Screening Tests and Pre-Anaesthetic Bloodwork in Veterinary Patients: Issues & Evidence

A perennially hot topic in human medicine is the risks and benefits of screening tests. Blood tests, imaging (like CT scans) and other diagnostic tests are usually seen by the general public as only beneficial. How could it be a bad thing to detect a disease, even before it is causing any symptoms? The reality, of course, is that such tests come with risks as well as benefits, like everything else in medicine.

I’ve written a bit about screening tests before, and I wrote an enthusiastic review of Gilbert Welch’s book Over-Diagnosed, which I believe should be required reading for anyone who is a healthcare provider or patient. The previously underappreciated dangers in inappropriate diagnostic tests have driven significant and sometimes controversial recommendations from the United States Preventative Services Task Force (USPSTF), the federal agency responsible for generating evidence-based guidelines concerning preventative medicine. And a broad coalition of medical specialty groups have formed an organization called Choosing Wisely which is dedicated to promoting sensible use of diagnostic tests by education physicians and the public about the risks and uncertainties, as well as the benefits, of such testing.

In general, the benefits of screening tests involve either allowing a disease to be treated at an earlier stage, even before the patient is aware of having it, and thereby improving the long-term outcome, or detecting risk factors for diseases which can be managed to reduce the chances of those diseases developing at all. For this to work, of course, the tests must screen for something which is treatable or preventable. A test which warns you in high school that you will die of some horrible disease in 30 or 40 years, and that there is nothing you can do about it, isn’t beneficial. In fact, it is more likely to do harm in that it generates anxiety and affects how you live your life in ways that don’t make you any healthier or happier.

Effective screening tests must also be accurate enough that they don’t miss a lot of cases of real disease or indicate disease is present in a lot of people when it really isn’t. No test is perfect, but most medical screening tests can be evaluated in people know to have, or not have, the condition tested for, which can give us an idea how accurate a particular test is. This generates the “sensitivity” and “specificity” numbers often cited to identify how reliable a test is.

For statistical reasons I won’t get into, these numbers can be misleading. Even a test which very rarely misidentifies someone as having a disease they don’t actually have will still misidentify a high proportion of people tested if the disease is really rare. So even the best tests aren’t very useful if we test people who are very unlikely to actually have the disease we are looking for. This is one reason why indiscriminate use of diagnostic tests is a not effective or reliable.

The devil, as always, is in the details, so it is difficult to generalize about when screening tests should or shouldn’t be used. For the most part, the guidelines in humans recommend using most screening tests only when there is some reason to suspect the disease one is looking for is present. If a person has typical symptoms, or is in a demographic group known to be frequently affected by the disease of interest, then a screening test might make sense.

Testing women for prostate cancer with a blood test such as the PSA, for example, is obviously ridiculous. The disease is never going to be present. And even with very good tests, false positives can show up, so what would a doctor do with such a positive test result? Most cases aren’t this clear cut, of course, but the same logic applies for all screening tests. The more likely the disease is to be present, the more reliable a positive test result is. And the less likely the disease is to be present, the more we can trust negative results. So choosing rationally who to test is a very important part of getting reliable results.

So what are the risks of screening test? Well, I’ve already touched on one—the unproductive anxiety associated with being misdiagnosed or with being correctly diagnosed with a disease you don’t have. Many people this hasn’t actually happened to will say they aren’t worried about this and would want to be tested even if this is a possible risk. However, people who have had the experience of a mistaken diagnosis, or a diagnosis they can’t do anything about, describe it as a terrible, life-altering experience. In veterinary medicine, this anxiety is unlikely to affect our patients directly. But there is no question it can profoundly affect their owners, as well as how their owners treat their pets, so this is still a risk to consider.

A more tangible risk of misdiagnosis is the danger and discomfort associated with unnecessary follow-up tests or treatment. Thousands of men have been seriously harmed by unnecessary testing and treatment for prostate cancer that they either never had or that would never have made them ill. This is one of the examples that has driven the more cautious and rational approach to screening tests in humans, and it is relevant to veterinary patients as well. If we diagnose disease that aren’t there, we are inevitably going to harm, and even kill, patients who would have been better off if we had not tested them in the first place. This risk has to be recognized and appropriate steps taken to minimize it, including using tests in a rational, evidence-based way.

