Adherence to biological therapies in patients with chronic inflammatory arthropathies

Abstract

INTRODUCTION: The aims of the study were to quantify adherence, determine the factors that can predict adherence and identify the consequences of poorer adherence in patients with chronic inflammatory arthropathies treated with biological therapies in daily clinical practice. METHOD: A descriptive, observational and retrospective study was carried out. Patients with rheumatoid arthritis, ankylosing spondylitis and psoriatic arthritis who started a biologic therapy between 1 January 2009 and 31 December 2016 were included. Variables related to socioeconomic status, the disease, the biological therapy and hospital resources were included. Adherence was calculated by using the medication possession ratio. RESULTS: Three hundred and sixty-two patients and 423 lines of biological therapy were included. Mean age +/- standard deviation was 50.3 +/- 13.9 years, and 228 (53.9%) were women. The percentage of adherent patients was 187 out of 216 (87%) in rheumatoid arthritis, 91 out of 107 (85%) in ankylosing spondylitis and 84 out of 100 (84%) in psoriatic arthritis. Greater adherence was associated with more frequent visits to the pharmacy service (odds ratio 1.2, 95% confidence interval: 1.1-1.3 [p = 0.001]) and poorer adherence with a failure to attend scheduled appointments at the rheumatology clinic (odds ratio 0.2, 95% confidence interval: 0.1-0.9 [p = 0.030]). There were no differences between adherent and non-adherent patients in terms of the number of hospital resources used. CONCLUSIONS: There are no differences in adherence to biological therapies among patients with chronic inflammatory arthropathies. Adherence correlates with attendance at outpatient appointments, but this does not imply an increase in the use of hospital resources.