To evaluate the applicability of the 12-Item Short-Form Health Survey (SF-12) as an instrument to measure health-related quality of life in a sample of patients with progressive systemic sclerosis (PSS) through the analysis of its reproducibility and its correlation with functional and clinical parameters. Methods: A test-retest reproducibility study for the comparative analysis of the intraclass correlation coefficients (ICCs) of the SF-12 and the SF-36. A total of 46 patients diagnosed with PSS were studied, regardless of the presence of respiratory symptoms. Results: The physical component summary 12 (PCS-12) score had an ICC of 0.47 (95%CI: 0.05-0.71; p < 0.02), whereas the mental component summary (MCS-12) score had an ICC of 0.72 (95%CI: 0.49-0.84; p < 0.001). The PCS-36 score had an ICC of 0.88 (95%CI: 0.78-0.93; p < 0.001), and the MCS-36 score also had an ICC of 0.88 (95%CI: 0.78-0.93; p < 0.001). Conclusion: The SF-12 is a reliable instrument for measuring health-related quality of life in patients with PSS, since it has been proven to be reproducible. However, this version of the SF-12 should only be used in clinical research settings.

Keywords: Quality of life; Questionnaires; Statistics; Scleroderma, systemic.

Objective: To estimate the frequency of interstitial lung disease in a group of patients with progressive systemic sclerosis, and to describe the clinical, functional and radiological characteristics of the patients studied. Methods: Fifty-eight patients diagnosed with progressive systemic sclerosis were submitted to high-resolution computed tomography of the chest, pulmonary function tests and a blood test for anti-Scl 70 antibodies. Comparisons were drawn between patients with interstitial lung disease and those without. Logistic regression with multivariate analysis was used to identify factors predictive of interstitial lung disease. Results: Of the 58 patients evaluated, 51.7% presented interstitial lung disease on high-resolution computerized tomography scans. Dyspnea and cough were the most common symptoms (seen in 65.5% and 39.7%, respectively). Bronchiolectasis and honeycombing were the most common tomographic abnormalities (observed in 83.3% and 80%, respectively). When compared to individuals without interstitial lung disease, patients with the condition had a comparable frequency of pulmonary and extrapulmonary symptoms but presented progressive systemic sclerosis of longer duration, a higher frequency of crackling rales, higher rates of anti-Scl 70 positivity, lower vital capacity and reduced total lung capacity. Only forced vital capacity < 80% was found to be a predictor of interstitial lung disease. Conclusion: Interstitial lung disease was common in this group of patients with progressive systemic sclerosis. No correlation with symptoms was found, although interstitial lung disease was found to correlate with crackling rales and with anti-Scl 70 positivity. Nevertheless, only reduced forced vital capacity was found to be predictive of interstitial lung disease.