Healthways Inc. has agreed to acquire a St. Louis-based company for $28.7 million to expand its services to health care providers such as hospital systems and doctor groups. The deal to acquire Navvis & Co. fits within Healthways' pursuit of opportunities beyond its core business of disease management and wellness services targeting health plans and employers. Navvis provides strategic counsel and change management services to help client health care systems to improve operations and clinical outcomes. Franklin-based Healthways expects to close the transaction by the end of the month. The $28.7 million price includes $23.7 million in cash and $5 million in Healthway's common stock. "It's not a huge deal..., but it just reinforces (Healthways') focus on hospitals and doctors," said analyst Brooks O'Neil of Dougherty & Co. in Minneapolis.