Preventable medical errors cost the country $19.5 billion in 2008 — or roughly $13,000 for each avoidable case, according to a report published Monday by the Society of Actuaries. And that number is likely low, according to consultants at Milliman, who crunched the data. More than half of those costs were associated with just five avoidable medical injuries: pressure ulcers; post-op infections; mechanical troubles with devices, implants or grafts; post-laminectomy syndrome; and hemorrhages. Aside from the direct financial effect, the 2008 errors also resulted in more than 2,500 avoidable deaths and more than 10 million missed work days.