Maintenance of Physical Activity and Dietary Change Following a Telephone-Delivered Intervention

Objective: To examine the maintenance of behavioral changes 6 months following a telephone-delivered physical activity and diet intervention. Design: Patients (n = 434) with Type 2 diabetes or hypertension were recruited from 10 primary care practices in a disadvantaged community; practices were randomized to a telephone-counseling intervention (TC; 5 practices, n = 228) or usual care (UC; 5 practices, n = 206). Main Outcome Measures: Validated, self-report measures of physical activity and diet were taken at baseline, 12 months (end-of-intervention), and 18 months (6 months postintervention completion). Results: For physical activity, the significant (p < .001) within-groups improvements from baseline observed at 12 months remained at 18 months, in both the TC (62.2 +/- 14.2 minutes/week; 2.2 +/- 0.3 sessions/week) and UC (74.7 +/- 14.9 minutes/week; 2.1 +/- 0.4 sessions/week) groups. For all dietary outcomes, significant (p < .05) between-groups maintenance effects, similar to end-of-intervention outcomes, remained [TC-UC changes from baseline to 18 months (95% CI)]: total fat [-1.33(-2.16, -0.50)% energy/day], saturated fat [-1.06 (-1.70, -0.43)% energy/day], fiber intake [1.90 (0.72, 3.15) grams/day], and fruit [0.22 (0.05, 0.40) servings/day]), except vegetables [0.59 (-0.01, 1.17) servings/day; p = .05]. Intervention effects across all health behavior outcomes were stronger for the subgroup (n = 145) adhering to the study protocol. Conclusion: Telephone-delivered interventions can promote maintenance of health behavior change. Studies with longer-term follow-up are needed, particularly to determine how intervention duration and intensity might further enhance maintenance.