An ensemble-based likelihood ratio approach for family-based genomic risk prediction / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

OBJECTIVE@#As one of the most popular designs used in genetic research, family-based design has been well recognized for its advantages, such as robustness against population stratification and admixture. With vast amounts of genetic data collected from family-based studies, there is a great interest in studying the role of genetic markers from the aspect of risk prediction. This study aims to develop a new statistical approach for family-based risk prediction analysis with an improved prediction accuracy compared with existing methods based on family history.@*METHODS@#In this study, we propose an ensemble-based likelihood ratio (ELR) approach, Fam-ELR, for family-based genomic risk prediction. Fam-ELR incorporates a clustered receiver operating characteristic (ROC) curve method to consider correlations among family samples, and uses a computationally efficient tree-assembling procedure for variable selection and model building.@*RESULTS@#Through simulations, Fam-ELR shows its robustness in various underlying disease models and pedigree structures, and attains better performance than two existing family-based risk prediction methods. In a real-data application to a family-based genome-wide dataset of conduct disorder, Fam-ELR demonstrates its ability to integrate potential risk predictors and interactions into the model for improved accuracy, especially on a genome-wide level.@*CONCLUSIONS@#By comparing existing approaches, such as genetic risk-score approach, Fam-ELR has the capacity of incorporating genetic variants with small or moderate marginal effects and their interactions into an improved risk prediction model. Therefore, it is a robust and useful approach for high-dimensional family-based risk prediction, especially on complex disease with unknown or less known disease etiology.

The adolescent physical exercise behavior-psychological measurement scale on the Chinese version and its reliability and validity study / 中华流行病学杂志

<p><b>OBJECTIVE</b>To develop a suitable physical exercise behavior-psychological scale for the Chinese adolescents and to evaluate its validity and reliability.</p><p><b>METHODS</b>A total of 3600 junior students were recruited and tested through multistage sampling method. Reliability was assessed, using Cronbach's α and split-half reliability; while exploratory factor analysis and confirmatory factor analysis were used to test its validity, with entries-dimension correlation coefficient (IIC), correlation coefficient between the scores and the dimension, the dimension of correlation coefficient test content validity.</p><p><b>RESULTS</b>The internal consistency reliabilities for total scale score (Cronbach's α = 0.888), Cronbach's α of four domains were 0.880, 0.706, 0.552 and 0.839, respectively. The four-domain split-efficacy reliabilities were ranged between 0.559 and 0.876. Data from the exploratory factor analysis revealed the following dimensions: the entries were all inclusive; the cumulative contribution rate was more than 40%.</p><p><b>RESULTS</b>from the confirmatory factor analysis showed that the absolute fit measures of GFI = 0.972, AGFI = 0.958, RMSEA = 0.032 (90%CI: 0.030 - 0.034) could satisfy the condition while the model fit was better. The results of IIC showed: in the four dimensions, and the contained entries between Spearman correlation coefficient range were 0.396 - 0.700, 0.470 - 0.709, 0.696 - 0.771 and 0.665 - 0.813, while other dimensions from weak to moderate relationships, the r value range was from 0.386 to 0.935. With the change of the phase changing process, decision balance, self-efficacy scores were differently prompting the health-related intervention periodically and pertinently.</p><p><b>CONCLUSION</b>The reliability and validity of the 'Adolescent physical exercise behavior-psychological scales (Chinese version) ' were good, and could be used to measure the adolescent's physical training behavior-psychological conditions.</p>

Evaluation on the effects of an education program regarding the sedentary behavior among school-aged children using Transtheoretical Model / 中华流行病学杂志

