Role of Physical Examination in 21st Century

Role of Physical Examination in 21st

Century

What If the Revolution Lies Within our Reach?

Yanis AFIR

Physical examination has always played a very important role in medical practice. However, it has lost a consequent amount of its value to new technologies and diagnostic methods. In this short review, we will discuss some of the issues faced by classic bedside physical examination in order to keep up with the challenges of the 21st century.

Even though the topic of this issue is The History of Medicine, we might have, confidently, written this article in the previous one. Indeed, in this era where technology dominates and primary care has nearly lost its humanistic dimension, the classi­cal physical examination and the dogma it represents plays a very important role in keeping the balance in medicine and might truly be the next “Cutting-Edge” of medical practice. A real revolution might very well come from our stethoscopes and reflex hammers...

Bedside physical examination has been a part of medicine from the beginning. Actually, for a very long time, its first pillar, the observation (or inspec­tion), represented almost the whole of medical prac­tice. However, physical examination really took a step forward and became truly scientific or “clinical” starting only from 18th century. Two main events mark this pe­riod. First, in Austria, Joseph Leopold von Auenbrugger observed his father, an innkeeper, tapping on barrels and, from the produced sound, establishing whether wine has yet reached the proper quality. Auenbrugger tried to use the same technique to detect abnormali­ties in the chest and described it in his book “Inventum Novum”. This is how Percussion was born and added to physical examination.

Few years later, in Paris, René Lænnec, finding it somewhat inappropriate to stick his head in young la­dies’ chests in order to listen to their hearts, had the idea of a little cylinder which he used to listen to heart abnor­malities from a safe distance. After describing this tool in his book “De L’auscultation Mediate, Traité du Diagnostic des Maladies des Poumons et du Coeur,” people developed it, and later it led to the stethoscope.

The invention and development of these new tech­niques brought a real revolution in medicine; in fact, we can state that modern medicine was invented in that era, as it was only then that healers really started making diagnoses.

However, we can easily notice a net drop in the classical bedside medicine in favor of new tech­nologies. Technologies, of course, are necessary and have led to many breakthroughs in medical research; however, considering the primary healthcare and the way we deal with patients, it is sad to realize how we moved from a philosophy of medicine in which the pa­tient is in the center of the inquiry to an environment full of computer devices and TV screens, where most of the discussions (and studies) occur away from the patient.  

Luke Fildes – The Doctor. 1891. Source

The image above is a famous painting by Luke Fil­des named “The Doctor”. We are not quite qualified to play the art critic, but something is really interesting about the painting : Fildes has perfectly captured the medical spirit of his era. A Doctor, sitting in a chair and looking at a sick little child. There is no physical barrier between them (indicating probably that there is no psychological barrier either). There is no book, no instrument and no complicated data or sophisti­cated machine; his eyes stare at the little child, not disturbed by the cup of tea that he had been given, nor the mother’s tears. The father seems to not even dare talk to him. The Doctor seems to have interrupted all the circuits of his brain to focus on one task only, sav­ing this little girl... Alright, we may have exaggerated a little bit, but you get the point!

What if all the doctors had been like this one? What if we treated our patients like our own lives were at stake?

Let’s go back to reality now. You have a very bad abdominal pain and you decide to go to the hospital. Without any overstatements, the image below is very close to what actually happens in our emergency rooms. Instead of focusing on the patient’s needs and trying to understand his com­plaint, we rather launch series of expensive, useless and sometimes dangerous, tests where a simple patient history and proper physical examination would have been more than enough. 

We can not in our modest review enumerate all the causes that pushed us away from our patients, nor can we nominate solutions. Thus, we will simply try to highlight the major challenges for physical exam­ination.

The first issue is the lack of research and the ne­cessity and benefit of promoting it in classic bed­side examination. The second point is about ratio­nalizing the physical examination and applying the researches results in an Evidence-based approach. Finally, we will try to discuss the challenges of phys­ical examination’s assessment in medical school.

A lack in research

There are many books dedicated to physical exam­ination, with usually high-quality explanations and illustrations. From medical school textbooks to whole signs dictionaries, one can easily find a great reference to study from. Nevertheless, we are forced to state that the scientific value of the information and the quality of evidence is in many cases very poor. We mean that, apart from general principles agreed on, many of the presented statements, observations, rules and even tricks often result from the author’s own experience, far from a strong evidence and with complete disre­gard to research findings and latest data.