And though it seems unpopular in America to acknowledge that it matters, the cost of unnecessary testing is a real issue. In human medicine, healthcare costs are a significant economic burden with widespread harm throughout the economy. And in veterinary medicine, where euthanasia is often chosen when money for further testing or treatment runs out, wasting money on unnecessary tests can easily lead to an inability to provide care that is actually needed.

As usual, the evidence concerning the risks and benefits of screening tests, and the attention given to the issue, are far less in veterinary medicine than in human medicine. However, there is some research evidence looking at screening tests in veterinary patients. Given the aggressive push from the AVMA for more preventative care, which is not a transparent, evidence-based effort and which in some ways appears driven as much by concern about revenue as concern about patient welfare, it is worthwhile to consider the issues involved in recommending screening tests for veterinary patients.

The most common and widely recommended screening tool is the annual physical examination. In human medicine, there is growing doubt about whether physical exams of apparently healthy people is useful or beneficial. There is almost nothing in the way of controlled research on the subject in veterinary medicine.

Certainly, every vet can think of examples of a patient whose owners were not aware of any problem but who turned out, after a good physical exam, to have a serious illness. We are most likely, of course, to remember those examples in which the illness was treatable, since happy endings that make us feel good about the work we do tend to stick in our minds. We may or may not remember cases in which the illness we identified couldn’t be treated or was treated in a way that did little to improve the well-being or longevity of the patient and perhaps even made it worse due to side effects of the treatment. And, of course, we can’t possibly remember those cases in which a client declined to accept the initial test or follow-up investigation and treatment and the disease never materialized. Our memory of individual cases is not, unfortunately, a very reliable way to decide whether physical exams of apparently health pets are beneficial to our patients or not. Availability bias, confirmation bias, cognitive dissonance, and many other cognitive quirks make such anecdotes deeply misleading.

One obvious difference between human and veterinary medicine is that people can tell their doctors about symptoms they experience which might suggest a disease even when there is no outward sign of one. Our pets have a much more limited ability to make known how they feel, and in fact may act8ively hide signs of illness from us. This supports the argument that physical exams, and other diagnostic tests, may be justified in apparently healthy pets even when they aren’t in apparently healthy humans. However, as reasonable as such an argument is, it remains unproven.

The other kind of diagnostic test frequently recommended is bloodwork. There is absolutely no consistency within the profession on what kind of screening blood tests should be done when, how often, and in which patients. It is common to recommend some kind of bloodwork before anaesthesia, and often on some regular basis in older pets, but there are few guidelines, those that do exist are based on opinion and experience rather than high-quality evidence, and individual veterinarians and hospitals vary widely in their recommendations.

There have been a couple of studies looking at how often abnormalities are detected on pre-operative bloodwork, and to a lesser extent whether these abnormalities affected the treatment the patient received. I will discuss a couple of these, which I think fairly represent the state of the evidence at this time.

Alef, M.; Praun, F. von; Oechtering, G. Is routine pre-anaesthetic haematological and biochemical screening justified in dogs? Veterinary Anaesthesia and Analgesia 2008 Vol. 35 No. 2 pp. 132-140

Abstract
Objectives: To determine if routine haematological and biochemical screening is of benefit in dogs requiring anaesthesia and to establish the most useful tests for pre-anaesthetic risk assessment. Animals: One thousand five hundred and thirty-seven client-owned dogs undergoing surgery at the University of Leipzig between January 2003 and April 2004.

Materials and methods: After obtaining a standardized history and a physical examination, all dogs requiring anaesthesia were assigned to an ASA physical status group, their needs for pre-anaesthetic therapy determined and an anaesthetic protocol proposed. Haematological (haematocrit, red blood cell count, white blood cell count, platelet count and haemoglobin concentration) and serum biochemistry tests (plasma urea, creatinine, glucose, total protein, sodium and potassium concentration; serum alanine aminotransferase, alkaline phosphatase and lipase activity) were then performed in all animals. The results of these were then used to: (1) re-define each dog’s ASA physical status; (2) determine any altered requirement for pre-anaesthetic therapy; (3) re-determine the suitability of the dog to undergo surgery; and (4) re-examine the suitability of the original proposed anaesthetic protocol.

