This study explores important factors of assistive technology (AT) and evaluates their relative impact on AT effectiveness and retention. Questionnaire based survey is used for data collection from 327 people with dementia (PWD). This empirical study uses statistical techniques including exploratory factor analysis for factor identification, linear regression for impact study, Kruskal Wallis H and Mann Whitney U tests for the statistical significant study in terms of demographic and characteristics. The exploratory factor analysis results into 11 factors: operational support, physical support, psychological support, social support, cultural match, reduced external help, affordability, travel help, compatibility, effectiveness and retention. The results reveal that social support, psychological support and travel help and reduced external help strongly impact on AT effectiveness and retention. The users are motivated by socialization support through using AT without any external help. The use of AT during travelling improves confidence of the PWD and helps them psychologically.