RESUMEN
BACKGROUND: There is no consensus method for determining progression of disability in patients with multiple sclerosis (MS) when each patient has had only a single assessment in the course of the disease. METHODS: Using data from two large longitudinal databases, the authors tested whether cross-sectional disability assessments are representative of disease severity as a whole. An algorithm, the Multiple Sclerosis Severity Score (MSSS), which relates scores on the Expanded Disability Status Scale (EDSS) to the distribution of disability in patients with comparable disease durations, was devised and then applied to a collection of 9,892 patients from 11 countries to create the Global MSSS. In order to compare different methods of detecting such effects the authors simulated the effects of a genetic factor on disability. RESULTS: Cross-sectional EDSS measurements made after the first year were representative of overall disease severity. The MSSS was more powerful than the other methods the authors tested for detecting different rates of disease progression. CONCLUSION: The Multiple Sclerosis Severity Score (MSSS) is a powerful method for comparing disease progression using single assessment data. The Global MSSS can be used as a reference table for future disability comparisons. While useful for comparing groups of patients, disease fluctuation precludes its use as a predictor of future disability in an individual.
Asunto(s)
Evaluación de la Discapacidad , Esclerosis Múltiple/diagnóstico , Índice de Severidad de la Enfermedad , Adulto , Edad de Inicio , Estudios de Cohortes , Estudios Transversales , Bases de Datos Factuales , Progresión de la Enfermedad , Femenino , Francia/epidemiología , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Modelos Neurológicos , Modelos Estadísticos , Esclerosis Múltiple/epidemiología , Esclerosis Múltiple/fisiopatología , Valor Predictivo de las Pruebas , Pronóstico , Recurrencia , Reproducibilidad de los ResultadosRESUMEN
OBJECTIVE: To determine the proportion of patients with multiple sclerosis (MS) who respond to interferon-beta (IFNB) therapy and assess whether clinical characteristics differ in IFNB responders vs nonresponders. METHODS: Data on all patients who received IFNB who were entered in the prospective European Database for Multiple Sclerosis (EDMUS) database in Lyon as of March 31, 2001, were reviewed. Responders were defined as having a lower relapse rate on IFNB compared with the year or 2 years prior to IFNB therapy. RESULTS: Two hundred sixty-two patients with relapsing MS received at least 6 months of IFNB: 200 relapsing remitting (RR) and 62 relapsing secondary progressive (SP). One-third of patients experienced a higher or identical annual relapse rate while on IFNB treatment. Compared with nonresponders, responders were older and had longer disease duration at the time IFNB was initiated. RRMS responders also had a higher relapse rate during the year prior to IFNB therapy and SPMS responders had a higher Disability Status Scale score at initiation of IFNB. CONCLUSION: Clinical profiles of patients with relapsing MS who respond to IFNB may differ from those who do not with a more inflammatory and less neurodegenerative disease at the time IFNB is initiated.