Understanding mediators of physical activity among individuals with diabetes

Abstract

Background. Exercise perceptions influence the adoption and maintenance of physical activity. This study investigated the following exercise perceptions: Self-efficacy for Exercise (SEE) and Outcome Expectations for Exercise (OEE-2), including Positive Outcome Expectations for Exercise (POEE) and Negative Outcome Expectations for Exercise (NOEE) and their influence on physical activity. Self-Efficacy for Exercise is operationally defined as an individual's perception that they can engage in a specified activity when faced with potential barriers. Outcome Expectations for Exercise is defined as an individual's belief that physical activity will produce either a positive outcome (POEE) promoting physical activity or result in a negative outcome (NOEE) deterring activity. Physical activity facilitates the regulation of blood sugar levels, yet a minority (44%) of individuals with diabetes engages in regular activity. Methods. This study was an ancillary study of the Drs. Elizabeth Walker and Hillel Cohen's Improving Diabetes Medication Adherence and Outcomes (I DO) study. The parent study was a 12-month randomized controlled trial with two treatment arms; telephone/print or print-only that focused on medication adherence. Participants had full prescription benefits provided by the 1199 National Benefit Fund and were almost exclusively New York City residents. This study assessed Self-efficacy for exercise (SEE), Outcome expectations for exercise (OEE-2) and self-report measures of physical activity at baseline and after 6 months. This study examined the effect of a 6-month telephone and/or mail health education intervention on the dynamics between the exercise perceptions: self efficacy for exercise and outcome expectations for exercise and physical activity levels among adults with uncontrolled diabetes. Results. There were 98 eligible participants (mean age 56.0 years, 62.2% female, 72.4% Black) who were recruited during the specified timeframe and completed all study measures. Most participants (56.1%) reported that they were advised to engage in a low level of physical activity by their health care team but more than half (51.1%) reported that they did not comply with this advice. The telephone intervention did not have a meaningful effect on exercise perceptions (SEE t(49)=0.08, p=.94; OEE-2 t(49)=-0.40, p=.70; POEE t(49)=-0.10, p=.92; NOEE t(49)=1.34, p=.18) but it did substantially increase the number of specific physical activity sessions, (i.e. bicycling, dancing etc.) engaged in per week (t(49)=-2.06, p=.05). The print-only arm demonstrated a significant effect on Negative outcome expectations for exercise (t(49)=3.84, p<.01), overall Outcome expectations for exercise (t(49)=-3.22, p<.01) and general activity levels (t(49)=-2.19, p=.03). Exercise perceptions were not found to predict changes in physical activity and did not meet Baron and Kenny's (1986) criteria for mediators. Conclusions. These findings suggest that a participant-tailored, telephone-based health education intervention over 6 months may increase specific physical activity sessions however these changes are not mediated by exercise perceptions. A primarily Black population of varying ethnic identities may also demonstrate different influences regarding exercise perceptions and physical activity levels than a primarily Caucasian population.