RESUMO
BACKGROUND: Post-marketing studies, including registries, mark an indispensable step in the establishment of drug side-effect profiles. In recent years, the inclusion of the patients' perspective has gained increasing relevance regarding pharmacovigilance. OBJECTIVE: Primary objective of this study was to analyse the concordance of subjectively experienced symptoms by multiple sclerosis (MS) patients treated with immunotherapy and the adverse events reported by their treating physicians. METHODS: REGIMS, the data source of this study, is a prospective registry investigating the long-term drug safety in the treatment of MS in Germany. Patients included had to meet the revised McDonald criteria (2005) and be treated with immunotherapy. Concordance of adverse events documented six and 12 months after baseline presentation in 642 MS patients from 46 different neurologic outpatient centres all over Germany was analysed. Physicians' documentation was done either on paper or electronically during routine visits, while patients' self-reports were based on mailed questionnaires. Regression models were used to analyse factors influencing reporting. RESULTS: During one year of follow-up patients reported a total number of 4,841 events per 1,000 patient-years (PYs) while physicians reported 467 events/1,000 PYs. Patients' and physicians' reports focused on different body functions and categories, respectively. Factors increasing patients' likeliness to report were female gender (ß-coefficient: 1.52, 95% CI: 0.96-2.09), a history of smoking (ß: 0.80, 95% CI: 0.13-1.47), a higher EDSS score (ß: 0.28, 95% CI: 0.10-0.46) and previous MS therapies (ß: 0.35, 95% CI: 0.11-0.59) increased the patients' reporting of AEs. Physicians were more likely to report an AE for Fingolimod than for Interferon beta preparations (OR = 3.22, 95% CI: 1.22-8.52). DISCUSSION: Underreporting of adverse events has been a known problem in clinical routine for several years without signs of substantial improvement. Encouraging patients' involvement in adverse event reporting offers the possibility to a more holistic approach to pharmacovigilance. Further investigations in patients' and physicians' strategies when it comes to causality assessment of adverse events related to MS medication may be insightful.
