Scientists from the federal Centers for Disease Control and Maryland health officials began a study yesterday of the mortality rate at Prince George's General hospital and what factors could be associated with deaths there, law enforcement and hospital officials said.

The study, which will take four to six months, is being done at the request of the Prince George's County police who are continuing a seven-month investigation into a number of suspicious cases of patient care at the county's largest public health facility.

Prince George's State's Attorney Arthur A. Marshall said the investigation will look for any unusual clusters of deaths during the last four years.

Marshall said the study is part of the investigation of Jane Frances Bolding, a former intensive care nurse at the hospital charged in the suspicious death of a 70-year-old patient who was under her care.

Marshall eventually dropped charges against Bolding, but said he was continuing to examine circumstances surrounding the death.

Fred R. Joseph, Bolding's attorney, said he welcomes "any investigation," and added that he believes results of the CDC study will benefit Bolding.

"At some point," he added, "you've got to ask whether taxpayers will be willing to finance what appears to be a fishing expedition."

The patient, Elinor S. Dickerson of Oxon Hill, died in September 1984. Hospital officials initially listed her cause of death as cardiac arrest.

In March, police charged Bolding, 27, of Southeast Washington, with first-degree murder.

In statements filed in Prince George's District Court, police alleged that Bolding administered lethal amounts of potassium to Dickerson, "knowing this amount would cause the death and relieve Dickerson from further suffering."

Mary Stuart Rizk, a Prince George's hospital spokesman, said that the CDC investigators were conducting "on-site evaluations with physicians" this week and would return in January for further study.

The hospital conducted its own investigation into Bolding's activities in early March, when a 16-year-old accident victim in the intensive care unit suffered three heart attacks that could not be explained while he was under Bolding's care. Bolding was not charged in that case.

The hospital fired Bolding after the murder charge was filed against her. Joseph said Bolding did not return to work at the hospital when the charges were dropped but that her firing "has been resolved." Joseph said Bolding is still living and working in the Washington area, but he declined to say where.

Marshall said he first asked the state to conduct a mortality study but was turned down. He then turned to the CDC, which has performed similar studies. The CDC's completed report will be turned over to Marshall's office.

At a preliminary hearing District Court last April, police testified that between January 1984 and March 1985 patients in the hospital's intensive care unit suffered a total of 105 cardiac arrests and that 51 of those arrests occurred to 22 of Bolding's patients, 17 of whom died. A hospital spokesman said yesterday that the unit has three shifts daily, each of which is staffed by at least 10 nurses.