Reports of errors in Oregon hospitals grew slightly last year, according to the Oregon Patient Safety Commission. But that might actually be good news. The commission relies on voluntary reporting, and has been struggling to persuade hospitals to improve their reporting. Lawmakers created the commission in 2003 as a collaboration between state officials and the health care industry, including hospitals. The number of hospital errors reported in 2011 represents a slight improvement over prior years, but is still a tiny fraction of the number thought to be occurring and go unreported, based on research.