Studies on Tiered vs. All ALS?

Lo2w

Forum Captain
403
187
43
Searched but the threads were 6 years old. I know since no one system is alike its hard to have a perfect data set. I'd just be curious to read and see if there's any significant differences for an urban, high volume system using one or the other.
 

NomadicMedic

EMS Educator
11,945
6,655
113
What differences would you like to see? Survival to discharge? OOHCA ROSC with CPC 1/2? Patient satisfaction? Prehospital pain management?

Each system will have pluses and minuses.

Some common complaints with ALS include skill dilution, rust out and fewer high acuity patients per provider. Tiered systems have issues with over/under triage and resource utilization.

If you want specific patient type outcome data, you’ll have to drill down.
 

DrParasite

The fire extinguisher is not just for show
6,049
1,935
113
How do you define significant differences? how do you define high volume?

Personally, I like tiered systems because studies show they produce more clinically astute paramedics (because they only see sick patients). Anecdotally, they produce better EMTs because the EMTs actually get to see sick patients, learn how to differentiate sick vs not sick, and they don't always have a paramedic holding their hand and telling them what to do.

But of course, there are also drawbacks, with the biggest being ALS is not available to all patients (and whether they need it or not is a different topic).

You know what they say, if you have seen one EMS system, you have seen one EMS system.
 
OP
OP
Lo2w

Lo2w

Forum Captain
403
187
43
How do you define significant differences? how do you define high volume?

Personally, I like tiered systems because studies show they produce more clinically astute paramedics (because they only see sick patients). Anecdotally, they produce better EMTs because the EMTs actually get to see sick patients, learn how to differentiate sick vs not sick, and they don't always have a paramedic holding their hand and telling them what to do.

But of course, there are also drawbacks, with the biggest being ALS is not available to all patients (and whether they need it or not is a different topic).

You know what they say, if you have seen one EMS system, you have seen one EMS system.

~116k/year

Mostly interested in response times, as well as patient outcomes if transported by BLS.

We're within a 15 minute transport to 2, level 1 traumas that can also handle stroke, stemi, pediatrics - really anything. That's not including another 7-12 hospitals of varying capability scattered in the city.
 

medicsb

Forum Asst. Chief
818
86
28
Searched but the threads were 6 years old. I know since no one system is alike its hard to have a perfect data set. I'd just be curious to read and see if there's any significant differences for an urban, high volume system using one or the other.

There are few studies that look at tiered systems and the ones that exist have many limitations. I don't have time to try and dig them up. www.pubmed.com is the place to start digging. I think what you are looking for doesn't actually exist.
 

EpiEMS

Forum Deputy Chief
3,768
1,113
113
Mostly interested in response times, as well as patient outcomes if transported by BLS.

Response times don't really matter.

Binary patient outcomes (dead vs. alive) if transported by BLS are as good or better than ALS for traumatic injury (OPALS) and cardiac arrest (see OPALS study - a nice brief review is here).

For respiratory complaints, ALS (as defined in the OPALS study) was shown to be superior to BLS, but I am suspicious of the findings, given that BLS providers can administer albuterol and use NIPPV, which would tend to reduce the "ALS" advantage (after all, why use ETI when CPAP is working?).

One very fun note: For penetrating trauma an urban setting, throwing a patient in the back of a police car produces equivalent (and even slightly better, after risk adjustment) outcomes than waiting for EMS.

Obviously, though, we care about more than just binary outcomes like survival. Patient experience (pain control, symptom relief...) matters. I haven't seen much on those measures, though I can say that I doubt an ice pack works as well as fentanyl. But our Australasian colleagues have a good solution to bridge the ALS/BLS gap - methoxyflurane.
 
OP
OP
Lo2w

Lo2w

Forum Captain
403
187
43
T
Response times don't really matter.

Binary patient outcomes (dead vs. alive) if transported by BLS are as good or better than ALS for traumatic injury (OPALS) and cardiac arrest (see OPALS study - a nice brief review is here).

For respiratory complaints, ALS (as defined in the OPALS study) was shown to be superior to BLS, but I am suspicious of the findings, given that BLS providers can administer albuterol and use NIPPV, which would tend to reduce the "ALS" advantage (after all, why use ETI when CPAP is working?).

One very fun note: For penetrating trauma an urban setting, throwing a patient in the back of a police car produces equivalent (and even slightly better, after risk adjustment) outcomes than waiting for EMS.

Obviously, though, we care about more than just (neurologically intact) survival. Pain control, symptom relief...all those things matter. Haven't seen much on those measures, though I can say that I doubt an ice pack works as well as fentanyl.

Thanks for the links. I wish we had albuterol in our scope for BLS.
 

EpiEMS

Forum Deputy Chief
3,768
1,113
113
T


Thanks for the links. I wish we had albuterol in our scope for BLS.

