Hospitals' mistakes are going unreported

But he also noted that the state, prompted by a complaint from the patient's family, began looking into the matter so quickly that the hospital hadn't had time to determine whether or not the incident had to be reported.

Still, the numbers suggest underreporting is more than just a passing problem.

Calvin Johnson, the Pennsylvania secretary of health, said only people with their "head in the sand" would fail to see the problem of uneven reporting by hospitals. But he noted that with about 200 hospitals and millions of patient visits each year, it is impossible for the state to check every chart.

"It requires that something trigger the system," he said, such as a patient complaint.

Plaintiff lawyers said there were many cases to examine because of a large loophole in reporting requirements.

Hospitals don't report serious events if patients have been warned of the possibility of them in consent forms, said Clifford Rieders, a trial lawyer and member of the Patient Safety Authority's board.

He said he thought one reason many hospitals don't want to report serious events is that the law also requires that patients be informed in writing within a week of such problems. So, if a hospital doesn't report a problem, it doesn't have to send the patient that letter.

Rieders says the agency has allowed hospitals to determine for themselves what constitutes a serious event and the agency has failed to come up with a solid definition in six years.

Fixing this "is not a priority," he added.

Others on the authority's 10-member board said the agency was working on more concrete definitions.

"We are trying to come up with a tighter interpretation," said Ana Pujols-McKee, chair of the authority's board and chief medical officer at Presbyterian Medical Center in Philadelphia.

McKee said the disparity in reporting just became apparent after three full years of results.

In 2007, the authority said hospitals and other health facilities reported 7,277 serious events and 204,706 near misses. Hospitals accounted for 99 percent of the reports.

While it's important to study each of those reports, it is at least as crucial to identify hospitals that are not participating at all, said Conway, of the health-care improvement institute.

"We cannot improve care unless we understand the problems," Conway said. "There can't be safety without transparency."

Care Complaints

To file complaints

about hospital care:

In Pennsylvania, call the Department of Health:

1-800-254-5164

In New Jersey, call the Department of Health and Senior Services:

1-800-792-9770

For a list of states that require hospitals to report patient-care problems: