Do the integrated theories of self-determination and planned behavior explain the change in active life engagement following a motivational counseling intervention among older people?

An integrated model based on self-determination and planned behavior theories has been used to explain physical activity and other health-related behaviors mainly among younger populations, not older adults. The present study aimed to conduct a secondary analysis to explore whether changes in theory-based constructs explain a change in activity level (including 17 activities in essential life areas) among 75- and 80-year-old individuals. Data came from the Promoting well-being through active aging (AGNES) study, a two-arm single-blinded randomized control trial, where participants in the intervention group (n = 101) received year-long individualized counseling between 2017–19 in Jyväskylä, Finland. Activity frequency was assessed using the University of Jyväskylä Active Aging Scale (UJACAS) activity sub-score, perceived autonomy support with the Health Climate Questionnaire, autonomous motivation with a sub-scale from the Self-Regulation Questionnaire, and attitude with three items. Subjective norm, perceived behavioral control, and intention were each assessed with one item. Change in variables between baseline and the 12-month follow-up was specified via latent factors. Various structural equation models were tested to assess whether the basic or modified model, including additional paths from baseline variables to change factors, provided a better data fit. In the modified integrated model, baseline attitude and change in attitude directly explained the change in activity frequency. Moreover, statistically significant indirect paths were observed from baseline autonomous motivation through baseline attitude, and from activity frequency through change in attitude to change in activity frequency. The theoretical integrated model did not account for the change in active life engagement. The modified integrated model revealed significant change paths, highlighting autonomous motivation and attitudes as influential change constructs. For future intervention design, the modified integrated model appears useful in identifying behavior change pathways for older adults.