社区医务人员干预成人超重和肥胖的行为机制：基于计划行为理论的实证研究

Overweight and obesity are major health problems for all age groups in the world. Community health professionals are well placed and expected to play a key role in prevention and treatment of overweight or obese people. Although most health professionals hold favorable attitudes concerning their role in preventing and treating overweight and obesity, many have expressed a lack of confidence in their ability to help people to lose weight or maintain healthy weight, and their actual weight management practice falls below current recommendations. Given a rapidly increasing prevalence of overweight and obesity in China, especially in large cities, it is important to understand health professionals' behaviors and behavioral mechanism related to weight management. However, very limited studies focused on health professionals themselves and their works, and no study had explored the reasons for above undesirable practice and confidence reported by health professionals. Further, our recent studies on Chinese and British nurses revealed that, there was a big gap between nurses' weight management practices (WMP) and current goals launched by local health policies, and nurses' self efficacy was the best predictor of weight management practice but only accounted for 20.2% of the variance of WMP in the model constructed by the study. We therefore hypothesized that there existed other more important variables or mediators. On the other hand, the theory of planned behavior (TPB) was identified by previous studies, as the most appropriate social cognitive theory to understand and change doctors' and nurses' professional behaviors, which could be very possibly to help to better understand the reasons that health professionals do or do not adopt weight management practice. In the present study based on the TPB, we will employ longitudinal design and comprehensively use qualitative and quantitative methods to examine all potential factors influencing weight management practices committed by community health professionals in a stratified random sample, and establish a structural equation model to explain community health professionals' managing overweight and obese adults. In addition, by controlling key variables related to WMP, we will further test these key variables correlated to health professionals' behaviors, and thus try to clarify the psychological mechanism about community health professionals' managing overweight and obese adults. The results of this study will generate new ideas about how to promote community health professionals' implementing weight management for overweight and obese people, and have a positive effect on prevention and treatment of overweight and obese adults in China.

超重和肥胖已成为我国一个严重的公共卫生问题。社区医务人员是实施体重管理的主体，他们干预超重和肥胖的态度和力度，关乎防治工作的成效。然而，国内外研究对医务人员的关注甚少，更没有探查医务人员干预超重和肥胖"执行力度弱、自我效能低"的形成原因。计划行为理论（TPB）已被成功地应用于多个行为领域，显示了很好的解释力和预测力。我们由此思考，能否构建基于TPB的预测模型，用以揭示社区医务人员实施体重管理行为的关键因素及其作用机制、解释他们"执行力度弱、自我效能低"的内在原因，为社区慢病防治提供政策参考。为此，本课题拟采用纵向研究设计，从计划行为理论的视角，分析社区医务人员干预成人超重和肥胖的现状及其影响因素，构建实施体重管理行为的模型。并通过改变关键变量的强度，进一步验证和修正模型，阐明医务人员干预成人超重和肥胖的行为机制，进而提出推进社区体重管理的政策建议，为提高超重和肥胖的社区防治水平提供新思路。

超重和肥胖已成为我国一个严重的公共卫生问题。社区医务人员是实施体重管理的主体，他们干预超重和肥胖的力度关乎防治工作的成效。国内外研究对社区医务人员群体的关注甚少，尚不清楚医务人员体重干预“执行力度弱、自我效能低”的形成原因。本课题采用纵向研究设计，综合质性和量性研究方法，从计划行为理论（TPB）的视角，分析当前社区医务人员干预成人超重和肥胖的现状，探查影响医务人员实施体重管理的关键因素及其相互关系，进而阐明医务人员干预成人超重和肥胖的行为机制。主要研究结果如下：（1）社区医务人员认同体重管理的重要性和必要性，但实际干预水平很低。以测算体重指数（BMI）为例，仅有约1/5的社区医务人员会对半数以上的就诊患者测算BMI，而测算腰围的比例则更低；（2）影响医务人员实施体重干预的因素包括：人口统计学因素（性别、地域）、职业因素（专业、工作年限、相关知识和培训）、态度和信念因素（自我效能、职业角色认同、结果期望、社会支持、权力），以及患者因素（患者就医意愿）。其中，知识技能水平、过去的行为习惯和感知的社会支持是影响社区医务人员实施体重管理的关键因素；（3）围绕关键因素制定和实施干预方案后，社区医务人员自觉知识技能、社会支持和自我效能感增强，其干预超重和肥胖的行为水平较干预前有显著提高；（4）干预后，社区医务人员的知识技能和社会支持对其实施体重管理行为的直接效应增强，基于TPB和SCT嵌套模型的解释力度显著增加（干预前，R2=0.293；干预后，R2=0.531）。综上结果表明：（1）知识技能水平和感知的社会支持是影响社区医务人员实施体重管理的关键因素，且可直接影响其体重干预水平的高低；（2）基于TPB和SCT嵌套形式的建模，从个体、人际间和社会三个层面揭示了行为发生的相互作用关系，可以有效解释社区医务人员干预成人超重/肥胖行为的作用机制。本课题的实施丰富了TPB理论的应用研究，为提高社区医务人员干预超重和肥胖的行为水平提供了政策建议和干预新思路，对切实提高成人超重和肥胖的社区防治水平具有积极且现实的意义。