Response to methotrexate predicts long-term patient-related outcomes in rheumatoid arthritis

This study was conducted to investigate the predictive value of the initial response to methotrexate (MTX) on long-term patient-related outcomes (PROs) in rheumatoid arthritis (RA). All RA patients starting MTX treatment between 1980 and 1987 in our department were enrolled in a prospective observational study. After an average of 18 years, patient-related outcomes were assessed in three dimensions according to the International Classification of Functioning, Disability and Health (ICF). Statistical analyses employed multivariable models with baseline values for age, gender, disease duration, rheumatoid factor positivity, disease activity, response to MTX after 1 year and continuous use of MTX as covariates. The 271 patients enrolled had a mean disease duration of 8.5 years, a mean number of swollen joints of 18 (out of 32), and a mean erythrocyte sedimentation rate of 55 mm/h. After 18 years, PRO was available in 89 patients (33 %). A clinical improvement of at least 20 % 1 year after the initiation of MTX was associated with a favourable outcome in all three dimensions of the ICF, independent of continuation of MTX (p < 0.05). The initial response to MTX is an independent predictor of PRO in RA as assessed after an average of 18 years.