caa a22 4500 386396914 CHVBK 20180307112141.0 cr unu---uuuuu 161130s1989 xx s 000 0 eng 10.1017/S0021932000025281 doi S0021932000025281 pii (NATIONALLICENCE)cambridge-10.1017/S0021932000025281 Community-based intervention trials [Elektronische Daten] The randomized controlled trial has become the standard basis for the evaluation of new therapeutic agents and procedures (and for measuring the protective efficacy of new vaccines or for assessing the value of screening procedures). Patients, who have met the criteria for eligibility and have agreed to participate in the trial, are allocated on a random basis to the alternative therapies under consideration. In order to avoid possible bias in the handling or assessment of these groups, a double blind procedure is preferred; the therapy given is not known to those who administer it, to those who assess the course of the disease thereafter, nor to the patients themselves. There is an extensive literature on clinical trials covering their logic and history, modern developments and the many complex, often controversial, issues that such trials have provoked. Not all issues have been fully resolved but by and large the principle, the practice and the ethical concerns of clinical trials are worked out and firmly established. Copyright © Cambridge University Press 1989 Kirkwood Betty R. Department of Epidemiology and Population Sciences, London School of Hygiene and Tropical Medicine, WHO, Geneva Morrow Richard H. Special Programme for Research and Training in Tropical Diseases, WHO, Geneva Journal of Biosocial Science Cambridge University Press 21/S10(1989), 79-86 0021-9320 21:S10<79 1989 21 JBS https://doi.org/10.1017/S0021932000025281 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1017/S0021932000025281 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Kirkwood Betty R. Department of Epidemiology and Population Sciences, London School of Hygiene and Tropical Medicine, WHO, Geneva NATIONALLICENCE 700 1- Morrow Richard H. Special Programme for Research and Training in Tropical Diseases, WHO, Geneva NATIONALLICENCE 773 0- Journal of Biosocial Science Cambridge University Press 21/S10(1989), 79-86 0021-9320 21:S10<79 1989 21 JBS CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge