Discussion
As health care costs continue to rise in Canada12,
more emphasis has been directed towards efficient usage of resources.
The first step is to evaluate the current landscape. As physicians,
there is an opportunity to address the health care system based on
medical necessity, and to look for efficiencies. This study evaluated a
large, comprehensive cohort from a single-payer healthcare system, and
identified current and historical anesthesia consult utilization.
Individual centres have demonstrated that preoperative anesthesia
consultations reduce patient anxiety13, reduce
cancellations on the day of surgery14-16, and reduce
hospital costs17. It is unclear though whether these
same benefits are borne out when applied to a population.
The Canadian Institute for Health Information reports that 15.1% of
health care expenditures are paid for physician
services18. In addition to the physician costs, there
are costs for facility/infrastructure, additional personal (including
nurses, receptionists, custodial staff), laboratory testing, and medical
imaging. Furthermore, it has been reported that preoperative anesthesia
consultations result in higher rates of ordering possibly unnecessary
specialized testing, including echocardiography8. It
is important to note that echocardiography provides minimal additional
prognostic information above clinical risk factors19and additional bloodwork, for example Brain Natriuretic Peptide
(BNP)20.
A major concern from a surgical and health systems/resource management
standpoint is the possibility of cancellation on the day of surgery. As
well, the authors recognize that system and cultural differences exist
at different hospitals, and by different physicians, in terms of
utilization of these preoperative consultations. This is supported by
the present study, which described geographic variability in the usage
of preoperative anesthesiology consultations. However, the worry of
surgery cancellation may feed, at least in part, increased usage of
preoperative anesthesia consultations. It may be possible that through
the use of structured medical directives and identification of patients
in need of consultation by the hospital’s presurgical screening clinic,
some fears can be mitigated. The authors acknowledge that this is a
much-needed area of research.
An interesting subgroup identified consisted of patients undergoing
preoperative anesthesia consults prior to cataract surgery. Thilen et
al.9 found a substantial increase from 1995 to 2006 in
preoperative consultation prior to cataract surgery. The current study
found that after knee and hip replacement, the third most common
operation leading to utilization of preoperative anesthesia consultation
was cataract surgery. This may be due in part to older and more
medically complex patients being offered cataract surgery than in the
past. Also, it may be that additional procedures are being completed at
the same time to address glaucoma or other concomitant issues. However,
it is also possible that policies and routine approaches in some centres
might find efficiencies by re-evaluating the need for such
consultations.
It is interesting that the percentage of ASA I and II patients who
receive preoperative anesthesia consultations has decreased markedly
over time (Figure 4). This may already reflect the strains and
limitations being placed on the healthcare system. There is a slight
tendency for early and late career surgeons to order more ASA I/II
preoperative consults compared to mid-career physicians (Figure 5). At
this time, it is not clear why this pattern was observed, however, the
findings are consistent with previous research showing a tendency for
younger physicians to order more preoperative
investigations21. As our system responds to the
pressures of increasing numbers and comorbidities of patients, likely
many hospitals are already finding efficiencies. Also, the movement
towards limiting unnecessary preoperative testing (Choosing Wisely
Canada) is likely taking hold. The results of this study provide data to
further the discussion surrounding preoperative anesthesia
consultations.
There are limitations that are intrinsic to administrative data. There
are many good reasons why some ASA I and II patients should undergo
preoperative anesthesia consultation that may not appear in the datasets
used. For example, patient factors such as features predicting very
difficult airway management, language barrier, extreme anxiety
surrounding anesthesia or a personal or family history of problematic
anesthesia would be good indications for anesthesia consultation. These
factors might not be captured by the ASA classification in terms of ASA
III or above. Similarly, longer or more complex surgeries requiring
management including prone positioning, one-lung ventilation, or the
anticipation of significant blood loss or fluid shifts or potential for
significant postoperative pain would be reasons for anesthesia
consultation in a healthy patient. Having said this, these sorts of
surgeries were not in the top five most common procedures captured by
this study.
Data quality also relies on initial accurate coding by the physician and
hospital coders. A comparison of administrative data with hospital chart
data concluded that major events (surgical procedures, mortality,
patient demographics, primary diagnoses) are accurately
coded22.
An interesting group of patients are those 19.3% who underwent an
anesthesia consultation and then did not proceed to surgery within 3
months. There are a few possible explanations for this. First, it may be
that after discussion with the anesthesiologist the patient decided not
to go ahead with the surgical procedure. This can occur after an
individualized explanation of medical risks or postoperative predicted
morbidity or mortality based on patient and surgical factors. For
example, a medically complex patient may choose not to undergo a hip
replacement to avoid a potential postoperative complication. This is a
great use of the system and allowed patient autonomy and informed shared
decision making. Secondly, it may be that the surgery was postponed
outside the 3 month window due to medical or scheduling reasons. This
patient would then likely undergo surgery at a later time (after
potentially undergoing further pre-operative assessment). This is a
reality of our medical system, and offers opportunities to ensure we
repeat as little as medically necessary to get the patient ready for the
delayed surgery. Finally, after undergoing anesthesia consultation, the
patient may not undergo surgery because it is no longer required, or the
patient changes his or her mind – unrelated to the anesthesiologist
assessment. Further understanding this group of patients could
potentially provide some areas for increasing efficiency.
The results demonstrated a doubling of anesthesia consults per year over
the course of the study. For a meaningful understanding of this number,
the denominator (number of surgeries per year) is needed. The authors
acknowledge that this information is not straightforward to obtain in a
reliable manner. To the best of our knowledge, the data from Statistics
Canada would be the most applicable. Evaluation of Statistics Canada
waiting times for non-emergency surgery23 revealed
that in Ontario, yearly surgical volumes increased modestly from 544,002
in 2005 to 704,890 in 2013, an increase of 29.6%. The data from the
present study indicates a much larger increase for anesthesia consults
of 92.9% (from 112,983 to 217,959) over this timeframe (2005-2013).
This may be due to many factors, including increased numbers of patient
medical comorbidities, increased surgical procedure complexity,
surgeon/anesthesiologist/hospital preference, and patient desire for
discussion surrounding the anesthetic itself.