RE: SSM from Canadian Emergency News

September 29, 2005

And what the heck...its only tax dollars we are wastin....er....I mean investing

in the future protection of the fine citizens of Community XYZ.

You want to impress people...with the increased risk and danger of firefighting

along with the decrease in fires...try some new ways of delivering the service

and get out of the rut of Fire Station = 1 Big Truck+12 (or more) new

employees+really big brick and mortar building, etc etc. How about plus up

staffing on the Big Fire Trucks in stations farther apart with some 2 person

quick attack vehicles in between the big truck stations to run EMS calls (the

majority of the work) nuisance runs (alarms, dumpster fires, smoke calls, etc)

so that you deliver the same timely response at a lower cost but still have the

adequate response for the rare 7% of the time you have real fires....just more

efficiently.

Sorry....but this has been on my mind for some time.

Dudley

Re: SSM from Canadian Emergency News

>

> My partner and I are EMS consultants and we never recommend SSM. We

always

> point out the things that Dr. Bledsoe has stated, and attempt to undo the

> damage that has been done by folks like Stout and his followers.

>

> Gene Gandy

> HillGandy Associates

> EMS Consultants

>

> > why I ask if it has been tried and tried in EMS do " consultants "

continue

> > to push the idea that SSM is the way? If these people were true

statisticians

>

> > they would know by now that this has failed time and time again.

> >

> > SSM from Canadian Emergency News

> >

> > The Fallacy of System Status Management (SSM)

> >

> > By Dr. E. Bledsoe

> >

> > The concept of System Status Management (SSM) was

introduced

> > to

> > EMS in the May, 1983 issue of JEMS magazine. <outbind://38/#_edn1> [1]

> > Stout

> > was a research fellow at the University of Oklahoma in the late 1970s

and

> > a

> > part of a team of economists and behavioral scientists that was

organized

> > to

> > perform a theoretical analysis of the prehospital care " industry. " The

> > team,

> > known as the Health Policy Research Team, was funded by a grant from

the

> > Kerr Foundation. The team was headed by Stout. However, Stout

subsequently

> > left the university and founded an EMS consulting firm known as The

Fourth

> > Party. The Fourth Party specialized in the development of " high

> > performance

> > EMS systems " which meant they primarily used the Public Utility Model

> > (PUM)

> > as a template for system design. Approximately 15 U.S. EMS systems

adopted

> > the PUM. However, there have been no new PUMs developed in the last 20

> > years

> > and several of the established PUMs have suffered significant

financial

> > problems, high employee turnover, and similar issues.

<outbind://38/#_edn2>

> >

> > [2]

> >

> > The SSM theory was first applied to EMS operations in

Tulsa

> > and

> > Oklahoma City and later to several other Midwestern U.S. cities.

Later,

> > several of the various components of " high performance EMS " were

adopted

> > by

> > systems that do not use the PUM. Several EMS systems in Canada have

> > adopted

> > SSM. It is important to point out that virtually all EMS systems and

fire

> > departments have had deployment plans. That is, when several units in

a

> > particular part of town are busy, other units are routed toward that

part

> > of

> > town in order to decrease response times in case a call is received.

Stout

> > took this one step further. He wrote, " System status management refers

to

> > the formal or informal systems protocols and procedures which

determine

> > where the remaining ambulances will be when the next call comes in. "

> > Stout

> > recommended that one look at both historic and geographic data in

order to

> > predict where the next ambulance call may occur and direct ambulances

in

> > that direction. He suggested that EMS follows a " weekly cycle " and SSM

> > should target that. Typically, 20 weeks of historic and geographic

call

> > data

> > are kept in the computer-aided dispatch (CAD) system. From this,

> > ambulances

> > are placed based upon perceived need. The foundation of SSM is to

develop

> > a

> > system status management plan.

> >

> > In 1986, Stout further detailed the use of CAD to enhance

SSM.

> > <outbind://38/#_edn3> [3] He stated, " My own opinion is that it

becomes

> > impossible to reliably handle SSM controls on a manual basis when your

pea

> > k

> > load coverage exceeds seven or eight units. After that level, you need

> > automation. "

> >

> > The advantages of SSM, as detailed by Stout, are:

> >

> > * Reduce non-emergency service delays

> > * Equalize service among neighborhoods

> > * Safely " make room " for non-emergency service production at low

> > marginal cost

> > * Reduce the use of on-call crews

> > * Reduce the frequency of post-to-post moves

> > * Equalize workloads among crews

> > * Differentiate workloads of 24-hour crews from those of short

shift

> > crews.

