Читать книгу The Pocket Guide to Critical Appraisal - Iain K. Crombie - Страница 27

An increasingly common research design is a special type of cohort study that evaluates the effectiveness of treatments. It compares the outcomes among a group of patients given one treatment with outcomes in other patients who have the same disease but were given a different treatment. The difference from a conventional RCT is that patients are not randomised to treatments. Instead the clinician responsible for the patient decides which treatment should be given. This type of study evaluates treatments as they are used in routine clinical practice. A common form of this design uses electronic health records to identify patients with a defined disease and the treatments that they were given. The effects of the treatments on the outcome measures are also obtained from electronic data. When the two groups are recruited and followed up in the same time period, this design is called a concurrent cohort study. In a different form of this design, recently diagnosed patients are given the new treatment and are compared with patients from the past who were given a different treatment. These studies are called historical cohort studies.