A Study of Pulsed Electro-Magnetic Field Therapy for Rheumatoid Arthritis Pateints: Analysis of Adjustment Period Data

In a study with a therapeutic treatment, the patients may need to be prepared for the application of therapy when the earlier medications, if any, are withdrawn. This withdrawal period, known as adjustment period, may induce some worsening of condition in the patients. This paper investigates the risk of such worsening before the therapy is applied. We consider a number of possible models for this purpose and consider maximum likelihood estimation of the related parameters. Different concepts of risk, depending on the patients' concern, are introduced and thereby estimated using the parameter estimates. We finally analyse a data set on Rheumatoid Arthritis patients with Pulsed Electro-magnetic Therapy.