Changes made five years ago to a Connecticut law aimed at revealing medical mistakes at hospitals have allowed the facilities to keep more errors secret, a Hartford Courant analysis shows.

The newspaper examined state health department records, death certificates, medical examiner reports and lawsuits. It found that narrower reporting requirements in the revised law have allowed hospitals to keep more mistakes from being reported to state regulators.

It also found fewer state investigations into such cases.

The General Assembly in 2002 ordered hospitals to disclose all serious patient injuries that were "associated with medical management." But that law was later changed in 2004 to limit the types of adverse events that must be revealed.