title: [Problems and pitfalls in controlled clinical studies (author's transl)].
abstract: The problems encountered in prospective clinical trials are discussed: knowledge of the literature, precise formulation of the question answering the problem, number and qualifications of patients, duration of the trial, parameters to be measured. A surgical trial can hamper the education of the residents, or it can be devaluated by incompetent surgeons. Patients do not come for follow-up for several reasons (change of domicile, absence of disturbances, disagreeable tests).
mesh_terms: D005069:Evaluation Studies as Topic; D005500:Follow-Up Studies; D006040:Goals; D006801:Humans; D010349:Patient Compliance; D011446:Prospective Studies; D011897:Random Allocation; D012107:Research Design; D013514:Surgical Procedures, Operative
vernacular_title: Probleme und Risiken kontrollierter klinischer Studien.