On a Thursday afternoon in early May, AlDora Sample was gasping for breath.

She called 911 a few minutes past 5 p.m. from her home in Camden. But the paramedic squad stationed in the city was tending to a drug overdose, so the dispatcher summoned a team from three miles away, in Pennsauken.

At rush hour, it took the medics more than 12 minutes to get to Sample's tan-sided house on Ware Street.

Was that fast enough?

Emergency medicine experts say evaluating a paramedic service based on its response times is a tricky proposition at best, depending on the type of emergency, geography, and other factors.

Yet last month, as New Jersey lawmakers passed a bill to transfer control of Camden's paramedic services from the Virtua health system to Cooper University Hospital, both sides cited response times to defend their positions.

In a battle of statistics, Cooper chairman George E. Norcross III said Virtua's paramedics too often failed to arrive within eight minutes. Virtua argued that a 10-minute standard was more appropriate.

The reality is more complicated, according to an Inquirer analysis of 2,952 paramedic runs in Camden during the first half of this year - covering 18 types of emergencies from gunshots to seizures.

Among the findings for the paramedics, who are trained in advanced life support:

In 69 percent of cases, Virtua's paramedics arrived on scene within eight minutes of being dispatched.

In 89 percent of cases, medics were on scene within 10 minutes.

For cardiac arrests, among the most time-sensitive of emergencies, medics got to the patient within eight minutes 84 percent of the time, and within 10 minutes 95 percent of the time.

For gunshots, a medic squad beat the eight-minute mark in 97 percent of cases - needing more time just once out of 29 such calls from Jan. 1 through mid-June.

The analysis was based on raw data provided by the Camden County Public Safety Department.

Sample, 52, who suffers from emphysema, said she could not remember the details of May 7, the day of her rush-hour crisis, other than that she was successfully treated. Due to chronic health problems, Sample had called 911 on several other occasions around the same time.

On five other calls this year when paramedics were sent to her address, records show they arrived much faster, twice in about five minutes. Her sister, Joanne, said at least one of those calls was for her, when she suffered an irregular heartbeat.

"They almost kicked my door in trying to get to me," said Joanne Sample, 61. "They are very good."

Still, her sister said she expected fast action every time. "The point is, I called," AlDora Sample said.

Speed is, indeed, of the essence for many types of crises, but emergency medical services know that some trips will take longer than they want.

Some EMS departments set a goal of getting paramedics on the scene within eight or nine minutes in at least 90 percent of cases.

New Jersey does not require a specific time. But a decade ago, a state panel recommended a target of 10 minutes, which Virtua says it routinely meets.

Those benchmarks grew out of an American Heart Association recommendation for just one type of emergency: cardiac arrests.

For most emergencies, there is no evidence that patients do better if aided by paramedics within eight or 10 minutes, said Ernest Yeh, chief of the EMS division at Temple University Hospital.

"There's no hard number," Yeh said. "There's not that standard across the board."

Depending on the type of emergency, the patient may simply need to get to the hospital quickly - whether accompanied by paramedics; by emergency medical technicians, who have less training; or by police officers.

In any event, Yeh said, it is important for EMS units to track their responses by type of emergency, including the amount of time needed to reach the patient and - even more important - whether appropriate care was provided.

Virtua says it measures how often its paramedics engage in a variety of best practices, such as administering an electrocardiogram to heart patients within five minutes. They do so in 99 percent of cases, the health system says.

A statewide advisory committee, chaired by Virtua paramedic Scott Kasper, is meeting this year to recommend performance standards.

Under the terms of legislation signed by Gov. Christie on July 6, Cooper is slated to take over Camden's paramedic services from Virtua in six months. Virtua officials have said they might challenge the move in court.

The law also would place Cooper in command of the city's emergency medical techs, who provide basic life support and drive ambulances. The techs are currently employed by Newark-based University Hospital.

Cooper has declined to say much about specifics of its plan, citing the need for approval by the state Department of Health, though a spokesman for Norcross, the chairman, has pledged that response times would improve.

Another element of Cooper's strategy does not involve response to emergencies at all, but ways to prevent them.

The Camden-based health system hopes to engage in "community paramedicine" - using paramedics to check on chronically ill patients in between emergencies, according to a letter to state lawmakers from Steven E. Ross, director of Cooper's Center for Trauma Services.

This model has been tried elsewhere and could help, in theory, provided that the EMS personnel get adequate training, said Temple's Yeh.

They could learn to help patients keep track of and refill medications, for example, potentially cutting down on hospital admissions, he said.

"The typical training for a paramedic or EMT does not cover that kind of preventive health maintenance," Yeh said.

Still unclear is how many paramedic units Cooper would employ and where they would be stationed.

The Inquirer analysis found several "hot spots" in the city that accounted for a disproportionate share of responses that took more than 10 minutes. These were generally on the outer edges of the city, away from Virtua's centrally located paramedic station on Atlantic Avenue.

And when paramedics from that station were tied up and dispatchers sent for squads from Pennsauken or farther away in Haddonfield, calls were more likely to take longer than 10 minutes.

Yeh said the key was to make sure squads arrive fast when it is most important, to maximize available resources.

"If you have pneumonia, and you get to the hospital five minutes sooner, does that make a difference?" he asked. "Probably not."