Investigation on public satisfaction with the enforcement of tobacco control regulations based on questionnaire survey —— a case study of Tianjin / 公共卫生与预防医学

Objective To analyze the residents' satisfaction with the enforcement of The Regulations of Tianjin Municipality on Smoking Control in Public Places (hereinafter referred to as The Regulations) and its influencing factors. Methods From November to December 2020, 16 districts of Tianjin were selected as the research site, and one street was randomly selected from each district. The accidental sampling was used to conduct a questionnaire survey on 4,160 permanent residents in Tianjin. χ2 test was used in univariate analysis and multivariate logistic regression model was used to analyze and adjust the confounding factors. The public satisfaction and its influencing factors were analyzed. Results A total of 4 022 questionnaires were collected and 2 730 were included in the study. In 2020, 89.3 percent of Tianjin residents were satisfied with the enforcement of the Regulations. Compared with residents aged 15-24, residents in other age groups were less satisfied with the enforcement of the Regulations. Compared with residents with primary school education or below, residents with high school education or bachelor's degree or the same educational level were less satisfied with the enforcement of the Regulations. Residents with chronic diseases (OR=1.885 , P<0.01) and exposure to second-hand smoke in the last 30 days (OR=1.903, P<0.01) were less satisfied with the enforcement of the Regulations, while those who supported the Regulations (OR=0.511, P<0.01) and residents who had been exposed to public service advertisements on tobacco control in the last 30 days (OR=0.043, P<0.01) were more satisfied with the enforcement of the Regulations. Conclusion The residents of Tianjin are highly satisfied with the enforcement of the Regulations. Age, education background, support for the Regulations, chronic disease, exposure to secondhand smoke in the last 30 days and exposure to public service advertisements in the last 30 days are the main influencing factors of satisfaction with the enforcement of tobacco control regulations.

Application of directed acyclic graphs in identification and control of selection bias in causal inference / 中华疾病控制杂志

In the etiology study of epidemiology, selection bias will lead to the fact that the research sample cannot represent the general population, the association between exposure and outcome among those selected for analysis differs from the association among those eligible, and the true causal association cannot be inferred. Directed acyclic graphs (DAGs) could visualize complex causality, introduce the Collider-stratification bias using simple graphics language, provide a simple and intuitive way to identify Selection bias, different types of selection bias are verified by the graphic structure of the Collider-stratification bias. In practical studies, there may be multiple biases at the same time, improper adjustment of the collider will lead to Collider-stratification bias, open a backdoor path, even change the size and direction of the confounding bias. In order to obtain an unbiased estimate of the exposure to the outcome, it is necessary to identify the collider and avoid the adjustment to prevent the occurrence of Collider-stratification bias by using DAGs.