The reason behind this is beyond the authors of these textbooks and lies in research itself. Very few research­es are conducted to study the bedside examination compared with other diagnostic tools. Infact, physical examination is only approached in its pedagogical di­mension. It is considered more of an “art” than a real science. Perhaps this is the reason that pushed some prestigious authors to name their books “Art & Sci­ence”1, 2, as to remind us that there is also a little sci­ence in it...

We look at physical examination only as a mandatory step in medical curriculum, taught only out of habit or tradition. Take a student who is having his first physical examination lecture; the joy and happi­ness of finally acting like a real doctor is very quickly replaced by the disappointment of noticing that none of his teachers really apply what they are teaching in their daily practices, not even a half of it! If that wasn’t enough, these same “teachers” pretend to have the ability to evaluate students... have you felt that frus­tration too? Sorry... let’s go back to research.

As said earlier, the number of papers talking about physical examination is really small. We can men­tion three great initiatives that promote Evidence-based physical examination: “The Rational Clinical Exam­ination” systematic reviews series in JAMA (Journal of The American Medical Association)3; the book “Evi­dence-Based Physical Diagnosis” written by Steve Mc­Gee4 and the Stanford25 education initiative5.

As a matter of fact, in 15 years, only about 70 arti­cles were published in The Rational Clinical Exam­ination. If you don’t see how little this is, maybe it will help you to know that approximately 2000 new articles are indexed in PubMed every day6!

The reason behind this lack in meta-analyses and systematic reviews is that the number of data available is very poor. Most of the studies include far less than 100 patients, sometimes only 2, and are old and conducted in questionable conditions. Even worse, we can evaluate the quality of evidence only after having done all the standardization and analysis, to often discover that the data is useless, discouraging researchers even more.

The initiators of the Rational Clinical Exam­ination wanted to “restore respectability to a part of medicine that seemed to have been eroding as aca­demic and financial rewards went to those who most resembled scientists relying on expensive diagnostic tests and least behaved as physicians relating to pa­tients”, said Drummond Rennie in his preface3. Accord­ing to Sackett, there are 5 main reasons behind the lack of research in physical examination field7:

1- Designing investigations on the precision and ac­curacy of the medical history and physical examina­tion is very arduous. First, we have to assemble a large number of appropriate patients, then proceed to their repeated examination by clinicians, either wide-rang­ingly experienced ones or those still in training, and then proceed to a gold standard examination, which can vary from the simple imaging to surgery or autop­sy! If the results were inconclusive, the data analysis is often unorthodox and challenging.

2- A clinical diagnosis rarely resides in a single symp­tom or sign, but rather in the patterns emerging from many symptoms and signs combined. The data is thus subject to multivariate phenomena.

3- Clinical examination researches often don’t grant any fame, prestige or reward. In result, researchers influenced by the exciting challenges and academic rewards, are much more interested in investigating laboratory or imaging tests.

4- Financial issues are probably the biggest reason be­hind this desert in research. Pharmaceutical and med­ical technology companies often promote and reward clinicians investigating in advanced technology. And one must not forget about political and financial pur­poses behind this: it is far more interesting for compa­nies to have physicians buying their “superadvanced” devices than taking their time with a thorough history taking and physical examination.

5- Finally, as mentioned earlier, many clinicians still consider bedside diagnosis as an “art” more than a real science.

At this point, only one question remains: why is it worth it to invest in physical examination research? A part of the answer is that these researches could help make the physical examination so accurate that in many cases we would not need imaging or laboratory results at all. As an example, Crombie found out that more than ¾ of the diagnoses in primary care are established after a brief history and a routine clinical examination8.

Steve McGee emphasizes on the importance of “Stop rules” in daily practice. These rules result from combinations of bedside findings that argue so much against the diagnosis that the investigation should stop and no imaging or laboratory test is needed9. Ex­amples of these include the Ottawa rules for ankle injury and the Alvarado score for appendicitis. If such stop rules were applied in the US, an estimated 700 billion dollars a year spent in unnecessary tests and procedures would have been saved10.

An Evidence-based approach4,9

As we mentioned above, one of the main reasons be­hind the delay which physical examination suffers from is the inability of physicians to rationalize their findings and fully benefit from Evidence-based re­searches. Here we will try to give examples of how to effectively use physical examination data.

1- Sensitivity and Specificity, classic but not very useful

We perfectly know that biostatistics are a very power­ful hypersomnic agent for most medical students, but we ask our beloved readers to forgive us, we have to dive into some details... it will be worth it (or else re­funded).

