did not recapitulate flow-FISH findings, as the telomere dynamics by qPCR followed a linear model. Conclusion: The quantile regression analysis accurately reproduced a third-orderpolynomial TL attrition rate in both women and men, but it depended on the technique applied to measure TL. The Flow-FISH reproduced the expected telomere dynamics through life and, differently from the qPCR, was able to detect the subtle TL variations associated with sex and aging.

Quantile regression model-based analysis of influencing factors on quality of life of inpatients with type 2 diabetes / 中华疾病控制杂志

Objective This study aimed to understand the status of health-related quality of life (HRQOL) among the hospitalized patients with type 2 diabetes (T2DM) in Yinchuan, so as to analyze the factors associated with HRQOL of hospitalized T2DM patients. The applied value of quantile regression in analysis of HRQOL was explored. Methods A cross-sectional study was conducted to obtain data of 480 hospitalized T2DM patients. The Chinese Normal Audit of Diabetes-Dependent Quality of Life (CN-ADDQoL) scale was used to assess the HRQOL status of patients. Traditional linear regression and quantile regression were used to analyze the influencing factors of HRQOL in hospitalized T2DM patients. Results The average weight impact (AWI) of hospitalized T2DM patients was-2.7(-3.6,-1.9), and the items with lowest score were in the dimension of “work life” (AWI,-4(-6,-2)), “eat” AWI,-4(-6,-2)) and “Anything of Drinking” (AWI,-4(-6,-2)). Linear regression results showed that 18-59 years old or the renal and circulatory complications were risk factors for HRQOL in T2DM hospitalized patients. Quantile regression further found that the better the quality of life, the weaker the effect on age (β1=0.931, P1=0.001; β2=0.699, P2=0.001; β3=0.370, P3=0.012; β4=0.313, P4=0.035), the rural residents (β5=-0.421, P5<0.001), insulin treatment (β3=-0.325; P3=0.024), the ocular (β1=-0.546, P1=0.008; β5=-0.352, P5=0.008), renal (β5=-0.358, P5=0.025) and circulatory complications (β1=-0.803, P1<0.001; β5=-0.302, P5=0.011) had effect on HRQOL at different quantiles. Conclusions Age, urban and rural residence, whether receive insulin therapy and complications are the influencing factors of HRQOL in hospitalized T2DM patients. The quantile regression model can show different factors affecting the quality of life of patients at different quintiles. The results from quantile regression can provide the targeted and reasonable recommendations for improvement of HRQOL of T2DM patients.

Nonlinear quantile regression to describe the dry matter accumulation of garlic plants / Regressão quantílica não linear para descrever o acúmulo de matéria seca de alho

ABSTRACT: The objective of this study was to adjust nonlinear quantile regression models for the study of dry matter accumulation in garlic plants over time, and to compare them to models fitted by the ordinary least squares method. The total dry matter of nine garlic accessions belonging to the Vegetable Germplasm Bank of Universidade Federal de Viçosa (BGH/UFV) was measured in four stages (60, 90, 120 and 150 days after planting), and those values were used for the nonlinear regression models fitting. For each accession, there was an adjustment of one model of quantile regression (τ=0.5) and one based on the least squares method. The nonlinear regression model fitted was the Logistic. The Akaike Information Criterion was used to evaluate the goodness of fit of the models. Accessions were grouped using the UPGMA algorithm, with the estimates of the parameters with biological interpretation as variables. The nonlinear quantile regression is efficient for the adjustment of models for dry matter accumulation in garlic plants over time. The estimated parameters are more uniform and robust in the presence of asymmetry in the distribution of the data, heterogeneous variances, and outliers.

