It's time to blunt dentists' incentives to use general anesthetics

I recently consulted a dentist about getting a tooth extracted. The dentist recommended getting it done under general anesthetic. I responded, "I've had four wisdom tooth extracted under local anesthetic. I've given birth to two children without medication. I think I can handle it." "Ah, but some patients say dental pain is worse than child birth."

Eventually the dentist agreed to extract the tooth under a local anesthetic, and I was presented with an estimate for procedure - $350. "Why so low?" I asked the receptionist, remembering past estimates for dental work. "It's because you're not having a general anesthetic - if you were the bill would be more like $700." Indeed, I checked against the Alberta Dental Association fee guide (one of the few available on-line). The recommended charge for straightforward extraction done by a general dentist in Alberta is $242.25; the recommended charge for two units of general anesthetic is $228.62. A general anesthetic just about doubles the amount a dentist can charge for an extraction.

Dentists have a strong financial incentive to put patients under a general anesthetic. That's setting aside any other reasons why dentists might prefer to operate on the anesthetized - see this fascinating New York essay which contrasts surgeons' immediate embrace of anesthesia with their grudging admission of the need for sterilization. Hence it is not surprising that some dentists encourage the use of general anesthesia.

And if it makes having a tooth extracted less unpleasant, what's the harm?

Well, the harm may be to your brain. General anesthesia may increase the chance of post-operative cognitive decline. This article using Taiwanese administrative data found a link between dementia and a history of surgery under general anesthetic. On the other hand, this study found no differences between patients receiving a general anesthetic and those receiving epidurals in terms of cognitive functioning three months post-surgery - although patients receiving an epidural had better surgical, as well as better short-term cognitive, outcomes.

Many surgical procedures can be performed either with an epidural or under a general anesthetic. It is hard to find any study suggesting that general anesthesia produces superior results in cases where local anesthetic is a viable option. This study finds that general and local anesthetics produces similar outcomes, but local is cheaper. This one found that epidurals produced better patient outcomes than general anesthetics, and this one also comes down in favour of the local option. 

This leaves aside the 40 percent risk of post-operative nausea and vomiting after having a general anesthetic.

Perhaps one day we'll see the Canadian dental association issuing guidelines on the use of general anesthesia. Insurance companies might step up and only reimburse the cost of general anesthesia in exceptional circumstances (Help! Teeth hurt! describes the dental challenges facing some people with disabilities, and why a general anesthetic may be necessary).

In the meantime, do your brain and your wallet a favour: just say no. I did, and I don't regret it.

Comments

[Alice]

In Alberta the general anaesthetic is administered by an anaesthetist so do we know the dentist makes anything from that extra charge?

[Frances Woolley]

Alice - you raise a really great point. Here's the Royal College of Dental Surgeons of Ontario's standard of practice with regards to anesthetics: http://www.rcdso.org/Assets/DOCUMENTS/Professional_Practice/Standard_of_Practice/RCDSO_Standard_of_Practice__Use_of_Sedation_and_General_Anesthesia.pdf.

In Ontario anesthetics may be administered by a dentist, a physician, a registered nurse, or a respiratory therapist. The later qualification is a three-year-college (ie non-university) program. Dentists using general anesthetics also have to have a recovery room and a recovery room supervisor.

I would guess that staff such as RNs, recovery rooms supervisors, respiratory therapists, etc., are typically paid a fixed wage. What that means is that once a dentist is doing any surgery requiring general anesthetics, it's profitable to do enough to keep the staff as busy as possible. So, yes, there are costs to administering anesthetics (including the costs of the drugs themselves). But lots of these are costs that are the same whether the marginal patient is/is not put under general anesthetics.

By the way, some more interesting things from the RCDSO document:

Sedation or general anesthesia may be indicated to:
• treat patient anxiety associated with dental treatment;
• enable treatment for patients who have cognitive impairment or motor dysfunction which prevents adequate
dental treatment;
• treat patients below the age of reason; or
• for traumatic or extensive dental procedures.

and also:

11. In order to avoid allegations of sexual
impropriety, additional appropriate staff should be
present in the treatment room at all times whenever
sedation or general anesthesia is used

[steve]

US anesthesiologist here. Chair our department. Unless there is a separate facility fee, i.e. that one fee covers everything, most of that fee may be going towards ancillary staff, equipment and medications. Really depends upon the set up, how fast and how many cases are being done. However, at least in the US, it is costly to set this up, so there are real fixed costs. Best guess is that the dentist makes some money on this, but not tons. (Would need to ask a Canadian dentist.)

As to the cognitive issue, that is a complex issue with hundreds of studies. I think it could be summed up by saying that if you are already at risk of cognitive decline (say some very early signs of dementia, past CVA) then you are at some risk. However, for shorter cases like this and if you don't have risk factors, the risks are very low. (Lots of stuff on kids also, but it looks like the risks are also low for healthy kids, but we aren't sure we have definitive studies yet so most of us suggest avoiding elective surgery on very young kids.) On epidurals, or any other regional or local anesthetic vs general anesthesia, for every study showing that there might be an advantage for an alternative to general anesthesia, there is one, at least, showing there is no advantage of one over the other, for the general population. The choice should be tailored to your individual needs and tolerance, which should include your financial preference. Assume that there is some small amount of risk no matter what you choose, even with that local anesthetic. Good luck!

