How to treat patients with rheumatoid arthritis when methotrexate has failed? The use of a multiple propensity score to adjust for confounding by indication in observational studies

Abstract

ObjectivesTo compare consecutive disease modifying antirheumatic drug (DMARD)-treatment regimes in daily practice in patients with rheumatoid arthritis (RA) who failed on initial methotrexate, while using a multiple propensity score (PS) method to control for the spurious effects of confounding by indication.MethodsPatients with newly diagnosed RA who had failed initial treatment with methotrexate were selected from METEOR, an international, observational registry. Subsequent DMARD-treatment regimens were categorised as: (1) conventional synthetic DMARD(s) (csDMARD(s)) only (143 patients), (2) csDMARD(s)+glucocorticoid (278 patients) and (3) biological DMARD (bDMARD)±csDMARD(s) (89 patients). Multiple PS that reflect the likelihood of treatment with each treatment-regime were estimated per patient using multinomial regression. Linear mixed model analyses were performed to analyse treatment responses per category (Disease Activity Score (DAS)) after a maximum follow-up duration of 6 and 12 months, and results were presented with adjustment for the multiple PS.ResultsAfter 6 months, follow-up PS-adjusted treatment responses yielded a change in DAS per year (95% CI) of −2.00 (−2.65 to −1.36) if patients received a bDMARD; of −0.96 (−1.33 to −0.59) if patients received csDMARD(s)+glucocorticoids and of −0.73 (−1.21 to −0.25) if patients received csDMARDs only. These changes were −0.91 (−1.23 to −0.60); −0.43 (−0.62 to −0.23) and −0.39 (−0.66 to −0.13), respectively after 1 year of follow-up.ConclusionsIn this analysis of worldwide common practice data with adjustment for multiple PS, patients with RA who had failed initial treatment with methotrexate monotherapy had a better DAS-response after a subsequent switch to a bDMARD-containing treatment regimen than to a regimen with csDMARD(s) only, with or without glucocorticoids.

Response to: ‘Catching the falling star: points to consider when using propensity scores’ by Ouyang et al

“…Response to: 'Catching the falling star: points to consider when using propensity scores' by Ouyang et al We would like to thank Dr Ouyang 1 for his thoughtful response to our article, including additional suggestions regarding the use of the multiple (or generalised) propensity score (PS), which we are sure will be helpful for other researchers who plan to use this technique. 2 We agree with the mentioned suggestions and will provide some additional clarifications.…”

Association of 17 Definitions of Remission with Functional Status in a Large Clinical Practice Cohort of Patients with Rheumatoid Arthritis

“…Details of the METEOR tool have been previously described. (16)(17)(18) The database used in this work included visits from June 1985 till November 2015.…”

Response to: ‘Metering the METEOR in methotrexate failure: is propensity score a falling star?’ by Ahmed et al

“…In our large, international daily practice database, we were able to compare three treatment strategies simultaneously, including a combination of csDMARD(s) with glucocorticoids. This is a therapy that has never been compared with triple therapy in clinical trials, but as shown by our data it was the therapy that was most frequently prescribed after MTX failure in daily practice 3…”