Ye Rong, Gao Yan-hui, Yang Yi, Chen Yue
Department of Epidemiology and Health Statistics, Guangdong Pharmaceutical University, Guangzhou 510310, China.
Zhonghua Liu Xing Bing Xue Za Zhi. 2010 May;31(5):576-8.
To estimate the prevalence ratios, using a log-binomial model with or without continuous covariates. Prevalence ratios for individuals' attitude towards smoking-ban legislation associated with smoking status, estimated by using a log-binomial model were compared with odds ratios estimated by logistic regression model. In the log-binomial modeling, maximum likelihood method was used when there were no continuous covariates and COPY approach was used if the model did not converge, for example due to the existence of continuous covariates. We examined the association between individuals' attitude towards smoking-ban legislation and smoking status in men and women. Prevalence ratio and odds ratio estimation provided similar results for the association in women since smoking was not common. In men however, the odds ratio estimates were markedly larger than the prevalence ratios due to a higher prevalence of outcome. The log-binomial model did not converge when age was included as a continuous covariate and COPY method was used to deal with the situation. All analysis was performed by SAS. Prevalence ratio seemed to better measure the association than odds ratio when prevalence is high. SAS programs were provided to calculate the prevalence ratios with or without continuous covariates in the log-binomial regression analysis.
为了估计患病率比，使用带有或不带有连续协变量的对数二项式模型。将使用对数二项式模型估计的与吸烟状况相关的个人对禁烟立法的态度的患病率比，与使用逻辑回归模型估计的优势比进行比较。在对数二项式建模中，当没有连续协变量时使用最大似然法，如果模型不收敛（例如由于存在连续协变量）则使用COPY方法。我们研究了男性和女性对禁烟立法的态度与吸烟状况之间的关联。由于吸烟不常见，患病率比和优势比估计为女性中的关联提供了相似的结果。然而，在男性中，由于结局的患病率较高，优势比估计值明显大于患病率比。当将年龄作为连续协变量纳入时，对数二项式模型不收敛，因此使用COPY方法来处理这种情况。所有分析均使用SAS进行。当患病率较高时，患病率比似乎比优势比更能衡量这种关联。提供了SAS程序以计算对数二项式回归分析中带有或不带有连续协变量的患病率比。