It can make a difference in symptom relief. Personally, I like having NIPPV - more versatile. Though it's not that I had a choice between one or the other ;)
 

DrParasite

The fire extinguisher is not just for show
6,049
1,935
113
~116k/year
So, that's a big number, but when I think of high volume, I am more interested in how many calls shift or how many patient contacts per shift, similar to UHU. I think my former employer did something in the area of 70,000 EMS calls annually, in an urban city (280,000 people over 26 sq miles), utilizing a tiered system, over 15 trucks. I consider that to be a high volume system, especially when you look at how many runs each unit goes on every day.

now compare that to NYC, which does 1.7 million calls a year.... high volume, sure, but that's also divided up over 764 trucks (227 ALS, and 537 BLS, and that might not be including the voluntary ambulances in the system), you will find the average number of calls per truck isn't super high.

And compare that to philly (1.5 million people over 142 sq mile area), which answers 270,000 911 calls a year, among 55 ALS ambulances, the busiest (Medic 2) does 8,700 calls a year.

So now you see how overall run volume doesn't always mean high volume, especially if you are looking for a high number of patient contacts.
Mostly interested in response times, as well as patient outcomes if transported by BLS.

We're within a 15 minute transport to 2, level 1 traumas that can also handle stroke, stemi, pediatrics - really anything. That's not including another 7-12 hospitals of varying capability scattered in the city.
There is probably some old data, but I think you will find patient mortality decreased, however quality of life is often better with ALS. But I am not aware of any recent studies on this topic, but several of the older ones are still valid today.

There is no perfect data set, unless your looking at finding a particular set of data that is designed to support your point of view.
 
Last edited:
OP
OP
Lo2w

Lo2w

Forum Captain
403
187
43
So, that's a big number, but when I think of high volume, I am more interested in how many calls per units or UHU. I think my former employer did something in the area of 70,000 EMS calls annually, in an urban city (280,000 people over 26 sq miles), utilizing a tiered system, over 15 trucks. I consider that to be a high volume system, especially when you look at how many runs each unit goes on every day.

now compare that to NYC, which does 1.7 million calls a year.... high volume, sure, but that's also divided up over 764 trucks (227 ALS, and 537 BLS, and that might not be including the voluntary ambulances in the system), you will find the average number of calls per truck isn't super high.

And compare that to philly (1.5 million people over 142 sq mile area), which answers 270,000 911 calls a year, among 55 ALS ambulances, the busiest (Medic 2) does 8,700 calls a year.

So now you see how overall run volume doesn't always mean high volume, especially if you are looking for a high number of patient contacts.
There is probably some old data, but I think you will find patient mortality decreased, however quality of life is often better with ALS. But I am not aware of any recent studies on this topic, but several of the older ones are still valid today.

There is no perfect data set, unless your looking at finding a particular set of data that is designed to support your point of view.

20-25 trucks, depending on staffing and how many trucks broke down for the day.
 

DrParasite

The fire extinguisher is not just for show
6,049
1,935
113
20-25 trucks, depending on staffing and how many trucks broke down for the day.
So assuming 25 trucks working 12 hour shifts (so a day crew and a night crew, so you have 50 trucks in 24 hours), that works out to about 6.35 calls per shift. If you are only running with 20 trucks, that number rises to 7.94 runs per 12 hour shift.

Compare that to philly's medic 2: They average 11.9 runs per 12 hour shift.

Going back to my former agency, 70,000 calls over 4 24 hour trucks and 4 12 hour peak time trucks (not counting ALS trucks, which are probably skewing numbers if they end up transporting a BLS patient who was dispatched ALS but no BLS units are available), they average 15.98 runs per 12 hour shift. But running a call in 30 minutes before being sent on the next one is not unheard.

Now looking at NYC, 1,700,000 over 537 bls units (and I'm sure those are either 8 or 12 hour trucks, on a 24 hour schedule), adding up all the EMS calls (ALS and BLS), and dividing by the number of BLS units (assuming they are 12s, since it makes it easier), you get an average number of 8.67 (and that's probably high, because many FDNY units are actually 8, while the hospitals run 12s, and I know they don't run nearly that much.

images.jpeg


So depending on how you represent the data, you can pull some really interesting analytical data. But you can also manipulate the date to support your hypothesis by deciding on what variables you are looking at (in this case, the definition of a high volume system).

Also, your definition of ALS (paramedic only, Intermediate, or enhanced EMT) can also skew the results.
 
OP
OP
Lo2w

Lo2w

Forum Captain
403
187
43
^ I know for us it depends on what truck you're on. I've been on some where you do 4-8 runs in a 12 hour shift and others where 10-14 is average.
 

EpiEMS

Forum Deputy Chief
3,768
1,113
113
Also, your definition of ALS (paramedic only, Intermediate, or enhanced EMT) can also skew the results.

Absolutely a good point - as does the definition of BLS. Lots of the interventions that really help in the OPALS study (albuterol, namely) are BLS measures in many places.
 
Top