The state agency responsible for determining which hospitals are most vulnerable to earthquakes got the OK Wednesday to use a new computer modeling program to re-evaluate buildings previously given "high-risk" labels.

The California Building Standards Commission's 7-0 decision to allow the use of the HAZUS program is expected to lead to hundreds of California hospital buildings being moved to lower risk categories.

Office of Statewide Hospital Planning and Development spokesman Pat Sullivan said tests run using data already submitted by a small pool of hospitals suggests 50 percent to 60 percent of the roughly 1,100 buildings labeled high risk could end up being reclassified under the new program.

Reclassified buildings' owners will get an extra 23 years to comply with a state mandate that high-risk structures be upgraded or replaced with earthquake-proof ones. Structures that retain their high-risk status will still have to meet a 2013 deadline.

The California Hospital Association quickly praised the commission's decision, saying it will help preserve patients' access to health care.

"We all want our local community hospitals to be able to withstand and remain operational following a major earthquake," association President C. Duane Dauner said in a news statement. "By implementing the new HAZUS methodology, resources can be directed towards ensuring that the most vulnerable buildings are addressed first."

Officials at North County and Riverside County hospitals have been grappling with the question of how they would comply with the state mandate. They had mixed reactions to the commission's decision.

Palomar Pomerado Health Chief Executive Officer Michael Covert, whose public hospital district runs Palomar Medical Center in Escondido and Pomerado Hospital in Poway, welcomed the news.

"It's going to give lots of hospitals around the state opportunities to do a better job of meeting those time frames, 'cause I know a lot of them couldn't," he said.

Julie Lee, spokeswoman for Scripps Memorial Hospital Encinitas, said the change was unlikely to help her hospital or other Scripps facilities in the San Diego area because it has so many fault lines.

Jeff Segall, spokesman for Tri-City Medical Center in Oceanside joined Teresa Fleege, spokeswoman for Rancho Springs Medical Center in Murrietta and Inland Valley Medical Center in Wildomar, in saying officials at their hospitals need more time to figure out exactly how the commission's decision might affect those facilities.

The California Hospital Association had supported the Office of Statewide Health Planning and Development's request for permission to use HAZUS to re-evaluate hospital buildings' seismic vulnerability.

Developed by the Federal Emergency Management Agency, the program is more accurate than others because it takes into account the type of soil a structure stands on, its proximity to major fault lines and other factors not considered when state officials made their original assessments.

Those were done after state legislators beefed up the earthquake standards for hospitals following the 1994 Northridge earthquake. Roughly 40 percent of hospital buildings in the state, or about 1,100, got the "high risk" classification.

Many hospitals had trouble meeting an original 2008 deadline for meeting the state mandate, with lack of money being a major roadblock. The state eventually extended the deadline to 2013 for hospitals that could show they were making progress toward meeting the mandate.

Tri-City Medical Center in Oceanside and Palomar Pomerado each have cited the deadlines in campaigns for the passage of large construction and renovation bonds. Voters approved a $496 million bond for Palomar Pomerado in November 2004.

Two different Tri-City bond measures failed at the ballot box, though. Officials at the district are considering whether to make a third try.

John A. Martin Jr., a structural engineer whose firm is working with Tri-City on its renovation plans, told the North County Times last month that the hospital's north wing is among those likely to be moved to a lower-risk category. Two other Tri-City buildings, which Segall identified Wednesday as the center and south structures, probably will stay on the high risk list, Martin said.

Segall said that while he does not dispute the engineer's assessment, the prevalence of fault lines in San Diego County means Tri-City will continue to face significant earthquake risks.

"The point is you never know where and when that one big earthquake is going to be," he said.

Palomar Pomerado is preparing to break ground on a new hospital that was sold to the public as being more economical than trying to upgrade two Palomar Medical Center towers rated as extremely vulnerable to earthquakes. Covert said Wednesday architects have told him the towers also are likely to be reclassified.

Still, he said, "I don't think it will change our time frame in terms of (construction) activity."

- Staff writer Paul Sisson contributed to this story. Contact staff writer Andrea Moss at (760) 739-6654 or amoss@nctimes.com.