Effects of lifestyle intervention on health care costs: Improving Control with Activity and Nutrition (ICAN).

OBJECTIVE: To evaluate program and health care costs of a lifestyle intervention in a high-risk obese population. DESIGN: Twelve-month randomized controlled trial comparing lifestyle case management to usual care. SUBJECTS/SETTING: Health plan members (n=147) with obesity (body mass index >/=27) and type 2 diabetes. INTERVENTION: Lifestyle case management entailed individual and group education, support, and referrals by registered dietitians. Those in the usual-care group received educational material. MAIN OUTCOME MEASURES: Medical and pharmaceutical health care costs reimbursed by the participant's primary insurance company. STATISTICAL ANALYSIS: Total costs were modeled using the four-equation model using previous year cost as a predictor. RESULTS: Net cost of the intervention was $328 per person per year. After incorporating program costs, mean health plan costs were $3,586 (95% confidence interval [CI]: -$8,036, -$25, P<0.05) lower in case management compared to usual care. The difference was driven by group differences in medical (-$3,316, 95% CI: -$7,829 to -$320, P<0.05) but not pharmaceutical costs (-$239, 95% CI: -$870 to $280, not statistically significant), with fewer inpatient admissions and costs among case management compared with usual care (admission prevalence: 2.8% vs 22.5% respectively, P<0.001). CONCLUSION: Addition of a modest-cost, registered dietitian-led lifestyle case-management intervention to usual medical care did not increase health care costs and suggested modest cost savings among obese patients with type 2 diabetes. Larger trials are needed to determine whether these results can be replicated in a broader population. The findings can be judiciously applied to support that the addition of a registered dietitian-led lifestyle case-management program to medical care does not increase health care costs.