Demographic Characteristics and Clinical Factors Affect Anti-TNF Treatment Adherence in Rheumatoid Arthritis

Adherence to subcutaneous anti-tumor necrosis factor (TNF) α treatment is influenced by both demographic characteristics and clinical factors, including injection site pain and skin perceptions, in patients with rheumatoid arthritis (RA), according to research results published in the International Journal of Rheumatic Diseases.

Researchers conducted a prospective study to evaluate treatment adherence in patients with RA receiving subcutaneously administered anti-TNFα agents. They also sought to assess the effect of injection site pain and skin perceptions on treatment adherence.

The total cohort included 206 consecutive patients with RA (141 women; mean age, 56.9±11.1 years) enrolled in a rheumatology center between March 2016 and June 2018. At baseline, investigators collected demographic data and comorbidities, disease activity level, radiographic severity, and biologic treatment method. Patients were followed up every 3 months for 1 year. Patients completed a 2-part self-injection assessment pain questionnaire (SIAPQ), before and after administration of the injection.

At the start of the study, patients were receiving adalimumab (n=87), etanercept (n=69), golimumab (24), or certolizumab pegol (n=26). After 1 year, complete data were available for 193 patients (93.7%), who were included in the analyses (68% women; mean age, 57.2 years). In this group, the mean RA duration at baseline was 7.4±2.7 years, and 33% of patients had longstanding RA (≥10 years). All medications were administered using the auto-injection pen.

Results indicated that after 1 year of anti-TNFα treatment, 14% of patients experienced remission, 21.3% had low disease activity, 35.7% had moderate disease activity, and 29% had high disease activity. The mean SIAPQ score was 4.12±1.80.

A total of 193 patients (21.7%) were nonadherent to their medication at 1 year, of whom 8 were nonadherent after 3 months, 24 at 6 months, and 10 after the 1-year assessment. Young age, elevated disease activity, a low number of comorbidities, and low SIAPQ scores at baseline were statistically significantly associated with an increased likelihood of adherence to medications.

Multivariate logistic model analysis confirmed these results and also indicated that medication adherence was significantly associated with higher baseline disease activity and lower baseline injection site pain and skin reactions.

Study limitations included possible inflation of adherence data, the inclusion of more women than men participants, which may have limited generalizability across sexes, and the lack of comparison between the single anti-TNFα agents.

“The results of this study suggest that the prevalence of nonadherence within 12 months after starting [subcutaneous] anti-TNFα therapy is a frequent condition,” the researchers concluded. “This research could provide suggestions on how to develop interventions to improve adherence.”

Reference

Salaffi F, Di Carlo M, Farah S, Carotti M. Adherence to subcutaneous anti-TNFα agents in patients with rheumatoid arthritis is largely influenced by pain and skin sensations at the injection site [published online March 2, 2020]. Int J Rheum Dis. doi:10.1111/1756-185X.13803