caa a22 4500 477057527 CHVBK 20180405111350.0 cr unu---uuuuu 170330e19960401xx s 000 0 eng 10.1007/s002280050061 doi (NATIONALLICENCE)springer-10.1007/s002280050061 Cleophas T. J. M. Department of Medicine, Merwede Hospital Dordrecht, P. O. Box 97, NL-3360 AB, Sliedrecht, The Netherlands, NL aut Clinical trials: relevance of correlation between treatment responses [Elektronische Daten] [T. J. M. Cleophas] Abstract.: Objective: Trials that do not allow rejection of the null hypothesis of no treatment effect may have had an inappropriate design. Trials are virtually never assessed for correlation between responses to different treatment modalities. Methods: Using a hypothetical example and several published studies we examine the influence of correlation levels between treatment modalities on the sensitivity of testing. Results: The level of correlation between responses to different treatment modalities is a major determinant of the sensitivity both of crossover and parallel group clinical trials. Conclusions: It is very relevant to assess a priori correlation levels between responses to the different treatment modalities of a trial. If a negative correlation is anticipated, a crossover design is likely to lack sensitivity. If a positive correlation is anticipated a parallel-group design seems less appropriate, because it would lack the extra sensitivity of accounting for the positive correlation. Both designs would seem suitable for approximately zero correlations (e.g. comparison vs baseline or vs placebo under the assumption that the number of placebo responders is negligible). Springer-Verlag Berlin Heidelberg, 1996 Key words Clinical trials nationallicence controlled nationallicence treatment response nationallicence crossover studies nationallicence parallel-group studies nationallicence levels of correlation nationallicence t-statistic nationallicence sensitivity of testing nationallicence https://doi.org/10.1007/s002280050061 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s002280050061 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Cleophas T. J. M. Department of Medicine, Merwede Hospital Dordrecht, P. O. Box 97, NL-3360 AB, Sliedrecht, The Netherlands, NL aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer