Mobility in community-dwelling adults with chronic conditions: the contribution of age and sex

Objectives: The study aimed to determine whether age and sex predict self-reported and performance-based mobility-related outcomes in community-dwelling middle and older aged adults with chronic conditions; and if sociodemographic factors and comorbidity influence this relationship. Methods: Data from a previous randomised controlled trial where the intervention had no clinical effect was analysed (n = 271). Unadjusted regression models and multivariate regression analyses including linear, median, logistic and ordered logistic regression were performed examining the relationship between participant characteristics at baseline and 9 months. Independent variables were: age, sex, comorbidity, education level, income level, marital status and age and sex interaction term. The dependent variables were: self-reported outcomes: fall history, Late Life Function and Disability Instrument function component score, Short Form 36 Health Survey Questionnaire physical component score and performance-based mobility outcomes: 2-minute walk distance, [Short Physical Performance Battery (SPPB)] balance, chair stands, eight-foot walk and SPPB total score. Results: Older age and female sex predicted poorer self-reported mobility, but only older age predicted performance-based mobility outcomes. Participants with more comorbidity, low income and lived alone had poorer mobility. Conclusion: The differences of the self-reported mobility outcomes but not the performance measures between males and females may be implicated by gender differences, more than sex differences. Our findings support the need for more mechanistic studies on the impacts of sex and gender on mobility.