Quality of life as measured by the short-form 36 (SF-36) questionnaire in patients with early systemic sclerosis and undifferentiated connective tissue disease

Patients consecutively admitted to the outpatient clinic of the Rheumatology Unit of the Second University of Naples for the evaluation of RaP from January 1st 2007 to December 31st 2011 were enrolled in the study if they fulfilled the following criteria: 1) Koenig et al.’s criteria for early SSc [10] (i.e., RaP with a marker autoantibody and/or a capillaroscopic scleroderma pattern without any clinical manifestation other than RaP, puffy fingers and/or present or past arthralgia/arthritis), or 2) Doria et al.’s criteria [11] for UCTD (i.e., they had serum ANA [antinuclear antibodies], but no marker autoantibody of SSc or specific of any other connective tissue disease, no scleroderma videocapillaroscopic findings or any clinical manifestation pathognomonic of any other connective tissue disease).

Patients fulfilling the American College of Rheumatology criteria for SSc [8] and those presenting at least one of the features of definite SSc according to Koenig et al. [10] were excluded. The diagnosis of RaP was confirmed if patients fulfilled LeRoy and Medsger’s criteria [9] i.e., if a cold challenge induced bilateral, episodic bi- or triphasic (pallor followed by dusky blueness and/or redness) color changes of fingers. The study was approved by the ethics committee of the Azienda Ospedaliera Universitaria, Seconda Università di Napoli. All patients agreed to participate to the study and provided written informed consent.

According to standard clinical practice and to ensure a correct classification, all patients underwent: a detailed history taking and a physical examination to identify the above-listed exclusion features, and puffy fingers and present or previous arthritis; routine laboratory investigations including cell blood count, urinalysis, BUN (blood urea nitrogen), ALT (alanine transaminase), AST (aspartate transaminase), erythrocyte sedimentation rate (ESR), serum protein electrophoresis and serum C3 and C4 concentration; widefield nailfold videocapillaroscopy (NVC) was carried out as described elsewhere [12] using a videocapillaroscope (Videocap 25-DS Medica-Italy) with optical probes of 200X. Stored images were reviewed by a physician (MI) experienced in NVC [13]. The degree of capillary enlargement on a scale of 0–3 and capillary loss (graded A–D) were investigated. Megacapillaries (capillary enlargement ≥2) and/or avascular areas (capillary loss grade ≥ C) were considered a scleroderma pattern [14, 15]; a serum autoantibody profile, carried out as described elsewhere [12] on sera collected at the first visit, stored at −20°C and heated at 56°C for 30 min before testing, and including ANA, SSc and other connective tissue disease marker autoantibodies. ANA were considered positive when a diluition ≥ of 1:160 was registered, in absence of other known conditions associated with ANA positivity (i.e. chronic B or C hepatitis infection, autoimmune thyroid and hepatic disorders, malignancies). Thorax X-ray, barium esophageal X-ray and electrocardiogram were performed to identify patients that should be excluded from the study because of findings consistent with lung, esophageal or cardiac SSc involvement. Moreover, at baseline patients underwent B-mode echocardiography and lung function tests, performed as described elsewhere [16, 17].

Each patient and 40 healthy subjects recruited from the administrative, nursing and medical staff of the Department of Internal Medicine and matched for sex and age with the enrolled patients, after giving a written informed consent, were asked to complete self-administered questionnaires namely the Italian version of SF-36 [18] and the Health Assessment Questionnaire-Disability Index (HAQ-DI) [19]. The Italian version of SF-36 [18] consists of 36 questions grouped into 8 domains physical functioning, social functioning, role limitations related to physical problems, role limitations related to emotional problems, mental health, vitality, bodily pain and general health perception. A score ranging from 0 (indicating the worse health status) to 100 (indicating the best health status) is assigned for each domain. Domain scores can be summarized into a Physical Component Score (PCS) and Mental Component Score (MCS) [18]. For these two summary scales, a score below 50 reflects a worse HRQOL compared to the average of the general population [18]. HAQ-DI is a disease-specific, musculoskeletal-targeted questionnaire designed to assess functional ability in rheumatoid arthritis, the Italian version of which has been validated [19]; it has been extensively used and validated in SSc patients [3, 4]. This questionnaire contains 20 items (each scored from 0 to 3) divided into 8 domains. The highest scores in each domain are summed and then divided by 8 to obtain the final HAQ-DI value, which ranges from 0 (no disability) to 3 (severe disability).

Descriptive statistics were used to summarize the patients’ baseline characteristics. The chi-squared test was used for comparison of proportions. The Mann–Whitney nonparametric test was used for between-group comparisons. Correlations among the SF-36 domains and HAQ-DI scores, clinical parameters and disease activity were investigated by Spearman’s correlation. Spearman’s coefficient values were defined excellent (>0.91), good (0.90-0.71), moderate (0.70-0.51), fair (0.50-0.31), or little or none (<0.30).