Objective To evaluate the outcome of a health education program on sedentary behavior among primary and secondary school children through Transtheoretical Model. Methods Five primary schools and four middle schools were selected and students from grade 3 to 5 in primary schools and grade 1 to 2 in middle schools were selected to take part in the program, as control and intervention groups respectively. Corresponding intervention measures were provided to the intervention group, with phase, process and level of changing on sedentary behavior measured for both groups during the follow-up period. Comparison to the above items on the two groups was measured statistically. Results Behavior among the intervention group was gradually changed regarding: phase contemplation, preparation and maintenance, with the proportions in phase action and maintenance higher than the control group. After carrying out of intervention programs, the sedentary time on weekdays between the two groups did not show significant differences. However, the sedentary time on weekends of intervention group was (2.53 ± 1.62) hours, significantly lower than the hours from the baseline survey (2.84 ± 1.82) and the control group (2.78 ± 1.72) respectively.During the follow-up period, the average score of intervention group in the changing process was (2.98 ± 0.77), higher than the control group (2.80 ± 0.81 ). At the same time, the average score of intervention group in the process of changing, decisional balance (pros) and self-efficacy were 2.98 ±0.77, 3.06 ± 0.75 and 3.13 ± 0.72, respectively, all higher than data from the baseline survey. In the control group, the process of changing and the average score on self-efficacy had improved.Conclusion The corresponding intervention program seemed to have played a significant role among the school-aged children on their sedentary behavior during the weekend but no significant difference was found in the weekdays.

Research on the behavior of fruit and vegetable intake in adolescents with Transtheoretical Model / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study the current situation and factors influencing the behavior of fruit and vegetable intake in adolescents, and to discuss health education strategy related to the behavior.</p><p><b>METHODS</b>1677 students were selected from primary school and middle school in urban area of Hangzhou by a multistage sampling method. The behavior of fruit and vegetable intake was surveyed by questionnaires of the patient-centered assessment and counseling for exercise plus nutrition project (PACE+) for adolescent-scale of fruit and vegetable consumption, and analyzed by Transtheoretical Model on the servings of intake, the stage of change, process of change, decisional balance and the current status of self-efficacy.</p><p><b>RESULTS</b>The average intake of fruit and vegetable in adolescents was (3.21 +/- 1.50) servings per day ("one serving" means 100 g cooked vegetable or 100 g fruit). The behavior of consuming fruit and vegetable in most of the adolescents was in the contemplation stage, accounting for 36.91% (619/1677). The process of behavior change, decisional balance (Pros) and self-efficacy existed a positive correlation with the process of stage (r(process) = 0.38, r(decisional balance (Pros)) = 0.26, r(self-efficacy) = 0.33, t values were 16.78, 11.02 and 14.31, P < 0.05). The servings of fruit and vegetable intake existed a positive correlation with stage transition and self-efficacy (beta(stage transition) = 0.665, t = 35.07, P < 0.05; beta(self-efficacy) = 0.050, t = 2.63, P < 0.05), and existed a negative correlation with decisional balance (Cons) (beta(decisional balance (Cons)) = -0.051, t = -2.84, P < 0.05).</p><p><b>CONCLUSION</b>Fruit and vegetable intake of these adolescents are under the recommended dietary intake. Along with behavior stage development and self-efficacy improvement, the intake of fruit and vegetable also increased correspondingly. Intervention strategies should aim at improving the awareness of adolescents on the health benefits of fruit and vegetable intake and promoting their confidence to reach the recommended servings.</p>

A cross-sectional study on the changes in dietary behavior stages in resident / 中华预防医学杂志

<p><b>OBJECTIVE</b>To explore the possibility of applying the concept of various stages of dietary behavior changes in Hangzhou residents.</p><p><b>METHODS</b>The dietary behavior was surveyed and analyzed in 1 388 Hangzhou residents with 18 year-old and older using the various dietary behavior change model model and stages of change.</p><p><b>RESULTS</b>The proportion of Hangzhou residents with unhealthy dietary behavior was high and associated with gender and education level. The changes of dietary behavior could be divided into 5 stages, i.e. preintention, intention, preparation, action and maintenance. These stages of change happen consecutively. The changes of unhealthy dietary behavior do not match the improvement of health knowledge. Although a significant proportion of the residents understand that it is unhealthy to eat too much fat, pickles and high salt food, there are only a few of them really take action to reduce the consumption of these foods and to consume more milk, fruit and vegetable.</p><p><b>CONCLUSIONS</b>There are multiple factors that affect the changes of dietary behavior in people. The changes of dietary behavior occur in various consecutive stages. Different intervention measures should be applied to people in different dietary behavior changes.</p>