As a quick recap, let’s review the definition of sensitivity and specificity.

Sensitivity is the ability of a test to be positive in pa­tients who have the disease. In other words, it is the proportion of patients with the disease who have the physical sign (i.e., have the positive result).

Specificity is the ability of a test to be negative in pa­tients who don’t have the disease. In other words, it is the proportion of patients without the disease in whom the physical sign is absent.

The calculation is simple, here is an example: let’s imagine a study of 100 patients to evaluate the power of a certain test to detect a disease. The follow­ing column summarizes the findings: 

Remember that Sensitivity is the number of sick pa­tients with a positive test compared with the total number sick patients. Thus, it is calculated by the fol­lowing formula: Sensitivity = TP/(TP + FN). In this ex­ample: 22/(22+20) = 52%.

Specificity is the number non-sick patients with a neg­ative test compared with the total number of non-sick patients. Thus, it is calculated by the following formula:

Specificity = TN/(TN + FP). In this example: 55/(55+3) = 95%.

Knowing how to calculate is good but dealing with the numbers’ meaning is what is most important. THAT is far more complex than seemingly thought. Consider a real example : a 40-year-old man with a history of chronic alcohol consumption comes to your office complaining of an increased abdomen volume. At a first glance, and given the history of the patient, you think of an ascites. Rather than directly requesting an abdominal ultrasound, you want to figure out how well physical examination alone can detect ascites. After a little research, you find 3 meta-analyses that reported the results of the different studies11-13. The following table summarizes the results: 

Great, now that you have the results, do you think you can interpret and use them in your practice? Let’s start with inspection, Bulging flanks and Edema seem to have very high sensitivities, which is a really good starting point. But how do you deal with Bulging flanks specificity? The variation among studies is very considerable, going from 44% to 70%. It is even worse for Flank dullness, going from 29% (which is very poor) to 69% (which is quite correct). So the first difficulty is variation in data results and the inability of making sense of the numbers. A simple way of correcting the problem is taking the average of the results. Although not very precise, it may be helpful.

However, the real problem is when trying to com­bine data. What do you say about a patient presenting to the ER with bulging flanks, shifting dullness and fluid wave but none of the other features? Notice that some signs with very high sensitivity are absent. On the other hand, some signs with very high specificity are present... It is very confusing and unless there is an effective meth­od to combine sensitivities and specificities, we are inca­pable of making any decision.

2- More simple and more practical : The likelihood Ratio

A very simple, effective and, most important, practical index to use with data is the Likelihood Ratio (LR). It summarizes the information contained in sensitivity and specificity to tell us how likely a given test result is in people who have the disease compared to how likely it is in people who do not have the disease. This method of describing the accuracy of diagnostic infor­mation, once mastered, is much faster and more pow­erful than the sensitivity and specificity approach.

The first concepts that one must understand are the Pre- and Post-test probabilities. Pre-test prob­ability is the probability of a person to have a disease before applying any test on him. In most cases, it cor­responds to the prevalence of the disease in the coun­try. For example, if the prevalence of a certain disease is 16%, any random patient has a probability of 16% to have that disease.

Post-test probability is the probability of a patient to have the disease after considering the results of a diagnostic test. The shift in the probability before and after applying the test expresses the « strength » of the test; it tells us how powerful our test is in recognizing the disease.

We should also remember that some findings, when positive, increase greatly the probability, but they change it very little when negative. In opposite, other signs are more useful if they are absent, because the negative finding decreases considerably the probability, although the positive one changes probability very little.

Here, the likelihood ratio is the most useful tool to show the strength of a test. Its definition is basical­ly « the proportion of patients with disease who have a particular finding divided by the proportion of patients without disease who also have the same finding. »4 

We add the adjectives « positive » and « negative » to indicate in which case the physical sign is present or absent. A positive LR, therefore, is the proportion of patients with the disease who have a physical sign divided by the proportion of patients without the disease who also have that sign. A negative LR, is the proportion of patients with the disease who lack a physical sign divided by the proportion of patients without the disease who also lack that sign.

The formula is very simple. In a positive LR, the numerator, i.e « the proportion of patients with the disease who have the physical sign » is basically the sign’s sensitivity. And the denominator, i.e « the

proportion of patients without the disease who have the sign » is the 1- specificity.

Thus: Positive LR = Sensitivity/(1- Specificity).

It seems a bit confusing but try to think of it slowly and you will see that it is really simple.

