Researchers call for more ambulances in hot spots during peak times.

A GROUP of medical researchers has found that emergency calls are not as random as they seem.

The researchers found patterns to the calls and believe their findings may help ambulances get to emergencies more quickly, raising the chances of saving more lives. The group is suggesting that rather than stationing ambulances at fire stations and posts the Singapore Civil Defence Force (SCDF) gets them out patrolling areas of high demand.

The Cardiac Arrest and Resuscitation Epidemiology study group looked at thousands of calls to the 995 hotline in the first five months of 2006 and found that Mondays had by far the highest number of emergency calls. The numbers gradually dipped over the week before rising slightly on Sundays. Saturdays saw the lowest number of calls - about 10 percent fewer calls than that on Mondays, or a difference of 600 calls.

One of the researchers, Dr Marcus Ong, said this is consistent with emergency department studies elsewhere, which also show that Mondays are the busiest.

Calls come more often in the day, with almost twice as many as at night. The peak hours are 9am to 1pm.

"This may be related to diurnal patterns of the body and hormone activity levels that trigger medical events," Dr
Ong, an emergency medicine consultant at the Singapore General Hospital, added.

Most of the daytime calls come from the commercial and business districts which are in the south of the island.

Calls at night are from the residential areas, when more people are at home.

The region that produced the most calls was the east where the population is densest, although the individual neighbourhoods with the highest demand were in the north and north-east.

The researchers hope the patterns they have identified help the SCDF deploy its fleet of 50 ambulances better.

"There has been a growing understanding that medical emergencies and ambulance calls are not random events but occur in patterns and trends that can be observed historically," said the group's study which was published in the Academy of Medicine Annals earlier this year.

And based on the results of the study, as well as patrolling areas of high demand, the researchers suggest more
ambulances be deployed at peak times.

"Ambulance manpower should be deployed to match these peaks rather than the current fixed manpower and shift system being used now," the study said.

Currently, each station has a certain number of paramedics on a 24-hour shift rotation although some fire stations
already have more ambulance crews than others because they are busier.

The SCDF already has more ambulances on call during the day than at night.

There are currently 15 fire stations and 26 fire posts spread out relatively evenly across the island. Fire posts, introduced in 2001, are like "branches" of fire stations located in the HDB heartland and key industrial areas, bridging operational gaps that bigger stations cannot address.

Ambulances are stationed at all fire stations except Jurong Island Fire Station and at all fire posts except six - Sentosa, Clementi West, Marine Parade, Loyang, Punggol North and Jurong West.

The SCDF said its deployment pattern was based on call load analysis, but added it will be evaluating the study's
findings. Its standard response time for ambulances is 11 minutes which it has been able to meet more often after 10 private ambulances were roped in to supplement the SCDF fleet in June.

Emergency calls have almost doubled from 60,300 cases in 1995 to last year's 117,896 cases. It is set to go up even more with the population ageing and growing. SCDF projections show that by 2030, it would clock 235,000 such calls a year.

The SCDF has also introduced ways to cut down on ambulance-response time.

For example, under the Medical Protocol System started in April, emergency call operators keep callers on the line after the ambulance has been sent out so they can establish patients' medical histories and exact nature of the situation.

Meanwhile, Dr Ong said the researchers plan to study the economic and social background of those calling ambulances, explaining: "This may reveal further patterns that may influence ambulance placement."

carolynq@sph.com.sg
jwang@sph.com.sg