Objectives: To study the actual use of orthopedic shoes by patients with degenerative foot disorders and to identify factors associated with use and nonuse, based on the parameters of the International Organization for Standardization definition of usability: effectiveness, efficiency, satisfaction, and context of use.
Design: Multicenter, prospective cohort study.
Setting: Outpatient clinics of 7 rehabilitation centers in the Netherlands.
Participants: One hundred consecutive patients with degenerative foot disorders.
Interventions: Not applicable.
Main outcome measures: Usability was assessed by means of the Questionnaire for Usability Evaluation of orthopedic shoes.
Results: Seventy of 93 patients with degenerative foot disorders wore their orthopedic shoes for more than 3 days a week after 3 months of follow-up. Factors significantly associated with the actual use of orthopedic shoes were (1) increase in stance duration (effectiveness odds ratio [OR]=2.14; 95% confidence interval [CI], 1.19-3.85), (2) decrease in skin abnormalities (effectiveness OR=1.35; 95% CI, 1.02-1.8]), (3) problems experienced with putting on and taking off orthopedic shoes (efficiency OR=.46; 95% CI, .26-.82), and (4) cosmetic appearance of orthopedic shoes (satisfaction OR=1.54; 95% CI, 1.1-2.15). The overall fit of the multiple logistic regression model ( R 2 ) was 56.3%.
Conclusions: By adding efficiency and satisfaction factors and not focusing only on the effectiveness factors, the amount of explained variance increases, and it becomes possible to evaluate and design products for people with special needs more comprehensively.