> > * Furnish better mutual aid service

> > * Reduce use of mutual aid service

> > * Cut overtime

> > * Employee schedules more convenient to crews

> > * Battle " cream-skimmers " working your market.

> > * Cut production costs without hurting response time performance.

> >

> > In 1989, in response to criticism of SSM, Stout published another

article

> > in

> > JEMS that supposedly debunked the 6 " so-called " myths of SSM.

> > <outbind://38/#_edn4> [4]

> >

> > Fallacies

> >

> > With this introduction in mind, let's look at the fallacies of this

plan.

> >

> > 1. No peer review publications. System status management was

> > introduced

> > in several issues of the Journal of Emergency Medical Services (JEMS).

> > JEMS

> > is a U.S. EMS trade magazine and not peer-reviewed. A literature

search

> > failed to identify any scientific paper detailing the effectiveness of

> > SSM.

> > Several papers are written in scientific journals-but each is written

> > under

> > the premise that SSM is a proven system. <outbind://38/#_edn5> [5],

> > <outbind://38/#_edn6> [6] The burden of proof for a particular system

or

> > practice is upon the proponents of such a system. With SSM, many in

EMS

> > adopted it at face value because it " intuitively " made sense or they

were

> > dazzled by suggested cost savings and improvements in efficiency.

> > 2. Calls are predictable. It is intuitive that there will be more

EMS

> > calls during times when there are more cars on the road. And, it is

> > intuitive that accidents are more likely to occur on roads. Thus, it

makes

> > sense to have an adequate number of ambulances during drive time and

to

> > position those ambulances where they can rapidly access major

> > thoroughfares.

> > Now, this is where SSM falls apart. It is statistically impossible,

with

> > ANY

> > degree of accuracy, to predict where an ambulance call will occur

(either

> > geographically or temporally) based upon 20 weeks of data. In

discussing

> > the

> > concept of SSM with 2 statisticians who hold doctorates, I asked how

many

> > weeks of data would be necessary to make an EMS call (or trend)

prediction

> > with any degree of scientific accuracy for a city the size of Fort

Worth

> > Texas (approximately 800,000 people). One said 20 years and the other

said

> > 100 years. Both pointed to the inability of weather service to

accurately

> > predict the high temperature for a day. With over 100 years of data,

> > meteorologists can predict, with limited scientific accuracy, what the

> > high

> > temperature for a given day will be. Despite this, they are often

wrong.

> > And, they are dealing with a single variable!

> >

> > The ability to predict where and when a call will occur is

> > nothing more than the statistical term probability. By definition,

> > probability is a numerical quantity that expresses the likelihood of

an

> > event and is written as:

> >

> > Pr {E}

> >

> > The probability Pr {E} is always a number between 0 and 1. For

example,

> > each

> > time you toss a coin in the air it will fall heads or tails. If the

coin

> > is

> > not bent, it will equally fall heads and tails:

> >

> > However, with SSM we are using multiple random variables. The mean of

a

> > discrete random variable (Y) is defined as:

> >

> > where all the y1's are the values that the variable takes on and

the

> > sum is taken over all possible values. The mean of a random variable

is

> > also known as the expected value and is often written as E(Y) (thus

> > E(Y)

> > = .)

> >

> > Consider trying to predict where a call will occur in Fort

> > Worth, Texas. Say, for example, there are 200,000 addresses in the

CAD.

> > There are 1,440 minutes in a day. Thus, what are the chances of making

a

> > calculation with this many variables that is nothing more than chance?

The

> > answer? Virtually impossible-even with a super computer. Furthermore,

if

> > an

> > EMS system ever gathered enough historic and geographic data to make a

> > prediction as to call time a location, the socioeconomic status of the

> > city

> > will have changed making the predictions irrelevant.

> >

> > 3. Reduce non-emergency service delays. In theory, SSM is designed to

> > reduce non-emergent delays. However, in most systems that use SSM,

> > non-emergency delays remain a major problem. The categorization of

calls

> > (and the low priority of non-emergency calls) continues to bump

> > non-emergency calls down while ambulances are posted to perceived need

> > areas

> > in the event an emergency call comes in.

