An easily customized, random allocation system using the minimization method for multi-Institutional clinical trials

In a randomized clinical trial, random allocation of patients to treatment groups should be done to balance in the distribution of prognostic factors. Random allocation in a multi-institutional randomized clinical trial is co nducted by a coordinating center, independent of the medical institution th e attending doctor uses for his/her practice. This study provides a sophist icated system for doing an exact random allocation of patients to treatment groups. The minimization method proposed by Pocock was applied to this sys tem to balance the distribution of prognostic factors between two treatment groups, even when the number of registered patients is relatively small (S .J. Pocock, Allocation of patients to treatment in clinical trial, Biometri cs 35 (1979) 183-197). Furthermore, Zelen's method is used to balance the n umber of patients allocated to the two groups within each institution (M. Z elen, The randomization and stratification of patients to clinical trials, J. Chron. Dis. 27 (1974) 365-375.). This system was created by the 'PERL' l anguage for writing common gateway interface (CGI) script, and can therefor e, be easily extended to include data entry function by attending doctors a s well as the random allocation function. This system is being used effecti vely in thirteen multi-institutional randomized clinical trials for stomach , colon-rectum and breast cancers in Japan. (C) 2000 Elsevier Science Irela nd Ltd. All rights reserved.