Steve

[Frances Woolley]

Steve - thanks for comments:

"Best guess is that the dentist makes some money on this, but not tons. (Would need to ask a Canadian dentist.)"

Let's say, because scheduling can be challenging, a dentist has to pay the respiratory technologist and the recovery room supervisor for a full day whether 25%, 50%, 75% or 100% of the patients that day use general anesthesia. Even if on average the dentist might not make a large profit on the anesthesia part of the practice, on the margin the revenues from putting another patient under would be expected to be greater than the costs.

On the health issue: "for every study showing that there might be an advantage for an alternative to general anesthesia, there is one, at least, showing there is no advantage of one over the other, for the general population"

I would find it more convincing if you said "there is one, at least, showing that general anesthesia has an advantage over local anesthetics." If some studies say local is better than general, and some studies say there is no difference, I'm opting for local if I can. Even if the difference is only a faster recovery time and less nausea.

[Kaleberg]

I've had extractions in the US. They just gave me a local, and that included a rather tricky extraction of a seriously bent tooth.

[Frances Woolley]

Kaleberg -

Did you have dental insurance that would have paid for a general anesthetic?

I think Ottawa, and particularly the one practice in Ottawa that dominates dental surgery, is particularly bad for pushing GA, possibly because there are so many government workers with dental insurance in this town, so it's an easy sell. . I have a friend who was told in Ottawa that they absolutely had to have a general anesthetic for their wisdom teeth extractions. Went down to Toronto and found a practice willing to remove the teeth without a general anesthetic no problem. Went absolutely fine.

The phrase for it is "treating the plan" - what happens when dental care is driven by what the plan pays for, not by what the patient needs.

[steve]

The kind of procedures amenable to use of just local anesthetics is more limited that those you do with general anesthesia. For example, you aren't really going to do heart surgery with local anesthesia. Local anesthetics have significant toxicities at larger doses and so you are limited to smaller procedures. So there is evidence, and old papers, showing that in some situations a general anesthetic is safer. However, you shouldn't be close to these kinds of doses for most dental procedures. Also, the use of local is going to be dependent upon the skill of the person administering the local and their ability to work under operative conditions that are often not as good as those you have under general. (This is not a trivial issue. I have a few younger surgeons who cannot operate very well at all without the absolutely still field provided by general anesthesia.) All that said, I think most of us who have been doing this for a long time think local, when done well and in appropriate patients probably has a small safety edge, even if it has been hard to prove. For what it is worth, I had my teeth extracted under local.

As to the economics, I think you are probably correct. Again, without knowing whether or not dentists are making money on this, I think that provider induced demand is a real entity. Frakt has written about this several times, so I think it is good to be aware of the issue.

https://theincidentaleconomist.com/wordpress/demand-inducement/

Steve

[Frances Woolley]

Steve - thanks for bringing these points to the conversation. I too worry about surgeons who are unable to operate without GA. There are parallels to this lots of areas of medicine - e.g. stubbornly high c-section rates because ob/gyns have no experience of vaginal breech or forceps deliveries. Even though my Ottawa surgeon was willing to operate under a local, I seriously contemplated going down to Toronto find someone who was more experienced in working with conscious patients.

It's not just the physical challenges of operating on non-anesthetized patients, it's the psychological challenges as well. My dental surgery went extremely well, but I was a little surprised by the lack of amenities one usually finds in a Canadian dental office, e.g. sunglasses to block the light, television on the ceiling, etc. Using a GA to block patients' anxieties means that there's little opportunity to practice other ways of blocking patients' anxieties, e.g. things to hold, soothing colours and images on the walls, etc.

My co-author Ake Blomqvist has also written quite a bit about supplier induced demand - like most economists I think it's a big issue. Ake and I have a paper coming out that shows huge differences in dental care utilization between the insured and uninsured which are totally unrelated to any observable differences in dental care needs e.g. pain in mouth.

[steve]

Glad it went well. Just from the POV of the anesthesiologist, the old argument about GA vs local vs regional and what is safer is probably somewhat akin to some of the long running controversies in econ, like what happens with minimum wage increases, what really happens when you cut taxes or supply vs demand side arguments. There are reasonable arguments on both sides and as far as I can tell they still give you PhD even if your beliefs (some) are very much opposed to the person sitting next to you also getting a PhD. I think that mostly means we don't know how to do the studies, but I hope someone smarter than me figures it all out some day.

My dentist never gives me sunglasses and most definitely does not have a TV on the ceiling. Who would have guessed that socialized medicine could have such nice amenities. :-) Will look for your paper.

Steve