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This model has been drawn upon the MSprogressionSimulation model and intends to provide a simplified view on what might happen to disease progression in terms of disability when some medication is introduced. The treatment impact on the patient is represented by means of Quality Adjusted Life Years (QALYs) gain that will be calculated for the time span in years specified by the user.
The second part of the model enables to monitoring the treatment in order to identify suboptimal responses and hence the need to change. Moreover, this is situated in terms of disease (disability) progression as defined by the disability curves and the Multiple Sclerosis Severity Score (MSSS).
Obviously, this is an experimental research model not yet to be used in the daily clinical practice.
The time from onset of the disease to assignment of the DSS scores of 4. 6 and 7 is calculated in terms of the BREMS score, which is derived from the patient characteristics introduced by the user. Then, the patient distribution per year in the different DSS scores (<4, 4, 6 and 7) is presented in two distinct graphical displays. QALYs are calculated in a yearly basis according to the current DSS distribution.
Treatment benefit assessment is based on the impact of relapse free and progression free at two years, as defined by the absolute risk reduction of the different disease-modifying agents, onto the time to assignment of the DSS scores of 4. 6 and 7.
The monitoring component of the system is based on published criteria for identifying patients with suboptimal response, and this component also provides a graphical presentation of the predicted disability progression, derived from the EDSS evolution entered by the user.
The first thing is to press the SETUP button. Then, after selecting the number of years for the prediction (maximum 30 years) and the patient characteristics, the button “go” must be pressed. At this point, the system graphically presents the patient distribution per year in the different DSS scores (<4, 4, 6 and 7). The distribution at the end (e.g. the number of years for the prediction) is presented in a different display by means of “persons” in a different color intensity of blue or pink (males and females, respectively). The BREMS score, the predicted QALYs and the probability of conversion to secondary progressive MS, are also numerically presented.
By selecting one of the disease-modifying agents and pressing the button “assess” the respective QALYs gain for the number of years defined by the user is presented.
Finally, for treatment monitoring the user must enter the respective data in ascending order. An error message will be presented if selected years are not in ascending order. For the yearly data to be processed the “new” button must be pressed after selecting all the data for the current year, including in the last entered year before pressing the “calculate” button. At least two consecutive years are required for treatment monitoring.
If any error occurs, re-start the system by pressing setup and then repeat the all process.
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Mário Veloso MD, Consultant Neurologist
marioveloso@centis.pt