Adherence to a physical activity intervention among older adults in a post-transitional middle income country: a quantitative and qualitative analysis.

Abstract

The effectiveness of community level interventions depends to a great extent on adherence. Currently, information on factors related to adherence in older adults from developing countries is scarce. Our aim was to identify factors associated to adherence to a physical activity intervention in older adults from a post-transitional middle income country. Using a combination of quantitative and qualitative methods we studied 996 older Chilean subjects (65-67.9 years at baseline) with low to medium socioeconomic status from 10 health centers randomized to receive a physical activity intervention as part of the CENEX cluster trial (ISRCTN48153354). Using a multilevel regression model, the relationship between adherence (defined a priori as attendance at a minimum of 24 physical activity classes spread over at least 12 months) and individual, intervention-related and contextual factors was evaluated. We also conducted 40 semi-structured interviews with older adults (n=36) and instructors (n=4). Transcripts of the interviews were analyzed using content analysis to identify barriers and facilitators to adherence. Adherence to physical activity intervention was 42.6% (CI 95% 39.5 to 45.6). Depression, diabetes mellitus, percentage of impoverished households and rate of arrests for violent crimes in the neighborhood predicted less adherence (p<0.05) while being retired, participation in physical activity prior to the intervention, and green areas per habitant were positively associated with adherence (p<0.05). The qualitative interviews identified three primary barriers to adherence: current health problems, lack of time due to commitments for caring for family members, and being employed, and two primary facilitators to adherence: the health benefits attributed to the intervention and the opportunity the classes provided for social interaction with others. In order to enhance effectiveness of community exercise interventions, strategies to improve participation should be targeted to older adults from deprived areas and those with psychological and medical conditions.