Each of those 71 physicians prescribed drugs to three or more patients who died.

Four of the doctors — including Vu — had 10 or more patients who fatally overdosed.

Vu had the highest total: 16.

Experts said the findings challenge the prevailing view of what is driving the surge in overdose deaths and should prompt closer scrutiny of doctors and their prescribing practices.

"The data you have is something that's going to shock everybody," said Dr. Jorge F. Carreon, a former member of the Medical Board of California.

Carreon, a South Gate physician whose term on the board ended in July, said he had long suspected that doctors' prescriptions were contributing to the increase in overdoses. The Times' analysis, he said, showed that it was "worse than what I thought."

President Obama's drug czar, R. Gil Kerlikowske, said of the findings: "Do I think this has the potential to change the game in the way it's being looked at and being addressed, both at the state and federal level? Yes, I do."

In its review of prescription drug fatalities, The Times examined cause-of-death findings, toxicology reports and other information in county coroners' files, including lists of prescription medications found at death scenes. Those lists typically identify the prescribing doctor.

The deaths often stemmed from multiple drugs, sometimes prescribed by more than one physician. In some cases, the deceased mixed alcohol or illicit drugs with prescription medications.

Medical experts say that even one overdose death should prompt a doctor to conduct a thorough review of his or her prescribing.

"Personally, it would be a big, big deal," said Dr. Peter Przekop, a pain and addiction specialist at the Betty Ford Center in Rancho Mirage and an assistant professor at Loma Linda University School of Medicine. "I would certainly want to stop using those medications until I knew what was going on."

The 71 doctors with three or more fatal overdoses among their patients are primarily pain specialists, general practitioners and psychiatrists. Almost all work alone, without the peer scrutiny that is standard in hospitals, group practices and HMOs.

Four of them have been convicted of drug offenses in connection with their prescriptions. A fifth is awaiting trial on charges of second-degree murder in the overdose deaths of three patients.

The rest have never faced criminal prosecution over their practice of medicine, and most — including Vu — have spotless records with the Medical Board of California, which licenses and oversees physicians.

Dr. Lynn Webster, president-elect of the American Academy of Pain Medicine, said many physicians lack an appreciation of how easily patients with chronic pain can become addicted to their medications, and how dangerous those drugs can be.

"It leads them down a path that can be very harmful, and that's what physicians have to watch for," said Webster, who practices in Salt Lake City.

He said physicians who prescribe pain medications have a duty to screen patients for risk factors for addiction, and then to watch them closely to prevent abuse.

In interviews, several of the 71 Southern California doctors with multiple patient deaths described themselves as compassionate caregivers who try to ease the suffering of those in pain.

Vu and others said they follow recommended practices to deter drug abuse, including requiring patients to sign "pain management contracts" in which they agree to take their medications as directed and not obtain more from other doctors.

Some of the 71 doctors said overdose victims caused their own deaths by ignoring instructions on the safe use of medications. Some said family members of the deceased bore responsibility too for failing to intervene. Some also faulted health insurers, saying that reduced payments to physicians have made it difficult to spend the time to monitor patients adequately.