Figure 1

Factor analysis of COMPASS autonomic symptom scale scores within pSS patients. (a) Scatterplot of rotated (varimax normalized) COMPASS subscale factor loadings for factor 1 (24% of total variance) and factor 2 (15% of total variance), both with appreciable loadings for the secretomotor subscale. Factor 1 had the highest loadings for secretomotor, orthostatic, gastroparesis, constipation and bladder subscales, which is indicative of a substantial clustering of these symptoms within patients who have primary Sjögren's syndrome (pSS). The highest loadings for factor 2 were observed with both the secretomotor and pupillomotor subscales. (b) Scatterplot of the COMPASS factor 1 scores for each pSS patient by results of the contemporaneous 15-minute unstimulated salivary flow test. The horizontal bars represent mean scores for each group. Factor 1 scores were significantly higher in patients with this objective measure of dryness (P = 0.025), whereas factor 2 scores were not (P = 0.40; data not shown). Scatterplot of the COMPASS factor 1 scores for each pSS patient by the FACIT-F scores. Factor 1 scores were significantly correlated with fatigue scores (P = 0.035), whereas factor 2 scores were not (P = 0.18; data not shown). COMPASS, Composite Autonomic Symptom Scale; FACIT-F, Functional Assessment of Chronic Illness Therapy-Fatigue.