RESUMO: Este trabalho teve como objetivo ajustar modelos de regressão quantílica não linear para o estudo do acúmulo de matéria seca total em plantas de alho ao longo do tempo, e compará-los com modelos ajustados pelo método dos mínimos quadrados. A matéria seca total de nove acessos de alho pertencentes ao Banco de Germoplasma de Hortaliças da Universidade Federal de Viçosa (BGH/UFV) foi avaliada em quatro períodos (60, 90, 120 e 150 dias após plantio), e estes valores foram utilizados para o ajuste de modelos de regressão - não linear - logística. Para cada acesso, foram ajustados um modelo de regressão quantílica (τ=0,5) e um modelo pela metodologia dos mínimos quadrados. Para avaliar a qualidade de ajuste dos modelos foi utilizado o Critério de Informação de Akaike. Os acessos foram agrupados pelo algoritmo UPGMA, utilizando as estimativas dos parâmetros com interpretação biológica como variáveis. A regressão quantílica não linear foi eficiente no ajuste de modelos para descrição do acúmulo de matéria seca ao longo do tempo. As estimativas de parâmetros foram mais uniformes e robustas na presença de dados assimétricos, variâncias heterogêneas e de valores discrepantes.

Effect of interpregnancy interval of childbearing aged women on birth weight of single live birth neonates / 中华流行病学杂志

Objective To understand the effect of interpregnancy interval (IPI) of childbearing aged women on the birth weight of single live birth neonates in Shaanxi province.Methods A questionnaire survey was conducted among the childbearing aged women selected through multistage stratified random sampling in Shaanxi during 2010-2013,all the childbearing aged women had definite pregnancy outcomes.The interpregnancy interval of the childbearing aged women and the birth weight of the newborns were used as the independent variables and dependent variables respectively in multiple linear regression model and quantile regression model,and confounding factors were controlled.Results A total of 13 063 women at childbearing age and their infants were investigated.The incidence of low birth weight and macrosomia was 3.54％ and 7.62％ respectively.Multiple linear regression analysis showed that there was no significant difference in birth weight among different IPI group and control group.Quantile regression analysis showed when birth weight was at 5 percentiles,the difference in birth weight between newborns whose mothers had short interpregnancy interval (＜12 months) and those in control group was significant,when the birth weight was ≥90 percentiles,the birth weights of newborns whose mothers had long interpregnancy interval (60-119 months) were higher than those in control group,the difference was significant.As the increase of the percentiles of birth weight,the extent of changes gradually increased.Conclusion The analysis indicated that both short (＜12 months) and long (60-119 months) interpregnancy interval would had negative effects on birth weights of newborns.Therefore,planning for pregnancy is important for having a good perinatal outcome.

Analysis on the Effect of Medical System Efficiency on Residents' Health: Based on Panel Quantile Regression Model / 中国卫生经济

Objective:Analyzing the efficiency of medical system in China and examining the impact of the imbalance of regional health system efficiency on the health status of residents.Methods:Using DEA method to measure the output efficiency of inter-provincial medical system in China;employing the panel quantile regression model to measure the health improvement effect and changing trend brought by the promotion of the efficiency of medical system.Results:The efficiency of health systems in different provinces in China showed the situation of high in the east and low in the west,regional imbalances were obvious;the impact of the promotion of efficiency of the medical system on the residents' health status would be weakened with improvement of residents' health status.In areas where the residents' health status was the best,the effect of improving the efficiency of medical treatment had no significant.Conclusion:It should give full play to improvement effect of medical system efficiency on the residents' health,focus on supporting the construction of medical systems in backward areas to promote the balanced development of China's regional medical system.

Comparison of Bayesian statistics and classical statistics in quantile regression analysis / 军事医学

Objective To compare the Bayesian statistics and the classical statistics in the quantile regression analysis in order to select a more effective method .Methods The large sample data was chosen , and the QUANTREG procedure in SAS was used for the classical statistics and the MCMC procedure in SAS for the Bayesian one , respectively .Using ten-fold cross-validation method , the goodness of fitting of the models was appraised in terms of the fitted effect based on the training dataset and the predicted effect based on the predictive dataset .Results In most cases, the indexes of the quantile regression models in the classical statistics were slightly worse than those of the Bayesian one .In the ten-fold cross-validation of the partial samples as a training dataset , the fitting effect of the lower quartile ( Q1 ) and upper quartile ( Q3 ) of the Bayesian statistics was better than that of the classical one .However , the median ( Q2 ) fitting effect of the Bayesian statistics was slightly worse than that of the classical one .As for the prediction effect , the Bayesian statistical quantile regression model was superior to the classic one .Conclusion To expect high accuracy , such as the predictive effects and fitting effects of each quantile , the Bayesian quantile regression analysis should be chosen .If the major concern is the fitting effect of the median , careful selection from the approaches mentioned above is needed .If time and energy are limited, and the sample size is large enough , the classic statistical quantile regression analysis is a good choice .

Effect of interpregnancy interval of childbearing aged women on birth weight of single live birth neonates / 中华流行病学杂志

Objective To understand the effect of interpregnancy interval (IPI) of childbearing aged women on the birth weight of single live birth neonates in Shaanxi province.Methods A questionnaire survey was conducted among the childbearing aged women selected through multistage stratified random sampling in Shaanxi during 2010-2013,all the childbearing aged women had definite pregnancy outcomes.The interpregnancy interval of the childbearing aged women and the birth weight of the newborns were used as the independent variables and dependent variables respectively in multiple linear regression model and quantile regression model,and confounding factors were controlled.Results A total of 13 063 women at childbearing age and their infants were investigated.The incidence of low birth weight and macrosomia was 3.54％ and 7.62％ respectively.Multiple linear regression analysis showed that there was no significant difference in birth weight among different IPI group and control group.Quantile regression analysis showed when birth weight was at 5 percentiles,the difference in birth weight between newborns whose mothers had short interpregnancy interval (＜12 months) and those in control group was significant,when the birth weight was ≥90 percentiles,the birth weights of newborns whose mothers had long interpregnancy interval (60-119 months) were higher than those in control group,the difference was significant.As the increase of the percentiles of birth weight,the extent of changes gradually increased.Conclusion The analysis indicated that both short (＜12 months) and long (60-119 months) interpregnancy interval would had negative effects on birth weights of newborns.Therefore,planning for pregnancy is important for having a good perinatal outcome.

Quantile regression of nonlinear models to describe different levels of dry matter accumulation in garlic plants / Regressão quantílica de um modelo não linear para descrição de diferentes níveis de acúmulo de matéria seca em plantas de alho

ABSTRACT: Plant growth analyses are important because they generate information on the demand and necessary care for each development stage of a plant. Nonlinear regression models are appropriate for the description of curves of growth, since they include parameters with practical biological interpretation. However, these models present information in terms of the conditional mean, and they are subject to problems in the adjustment caused by possible outliers or asymmetry in the distribution of the data. Quantile regression can solve these problems, and it allows the estimation of different quantiles, generating more complete and robust results. The objective of this research was to adjust a nonlinear quantile regression model for the study of dry matter accumulation in garlic plants (Allium sativum L.) over time, estimating parameters at three different quantiles and classifying each garlic accession according to its growth rate and asymptotic weight. The nonlinear regression model fitted was a Logistic model, and 30 garlic accessions were evaluated. These 30 accessions were divided based on the model with the closest quantile estimates; 12 accessions were classified as of lesser interest for planting, 6 were classified as intermediate, and 12 were classified as of greater interest for planting.

RESUMO: Análises de crescimento de plantas são importantes, pois geram informações sobre a demanda e os cuidados necessários para cada etapa de seu desenvolvimento. Modelos de regressão não linear são apropriados para descrever curvas de crescimento por apresentarem parâmetros com interpretação prática biológica. Entretanto, estes modelos apresentam informações em termos médios, e estão sujeitos a problemas no ajuste proporcionados por possíveis valores extremos ou assimetria na distribuição dos dados. A regressão quantílica pode contornar estes problemas, e ainda permite estimativas de diferentes quantis, gerando resultados mais completos e robustos. Assim, o objetivo deste trabalho foi ajustar um modelo de regressão quantílica não linear para o estudo do acúmulo de matéria seca em plantas de alho (Allium sativum L.) ao longo do tempo, estimando seus parâmetros em três diferentes quantis e classificando cada acesso de alho de acordo com sua taxa de crescimento e peso assintótico. O modelo de regressão não linear ajustado foi o Logístico, e foram utilizados 30 acessos de alho. Estes foram divididos de acordo com a curva do quantil de estimativas mais próximas, sendo classificados 12 acessos como de baixo interesse para o plantio, 6 de interesse intermediário e 12 como de alto interesse.

