Chan D H, Donnan S P, Chan N F, Chan C, Lui G
Department of Community Medicine, Chinese University of Hong Kong.
Fam Pract. 1989 Jun;6(2):125-9. doi: 10.1093/fampra/6.2.125.
A low cost microcomputer-based medical record system was used to facilitate opportunistic research projects in the teaching clinic of the Chinese University of Hong Kong. An example of an actual clinical trial comparing the effectiveness of three methods of teaching breast self-examination to clinic patients was used and the process of setting up the research protocol, the sampling of patients, and the analysis of early results after one and a half years were described. It was found that the sampling bias in opportunistic research was that subjects selected were more likely to be older with more problems, and have a higher attendance rate at the clinic. The bias could be corrected during the analysis of data by stratifying the selected sample into groups of different attendance rates. Another potential sampling bias was due to non-compliance of both the patients and the clinical staff. However, it was found to be possible to obtain useful results from opportunistic research. It was easy to implement this type of research with the help of a computerized medical record system.
香港中文大学教学诊所采用了一种低成本的微机化病历系统，以推动机会性研究项目。文中以一项实际临床试验为例，该试验比较了向诊所患者教授三种乳房自我检查方法的有效性，并描述了制定研究方案、患者抽样以及一年半后早期结果分析的过程。研究发现，机会性研究中的抽样偏差在于所选受试者更可能年龄较大、问题较多，且在诊所的就诊率较高。在数据分析过程中，可以通过将所选样本按不同就诊率分层来纠正这种偏差。另一个潜在的抽样偏差是患者和临床工作人员的不依从性。然而，研究发现从机会性研究中获得有用结果是可能的。借助计算机化病历系统，实施这类研究很容易。
