ADA_ETA_BIO2021: real-world evaluation of adherence, persistence, and cost-effectiveness of originator and biosimilar biologic drugs in the treatment of rheumatoid arthritis: a multicenter study in Italy

AbstractObjectives The objective was to assess the adherence, persistence, and costs of bDMARDs through a multicentre study of 9 Italian hospital pharmacies.Methods The drugs analysed were Abatacept, Adalimumab, Certolizumab, Etanercept, Golimumab and Tocilizumab. Adult subjects with Rheumatoid Arthritis were considered in the analysis. In this study, we calculated the following metrics: Adherence to treatment was evaluated as dose-intensity, which is the ratio between the amount of medication received and probably taken by the patient at home (Received Daily Dose, RDD) and the amount prescribed by the clinician (Prescribed Daily Dose, PDD). Persistence was calculated as the number of days between the first and last dispensing of the same drug. Lastly, costs were assessed based on persistence to treatment and normalised for adherence.Results Adherence to treatment was found to be above 0.8 for all drugs studied. The median persistence for a 5-year treatment period was 1.4 years for Abatacept, 1.7 years for Adalimumab, 1.8 years for Certolizumab, 1.4 years for Etanercept, 1.3 years for Golimumab, and 1.6 years for Tocilizumab.Conclusions This multicentre retrospective observational study of bDMARDs used in the treatment of RA showed that, for all the drugs studied, there was no problem with adherence to treatment but rather a difficulty in maintaining treatment with the same drug over time.Keywords: Rheumatoid arthritisbDMARDsAdherence to treatmentPersistenceCost-effectivenessDisclaimerAs a service to authors and researchers we are providing this version of an accepted manuscript (AM). Copyediting, typesetting, and review of the resulting proofs will be undertaken on this manuscript before final publication of the Version of Record (VoR). During production and pre-press, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal relate to these versions also.