Validity of clinically derived cumulative somatosensory impairment index.

Abstract

Prospective cohort study. Population-based cohort. InCHIANTI ("Invecchiare in Chianti" or aging in the Chianti area) study participants (N=960; age, 21-91 y, 51.8% women). Not applicable. The Cumulative Somatosensory Impairment Index was derived from baseline performance on clinical tests of pressure sensitivity, vibration sensitivity, proprioception, and graphesthesia. Global postural control was assessed using Frailty and Injuries Cooperative Studies of Intervention Techniques (FICSIT) balance test, time to complete 5 repeated chair stands, and fast walking speed, at baseline and at 3-year follow-up. In participants without neurologic conditions (n=799), the Cumulative Somatosensory Impairment Index was significantly different in age groups classified by decades (P<.001). Compared with participants without prevalent conditions, the Cumulative Somatosensory Impairment Index was significantly higher in persons with diabetes (P=.017), peripheral arterial disease (P=.006), and a history of stroke (P<.001). In the overall population (N=960), in the fully adjusted multiple regression models, the Cumulative Somatosensory Impairment Index independently predicted deterioration in FICSIT scores (P=.002), time for 5 repeated chair stands (P<.001), and fast gait speed (P=.003) at 3-year follow-up. The Cumulative Somatosensory Impairment Index is a valid measure that detects relevant group differences in lower limb somatosensory impairment and is an independent predictor of decline in postural control over 3 years.