Systemic sclerosis and its pulmonary complications in the Netherlands An epidemiological study

The prevalence and incidence of systemic sclerosis (SSc) in The Netherlands is unknown. The same holds true for its leading causes of death: pulmonary fibrosis and pulmonary arterial hypertension (PAH), for which effective treatment options have recently become available. Objective: To establish the prevalence and incidence of SSc and its pulmonary complications. Methods: Detailed information on patients in the POEMAS registry, "Pulmonary Hypertension Screening, a Multidisciplinary Approach in Scleroderma", consisting of 819 patients, was combined with a nationwide questionnaire. Results: By combining the two sources the prevalence of SSc was found to be 8.9 per 100 000 adults. The incidence was 0.77 patients per 100 000 per year. PAH was diagnosed in 9.9% of SSc patients. The prevalence of interstitial lung disease in SSc varied from 19% to 47% depending on the definition used. Conclusion: This study clarifies the epidemiology of SSc in The Netherlands and confirms the frequent occurrence of pulmonary complications, based on 654 cases. This can and will be studied further in the ongoing POEMAS study.