Evaluation of two cane instruments in older adults with knee osteoarthritis

The objectives of this study were to describe the psychometric properties of the Cane Cognitive Mediator Scale (CCMS) and the Psychosocial Impact of Assistive Devices Scale (PIADS) in adults with knee osteoarthritis (OA) and to determine the feasibility of applying these instruments as screening tools to identify patients with the propensity to use a cane. Data from a randomized crossover trial were analyzed for 53 older adults with knee OA. Perceptions on using a cane were measured at baseline using the CCMS and PIADS. The CCMS was repeated 1 wk later. At 6 mo, subjects rated their intention to use a cane. The findings indicated that 1 wk test-retest reliability was acceptable for the CCMS Attitudes and Subjective Norms subscales (r = 0.48 to 0.93) and low for the CCMS Perceived Behavioral Control subscale (r = 0.15). Internal consistency reliability was good for each CCMS and PIADS subscale. The CCMS Subjective Norms subscale demonstrated acceptable predictive validity across all subgroups (r = 0.53 to 0.88). The PIADS Adaptability subscale demonstrated acceptable predictive validity for the 45 to 64 yr-old age group (r = 0.54). The findings indicate that the CCMS Subjective Norms subscale exhibits good psychometric properties and has potential application as a screening tool.