Drug spending per member for public health insurance exchange plans sponsored by Express Scripts clients increased 14% in 2016, driven by increases in both unit costs and use, according to a new report by the pharmacy benefit management company. Drug spending per member for Medicaid, Medicare Part D, and commercial plans for employees and their families sponsored by Express Scripts clients rose 5.5%, 4.1% and 3.8%, respectively, in 2016, the company said.