At one hospital, patients arriving with heart attacks always get an aspirin, a simple but effective measure that helps save lives.

At another, though, that doesn't happen. Until now, the public couldn't find out which hospital was which.

The federal government today unveiled a public Web site comparing different hospitals' use of "best practices" in the care of patients with pneumonia, heart failure and heart attack. It is searchable by state, city, county or ZIP code.

According to the Centers for Medicare & Medicaid Services (CMS), which developed the Web site, about 98 percent of hospitals in the U.S. supplied data on 10 evidence-based best practices.

CMS officials said the information should help patients make more informed decisions when picking a hospital, and encourage hospitals to improve their care.

Hospital participation in the quality comparison is voluntary, sweetened by the promise of increased reimbursement for patients covered by the government health-care programs.

And although hospitals self-report information, the federal agency — which requires audits and is the largest source of reimbursement for most hospital costs — "carries a big stick," said Lisa McGiffert, of the advocacy group Consumers Union.

In this state, all acute-care hospitals participated, with the exception of rural facilities too small for reports to be statistically significant, said Cassie Sauer, spokeswoman for the Washington State Hospital Association. Hospitals haven't always been happy to provide data publicly, she said, but were "enthusiastic" about this project.

"I think it will encourage hospitals to really improve their quality and focus on things we know will work," she said. Many have already improved low scores since the first quarter of last year, the time period covered by the report.

Although most consumer and industry watchdog groups say they see the hospital comparison as a laudable first step, they caution that the data available won't give patients a true picture of a hospital's actual quality of care. Some groups have actively urged reporting of infection rates, patient outcome information and medical staff-per-patient ratios.

"We think that this is some progress," said McGiffert, who heads the Consumers Union campaign for public disclosure of hospital infection rates. "They tell you how often [the hospital] gives a beta blocker when patients are discharged from the hospital. What we also want to see is how many people who had coronary bypass surgery died."

Charles Idelson, spokesman for the California Nurses Association, which has pushed for hospital staffing-ratio requirements in that state, said the information is "minimally useful for patients."

"They're looking at whether the hospital followed standardized protocols," Idelson said. "They're not even looking at whether the patient lived or died."

In addition, said McGiffert, the data is a year old, and may have changed significantly since then.

For example, at Swedish Medical Center's First Hill and Providence campuses, only 22 and 31 percent of pneumonia patients, respectively, got vaccine against a common form of the disease during the study period. Swedish's rates are now around 90 percent, said Dr. Curtis Veal, a pulmonologist who heads Swedish's Medical-Staff Quality Committee.

The Web site lists 17 best practices, but only 65 percent of hospitals around the country opted to provide data for all 17, said CMS' local spokesman Rod Haynes.

Swedish and Northwest Hospital & Medical Center said they were not providing data for all measures.

For many hospitals, in that awkward stage between electronic and paper records, pulling out the data has been difficult, hospital officials said.

"We track the data, but not in the way that CMS wants it," said Jennifer Harville, Swedish's director of clinical effectiveness.

Idelson, the nurses-association spokesman, said spending money on data collection may drain resources from staffing, leaving "clinical medical judgment" in the dust and harming patients' outcome — the real measure of hospital quality.

Hospitals have long resisted reporting patient outcomes publicly, saying the data is too complicated for patients to understand. Because different hospitals get patients with differing levels of complexity, formulas are used to adjust mortality rates, for example, but they're not easily explained. The same may hold for staffing ratios, hospital leaders said.

"The health-care marketplace is extremely difficult for consumers to assess," said Dr. Scott Barnhart, medical director of Harborview Medical Center. "What all these comparisons do is bring the patient into the dialogue about quality. As uncomfortable as that makes all of us feel, that is a conversation we all need to have."

Eventually, predicted Dr. Gregory Schroedl, Northwest Hospital & Medical Center's chief quality officer, the public will demand information about patient outcomes. Four states have adopted infection-rate disclosure laws, and 28 states, including Washington, considered such laws this year, Consumer Union said. In Washington, the bill did not make it out of a legislative committee.

Schroedl said Northwest supports public reports of both best-practices measures and outcomes. "The public has a right to know what the results are," he said.

Carol M. Ostrom: 206-464-2249 or costrom@seattletimes.com