Risk perception in natalizumab-treated multiple sclerosis patients and their neurologists

Abstract

Background:<br />Natalizumab is associated with the potentially life-threatening side-effect progressive multifocal leukoence- phalopathy (PML). Little is known about patients' and physicians' risk estimates and attitudes towards natalizumab treatment.<br /><br />Methods:<br />Consecutive natalizumab-treated patients (n = 69) and neurologists (n = 66) in two centres and cooperating private practices received an evidence-based three-page information leaflet about natalizumab-associated PML and an evaluation sheet.<br /><br /><br />Results:<br />After reading the information, patients were significantly more likely than physicians to intend continuation of natalizumab treatment and willing to accept higher risks of PML: 49% of physicians would stop treatment at a PML risk of 2 : 10,000 or lower, while only 17% of patients would do so (p < 0.001). This difference could not be explained by risk calculation abilities or lack of understanding. Both groups overestimated natalizumab treatment effects.<br /><br /><br />Conclusion:<br />Patients had a significantly worse perception of multiple sclerosis as a malignant disease. We conclude that patients were willing to accept a higher risk of PML than neurologists. Coherent with their perception of risks and benefits, patients were also more willing to continue treatment. Open information about treatment-related risks is appreciated and might support shared decision making.