Adherence to biological therapies in patients with chronic inflammatory arthropathies.

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.