Results: The history and clinical examination in 1293 out of 1537 dogs (84.1%) revealed that haematological and biochemical tests would have been considered unnecessary under normal conditions. Of these, 63.9% were categorized as ASA 1, 28.5% as ASA 2, and 7.6% at higher risk. In some dogs, screening tests showed abnormal results: 16.7% of 1293 dogs had abnormal plasma urea levels, with 5.9% of values above the reference range. However, only 104 dogs (8%) would have been re-categorized at a higher physical status category had the laboratory results been available. Additional screening data indicated that surgery would have been postponed in 10 dogs (0.8%) additional pre-anaesthetic therapy would have been provided in 19 animals (1.5%) and the anaesthetic protocol altered in two dogs (0.2%).

Conclusion: The changes revealed by pre-operative screening were usually of little clinical relevance and did not prompt major changes to the anaesthetic technique.

Clinical relevance: In dogs, pre-anaesthetic laboratory examination is unlikely to yield additional important information if no potential problems are identified in the history and on physical examination.

This study fairly clearly shows that only a very small number of dogs presenting for surgery with no reason to suspect illness actually show abnormalities on screening bloodwork, and these abnormalities almost never influence the care these dogs are given. Of course, the question remains open whether testing thousands of dogs to identify relevant problems in maybe 2% is appropriate. Do the benefits for a few individuals (whatever those are, since the study didn’t actually look at the outcome of the procedure) outweigh the costs, the risk of misdiagnosis, harm from unnecessary follow-up testing or unnecessary deferral of needed surgical procedures, and the stress to the owners of dogs who are misdiagnosed?

Another similar study looked at a population for which there is a reasonable rationale to performing pre-operative screening; geriatric dogs.

K E Joubert. Pre-anaesthetic screening of geriatric dogs. J S Afr Vet Assoc. March 2007;78(1):31-5.

Introduction: Pre-anaesthetic screening has been advocated as a valuable tool for improving anaesthetic safety and determining anaesthetic risk. This study was done determine whether pre-anaesthetic screening result in cancellation of anaesthesia and the diagnosis of new clinical conditions in geriatric dogs.

Methods: One hundred and one dogs older than 7 years of age provided informed owner consent were included in the study. Each dog was weighed, and its temperature, pulse and respiration recorded. An abdominal palpation, examination of the mouth, including capillary refill time and mucous membranes, auscultation, body condition and habitus was performed and assessed. A cephalic catheter was placed and blood drawn for pre-anaesthetic testing. A micro-haematocrit tube was filled and the packed cell volume determined. The blood placed was in a test tube, centrifuged and then analysed on an in-house blood analyser. Alkaline phosphatase, alanine transferase, urea, creatinine, glucose and total protein were determined. A urine sample was then obtained by cystocentesis, catheterisation or free-flow for analysis. The urine specific gravity was determined with a refractometer. A small quantity of urine was then placed on a dip stick. Any new diagnoses made during the pre-anaesthetic screening were recorded.

Results: The average age of the dogs was 10.99 +/- 2.44 years and the weight was 19.64 +/- 15.78 kg. There were 13 dogs with pre-existing medical conditions. A total of 30 new diagnoses were made on the basis of the pre-anaesthetic screening. The most common conditions were neoplasia, chronic kidney disease and Cushing’s disease. Of the 30 patients with a new diagnosis, 13 did not undergo anaesthesia as result of the new diagnosis.

Conclusions: From this study it can be concluded that screening of geriatric patients is important and that sub-clinical disease could be present in nearly 30 % of these patients. The value of screening before anaesthesia is perhaps more questionable in terms of anaesthetic practice but it is an appropriate time to perform such an evaluation. The value of pre-anaesthetic screening in veterinary anaesthesia still needs to be evaluated in terms of appropriate outcome variables.

This study appears to find more real and meaningful abnormalities, as one would expect in an older population. However, the details still showed that age did not reliably predict which dogs would have bloodwork abnormalities:

The effect of age and/or breed on the choice of pre-anaesthetic laboratory testing was not fully elucidated in the current study. However, preliminary results show only statistically significant differences (p < 0.05) in platelet count and ALT activity in dogs over 10 years of age. No consistent differences could be found between age groups (<2, 2–7, 7–10 and over 10 years) for the plasma concentrations of glucose, urea and lipase activity. Young dogs (<2 years) showed statistically significant but only slight differences to other age groups in total protein and sodium concentration.

Furthermore, there was no detectable difference in the chances of a pre-operative abnormality in dogs that did or did not have complications during surgery, so it is questionable whether the abnormalities that were found actually helped prevent problems from surgery (though this might have been affected by the deferral of surgery in dogs with some detected abnormalities):

Laboratory test results were within the reference range or interpreted as being clinically irrelevant in 21 of 25 dogs experiencing complications. Relevant laboratory findings were found in only four. The incidence of adverse incidents was 3.8% in dogs with ‘abnormal’ laboratory results and 1.8% in animals with ‘normal’ values. Because of the limited number of complications, no statistical difference could be shown between groups.

Certainly, more research is needed on this topic. However, the existing research suggests that routine pre-operative bloodwork is likely to benefit only a very few patients, so the questions about whether this justifies the costs and risks is still not easy to answer.

In human medicine, guidelines for pre-anesthetic screening are more conservative that what is routinely done by veterinarians:

The guidelines from the American Society of Anesthesiology Task Force on Pre-anesthetic Evaluation state the following:

Routine Preoperative Testing
• Preoperative tests should not be ordered routinely.
• Preoperative tests may be ordered, required, or performed on a selective basis for purposes of guiding or optimizing perioperative management.

• The indications for such testing should be documented and based on information obtained from medical records, patient interview, physical examination, and type and invasiveness of the planned procedure.

Preanesthesia Hemoglobin or Hematocrit

• Routine hemoglobin or hematocrit is not indicated.

• Clinical characteristics to consider as indications for hemoglobin or hematocrit include type and invasiveness of procedure, patients with liver disease, extremes of age, and history of anemia, bleeding, and other hematologic disorders.

• Preanesthesia Serum Chemistries (i.e., Potassium, Glucose, Sodium, Renal and Liver Function Studies)

• Clinical characteristics to consider before ordering preanesthesia serum chemistries include likely perioperative therapies, endocrine disorders, risk of renal and liver dysfunction, and use of certain medications or alternative therapies.

• The Task Force recognizes that laboratory values may differ from normal values at extremes of age.

• Preanesthesia Urinalysis • Urinalysis is not indicated except for specific procedures (e.g., prosthesis implantation, urologic procedures) or when urinary tract symptoms are present.

The general policy in humans is to recommend specific tests based on specific indicators of risk for each individual patient, not to routinely screen everybody who is going to undergo anaesthesia.

A recent paper in the Journal of Feline Medicine and Surgery found a relatively high incidence of common problems (dental disease, kidney disease) etc. in cat over 10 years of age, which would support screening for these disorders in this population. However, this was a small study, and the population was different in some significant ways from those in other places (for example having a much higher incidence of FIV infection that is typical in the U.S.), so we must be cautious about generalizing these results.

I think a rational approach in veterinary medicine is to screen those patients which there are reasons to suspect may have relevant abnormalities, such as animals with clinical symptoms, older animals, animals with known pre-existing conditions, etc. In the absence of better evidence, the only firm conclusion we can make is that firm conclusions are probably not justified. Anyone who says that pre-operative screening or annual examinations of young, apparently healthy pets is mandatory and that not doing it is malpractice is expressing only their opinion, not a conclusion based on reliable scientific evidence. And anyone who states that such screening is worthless is also going beyond the evidence.

Decisions about screening tests in veterinary medicine are, like so many decisions in our business, as much about the values and risk tolerance of individual doctors and owners as about what can be demonstrated to be the best practice. The major deficiency at this point seems to me to be a failure of veterinarians to recognize that screening has costs and risks that should be considered as well as benefits. True informed consent requires that we make our clients aware of the concerns that have emerged in human medicine over irrational or indiscriminate use of screening tests, and of the limited evidence to support screening asymptomatic pets. Clients should be helped to make informed decisions which consider both the possible benefits of screening and also the costs and risks for them and their pets.

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19 Responses to Screening Tests and Pre-Anaesthetic Bloodwork in Veterinary Patients: Issues & Evidence

  1. v.t. says:

    I see a couple problems with this. One, feline patients, who are terribly underserved in vet care. There is strong evidence suggesting that a high percentage of feline patients are not seen for routine exams, thereby missing the opportunities to detect disease early, or even to determine if they may in fact be in a risk category, etc. Yes, we may suggest these patients may be at risk, but the owner may not acknowledge the same.

    Two, informing the owner and the options of blood work, whether it is pre-op or because the patient is in a category of risk for a particular disease. The average time slot for patient and owner is less than 15 minutes, and I’d wager half of those minutes are waiting for the vet (or tech) to enter the room. It is becoming the norm for the vet to pass on the responsibility of disclosure to the vet techs, which does not leave much room for the owner to make truly informed decisions, since they would likely place more trust in the recommendations if given directly from the vet. Vet techs can sound (or be instructed) very persuasive and combined with limited time, practically push the client into one decision or another, without the owner ever having heard from the vet directly.

    I personally test all my pets pre-op, and perhaps because I’m fearful, in that I’ve seen patients die on the operating table when their exams were perfect but no pre-op blood work was done (clients opted out due to additional costs, not due to whether there was an evidence base to support pre-anesthetic blood work). That number may be low in terms of statistics, but every patient was somebody’s treasured friend and it can really take a toll on the vet and staff. I realize there is the element of the unknown, the risks vs the benefits, just stating that I prefer to test, and I don’t mind the costs.

    There’s also the factor of liability on the part of the vet, hence the client consent form. Because in every practice, there will be litigation brought against the vet or clinic.

  2. skeptvet says:

    All good points, as always.

    There’s no question that many pets get little or no veterinary care. In the case of obvious illness, that’s unquestionably a problem. In the case of young animals with no clinical symptoms, I don’t think we can honestly say that regular physical exams will benefit them. As I pointed out, that has been the assumption in human medicine for a long time, and there is growing evidence that it isn’t true. It would be better to have some empirical evidence that pets seen regularly by veterinarians are healthier or live longer than pets who are not. My own guess is that will prove to be true, but I don’t think we can just assume it is because it is reasonable.

    Lack of time to provide informed consent isn’t really something I consider a compelling excuse for mandating a screening test. It’s ultimately not ethical not to share relevant information with owners, and while we always have to make pragmatic decisions about what to share and how, I wouldn’t support requiring bloodwork without any discussion with owners about it.

    And the problem, as always, with the cases we remember in which important problems were detected by bloodwork, or patients were harmed by the failure to detect such problems, is that we don’t know if they are representative of what actually happens. What we tend to remember is often a very skewed, inaccurate version of what happens. Individual case anecdotes are used to justify all the nonsense we criticize regularly here, so we have to be careful not to fall into the same trap of substituting our anecdotes for better evidence.

    And it’s not simply a question of such tests only helping a small percentage of patients, though that is a factor. It’s a question of figuring out how many they harm. All those men permanently damaged by unnecessary prostate biopsies or treatment based on PSA screening are a clear reminder that screening comes with risks. If I choose not to remove a mass because of a spurious blood test result, and the pet dies of say a mast cell tumor or other cancer than could have bee cured by the surgery, then we’ve done harm. Lot’s of other such cases can be imagined, and they probably occur but we don’t notice or keep track of them.

  3. Art says:

    When people call for a phone quote for annuals what do you tell them? I do not recommend annual anything. This just confuses phone callers trying to shop for something they think has been show to produce better outcomes.
    Art Malernee Dvm

  4. v.t. says:

    Perhaps that is because it has been ingrained to clients so frequently…”annual (or bi-annual) exams, or wellness exams help detect problems early on!”. And, emphasis (many times, over-emphasis) on routine blood screening to detect those problems. And due to those patients rarely seen. And now, as revenue generating. Did I miss anything? 🙂 IMO, I’m not seeing the profession rush to change those recommendations.

    Thanks, skeptic for the response. Puppy and kitten exams, though, just for thought: each vaccination series, allows the pet to be examined several times for first 4-6 months then the annual! I spread vaccination types apart as well, so my new kitten saw more of the clinic than she wanted to 🙂 But, this is my personal preference, and one I feel comfortable with.

  5. Art says:

    IMO, I’m not seeing the profession rush to change those recommendations.>>>>

    We need a list of unproven medical care promoted in the market place by the profession. Those who control the Avma are out of control promoting annuals. We have become astrologist not scientist.
    Art

  6. skeptvet says:

    Art,

    Well, of course at my practice I don’t have to take those phone calls, and I’m not an owner so I don’t set fees or anything. But when people ask me about annual exams, I tell them that my personal belief is they are a good idea because I do see patients with medical problems that are obvious to me but that the owner hasn’t noticed at all. However, I also am clear that is not a recommendation based on controlled research but only on my own uncontrolled observations.

    As I’ve said many times, we cannot refuse to make judgments or recommendations when we lack comprehensive evidence to support them or we will be effectively unable to provide care at all given how weak the evidence base is. EBM doesn’t require this, it simply requires that we are honest with ourselves and our clients about the level of evidence upon which our recommendations are based. In this case, as in many, the level is low but it’s what we have.

  7. skeptvet says:

    Sure, and as I told Art, I also think annual exams and many other screening tests are probably a good idea. I just feel obliged to be clear that this hasn’t been proven and it is simply my personal judgment, subject as always to revision as new evidence is developed.

  8. Art says:

    I think pet owners need to know the data about how often unproven medical care turns out to be safe and effective. Even after millions and millions of dollars spent by drug companies to bring treatments to the FDA for final approval the FDA rejects about 80% of them. The fact that human medicine cannot produce better outcomes giving annual exams yet vets still “believe” they can surprises me.
    Art Malernee Dvm
    Fla Lic 1820

  9. Scott says:

    This is a tricky issue when dealing with clients. I’ve tried to handle this in many different ways, with many different results.

    When I first graduated from veterinary school (1987) I was taught to present the facts to clients and let them make an informed decision. I do a lot of orthopedics. At the time I did a lot of cast placements. Because the clients did such a stellar job of using the information I provided to them. I found out that at least in my hands providing a short list of options was a very bad idea. Even if the cast was only $5 cheaper than putting a dynamic compression plate on the fracture, they would choose it, because it was the middle option, and they would always choose the middle option. The first option was apparently out because it was expensive and what the doctor was pushing. The bottom option would make them look cheap (or something, I dunno). So casting it was. Beats me, all I know is… what I was taught in school about informed consent and explaining all the options and percentages etc. was a miserable failure in my poor hands. Lots of bad choices on the part of clients. And they they were kind of trusting the doctor to help them make good choices. Maybe would have worked out better if I was one of those grand salesmen doctors.

    When presurgical blood screens were initially presented as a recommendation, we had nearly 100% compliance from some clients and 30% from others. The difference? Which team doctors and nurses/receptionists were working that day. Client skills, experience levels, all fed into what ended up happening. And virtually the same words were supposedly being used to educate the clients. Hmmm. 20 years later I just gave up on the “recommending, arguing, educating” about blood work. Too much effort and time for too much confusion in the client’s mind. Much easier. And if I decide the evidence is that it is not indicated, I’ll drop it too (and that is sure looking fairly likely). And I really don’t feel too bad about that – because I don’t have a session with the clients on whether to use propofol or ketamine either.

    But you know, a lot of the time it boils down to MONEY in the client’s mind, not SCIENCE. We go through the same stuff ever day with regards to histopathology. Does anyone doubt that histopathology is mostly useful? (And no, we’re not talking about getting a 15-20 prostate biopsies here like they are in a human patient and sending someone off for an undeserved trip to surgery). Well, the clients apparently do, because I get to fight with the clients every day about histopathology. And my rule there is you want me to cut it off, it goes to the pathologist. That rule came about because I got sick of clients coming back to me asking me what it was 6 months after they refused a biopsy from one of my colleagues.

    And we can get a little selective here when we’re talking about informed consent. I keep seeing people talking about this when using a new drug off-label. Great. Good idea. But really, are we all getting off-label informed consent forms signed with informed consent when we used Dexamethasone Sodium Phosphate in a dog or cat? (and I’m absolutely positive that it is not FDA-approved for any use in either species last time I checked my bottles). I don’t know that I feel obligated to inform a client about every potential issue that may be brewing in the world of human or veterinary medicine. Just the ones most pertinent to what is going on with their particular patient.

    I’m rambling a bit here, but my suggestion here is that although the risk of performing unnecessary tests etc is real, I believe that the doctor(s) need to evaluate it. Throwing it open to a daily discussion with the clients is just bound to be a fail. They’ll decline virtually everything in such a circumstance. Just as easy to say “we could do some blood tests, but I don’t recommend them”. Or not open your mouth in the first place. We get paid to make recommendations. Make them. Change them as the information becomes available.

