Читать книгу Randomised Clinical Trials - David Machin - Страница 35

A case series consists of a study in which the experience of an investigator treating a series of patients with a particular approach reports on their outcome. This may be the only ‘design’ option available in rare or unusual circumstances but is unlikely to provide clear evidence of efficacy. There are many criticisms of this design. Generally one may not know how the patients have been selected; the clinical team may have an eye for selecting those patients to be given the treatment who are likely to recover in any event: without further evidence of the natural history of the disease, we do not know whether the patients may have recovered spontaneously, without intervention: we do not know whether their approach to treatment is better than any alternatives.