Same thing for the Negative LR: the nominator, i.e « the proportion of patients with the disease lacking the finding », is 1 - sensitivity. And the denominator, i.e « the proportion of patients without the disease lacking the finding », is the specificity.

Therefore: Negative LR = (1- Sensitivity)/Specificity.

Now the most most important part: what do these information tell us ? When the LR of a test is above 1.0, it means that the finding is more likely among patients with the disease than those who lack the disease. Thus, a LR > 1 means that the probability of the disease increases. By applying the same reasoning, we deduce that when the LR is below 1, the probability of the disease decreases. Finally, when the LR is 1, or very close to it, it means that the probability of the disease is unchanged

(because the finding is equally likely in patients with and without the disorder).

Now let’s apply these findings to our example. Remember that the Sensitivity of the Edema was 87%, and the Specificity 77%. Thus the positiveLR = 0.87/ (1- 0.77) = 3.8. The negativeLR = (1- 0.87)/0.77 = 0.2. We calculate the remaining LRs and summarize the results in the table: 

Now that we have all the LRs, the final step is to know how to use them. With some complicated formulas and statistical methods, which we will not demonstrate here, we calculate the shift in probability related to each likelihood ratio. We obtain the following results. 

This means that if a sign has a likelihood ratio of 10, your patient, who has the positive sign, has 45% more chances of having the disease. As well, if your patient has a sign whose is 0.2, he has 30% less chances of having the disease.

If we apply these to our example, we obtain this: 

Dr. McGee proposes to simplify the results and to consider only values above 3, which correspond to a 20% increase in probability, and below 0.3, which correspond to a 25% decrease in probability14. In our case the results are much more simple : 

Now as a clinician, if your patient has Fluid wave and Edema, you know that he has 25% + 30% = 55% more chances of having an ascites. On the other hand, if your patient doesn’t have Edema and has Flank tympany, then he has 55% less chances of having Ascites.

Let’s apply this to our confusing example; remember we had Bulging flanks (+ 15%), shifting dullness (+ 15%), fluid wave (+30) and an absence of all the other features (- 50%). Thus, our patient has 10% more chances of having ascites by the findings of physical examination alone.

Of course we should incorporate this in a whole process of reasoning including the patient’s history and para-clinical features but it is a simple and fast way to rationalize data and make the most practical use of it in order to save time and money and help you know what is really going on in your patient.

In fact, if you can master this, it would be as if you personally examined all the patients in the studies and remembered how accurate the bedside exam was for each of them!

Physical examination assessment and teaching

Teaching and evaluating physical examination skills is a very challenging issue. Assuming that the teacher is himself qualified and skilled enough, it is very hard for him to teach his techniques, and even harder to distinguish among his students those who have really mastered them. Have you tried to teach cardiac or pulmonary auscultation abnormalities to a student? It is easy to tell him that this patient has a pneumonia and that he should hear crackles, and he will often tell you that he had indeed listened to them, but how can you be sure of that? And even if you are, how can you be sure he will recognize crackles next time he hears them? Even worse are physical signs that do not obey the dichotomous answer present/absent. How to teach your student that this deep tendon reflex or this mitral valve S1 sound is exaggerated or diminished?

Here again we do not pretend to give solutions, but we must point out some major mistakes present in the medical curriculum. First, many studies show a very big lack in new generation doctors skills15, 16 and This is due to the very little attention given by medical curriculum to clinical examination, even in traditional programs, and this is way far from being resolved by simple lecture courses16. The only method that seems reliable is more hours of practice and more patient-focused training sessions. The willingness of going in contact with patients and examine them must be taught and established in very early stages of medical curriculum, otherwise future doctors would get used to being away from patients and remain like that for the rest of their careers.

Perhaps the best illustration of the commitment of a teacher is the famous sentence of Baily, while asking his students to perform a rectal examination: “If you don’t put your finger in, you might put your foot in it”.

Another problem of physical examination teaching is the lack of a precise organized plan and check-list. Of course techniques and tricks are taught everywhere, but very few textbooks provide general

examination sequences. This is due to the idea that a physician should build his own sequence, however we believe (from experience) that most of medical students get confused and don’t know how to start their physical examination and whether they performed all the techniques required or not. We invite you to take a look at this study showing most physical examination mistakes among young physicians17. One can easily notice that most of these techniques are well known and quite easy to master, physicians simply forget to use them, this can be prevented with a simple checklist.

