Automatic search for optimal conditions in clinical studies

Background: A program for an automatic search for the optimal conditions of important prognostic factors in clinical studies was developed Methods: Th e program was developed for the following steps: (1) Input of the maximum a nd minimum values and of the interval of the variable to be investigated Au tomatic calculation of the Cut Points (2) Division of the patient data into two groups at every Cut Point and calculation of survival rates. (3) Seque ntial calculation of P-values and chi-square values for the two sets of sur vival rates. To determine the usefulness of this program, the optimal irrad iation dose was searched for 537 patients with non-small cell lung cancer: Results: The P-value reached its minimum value and the chi-square value its maximum when the Cut Point was 5,925cGy (0.0001 and 30.18). Between 5,925c Gy and 6,900cCy, the P-value stayed at less than 0.05. Conclusion: Artifici al errors in grouping by prognostic factors can be avoided and the search f or optimal conditions can be conducted automatically and scientifically.