What began last June with a missing government computer drive small enough to hold in one hand led to 100,000 letters of apology to Medicaid patients, a probe by the Colorado Bureau of Investigation and a retraining program for 31,000 state employees. That security breach now reverberates throughout a major 2011 push for digitizing patient medical records in Colorado. After months of arguments over WikiLeaks and a brutal audit of state security measures, health officials are moving to reassure consumers their most intimate secrets will stay safe amid a federal rush to centralize data. In coming weeks, patients across Colorado will receive letters saying their healthcare provider is about to join an "information exchange." More than 800 Colorado providers have signed agreements with the state agency sponsoring the exchanges.