Showing papers by "Chun-Quan Ou published in 2009"

Health-promoting lifestyles of university students in Mainland China

Abstract: Health-promoting lifestyles of adolescents are closely related to their current and subsequent health status. However, few studies in mainland China have examined health-promoting behaviors among university students, notwithstanding the dramatic development of higher education over the past two decades. Moreover, no study has applied a standardized scale to such an investigation. The adolescent health promotion (AHP) scale has been developed and is commonly used for measuring adolescent health-promoting lifestyles in Taiwan. The aim of this study is to determine the appropriateness of the AHP for use in mainland China. A cross-sectional study was performed on a total of 420 undergraduates, who were randomly selected using a two-stage stratified sampling method in a university in Guangzhou city, mainland China. The simplified Chinese version of the AHP scale, comprising six dimensions (Nutrition behavior, Social support, Life-appreciation, Exercise behavior, Health-responsibility and Stress-management), was used to measure health-promoting lifestyles among undergraduates. The reliability of the AHP scale was assessed using split-half reliability coefficients, intraclass correlation coefficients and Cronbach's α coefficient. Validity was assessed by factor analysis and correlation analysis. Factors associated with health-promoting lifestyles were identified using multiple linear regression. Cronbach's coefficients were greater than 0.7 in all dimensions of the AHP scale except for Nutrition behavior (0.684). Intraclass correlation coefficients ranged from 0.689 to 0.921. Split-half reliability coefficients were higher than 0.7 in three AHP dimensions (Social support, Life-appreciation and Exercise behavior). Our results were generally in accordance with the theoretical construction of the AHP scale. The mean score for each of the six dimensions was lower than 70. Gender and grade were the factors primarily associated with health-promoting lifestyles among undergraduates. The AHP is a valid and reliable instrument for assessing health-promoting lifestyles of undergraduates in mainland China, which remain at a low level. Health behavior education taking account of gender and grade differences may also be applied.

The Study on Reasonability of Retrospective Power

Abstract: There is an increasingly concern with the use of retrospective power. Some researchers suggested calculating the retrospective power after conducting hypothesis testing, particularly in meta-analysis. They considered that retro-spective power can be used to determine whether the sample size is sufficient in an experiment and that the combination of retrospective power and prior power can enhance the power of current and future studies. Furthermore, the commonly used statistical software packages, such as SPSS and SAS, provide retrospective power analysis in some modules. However, some pointed out the abuse of retrospective power. In this study, we used Monte Carlo technique to estimate the retrospective power in t-test and ANOVA to address this issue. We found that four styles of retrospective powers, including observed power, plug-in power, unbiased power and median power, are highly positive correlated. They dispersed distribute in the range of (0.05, 1). The width of 25th-75th percentages achieved 0.38-0.54, the standard deviations 0.25-0.30 for 0.7 of the statistical power. However, they all monotonously decreased in respect to P value. The retrospective powers were negatively correlated with P values with Pearson coefficients ranged from -0.753 to -0.831 (p