Quantile Regression of Depression and Body Mass Index in Patients with Cor-onary Artery Disease in China / 中国卫生统计

Objective Depression and obesity are two major disorders associated with coronary heart disease ( CHD) , and both have a high prevalence. Different studies concluded different outcomes about the relation between body mass index ( BMI) and depression. The aim of this study was to assess the status of depression and investigate the relationship between de-pression and BMI in CHD patients using quantile regression. Methods 580 patients were enrolled. Depression was tested using the Zung Self-Rating Depression Scale ( SDS) . Demographic data and clinical data were recorded. Quantile regression was con-ducted to determine whether BMI was a predictor of depression. Results SDS scores were significant different in underweight, normal weight,overweight and obesity group (P<0. 001). Overweight and obesity patients were least depressed. Differences in SDS scores increased steeply as depression increased at 5th,10th,25th,50th,75th,90th and 95th percentiles,with the coefficients ranging from -0. 36 to -0. 88 in total population,-0. 26 to -1. 09 in male and -0. 46 to -0. 75 in female respectively. The effects of BMI on depression were significantly different in different quantiles of depression in total population ( P=0. 04 ) and in male (P=0. 006),but no difference in female. Conclusion There was also a phenomenon of "obesity paradox" between BMI and depression in CHD patients. The effects of BMI on depression were significantly different in different quantiles in total population and in male.

Quantile Regression of Depression and Body Mass Index in Patients with Cor-onary Artery Disease in China / 中国卫生统计

Objective Depression and obesity are two major disorders associated with coronary heart disease ( CHD) , and both have a high prevalence. Different studies concluded different outcomes about the relation between body mass index ( BMI) and depression. The aim of this study was to assess the status of depression and investigate the relationship between de-pression and BMI in CHD patients using quantile regression. Methods 580 patients were enrolled. Depression was tested using the Zung Self-Rating Depression Scale ( SDS) . Demographic data and clinical data were recorded. Quantile regression was con-ducted to determine whether BMI was a predictor of depression. Results SDS scores were significant different in underweight, normal weight,overweight and obesity group (P<0. 001). Overweight and obesity patients were least depressed. Differences in SDS scores increased steeply as depression increased at 5th,10th,25th,50th,75th,90th and 95th percentiles,with the coefficients ranging from -0. 36 to -0. 88 in total population,-0. 26 to -1. 09 in male and -0. 46 to -0. 75 in female respectively. The effects of BMI on depression were significantly different in different quantiles of depression in total population ( P=0. 04 ) and in male (P=0. 006),but no difference in female. Conclusion There was also a phenomenon of "obesity paradox" between BMI and depression in CHD patients. The effects of BMI on depression were significantly different in different quantiles in total population and in male.

Gender-specific Association of Sleep Duration with Body Mass Index, Waist Circumference, and Body Fat in Chinese Adults / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To examine the association between habitual sleep duration and obesity among Chinese adults.</p><p><b>METHODS</b>The association of sleep duration and obesity was investigated among 7,094 community-dwelling Chinese adults. Sleep duration was self-reported. In this study, obesity was defined as follows: body mass index (BMI) ⋝ 28 kg/m2, waist circumference (WC) ⋝ 85 cm in men and ⋝ 80 cm in women, and percent body fat (%BF) ⋝ 25 in men and ⋝ 35 in women. Logistic and quantile regressions were employed to examine relationships of interest.</p><p><b>RESULTS</b>Overall, 6.42% of the participants reported short sleep durations (< 6 h/d) while 14.71% reported long (⋝ 9 h/d) sleep durations. Long sleepers (⋝ 9 h/d) represented a greater frequency of women with obesity [odds ratio (OR): 1.30; 95% confidence interval (CI), 1.02-1.67] and high body fat (1.43, 1.04-1.96) than those who slept 7-8 h/d. An association between long sleep times and higher BMI estimations was found across the 10th-75th percentile of the BMI distribution. Among men, long sleepers (⋝ 9 h/d) presented lower risks of developing abdominal obesity compared with individuals who slept 7-8 h/d (OR = 0.79, 95% CI: 0.44-0.99).</p><p><b>CONCLUSION</b>Our study suggests that long sleep durations are associated with general obesity in Chinese women but reduced waist circumferences in men. Confirmatory studies are needed to determine the heterogeneous association of sleep time and obesity by gender.</p>

