SAT0490 Incidence and prevalence of systemic sclerosisin an italian alpine valley during a 18-year long period
Authors: F. Dall’ara, A. Premoli, S. Zingarelli, M.G. Lazzaroni, A. Tincani, M.G. Fenini, F. Inverardi, R. Furloni, M. Scarsi, P. Airò
Journal: Annals of the Rheumatic Diseases (2018)

<h3>Background</h3> Not much information is available on the variations in the incidence and prevalence of Systemic Sclerosis (SSc) over time. <h3>Objectives</h3> To investigate the epidemiology of SSc in Valcamonica, an Alpine valley in northern Italy (Brescia Province, Lombardy region), during a 18-year-long period. <h3>Methods</h3> All patients with diagnosis of SSc living in Valcamonica between 1999 and 2016 were identified by capture/recapture method using: 1) clinical databases of the only secondary Rheumatology Unit present in the valley (Esine Hospital), and of the only tertiary referral centre for this area (Spedali Civili, Brescia); 2) administrative data (ASST Valcamonica, Esine), extracting all records with the ICD-10 code for SSc (710.1). Clinical charts were reviewed and patients included in the analysis when either the 1980 ARA or the 2013 ACR/EULAR classification criteria for SSc were satisfied. Incidence was calculated using the number of new cases observed as the numerator, and the Valcamonica population as the denominator for each year; to study temporal changes, mean yearly incidence during 3 different 6 year intervals was calculated (table 1). Prevalence rates were estimated at 4 different time points dividing the number of living patients by the number of individuals in the population (table 2).Survival, incidence and prevalence rates were expressed with 95% confidence intervals. Incidence and prevalence rates observed in different periods were compared using ANOVA test. Demographic data were expressed as the medians (IQR). <h3>Results</h3> General population with age over 14 years living in Valcamonica varied during the evaluated period between 85 168 (1999) and 91 245 inhabitants (2011). Fifty-six patients with SSc fulfilling the 2013 ACR/EULAR criteria, and in 68% of them also the 1980 ARA criteria were identified (Female 85.7%, Male: 14.3%; Caucasian: 96.4%, African 3.6%; age at diagnosis: 58;<sup>47–80</sup> deaths: 13 (8 because of SSc); survival: at 5 years: 89.4% (76.2–95.5), at 10 years: 84.4% (69.9–92.3); diffuse SSc: 17.9%, limited SSc: 82.1%; anticentromere: 62.3%, anti-topoisomerase I (topo I): 20.8%, anti-RNA polymerase III (RNAP3): 5.4%; anti-topo I and RNAP3: 1.9%; Anti-Th/To: 1.9%; interstitial lung disease: 23.1%; group 1 pulmonary arterial hypertension 19.6%; renal crisis 5.4%). No significant variation of incidence was observed during the period of time evaluated in the study (table 1). Analysis of prevalence revealed a continuous increase of the disease using both the 1980 ARA criteria or 2013 ACR/EULAR criteria (p&lt;0.001 for both comparisons; table 2). The prevalence on 2016 was 50.9 per 1 00 000 persons aged &gt;14 years, one of the highest ever recorded by SSc epidemiology studies. However, notably, the prevalence in Valcamonica during the first years of the 21 st century was similar to that reported by previous other studies performed in Italy in the same years.<sup>1–2</sup> <h3>Conclusions</h3> Although the incidence of SSc did not change significantly over time in this area, the disease prevalence constantly increased, with recruitment of new cases exceeding the number of deaths. <h3>References</h3> [1] Airò P, et al. Clin Exp Rheumatol2007;25:878–80. [2] Lo Monaco A, et al. Clin Exp Rheumatol2011;29:S10–4. <h3>Disclosure of Interest</h3> None declared