Development, reliability and validity of the Safe Use of Mobility Aids Checklist (SUMAC) for 4-wheeled walker use in people living with dementia

Abstract

Abstract Background Balance and gait problems are common and progressive in dementia. Use of a mobility aid provides physical support and confidence. Yet, mobility aid use in people with dementia increases falls three-fold. An assessment tool of mobility aid safety in people with dementia does not currently exist. The objectives of this study were: 1) to develop a tool for the evaluation of physical function and safe use of a 4-wheeled walker in people with dementia, and 2) to evaluate its construct and criterion validity, inter-rater and test-retest reliability and minimal detectable change. Methods Healthcare professionals (HCP) experienced in rehabilitation of people with dementia participated in focus groups for item generation of the new tool, The Safe Use of Mobility Aid Checklist (SUMAC). The SUMAC evaluates physical function (PF) and safe use of the equipment (EQ) on nine tasks of daily life. Reliability was evaluated by HCP (n = 5) scored participant videos of people with dementia (n = 10) using a 4-wheeled walker performing the SUMAC. Inter-rater and test-retest reliability was assessed using intra-class correlation coefficients (ICC). Construct validity evaluated scores of the HCPs to a consensus HCP panel using Spearman’s rank-order correlations. Criterion validity evaluated SUMAC-PF to the Performance-Oriented Mobility Assessment (POMA) gait subscale using Spearman’s rank-order correlations. Results Three focus groups (n = 17) generated a tool comprised of nine tasks and the components within each task for physical function and safe use. Inter-rater reliability was statistically significant for SUMAC-PF (ICC = 0.92, 95%CI (0.81, 0.98), p < 0.001) and SUMAC-EQ. (ICC = 0.82, 95%CI (0.54, 0.95), p < 0.001). Test-retest reliability was statistically significant for SUMAC-PF (ICC = 0.89, 95%CI (0.81, 0.94), p < 0.001) and SUMAC-EQ. (ICC = 0.88, 95%CI (0.79, 0.93), p < 0.001). As hypothesized, the POMA gait subscale correlated strongly with the SUMAC-PF (rs = 0.84), but not EQ (rs = 0.39). Conclusions The focus groups and research team developed a tool of nine tasks with evaluation on physical function and safe use of a 4-wheeled walker for people with dementia. The SUMAC tool has demonstrated content validity for the whole scale and good construct and criterion validity for the SUMAC-PF and SUMAC-EQ. The subscores of the SUMAC demonstrated excellent to good inter-rater and test-retest reliability.