> >

> > 4. Equalize service among neighborhoods. This is one of the biggest

> > fallacies of SSM. We know, from empiric studies, that ambulance demand

is

> > higher in low socioeconomic areas and areas where large numbers of

elderly

> > people live (also often low socioeconomic areas). Cadigan and Bugarin

> > found

> > that differences in EMS demand are related to median income,

percentage of

> > the population more than 65 years of age, and percentage of people

living

> > below the poverty level. Increased EMS demand was found in areas where

a

> > significant percentage of the population is greater than 65 years of

age

> > or

> > living below the poverty level. <outbind://38/#_edn7> [7] Thus, if SSM

is

> > working as it should (diverting ambulances from predicted low call

volume

> > areas to predicted high call volume areas), ambulances should be

routinely

> > diverted from the younger and more affluent areas of town to regions

where

> > the population is older and living below the poverty level. This, in

fact,

> > discriminates against parts of town that use EMS infrequently (and

parts

> > of

> > town where the majority of taxes are paid).

> >

> > 5. Safely " make room " for non-emergency service production at low

> > marginal cost. In the U.S., reimbursement is better (and more

reliable)

> > for

> > non-emergency calls than emergency calls. However, in Canada, the

> > differences in reimbursement are much less. Thus, SSM will not

> > significantly

> > benefit Canadian EMS systems from this perspective.

> > 6. Reduce the use of on-call crews. Here, Stout is being honest.

SSM

> > is

> > designed to reduce staffing. More importantly, it is designed to

reduce

> > costs as posting ambulances from a central facility decreases the need

for

> > brick and mortar stations-a significant cost for EMS systems. This is

> > particularly true for " for-profit " EMS systems in the U.S. that must

also

> > pay property taxes (ad-valorem) on brick and mortar stations

(governmental

> > agencies do not have to pay taxes). Looking beyond the smoke and

mirrors,

> > one of the main purposes of SSM is to get as much work as possible out

of

> > a

> > subset of employees before bringing in back-up personnel which may

cost

> > overtime.

> > 7. Reduce the frequency of post-to-post moves. Another fallacy!

It is

> > not uncommon for an EMS unit to travel 100-200 miles in a day and only

run

> > 3

> > calls-the remainder of the time moving from post-to-post. Remember,

the

> > CAD

> > cares not about the crew-only the location of the ambulance.

> > 8. Equalize workloads among crews. If the system is not busy, SSM

can

> > equalize the workload. However, if the system is busy, EMS units that

are

> > busy stay busy. In many cities, hospitals are located downtown or in

lower

> > socioeconomic areas. Thus, every time a crew takes a patient to the

> > hospital, they are closer to the next call when they clear the

hospital.

> > This is why some crews will run emergency calls all day while another

crew

> > does nothing but posts.

> > 9. Differentiate workloads of 24-hour crews from those of short

shift

> > crews. This sounds good on paper. But, the CAD does not know a 24-hour

> > crew

> > from another crew. It simply selects the next closest ambulance

> > regardless.

> > 10. Furnish better mutual aid service. In the PUM, EMS systems

are

> > often

> > financially penalized when they provide mutual aid-especially if it

delays

> > response times in their primary response area. Thus, systems using SSM

are

> > often reluctant to enter into mutual aid agreements with surrounding

> > agencies. When this does occur, mutual aid is provided to the system

using

> > SSM more than system ambulances responding to neighboring communities

> > (which

> > are often suburbs).

> > 11. Reduce use of mutual aid service. This is a non-sequitur.

Stout

> > wants to furnish better mutual aid service and, at the same time,

reduce

> > the

> > use of mutual aid. The latter is the real preference as using mutual

aid

> > may

> > be accompanied by a financial penalty. Thus, in many SSM systems, when

the

> > system reaches capacity-ambulances are asked to use lights and sirens

to

> > decrease transport times instead of asking for help from neighboring

> > agencies.

> > 12. Cut overtime. This is absolutely a goal. Cutting overtime

cuts

> > expenses. However, it fails to take into consideration other factors.

> > Using

> > a weekly cycle, the EMS system using SSM may drop the number of

ambulances

> > on a Saturday. But, if the weather on that day happens to turn bad, or

a

> > localized disaster occurs, personnel must be called in.

> > 13. Employee schedules more convenient to crews. I dare you to

find

> > an

> > SSM system where people like the schedules. Sometimes the schedules

are

> > contrary to the normal circadian rhythm and, other times, the schedule

is

> > so

> > awkward that people have trouble adapting. For example, going in at

7:00

> > PM

> > and working until 3:00 AM is more stressful than typical 12-hour or

8-hour

> > shifts.