Effect of folic acid supplementation in childbearing aged women during pregnancy on neonate birth weight in Shaanxi province / 中华流行病学杂志

Objective To investigate the effect of folic acid supplementation in childbearing aged women during pregnancy on the birth weight of newborns in Shaanxi province.Methods A questionnaire survey was conducted among the childbearing aged women selected through multistage stratified random sampling in Shaanxi during 2010-2013,all of these childbearing aged women were in pregnancy or had definite pregnancy outcomes.The birth weight of newborns and folic acid supplementation during pregnancy were used as the dependent variables and independent variables respectively in multiple linear regression model and quantile regression model and confounding factors were controlled.Results Multiple linear regression analysis showed that the birth weight of newborns whose mothers had folic acid supplementation during pregnancy were significantly higher than those whose mothers had no folic acid supplementation during pregnancy,an average increase of 29.56 g (B=29.56,t=4.69 and P＜0.01).Quantile regression analysis showed from very low to higher percentiles (q=0-0.55,q=0.65,q=0.75-0.80),the birth weights of newborns whose mothers supplemented folic acid were higher than those whose mother did not supplement folic acid,the difference was significant,but the increase varied.As the increase of the percentiles of birth weight,the body weight increase declined gradually in those whose mothers had folic acid supplementation compared with those whose mothers had no folic acid supplementation.Conclusion Folic acid supplementation during pregnancy can increase the birth weight of newborns,the influence was greater in newborns with lower body weight than in newborns with higher body weight.

Effect of folic acid supplementation in childbearing aged women during pregnancy on neonate birth weight in Shaanxi province / 中华流行病学杂志

Objective To investigate the effect of folic acid supplementation in childbearing aged women during pregnancy on the birth weight of newborns in Shaanxi province.Methods A questionnaire survey was conducted among the childbearing aged women selected through multistage stratified random sampling in Shaanxi during 2010-2013,all of these childbearing aged women were in pregnancy or had definite pregnancy outcomes.The birth weight of newborns and folic acid supplementation during pregnancy were used as the dependent variables and independent variables respectively in multiple linear regression model and quantile regression model and confounding factors were controlled.Results Multiple linear regression analysis showed that the birth weight of newborns whose mothers had folic acid supplementation during pregnancy were significantly higher than those whose mothers had no folic acid supplementation during pregnancy,an average increase of 29.56 g (B=29.56,t=4.69 and P＜0.01).Quantile regression analysis showed from very low to higher percentiles (q=0-0.55,q=0.65,q=0.75-0.80),the birth weights of newborns whose mothers supplemented folic acid were higher than those whose mother did not supplement folic acid,the difference was significant,but the increase varied.As the increase of the percentiles of birth weight,the body weight increase declined gradually in those whose mothers had folic acid supplementation compared with those whose mothers had no folic acid supplementation.Conclusion Folic acid supplementation during pregnancy can increase the birth weight of newborns,the influence was greater in newborns with lower body weight than in newborns with higher body weight.

Factors Associated with Dental Revenue and Income of Self-Employed Dentist by Using a Quantile Regression Method / 보건행정학회지

BACKGROUND: Dentist's income is quite variable. We investigate the factors underlying the distribution of dental revenue and dentist income. METHODS: Financial and structural variables of private dental practices(N=13,967) were examined with 2010 Economic Census microdata which include non-insurance revenue. We conducted quantile regression method(QRM) and ordinary least square(OLS) in treating skewness and heteroskedasticity of distributions. The effective estimation for the upper and lower range of distribution becomes possible by QRM. RESULTS: Mid-career dentists are shown to have higher revenue and income. Male dentists achieve the higher revenue and income than female dentists in all quantiles. Group practices show lower income per owner than solo practices significantly. The revenue and income are increased with increasing size of clinics. The high cost in renting the clinic office is found to have a big positive effect on the revenue but a little positive effect on the income. Interestingly the density of dentists shows negative effect on the lowest quantile of the revenue but positive effect on the highest quantile. The lowest quantile of the revenue in the capital areas have the relatively high revenue. The lowest quantile of the income in metropolitan city show higher income than those in other areas significantly. CONCLUSION: The suggested QRM is shown to have more effective and efficient tool in finding out determinants of dentists' revenue and income of our concern. The results of this study are expected to be employed for dentists preparing for the opening practices in their organizational settings and locational selections. The distributional efficiency of dental human resources could be accomplished if policy makers guide dentists with this knowledge.

