Eccles M, Ford G A, Duggan S, Steen N
Centre for Health Services Research, University of Newcastle Upon Tyne.
Br J Gen Pract. 1999 Jan;49(438):35-8.
Postal questionnaire surveys are commonly used in general practice and often ask about self-reported activity. The validity of this approach is unknown.
To explore the criterion validity of questions asking about self-reported activity in a self-completion questionnaire.
A comparison was made between (a) the self-reported actions of all general practitioner (GP) principals in 51 general practices randomly selected within the nine family health services authorities of the former northern regional health authority, and (b) the contents of the medical records (case notes and computerized records) of patients classified as hypertensive from a 1 in 7 random sample of all patients registered in these practices and aged between 65 and 80. Data were gathered from the GPs by self-completion postal questionnaires. Six comparisons were made for two groups of items: first, target and achieved blood pressure; secondly, patient's weight, smoking status, alcohol consumption, exercise and salt intake. The frequency with which the data items were recorded in patient records was compared with the GPs' self-reported frequency of performing the actions.
No relationship was found between achieved blood pressure and stated target levels. For each of the other actions, more than half of the responders reported that they usually or always performed the activity. For four of these (smoking, weight, alcohol and exercise), a significant association was noted, but the size of this varied considerably.
There is a variable relationship between what responders report that they do in self-completion questionnaires, and what they actually do as judged by the contents of their patients' medical records. In the absence of prior, knowledge of the validity of questions on reported activity, or of concurrent attempts to establish their validity, the questions should not be asked.
邮政问卷调查在全科医疗中普遍使用，且常涉及自我报告的活动情况。这种方法的有效性尚不清楚。
探讨在自填式问卷中询问自我报告活动的问题的标准效度。
对以下两方面进行比较：（a）在前北方地区卫生局的九个家庭健康服务机构中随机抽取的51家全科医疗诊所中，所有全科医生（GP）负责人自我报告的行为；（b）从这些诊所登记的所有65至80岁患者的七分之一随机样本中归类为高血压患者的病历（病历记录和计算机化记录）内容。通过自填式邮政问卷从全科医生处收集数据。对两组项目进行了六项比较：第一，目标血压和实际达到的血压；第二，患者的体重、吸烟状况、饮酒量、运动和盐摄入量。将患者记录中数据项的记录频率与全科医生自我报告的执行这些行为的频率进行比较。
未发现实际达到的血压与设定的目标水平之间存在关联。对于其他各项行为，超过一半的受访者表示他们通常或总是进行该活动。对于其中四项（吸烟、体重、饮酒和运动），发现有显著关联，但关联程度差异很大。
受访者在自填式问卷中报告的行为与根据患者病历内容判断他们实际所做的事情之间存在可变关系。在缺乏关于报告活动问题有效性的先验知识或同时未尝试确定其有效性的情况下，不应提出这些问题。
