caa a22 4500 386356688 CHVBK 20180307111855.0 cr unu---uuuuu 161130e198907 xx s 000 0 eng 10.1017/S026646230000739X doi S026646230000739X pii (NATIONALLICENCE)cambridge-10.1017/S026646230000739X Randomized Clinical Trials in Surgery [Elektronische Daten] When it is well conducted, a randomized clinical provides the strongest evidence available for evaluating the comparative effectiveness of the interventions tested. Over the last two generations, we have learned much about various devices for strengthening them and about methods of avoiding between in their design, execution, analysis, and reporting. In a trial, we seek evidence for a causal link between treatment and observed outcomes. Becaues the controlled trial depends on an argument based on exculsion (i.e., no other causes or differences affected the experimental groups), we strengthen its inference by taking steps to exclude any such differences. This article discusses a number of issues that deserve consideration: problems of multiplicity and generalizability, devices for strengthening trials, issues of power and sample size, the relationship between study design and reported gains, when to undertake a trial, the role of collaborative trials, and ways to make trials more feasible in clinical settings. Copyright © Cambridge University Press 1989 McPeek Bucknam Harvard University and Massachusetts General Hospital Mosteller Frederick Harvard University McKneally Martin Albany Medical College International Journal of Technology Assessment in Health Care Cambridge University Press 5/3(1989-07), 317-332 0266-4623 5:3<317 1989 5 THC https://doi.org/10.1017/S026646230000739X text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1017/S026646230000739X text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- McPeek Bucknam Harvard University and Massachusetts General Hospital NATIONALLICENCE 700 1- Mosteller Frederick Harvard University NATIONALLICENCE 700 1- McKneally Martin Albany Medical College NATIONALLICENCE 773 0- International Journal of Technology Assessment in Health Care Cambridge University Press 5/3(1989-07), 317-332 0266-4623 5:3<317 1989 5 THC CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge