Effect of computed tomography of the appendix on treatment of patients and use of hospital resources
CommentIn this study, the effect of appendiceal CT scanning on overall hospital costs was studied. In patients who were felt to be at high risk of appendicitis, CT scanning not only greatly improved diagnostic precision but also reduced overall hospital resource use, since unnecessary appendectomies and unnecessary delays in surgery were avoided.
I have one methodologic criticism of this study. The effect of CT scanning on patient management was determined by comparing surgeons' plans before CT scanning with their plans after the results of the scan were known. However, knowledge that patients were to undergo CT scanning might have influenced the surgeons' pre-scan assessments.
For example, a surgeon might be more likely to record "immediate surgery" rather than "observation" as the plan if he or she knew that a CT scan was about to be performed and that the final decision would be made after that. This would increase the number of pre-scan assessments pointing to surgery, and would increase the number of unnecessary appendectomies prevented by CT scanning. We cannot automatically assume that surgeons who knew that their patients were about to undergo a very precise diagnostic test would necessarily make the same decisions for the purpose of the study as they would have in caring for the patient in the absence of CT scanning.
A second point, noted by both the authors and the author of the editorial, needs to be emphasized. The cost savings were determined in a population at high risk for appendicitis; only patients who were felt to require either urgent surgery or admission for observation were eligible for this study. If the technique becomes more widespread and available, it will most certainly be applied to a population at much lower risk. In a lower risk population, the cost savings would be substantially lower and could easily turn into a cost increase. If every patient who comes to the emergency room with unexplained nausea and fever or vague abdominal pain is given the benefit of an appendiceal CT scan, no money is likely to be saved. This doesn't mean that the CT scan is less useful in a lower-risk population, only that the cost-savings are likely to disappear.
This paper contributes more evidence to the notion that appendiceal CT scanning is a better way to diagnose acute appendicitis. The paper's focus is on cost reduction, however. I do not believe these results, in terms of dollars saved per patient scanned, will be borne out in practice.
February 15, 1998
ReferencesReferences related to this article from the NLM's PubMed database.
Reader CommentsDate: Thu, 05 Mar 1998
From: sachin dave <email@example.com>
I feel there is a possibility of observer bias more than what we realize. Surgeons may not have performed a detailed clinical exam, knowing that patients will undergo helical ct with gastrograffin anyways. Surgeons/ER physicians should have been blinded to the fact that patients were undergoing the study investigation.
Long term follow-up is not available. We do not know of the cost incurred from a ruptured appendix that should have been removed, but was not because of a negative ct scan (false negative).
I think we need a more well designed study. Clinical exam is still next
to gold standard (surgical specimen). Comparision should be made between
clinical exam and helical ct in a prospective manner.
The problem of false negatives causing increased costs that were not accounted for is a potential one, but patients were followed up 2 months after discharge. This would probably be long enough to catch most late complications. -- mj
Date: Tue, 07 Apr 1998
Both the article and the comment mentioned the use of CT and US for the diagnosis of appendicitis.I would like to add further that labelled WBC has been used for such application. First TC-WBC has been used. It is highly specific, but it takes at least 90 min. to prepare and further one hour to image. More recently An anti-bodies (fragments) labelled with Tc-99m were used to label the white cells IN-VIVO and image in an hour.
It has already been approved by the FDA recently. I think now it would be fair to note that Nuclear Medicine is all the time ignored. It is unfair! or IS it lack of awareness?
July 12, 1998
Letters to the editor about this article, from the June 18, 1998 New England Journal of Medicine.
January 31, 1999
Date: Mon, 25 Jan 1999
I feel there is another advantage to helical scanning for appendicitis in addition to the possible cost savings put forth in this article. From the stand point of an emergency medicine resident operating in an academic center, scanning can accelerate the diagnosis in cases in which appendicitis is high on the differential, but the exam and lab findings are equivocal (as they often are). The time involved in having these patients evaluated by multiple levels of surgeons, at various points in their training, not to mention OB-Gyne consults frequently performed at the behest of surgeons in female patients, can lead to hours upon hours in the Emergency Room before a disposition is achieved. In my experience, surgery almost inevitably requests a CT rather than taking the patient straight to the OR anyway, so we often order a CT in equivocal cases and call surgery based on the results.
I believe this will become more standard in the future, and perhaps in 5-10 years appendicitis will be, if not an emergency medicine disease, a diagnosis made or ruled out reliably by emergency physicians rather than surgeons.
Patrick J. Dowling M.D.
Date: April 8, 1999
Don't forget, the first walkin centers were started in chicago, just across the street from the ER, by combining time/cost considerations, without compromising patient care. Sounds like the time has come for CT to be the dx method of choice for appendectomy.
Paul Appleton, MD
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