As a result of these issues, not only did our skills severely decrease, but also we believe that it is impossible for us to go further! We do not even try. We all agree that old doctors know how to diagnose a valvulopathy by auscultation alone where it is still difficult for us to recognize a stenosis bruit... And we convince ourselves that it is not a big deal as long as we have CT and ultrasound. In fact, we do not even know how far we can go with physical examination. For example, where it is hard for us to recognize dullness or tympany, Adolphe Piorry described nine distinct percussion sounds. Holmes and the neurologists of the early 20th century used to make diagnosis of patients before entering the examination room, simply by hearing the rhythm and pitch of their steps as they walk! We highly invite you to read what Conan Doyle (who was a doctor by the way) used to say about his master, Joseph Bell, and how he could obtain a tremendous number of information from his patients with only inspection.

Finally, one big problem in learning physical examination is the incredible amount of new information and techniques provided in each course, it is very difficult to remember them all. We believe that one really effective way to help students is to include the underlying mechanisms and pathophysiology of each sign and examination method. Students will then understand and conclude rather than stupidly memorize and recite. As a good example, the book “Mechanisms of clinical signs” by Dennis & al18 is really helpful for students and such initiatives should be encouraged both for textbooks and researches.

Conclusion

Physical examination has always been and still is a pillar absolutely necessary to medicine, and should remain so. Beyond its scientific and pedagogic values, it is truly in its humanistic dimension that basic bedside examination is ineffable. It is the only way to put the patient in the center of the question and remember his need all the time. More than a simple multitask sequence, it is an important ritual necessary for the physician to gain patients trust and respect and to definitely seal the patient/ physician relationship. Because patients are priceless, the “Doctor’s touch” is obediently the proper way to bring back medicine to its original purpose: to care about patients. As students or physicians, we should of course make the best of new discoveries and technologies but never forget that there is a real person behind each case, and perhaps the truth is not very far from him, as used to say William Osler: “Listen to your patient, he is telling you the diagnosis.”

References

1- Orient, J. M., & Sapira, J. D. (2010). Sapiras art & science of bedside diagnosis. Philadelphia: Wolters Kluwer Health/ Lippincott Williams & Wilkins.

2- Ranganathan, N., Saksena, F. B., & Sivaciyan, V. (2006). The art and science of cardiac physical examination. Totowa, N.J: HUMANA PRESS.

3- Simel, D. L., Rennie, D., & Keitz, S. A. (2009). The rational clinical examination: Evidence-based clinical diagnosis. New York: McGraw-Hill.

4- McGee, S. R. (2017). Evidence-based physical diagnosis. Philadelphia, PA: Elsevier.

5- https://stanfordmedicine25.stanford.edu/

6- Glasziou P, Burls A, Gilbert R. Evidence based medicine and the medical curriculum. BMJ. 2008;337:a1253.

7- Sackett DL, Rennie D. The Science of the Art of the Clinical Examination. JAMA. 1992;267(19):2650–2652.

8- Crombie DL. Diagnostic process. J Coll Gen Pract. 1963;6:579-589.

9- Steve McGee M.D. Conference at Stanford25 : https:// www.youtube.com/watch?v=0vSuPSVcWXA

10- Peter R. Orszag (2008). Increasing the Value of Federal Spending on Health Care. Congressional Budget Office.

11- Cattau EL, Benjamin SB, Knuff TE, Castell DO. The accuracy of the physical examination in the diagnosis of suspected ascites. JAMA. 1982;247:1164-1166.

12- Simel DL, Halvorsen RA, Feussner JR. Quantitating bedside diagnosis: Clinical evaluation of ascites. J Gen Intern

Med. 1988; 3:423-428.

13- Cummings S, Papadakis M, Melnick J, et al. The predictive value of physical examination for ascites. West J Med. 1985;142:633-636.

14- McGee S. Simplifying likelihood ratios. J Gen Intern Med. 2002;17:646-649.

15- Kern DC, Parrino TA, Korst DR. The Lasting Value of Clinical Skills. JAMA. 1985;254(1):70–76.

16- Mangione, S., Peitzman, S.J., Gracely, E. et al. Creation and assessment of a structured review course in physical diagnosis for medical residents. J Gen Intern Med (1994) 9: 213

17- Wiener S, Nathanson M. Physical Examination Frequently Observed Errors. JAMA. 1976;236(7):852–855.

18- Dennis, M., Bowen, W. T., & Cho, L. (2016). Mechanisms of clinical signs. Chatswood, N.S.W.: Elsevie