  10. skeptvet says:

    Thanks for the comment. I certainly don’t have a solution to the issue you raise. We have a great deal of influence over clients’ choices, largely through how we present information. Finances do play a big role, though my experience is that varies a lot with the client population. I work with a very different population now that I did in my first practice, and when I moved the money went from being the biggest issue maybe 80% of the time to being the biggest issue maybe 20% of the time.

    And, of course, there is huge individual variation. Some clients view me as a consultant or advisor, which I think is ideal. Others view me as a salesman trying to push a product. And some want me to play the old-fashioned father figure and make all the decisions for them. How I communicate, and how I influence their decision making has to depend on the temperament, education, finances, values, etc. of the individual client, which makes such communication a enormous part of the challenge of my work. After so many years in practice, the communication aspect is usually more the challenge than the medicine.

    Still, I haven’t given up on the idea of informed consent or of shared decision making with clients. There is a huge range of possibilities between “Do whatever you want” and “Do it my way,” and while I don’t think perfection is achievable, I think the harder we try the better we can do. If money drives the decision, that gives me the opportunity to emphasize why what may seem the cheaper option (e.g. glucosamine over an NSAID for DJD) is actually a waste of money based on the evidence, and maybe we should look at other inexpensive options (e.g. weight loss).

    And like anything else, we can’t make the perfect the enemy of the good. Informed consent doesn’t mean reading a list of all possible side-effects, meaningful or not, for every drug. That is clearly ineffective communication. But it does mean discussing recommendations in terms of risks and benefit and openly acknowledging the level of uncertainty. For what it’s worth, I feel like this kind of communication has worked better over the years as I’ve gotten better at doing it, though none of the problems you raise will ever go away entirely. All we can do is the best we can do in context. I do think there is a place for an EBM style of shared decision making with clients even though it won’t work perfectly every time.

    Thanks again for you insights.

  11. Art says:

    We go through the same stuff ever day with regards to histopathology. Does anyone doubt that histopathology is mostly useful?>>>>
    I get to fight with the clients every day about histopathology. And my rule there is you want me to cut it off, it goes to the pathologist>>>>

    put them in a biopsy jar and send them home with the owner to keep. It’s an alternative to sending off every lipoma you remove. You can always biopsy years later if they want.
    Art

  12. Art says:

    http://en.wikipedia.org/wiki/Wilk_v._American_Medical_Association
    Above is the link to the change in law that started the medical problem. It’s difficult under current law not to get in line when someone is handing out money.
    Art

  13. Art says:

    Those who control the Avma want me to join them. The FDA defines health fraud as the promotion of unproven medical care in the market place.
    Art Malernee Dvm

    Dear AVMA Colleague,

    The $5.5 million consumer awareness campaign of the Partners for Healthy Pets has officially launched! Our friends Henley and Oz and their compelling message, “A yearly visit to your family vet is as essential as food and love. Make an appointment for an annual check up today,” will soon be familiar to millions of pet owners.

    The support for this campaign is unprecedented, and I personally invite you and your practice to be a part of the effort to ensure that more pets visit a veterinarian on at least an annual basis.

    By signing up as an enrolled practice, you will receive a monthly newsletter containing colorful and compelling campaign materials that you can use on your websites, in your newsletter and blogs, and in your practice. By doing so, you will expand the reach of the campaign and ensure that your clients will be reminded that regular preventive healthcare is as essential as food and love and will take action by calling for an appointment. Enrolling is free, and there is no cost for the newsletter or any of the materials.

    Our pet owner web site,www.healthypetcheckup.org, launched on September 15, and digital ads will appear onCNN and Everyday Health, SheKnows, Pet MD, and Yahoo Finance as well as onFacebook.

    Print advertising in People, O (Oprah magazine), Everyday with Rachel Ray,Family Fun, and Prevention magazine begins in November issues, on newsstands in mid-October.

    These online and print placements reflect those online sites and magazines most frequently visited by the pet owners that research indicates will be most likely to respond to our call to action – to call for an appointment today.

