Sex distribution in psoriatic arthritis: a systematic literature review

Although the prevalence of psoriatic arthritis (PsA) is considered equal between the sexes, recent PsA studies have reported a female predominance, with female-to-male ratios between 1.2:1 and 2:1. It is not clear whether this is related to a change in the epidemiology of the disease or to different patterns of patients attending outpatient clinics. We aimed to assess the female-to-male ratios in recent PsA studies.

A systematic review of the literature (January 2020 to September 2022) was performed using the PubMed database with keywords and MeSH terms referring to 'psoriatic arthritis'. Randomized controlled trials (RCTs), and cross-sectional, prospective, and retrospective cohort studies involving at least 20 patients and specifying the number of males and females were considered eligible.

From 2800 initially identified articles, 481 eligible studies with 871 144 participants were analysed, revealing a female majority (54.1%). When we evaluated the studies based on their design, we found that female sex was more predominant in each type of design, with retrospective cohort studies having the highest prevalence. According to the number of centres involved, multi-centre studies demonstrated a greater representation of female participants than single-centre studies (54% vs 50%). Regarding the geographical locations, studies conducted in America, Europe, and multinational contexts displayed a female predominance.

In our assessment, RCTs had the closest sex equality, with a slight preponderance of females. The real-life and multi-centre studies had more pronounced female rates, with several differences observed in different geographical locations.