Background/Purpose: The influence of sex in psoriatic arthritis (PsA) features and treatment outcomes has not been fully elucidated. We investigated the differences between sexes in biologic initiation and methotrexate (MTX) retention rate in a large real-life cohort of patients with PsA .

Methods: This is a retrospective cohort study based on administrative health databases of the Northern Italian Lombardia region (with a 10 million population). Data were extracted from the RECORD database of the Italian Society for Rheumatology. Patients with PsA were defined by the presence of disease specific copayment exemptions, and MTX treatment included as its first prescription. Demographic data, comorbidities (measured using the Charlson Index) and concomitant treatments were recorded. Baseline demographic and disease variables were compared using the chi squared test, two-sample t test or Mann-Whitney U test, as appropriate. Cox regression analysis was used for comparing initiation of biologic treatment and MTX retention rate. All statistical tests were two-sided with a level of significance set at 0.05.

Results: A total of 2,118 PsA cases treated with MTX were included and their demographic, clinical and therapeutic features are reported in Table 1. We observed significant differences between sexes in the age at the first MTX prescription (55.1±12 in women vs. 51.9±12.5 in men) and concomitant treatment with antidepressants (7.2% in women vs. 2.2% in men). Men and women with PsA were comparable for disease duration, Charlson Index and concomitant arthritis medications (NSAIDs and glucocorticoids). MTX was discontinued in 984 subjects (person-year 8,807.53, incidence rate 0.11, 95% CI 0.10-0.12). The Cox regression analysis for MTX retention rate reported a crude HR of 1.00 (95% CI 0.88-1.14), while the adjusted HR was 1.09 (95% CI 0.96-1.24). A total of 616 subjects (person-year 10,823.3, incidence rate 0.05, 95%CI 0.047-0.055) started a biologic treatment (283 etanercept, 45.9%; 185 adalimumab, 30%; 121 infliximab, 20%, 27 golimumab, 4.4%). No differences were observed between sexes (etanercept 56% vs. 43.8%, adalimumab 50% vs. 49.7%, infliximab 54.5% vs. 45.4%, golimumab 59% vs 40%). The Cox regression analysis for biologic initiation reported a crude HR for sex of 0.81 (95%CI 0.69-0.96, p=0.018) and an adjusted HR of 0.80 (95%CI 0.68-0.95; p=0.012).

Conclusion: Our data from a real-life cohort of patients with PsA treated with MTX suggest that women are younger at first MTX prescription and are more frequently precribed antidepressants despite similar use of  NSAIDs and glucocorticoids or comorbidities. MTX retention rate does not differ between sexes. Female sex is negatively associated with biologic initiation, possibly reflecting different prescription patterns between sexes.

Table 1.

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/sex-differences-in-psoriatic-arthritis-evaluation-of-a-real-life-cohort-of-2118-italian-patients-treated-with-methotrexate/