Interventions to Increase Physical Activity Among Older Adults: A Meta-Analysis

Purpose of the Study: To determine the overall effectiveness of interventions designed to increase physical activity (PA) behavior among community-dwelling older adults. Design and Methods: Comprehensive literature searching identified eligible PA intervention studies among community-dwelling adults aged 65 and older, or sample mean age of 70. Diverse study characteristics were extracted and outcome data were duplicate coded. Overall mean effect sizes (ESs) were synthesized using a random-effects model. Heterogeneity of effects was analyzed using Q and I-2 statistics. Moderator analyses were conducted using meta-analytic analogues of ANOVA and regression for dichotomous and continuous moderators, respectively. Results: ESs were calculated from 13,829 primary study subjects. The overall mean ES for two-group posttest comparisons was 0.18 (95% CI 0.10-0.26, p < .001). This represents a difference of 620 steps/day or 73 min of PA/week between treatment and control groups. Significant moderators included the use of theory, how interventions were delivered, and cognitive plus behavioral-type intervention components. Non-significant moderators include the type of interventionist, delivery setting, and various measures of intervention dose. Implications: PA interventions significantly improved PA behavior among community-dwelling older adults. Effective PA interventions may be efficiently delivered using already available resources and personnel. Future PA intervention research should be theoretically based, incorporate more diverse subjects, and compare intervention delivery methods.