Promoting Physical Activity in People With Type 2 Diabetes: Findings of an N-of-1 Study

Abstract

Background: To test within an n-of-1 design whether brief interventions (1) increase physical activity (PA)and (2) reduce sedentary activity (SA) in people with Type 2 Diabetes; and to examine whether effects are mediated by psychological process measures taken on a daily basis. Methods: Six participants wore an accelerometer device for 6 months that deliver different instructions on alternate days (either to improve PA, reduce SA or no instruction) while measuring physical activity levels. Participants recorded levels of confidence, self-efficacy, stress, pain, happiness and motivation on a daily basis. Results of the n–of-1 study were analysed by bootstrapped time series analyses. Findings: Participants varied in response to the PA and SA interventions with some being more responsive to PA whereas others were more responsive to SA. Self-efficacy and happiness were routinely predictive of physical activity levels Discussion: The n-of-1 design highlighted how participants respond differentially to interventions targeting PA as opposed to SA and that level of response to an intervention was mediated by psychological processes.