Quantile regression analysis of health-related quality of life of rural residents in Shaanxi and its associated factors / 中华流行病学杂志

Objective This study aimed to apply quantile regression to study Hanzhong rural residents health survey data,explore the local distribution characteristics of health-related quality of life (HRQOL) and influencing factors and present the value of quantile regression applying in analysis of HRQOL.Methods In this cross-sectional population-based study,we evaluated the HRQOL of 2 737 subjects through filling Short-Form Health Survey (SF-36).Quantile regression model was used to compare MCS and PCS scores and evaluate the associated factors.Results With different quantiles MCS and PCS score,the associated factors and influence degree were different.In general,the influences of marital status,educational level,physical activity,history of disease and HRQOL in the part of the percentile scores were significant.Conclusion Analysis of the distribution of HRQOL of rural residents in Hanzhong and influencing factors would benefit the improvement of HRQOL of local residents.

Estimation of Effects of Factors Related to Preschooler Body Mass Index Using Quantile Regression Model

PURPOSE: The purpose of this study was to investigate Korean preschoolers' obesity-related factors through an ecological approach and to identify Korean preschoolers' obesity-related factors and the different effects of ecological variables on body mass index and its quantiles through an ecological approach. METHODS: The study design was cross-sectional. Through convenience sampling, 241 cases were collected from three kindergartens and seven nurseries in the Seoul metropolitan area and Kyunggi Province in April 2013 using self-administered questionnaires from preschoolers' mothers and homeroom teachers. RESULTS: Results of ordinary least square regression analysis show that mother's sedentary behavior (p < .001), sedentary behavior parenting (p = .039), healthy eating parenting (p = .027), physical activity erelated social capital (p = .029) were significant factors of preschoolers' body mass index. While in the 5% body mass index distribution group, gender (p = .031), preference for physical activity (p = .015), mother's sedentary behavior parenting (p = .032), healthy eating parenting (p = .005), and teacher's sedentary behavior (p = .037) showed significant influences. In the 25% group, the effects of gender and preference for physical activity were no longer significant. In the 75% and 95% group, only mother's sedentary behavior showed a statistically significant influence (p < .001, p = .012 respectively). CONCLUSION: Efforts to lower the obesity rate of preschoolers should focus on their environment, especially on the sedentary behavior of mothers, as mothers are the main nurturers of this age group.

Analysis on the premium standard for minors of urban residents with basic medical insurance in Tangshan city / 中华医院管理杂志

Objective To analyze the factors for willingness to pay(WTP)in different quantiles and to provide evidence for formulating premium of minors covered by Urban Residents'Basic Medical Insurance.Methods In a field survey,the study adopted the contingent valuation method and quantile regression to measure and analyze the WTP.Results The influencing factors and degree of influence varied in different quantiles.Annual household income was significant in 10 of 11 quantiles with the maximum marginal effect of 350 yuan.Whether the insured comes from a village in a city affects 8 of the 11 quantiles whereas gender,age and health conditions of minors have minor effect on willingness to pay.Conclusion The premium standard should be raised from 40 yuan per person per year to 100 yuan.Minors can be categorized into subgroups and be set with distinct premiums in terms of the significant influencing factors and its influence degree.