    AVMA is proud to have been a leading member of the Partners for Healthy Pets initiative since its inception. Now that the consumer awareness campaign is underway, I urge you to join this industry-wide effort. Simply click this linkhttp://www.partnersforhealthypets.org/Join.aspx and register your practice today! Be part of it! It’s Important!

    Sincerely,

    W. Ron DeHaven, DVM, MBA
    Chief Executive Officer, American Veterinary Medical Association and
    Chair, Partners for Healthy Pets

  14. v.t. says:

    Well they sure know their target market, Oprah, Prevention, Rachel Ray. Yuck, the irony.

    I wonder how many millions of dollars have been put into marketing over the last decade for the same marketing message, “annual checkups”. Are pet owners listening any more than they were a decade ago? Not that I’m against the message, I just think that could be fostered better between vets and their clients, and those advertising millions spent better on far more useful and urgent things.

  15. Art Malernee Dvm says:

    Last month the speciality group the American board of internal medicine informed doctors in new guides “don’t perform routine health checks for asymptomatic adults.”
    There is a good article now in the NYT written by an internist called “doctors bad habits ” as he tell everyone how hard it is to stop giving up annual exams. At least he does not have the AMA telling people it’s “as essential as food”
    Art Malernee Dvm

  16. Art says:

    http://ebvma.org/home/blog/diagnostic-error-veterinary-medicine

    Anyone know of any human studies that look at diagnostic error rates in check ups? I wonder if it’s in the same 10-15% range. If a patient gets an exam with no history of having any symptoms I wonder if the dx error rate is higher or lower than patients who have exams with a history of symptoms

  17. skeptvet says:

    Well, as to the second question it is guaranteed that a screening test will produce more false positives if applied to a population with a low prevalence of the disease, so it seems very likely that more false positive diagnoses would be made on examination of asymptomatic individuals than those with symptoms. This would be true even if the error rate itself were really low.

    Her are some of the papers I’ve seen on error rates in human medicine:

    Graber ML, Franklin N, Gordon R. Diagnostic error in internal
    medicine. Arch Intern Med 2005;165:1493–1499.

    Neale G, Hogan H, Sevdalis N. Misdiagnosis: analysis based on
    case record review with proposals aimed to improve diagnostic
    processes. Clin Med 2011;11:317–321.

    Blendon RJ, DesRoches CM, Brodie M, et al. Views of practicing
    physicians and the public on medical errors. N Engl J Med
    2002;347:1933–1940.

    Shojania KG, Burton EC, McDonald KM, et al. Changes in rates
    of autopsy-detected diagnostic errors over time: a systematic review.
    JAMA 2003;289:2849–2856.

    Zwaan L, de Bruijne M, Wagner C, et al. Patient record review of
    the incidence, consequences, and causes of diagnostic adverse
    events. Arch Intern Med 2010;170:1015–1021.

  18. Art Malernee Dvm says:

    Found this looking for prospective studies on the Internet.
    Article
    A prospective study of 1152 hospital autopsies: I. Inaccuracies in death certification

    Issue
    The Journal of Pathology
    Volume 133, Issue 4, pages 273–283, April

    Comparison of certified clinical diagnoses with autopsy findings showed that, while the major cause of death was confirmed in 61 per cent. of cases, many diagnoses—both major and contributory—were wrong; many clinical diagnoses were either disproved or relegated to a less important role, and many autopsy findings had not apparently been anticipated. Accuracy was particularly poor in some clinical categories: notably cerebro-vascular disease and infections. In these, the diagnosis was more often wrong than right. Thus, death certificates are unreliable as a source of diagnostic data.

  19. Art says:

    Here is another prospective study wrong diagnosis abstract from British Journal of Surgery vol 69. I was thinking a check up may have a lower rate of the wrong diagnosis because the doctor would not “feel” they had to find something because the patient had no symptoms. You are not going misdiagnose appendicitis during a check up

    “More than one-third of all appendicectomies are unnecessary. A study was directed towards reducing the misdiagnosis of appendicitis, thus preventing needless operations. Thirty-six women in the fertile age group and with a diagnosis of appendicitis were subjected to laparoscopy before surgery. All women had undergone a gynaecological examination to rule out disease of the female genitalia. As a result of the laparoscopy, surgery was cancelled in one-third of the cases, which were found to have acute gynaecological disease not requiring surgery”

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