David M Eddy1, Leonard Schlessinger. 1. Care Management Institute, Kaiser Permanente and Kaiser Permanente Southern California, Oakland, California, USA. eddyaspen@yahoo.com
Abstract
OBJECTIVE: To validate the Archimedes model of diabetes and its complications for a variety of populations, organ systems, treatments, and outcomes. RESEARCH DESIGN AND METHODS: We simulated a variety of randomized controlled trials by repeating in the model the steps taken for the real trials and comparing the results calculated by the model with the results of the trial. Eighteen trials were chosen by an independent advisory committee. Half the trials had been used to help build the model ("internal" or "dependent" validations); the other half had not. Those trials comprise "external" or "independent" validations. RESULTS: A total of 74 validation exercises were conducted involving different treatments and outcomes in the 18 trials. For 71 of the 74 exercises there were no statistically significant differences between the results calculated by the model and the results observed in the trial. Considering only the trials that were never used to help build the model-the independent or external validations-the correlation was r = 0.99. Including all of the exercises, the correlation between the outcomes calculated by the model and the outcomes seen in the trials was r = 0.99. When the absolute differences in outcomes between the control and treatment groups were compared, the correlation coefficient was r = 0.97. CONCLUSIONS: The Archimedes diabetes model is a realistic representation of the anatomy, pathophysiology, treatments, and outcomes pertinent to diabetes and its complications for applications that involve the populations, treatments, outcomes, and health care settings spanned by the trials.
OBJECTIVE: To validate the Archimedes model of diabetes and its complications for a variety of populations, organ systems, treatments, and outcomes. RESEARCH DESIGN AND METHODS: We simulated a variety of randomized controlled trials by repeating in the model the steps taken for the real trials and comparing the results calculated by the model with the results of the trial. Eighteen trials were chosen by an independent advisory committee. Half the trials had been used to help build the model ("internal" or "dependent" validations); the other half had not. Those trials comprise "external" or "independent" validations. RESULTS: A total of 74 validation exercises were conducted involving different treatments and outcomes in the 18 trials. For 71 of the 74 exercises there were no statistically significant differences between the results calculated by the model and the results observed in the trial. Considering only the trials that were never used to help build the model-the independent or external validations-the correlation was r = 0.99. Including all of the exercises, the correlation between the outcomes calculated by the model and the outcomes seen in the trials was r = 0.99. When the absolute differences in outcomes between the control and treatment groups were compared, the correlation coefficient was r = 0.97. CONCLUSIONS: The Archimedes diabetes model is a realistic representation of the anatomy, pathophysiology, treatments, and outcomes pertinent to diabetes and its complications for applications that involve the populations, treatments, outcomes, and health care settings spanned by the trials.