Iniquidades socioeconômicas na conformação dos padrões alimentares de crianças e adolescentes / Socioeconomic inequality shaping the dietary patterns of children and teens

OBJETIVO: Identificar e quantificar a influência dos fatores socioeconômicos sobre os padrões alimentares. MÉTODOS: Estudo transversal de base populacional com amostra de 1.136 crianças e adolescentes de 7 a 14 anos de idade, de ambos os sexos, matriculados na rede pública de Salvador (BA), Brasil. O consumo alimentar foi medido por meio do questionário qualitativo de frequência alimentar. Os padrões de consumo foram identificados por meio de análise de componentes principais. Para o estudo da influência dos indicadores socioeconômicos na conformação dos padrões alimentares, foram utilizados modelos de regressão quantílica. RESULTADOS: Os padrões alimentares extraídos foram classificados em padrão obesogênico e padrão tradicional. Nos modelos de regressão quantílica, ajustados por faixa etária e por sexo, o menor grau de instrução materna esteve associado negativamente, em níveis significantes, na maioria dos percentis, ao consumo de alimentos que integram o padrão obesogênico. A baixa renda associou-se negativamente aos maiores percentis (p>95). Os dados indicam não haver influência dos indicadores socioeconômicos sobre o consumo de alimentos que integram o padrão tradicional. CONCLUSÃO: Conclui-se que há influência dos fatores socioeconômicos na adesão ao padrão obesogênico de consumo. Esse conjunto de resultados requer a atenção dos gestores públicos para a identificação de um padrão de consumo ocidental, visualizado amplamente nos estudos em que se avaliam padrões de consumo adotados na atualidade pela população brasileira - sobretudo por crianças e adolescentes -, caracterizados por englobar componentes alimentares de risco para as doenças crônicas não transmissíveis.

OBJECTIVE: The present study identified and quantified the influence of socioeconomic factors on dietary patterns. METHODS: This cross-sectional, population-based study investigated the food habits of 1136 children and adolescents of both genders, aged 7 to 14 years, enrolled in public schools of Salvador (BA), Brazil, using the qualitative food frequency questionnaire. Intake patterns were identified by principal component analysis. Quantile regression models were used to study the influence of socioeconomic indicators on dietary patterns. RESULTS: The sample’s eating patterns were classified into obesogenic or traditional. Quantile regression models adjusted for age and gender showed that, for most percentiles, low maternal education level was significantly negatively associated with consumption of foods included in the obesogenic pattern. Low income was negatively associated with the highest percentiles (p>95). The data showed that socioeconomic indicators do not influence the consumption of foods included in the traditional pattern. CONCLUSION: Socioeconomic factors promote adherence to obesogenic eating patterns. These results indicate that public authorities need to identify the Western consumption pattern, commonly observed in studies that assess the current consumption patterns of the Brazilian population, especially of children and adolescents, characterized by foods that promote non-communicable chronic diseases.

Relationships between smoking behavior and obesity in men from 9 rural districts of Hanzhong in Shaanxi province / 中华流行病学杂志

Objectivc To examine the relationship between cigarette smoking and body mass index(BMI) as well as waist circumfcrcnce (WC) of men from 9 rural districts ofHanzhong,Shaanxi province.Methods Cross-sectional data was analyzed from Hanzhong Health Survey on rural residents in 2010.Quantile regression mode was used to compare the results using the BMI (WC) and smoking slatus (degree) as the dependent variables and independent variable and confounding factors were also controlled.Results 1039 rmale residents of rural areas of Hanzhong city were investigated.The prevalence rates on overweight and obesity among the males were 28.0％ and 5.9％,with central obesity as 35.0％ and the rate of currcnt cigarette smoking was 63.6％ in the areas.Results from the quantile regression showed that the relationship between smoking status and BMI beyond 80 percentile in men (BMI=24.4) which was not significantly different BMI among the heavy smokers,was much higher than those mild smokers beyond 90 percentile (BMI=24.9).WC of the current smokers was significantly higher than those ex-smokers beyond the 95 percentile (WC=96.7 cm).WCs of the moderate and heavy smokers had an increase along with the increase of WCs beyond the 85 percentiles (WC=89.9 cm).Conclusion The effect of smoking status and BMI (WC) were inconsistent,however,with BMI and WC increased among the subjects whose BMI or WC were at the high extreme end of the distribution.Thus,we should advise the obese subjects to quit smoking.