Background Severe central nervous system disorders are rare in patients with Sjogren’s syndrome, whereas cognitive symptoms are reported by as many as 30-40% of pSS patients1 The Cognitive Symptoms Inventory(CSI) has been validated in patients with SLE2. The Brief Cognitive Symptoms Index(BCSI) consists of 6 items selected from the 21-item CSI3. The BCSI provides a state measure of cognitive symptoms insofar as it indicates present levels of functioning and is limited to the four-week interval preceding its administration.
Objectives To measure mood, sleep quality, cognitive symptoms and health-related quality of life in patients with pSS and to evaluate the psychometric properties of the BCSI in the SS population.
Methods 68 pSS patients at two university centers completed a health survey which included the SF-12, FSS, HADs, PSQI, SIQR and BCSI. Internal consistency of the BCSI was evaluated with Chronbach’s alpha. The pattern of interrelationship between items comprising the BCSI was assessed with principal components analysis. Pearson Correlation coefficients were calculated to assess relationships between cognitive scores and other clinical variables.
Results Missing response rate was < 2%. Analyses were based on complete data avalilable in a total N=66 pSS patients, mean age 59.6, 96% female (62% seropositive, N=41 and 38% seronegative, N=25.) Patients indicated current symptoms of fibromyalgia (13%), neuropathy (20%), depression (31%) and sleep disorders (29%). Mean BCSI, FSS, SF-12 emotional and physical domain scores were similar in seropositive and seronegative SS groups (p> 0.5.) Internal consistency reliability was high (Chronbach’s alpha = .907) and item-to-total correlations for the individual test questions ranged from .61 to .85, indicating that all items measured the same construct. Principal Factor Analysis revealed only one underlying factor, indicating a single domain structure of the BCSI. The BCSI correlated with anxiety, depression, pain, fatigue and with the SF-12 emotional and physical domain scores (all r’s - .40-.70, all p’s ≤.0001).
Conclusions Cognitive function as measured by the BCSI is correlated with mood, fatigue, pain, sleep quality and overall health related quality of life in patients with PSS. The BCSI is a simple, easily administered measure of cognitive symptoms which is suitable for assessment of patients in clinical research and practice settings.
Segal BM et al. Involvement of Nervous system pathways in primary Sjogren’s syndrome. Rheumatic Disease Clinics of North America Vol 34, number 4; 2008, editor Carsons SE. WB Saunders Co. Philadelphia.
Alarcon GS et al. Systemic lupus Erythematosus in Three Ethnic Groups. X. Measuring Cognitive Impairment with the Cognitive Symptoms Inventory. ArthRheum 2002;47, 310-319.
Yu EB, et al Validation of LUP-QOL: a lupus-specific measure of health-related quality of life. AnnRheumDis 2006;65 Supple II: 601.
Disclosure of Interest None Declared