Prognosis of the individual course of disease--steps in developing a decision support tool for Multiple Sclerosis

Abstract

Background: Multiple sclerosis is a chronic disease of uncertain aetiology. Variations in its disease course make it difficult to impossible to accurately determine the prognosis of individual patients. The Sylvia Lawry Centre for Multiple Sclerosis Research (SLCMSR) developed an "online analytical processing (OLAP)" tool that takes advantage of extant clinical trials data and allows one to model the near term future course of this chronic disease for an individual patient.

Results: For a given patient the most similar patients of the SLCMSR database are intelligently selected by a model-based matching algorithm integrated into an OLAP-tool to enable real time, web-based statistical analyses. The underlying database (last update April 2005) contains 1,059 patients derived from 30 placebo arms of controlled clinical trials. Demographic information on the entire database and the portion selected for comparison are displayed. The result of the statistical comparison is provided as a display of the course of Expanded Disability Status Scale (EDSS) for individuals in the database with regions of probable progression over time, along with their mean relapse rate. Kaplan-Meier curves for time to sustained progression in the EDSS and time to requirement of constant assistance to walk (EDSS 6) are also displayed. The software-application OLAP anticipates the input MS patient's course on the basis of baseline values and the known course of disease for similar patients who have been followed in clinical trials.

Conclusion: This simulation could be useful for physicians, researchers and other professionals who counsel patients on therapeutic options. The application can be modified for studying the natural history of other chronic diseases, if and when similar datasets on which the OLAP operates exist.

Figure 1

Screenshot from the OLAP-tool "Individual Risk Profile" displaying the demographics of the selected subgroup (blue). The green dot indicates the requested patient characteristics (RR disease course, baseline EDSS 2, age at onset 30 years, disease duration 36 months and 2 relapses in the last 12 months). In addition the distributions of all patients from the clinical trial data having the same course of the disease are displayed to give the user the impression on how representative the selected subgroup for the selected course is (gray).

Figure 2

Screenshot from the OLAP-tool "Individual Risk Profile" displaying EDSS courses and regions of EDSS evolution. The interior band defines the middle 50% of EDSS courses. The other bands outline (from the inside to the outside) 75%, 90% and 95% of the individual disease courses. Additional information about the disease course is provided by the annual relapse rates. These are displayed as box plots and illustrate the disease activity.

Figure 3

Screenshot from the OLAP-tool "Individual Risk Profile" displaying the Kaplan-Meier curves for the time to sustained progression (6 months confirmation period) and time to EDSS 6. For illustration purposes Kaplan-Meier curves are displayed for a SPMS population. In the background the curves for the population as defined in Figure 1 are displayed.