Geographical equity in chronic disease control: Improving Control with Activity and Nutrition

Equal access to effective lifestyle change programs is crucial if we are to achieve chronic disease prevention and control for all. Geographical access may influence program participation. One geographical barrier to sustained participation may be long travel times to program sites. We used data from a multi-site clinical trial of diabetes control among people with obesity to determine whether travel time predicted participant retention over the course of the study. Using geographical information system mapping, we calculated road distance and travel time from participants‘ residences to their clinical sites (one urban, one small city, and two rural sites), and used those data to predict participant retention over the course of the 42-month follow-up. Mean travel time was 22.0 minutes (SD=24.7). In logistic models, travel time was associated with program withdrawal in both adjusted models (odds ratio [OR]=1.012, 95% confidence interval [CI]=1.002-1.021) and after adjustment for hemoglobin A1c, body mass index, age, gender, race, education, income, and clinical site (odds ratio [OR]=1.012, 95% confidence interval [CI]=1.002-1.022). Exponentiating the log odds of withdrawal suggested that 22 minutes of travel time was associated with 30% increased risk of withdrawal from the program. In this setting travel time was predictive of participant retention in the intervention in unadjusted and adjusted analyses. To assure equity of access, chronic disease lifestyle intervention programs should use participant travel time to locate their program sites.