The global incidence and prevalence estimates of systemic sclerosis (SSc) vary considerably between studies, according to the findings of a systematic review and meta-analysis published in Rheumatology.

The objective of the current systematic review and meta-analysis was to determine the incidence and prevalence of SSc globally.

Among 6893 articles found on MEDLINE, Web of Science, and EMBASE, which included data on incidence or prevalence of SSc, the study authors assessed the full texts of 201 records for eligibility; after exclusion of 130 studies, they included 61 studies of prevalence and 39 studies of incidence of SSc in the current systematic review. The meta-analysis of SSc incidence and prevalence included 28 and 46 studies, respectively.


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The prevalence of SSc ranged from 3.1 to 144.5 per 100,000 person-years, with a pooled prevalence of 17.6 (95% CI, 15.1-20.5) per 100,000 person-years (I2=100%). The pooled prevalence among men was 6.0 (95% CI, 4.8-7.5) per 100,000 person-years (I2=97%), and among women it was 28.0 (95% CI, 23.1-33.9) per 100,000 person-years (I2=99%). Stratification by region showed significant variations in different parts of the world. The pooled prevalence in studies from Asia was the lowest (6.8 per 100,000 person-years; I2=98%), with relatively low estimates consistently reported.

The pooled incidence of SSc was 1.4 (95% CI, 1.1-1.9) per 100,000 person-years (I2 = 100%). Stratification by sex indicated a pooled incidence of 0.5 (95% CI, 0.4-0.7) per 100,000 person-years in men and 2.3 (95% CI, 1.8-2.9) per 100,000 person-years in women (I2=96% and 98%, respectively).

A meta-regression analysis of prevalence or incidence against calendar period indicated that more recent studies reported higher prevalence and incidence rates of SSc.

Limitations of the analysis included the fact that it was restricted to research published in English, the inability to account for the methods used to identify patients in primary studies, and the large heterogeneity observed among studies.

“[T]he incidence and prevalence of SSc vary significantly depending on study settings, acquisition routes, region and calendar period in addition to the considerably higher occurrence of SSc in women in comparison [with] men. Our results should therefore be interpreted taking these issues into consideration,” the study authors concluded.

Disclosure: One study author declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of the author’s disclosures.

Reference

Bairkdar M, Rossides M, Westerlind H, Hesselstrand R, Arkema EV, Holmqvist M. Incidence and prevalence of systemic sclerosis globally: a comprehensive systematic review and meta-analysis. Rheumatology (Oxford). Published online February 25, 2021. doi:10.1093/rheumatology/keab190