A new state law taking effect Monday will determine how end-of-life decisions are made for Pennsylvanians who don't leave a living will or other instructions should they become incapacitated.

Supporters of the law, which Gov. Ed Rendell signed in November, said an existing state statute on end-of-life care did little to help guide those decisions.

"We came to rely on families and friends, if there were no families around, to help us with these decisions," said Dr. Chris Hughes, a suburban Pittsburgh intensive-care doctor and member of the board of the Pennsylvania Medical Society. "That worked out pretty well, but we had no legal basis for this."

It also led to family arguments and misunderstandings, he said.

Under the new law, if a person hasn't designated someone in advance, the decision-maker shall generally be a spouse, adult child, parent, adult sibling, adult grandchild or close friend, in that order.

Hughes said many problems arise when a patient's wishes — such as orders not to resuscitate — are clearly indicated on their chart, yet that patient then is transferred to a hospice or nursing home and then back to the hospital and those records are not transferred with them.

The new law requires that a panel be established to address the problem and possibly implement a system already in use in states including Oregon and West Virginia.

Known as POLST — Physicians Orders for Life-Sustaining Treatment Paradigm — the system involves filling out a brightly colored form signed by the patient or the patient's surrogate that clearly spells out his or her wishes. The form, or a copy of it, stays with the patient wherever he or she goes.

Judith Black, medical director of senior products for Highmark Inc., a health insurance company, said dozens of organizations have been working collaboratively with Highmark since 2000 to voluntarily implement the program. The goal is to make sure patients are getting the treatments they want and not getting treatments they don't want.

"What this program does is it really puts to the forefront that advanced care is really a process," Black said. "People think they do a living will and they're done, but that's really not the case. It's as process."

Hughes said people with living wills need to make sure their relatives and their doctors know about it and know their wishes before they become ill.

"Communicating your wishes with your loved ones and your doctor is the key," Hughes said. "That's the best case scenario, and it will more than likely avoid family disputes."

The Pennsylvania Medical Society has posted information about the new law and end-of-life care planning at www.myfamilywellness.org.

The law was crafted with input from advocates for the disabled, associations representing doctors and lawyers, and faith-based groups. The disabled, in particular, were concerned about making sure they had a say in their care decisions.

"We wanted to make it clear that their lives are valued," Hughes said.

Patti Spencer, a Lancaster lawyer whose practice is devoted to estate planning and administration, said she's generally happy with the changes. But she said she's concerned about the state dictating who should make decisions for an ill patient.

"It's an attempt to write a health care directive for people who don't have one. It attempts to be one-size-fits-all and I'm afraid it's one-size-fits-none."

Spencer said she's concerned about families who are estranged or vulnerable elderly people who may be taken advantage of by a caregiver.

"It's impossible for the Legislature to cover every person's scenario," Spencer said.