Diomidus Marianna
University of Athens, Faculty of Nursing, Lab. of Health Informatics, Goudi, Greece.
Stud Health Technol Inform. 2002;65:126-35.
This chapter illustrates the study designs most frequently encountered in the medical literature. In medical research, either subjects are observed or experiments are undertaken. Experiments involving humans are called trials. Experimental studies may also use animals and tissue, although we did not discuss them as a separate category; the comments pertaining to clinical trials are relevant to animal and tissue studies as well. Each type of study discussed has advantages and disadvantages. Randomized, controlled clinical trials are the most powerful designs possible in medical research, but they are often expensive and time-consuming. Well-designed observational studies can provide useful insights on disease causation, even though they do not constitute proof of causes. Cohort studies are best for studying the natural progression of disease or risk factors for disease; case-control studies are much quicker and less expensive. Cross-sectional studies provide a snapshot of a disease or condition at one time, and we must be cautious in inferring disease progression from them. Surveys, if properly done. are useful in obtaining current opinions and practices. Case-series studies should be used only to raise questions for further research.
本章阐述了医学文献中最常遇到的研究设计。在医学研究中，要么对受试者进行观察，要么开展实验。涉及人类的实验称为试验。实验研究也可能使用动物和组织，尽管我们没有将它们作为一个单独的类别进行讨论；与临床试验相关的评论同样适用于动物和组织研究。所讨论的每种研究类型都有其优缺点。随机对照临床试验是医学研究中最有效的设计，但它们通常成本高昂且耗时。设计良好的观察性研究可以提供有关疾病病因的有用见解，尽管它们并不构成病因的证据。队列研究最适合研究疾病的自然进展或疾病的风险因素；病例对照研究速度更快且成本更低。横断面研究在某一时刻提供疾病或状况的快照，我们在从这些研究推断疾病进展时必须谨慎。如果调查做得恰当，有助于获取当前的观点和做法。病例系列研究仅应用于提出进一步研究的问题。
