Polymyositis--a further investigation.

In essence, this paper describes the model-based interpretation of measurements in order to gain insight into physiological processes. The paper extends the mathematical model developed previously to control and monitor a polymyositis patient. The extension considers two further yet different types of muscle attack. The model is applied to simulate, first, the total serum creatine kinase levels, which then are matched to the observed values. The outcomes of this approach yield considerable information about the reactions taking place including various concentration levels over time such as prednisolone. The changes in the muscle attack are estimated. Examples illustrate how the model may be used to assess, for a single patient, the maximum reduction of the muscle attack whilst keeping the prednisolone concentration as low as possible. The model has been successfully used to interpret variations in daily heart rate measurements of a polymyositis patient. Consequently, it is shown how daily heart rate measurements may now be used to complement the control and monitoring of the polymyositis patient. The model is used to explore multi-patient statistics. It shows the dangers of using such an approach. The model illustrates the need for longitudinal studies.