> > 14. Battle " cream-skimmers " working your market. This is more a

U.S.

> > phenomenon, But, as stated above, part of the goal of SSM is to keep

" for

> > profit " ambulances out of the non-emergency transfer market. In fact,

most

> > PUMs have exclusivity agreements where they are the only service used

to

> > transport any patient within the city. This leads to the problems with

> > non-emergency patients already described.

> > 15. Cut production costs without hurting response time

performance.

> > There is some truth here. Production costs are cut at the expense of

> > personnel! Ambulances and personnel are relatively inexpensive

(compared

> > to

> > brick and mortar stations). Thus, push personnel and the ambulances to

> > their

> > maximum-after all, they are expendable. It is no wonder that the

incidence

> > of back pain in Ottawa increased by 71% following the implementation

of

> > SSM.

> > <outbind://38/#_edn8> [8] Furthermore, EMS personnel in Ottawa spent

51%

> > of

> > their time roaming.

> >

> > Summary

> >

> > Thus, to my colleagues in Canada, do not make the same mistake we have

in

> > the States. SSM is a bad idea and totally based on pseudoscience. It

is

> > promoted by consultants and experts who have never taken a look at the

> > science (or lack thereof) behind the practice. Canada has a good EMS

> > system

> > and low employee turnover. SSM will drive away personnel in Canada as

it

> > has

> > in the U.S. Consider this, why has not a single major fire department

in

> > the

> > US (including those who operate the ambulance service) adopted SSM?

The

> > reason is obvious. They looked and did not find the system sound.

Don't be

> > dazzled by statistics and buzz words. The consultants will tell you

that

> > once SSM was instituted in Tulsa, Oklahoma, the response time

decreased

> > from

> > 6 minutes 46 seconds to 6 minutes 9 seconds (statitistically

> > significant-but

> > not clinically significant). At the same time, maintenance costs

increased

> > by 38% and miles travelled increased by 19%. <outbind://38/#_edn9> [9]

> > They

> > always seem to leave that last part out. <outbind://38/#_edn10> [10]

> >

> > References

> >

> > _____

> >

> > <outbind://38/#_ednref1> [1] Stout JL. System Status Management: The

> > Strategy of Ambulance Placement. Journal of Emergency Medical Services

> > (JEMS. 1983;9(5):22-32,

> >

> > <outbind://38/#_ednref2> [2] Stout J. The public utility model, Part

I:

> > Measuring your system. Journal of Emergency Medical Services (JEMS).

> > 1980;6(3):22-25.

> >

> > <outbind://38/#_ednref3> [3] Stout JL. Computer-Aided What? Journal of

> > Emergency Medical Services (JEMS). 1986;12(12):89-94.

> >

> > <outbind://38/#_ednref4> [4] Stout JL. System Status Management: The

Fact

> > Is, It's Everywhere. Journal of Emergency Medical Services (JEMS).

> > 1989;14(4):65-71

> >

> > <outbind://38/#_ednref5> [5] Stout JL, Pepe PE, Mosseso VN Jr. All

> > advanced

> > life support versus tiered response ambulances. Prehospital Emergency

> > Care.2000:4(1):1-6

> >

> > <outbind://38/#_ednref6> [6] Hauswald M, Drake C. Innovations in

emergency

> > medical services. Emergency Medicine Clinics of North America.

> > 1990;8(1):135-144

> >

> > <outbind://38/#_ednref7> [7] Cadigan RT, Bugarin CE. Predicting demand

for

> > emergency ambulance service. ls of Emergency Medicine.

> > 1989;18:618-621.

> >

> > <outbind://38/#_ednref8> [8] Morneau PM, Stothart JP. My aching back:

Th

> > effects of system status management and ambulance design on EMS

personnel.

> > Journal of Emergency Medical Services (JEMS);1999:24(8):36-40

> >

> > <outbind://38/#_ednref9> [9] Hough TH. A View from the Street: System

> > Status Management. Journal of Emergency Medical Services (JEMS).

> > 1986;12(12):48-50

> >

> > <outbind://38/#_ednref10> [10] Bledsoe BE. EMS Myth # 7: System Status

> > Management lowers response time and enhances patient care. Emergency

> > Medical

> > Services. 2003;32(9):158-159

> >

September 29, 2005