I In this proposal, we address the important role of the health care system and social context in the management of weight loss among low income patients with cardiovascular disease. We have partnered with Boston HealthNet, a network of 10 community health centers that provide care to low income and racial/ethnic minority populations, and will conduct a practical clinical trial that will allow us to address issues of effectiveness, generalizability, cost and sustainability and potential for wide-scale dissemination. A key goal of the intervention design has been to use multiple health information technologies to maximize the maintenance of behavior change and the cost-effectiveness of the intervention. 624 Obese, lower income, predominately racial/ethnic minority health center patients who have been diagnosed with hypertension will be enrolled and randomized into one of three conditions: (1) Usual care (UC) plus the NHLBI's Aim for a Healthy Weight brochure;(2) Lifestyle modification with electronic supports (ES), which includes a weight loss 'prescription', skills training and self-monitoring for patients, with all intervention strategies delivered through interactive, phone-based, and print methods, without personal contact but with strong linkages to primary care;and (3) Lifestyle modification with electronic support plus interpersonal and socio- environmental support (ES + SS) provided by community health workers and through linkages to community resources. The conditions have been selected to determine if a multi-level interpersonal component increases the cost-effectiveness of the automated intervention. The primary outcome is weight loss measured at 2 years (intermediate assessments at 6, &12 months).
We aim for a 7% weight loss at 24 months in condition 3 (ES+SS) vs. usual care, based on the changes achieved in the diabetes prevention trial. We assume that condition 2 (ES) will achieve half this level of weight loss over 24 months. 208 patients per condition gives us 80% power after Bonferroni correction to evaluate the weight changes between the three groups. In addition to the primary analysis we will also evaluate the role of mediators and using the RE- AIM theory to implement a multi-faceted dissemination plan and to report on key issues such as moderator characteristics at both practice/clinician and patient/social environmental level.
