Influence of Clinical and Immunological Parameters on the Health-related Quality of Life of Patients with Primary Sjögren's Syndrome

Objective: To evaluate health-related quality of life (HR-QoL) in patients with primary SS patients using the SF-36 questionnaire and to analyse the association between the main clinical features and the SF-36 scales.

Methods: We studied 110 patients (105 women and 5 men, mean age of 56 years) with primary SS seen consecutively in the outpatient clinic of our Department. We used the population-based reference values for the Spanish version of the SF-36 health survey as control values for a healthy population.

Results: Comparison between patients with primary SS and the control population showed lower scores in all SF-36 scales (p < 0.001). Analysis of the SF-36 scales by gender showed a significant correlation between age and the values for physical functioning (p = 0.013) and bodily pain (p = 0.016) scores. No significant differences in SF-36 scores were found when comparing patients according to the presence or absence of sicca features. Women with vaginal dryness had lower scores for social functioning (61.9 vs. 74.4) and general health (37.2 vs. 44.7) than those without, although the differences were not statistically significant (p > 0.05). Patients with extraglandular involvement had lower scores for the vitality scale (40.8 vs. 54.5 p = 0.007), social functioning (67.0 vs. 79.8, p = 0.010), bodily pain (49.5 vs. 62.5, p = 0.018) and general health (38.6 vs. 49.4 p = 0.001) than those without.

Conclusion: Patients with primary SS had clearly lower HR-QoL scores than the healthy population; with significantly lower scores in all SF-36 scales and in both summary measures. We identified several epidemiological and clinical SS features related to these lower SF-36 scores. Age at protocol correlated with physical functioning and bodily pain. Vaginal dryness was the sicca feature that most affected the HR-QoL of female SS patients, and a poor HR-QoL was also observed in those patients with a systemic expression of the disease, with pulmonary involvement being the extraglandular manifestation that most contributed to a poor HR-QoL. Our results highlight the importance of earlier diagnostic and therapeutic management of patients with primary SS, which, together with a close follow-up, may contribute to a significant improvement in their HR-QoL.