Clinical trials randomised allocation

A controlled clinical trial is an experiment and, as just mentioned, it deliberately alters the fabric of routine management of study subjects. It does so in two ways. First, it directs which treatment modality will be given to a particular subject, usually by randomised allocation without the doctor or subject knowing which treatment they will receive out of the two or three chosen for the trial. Therefore, a subject may not receive the conventional treatment that the clinician might otherwise have chosen. Second, the selection and... 

Thus, the description of a study as being a prospective, randomised double-blind clinical trial implies that both allocation and assessment bias have been eliminated in the design of the trial. 

Snowdon C, Garcia J, Elbourne D (1997). Making sense of randomisation response of parents of critically ill babies to random allocation of treatment in a clinical trial. Soc Sci Med 45 1337-1355. 

Clinical trial A formal study of a treatment conducted in patients with a specific disease indication. Such studies usually involve comparison with placebo or an alternative treatment and a randomisation process is used to determine the allocation of treatments. Ideally, they also involve blinding of patients and clinicians (i.e. they are double-blind ) to treatment allocations. Conducting a clinical trial involves intervening in patients treatments for research purposes and therefore informed consent from each patient and ethical committee approval are essential (see p. 31). 

Finally, an investigation of the effectiveness of ulfrasound-guided corticosteroid injection for the treatment of plantar facilities was conducted by a randomised investigator- and participant-blinded, placebo-controlled trial 82 people with a clinical and ultrasoxmd diagnosis of planfar fasciitis unrelated to systemic inflammatory disease were examined. The participants were randomly allocated to ultrasound-guided injection of the plantar fascia with either 1 ml of 4 mg/ml dexamefhasone sodium phosphate (experimental group) or 1 ml normal saline (placebo) [70 -]. 

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