Tuesday, November 20, 2012

The Existential Diagnosis


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When I was in practice in Denver, a Family Physician won a court case by insisting that his diagnosis was his alone, and that the diagnosis did not exist until he made it. --- Lawyers like this kind of thinking. --- The doctor claimed that the same pattern of symptoms and complaints could be called many things, but as the patient’s physician, only he and the patient were privy to those complaints and, therefore, whatever diagnosis the doc assigned to that condition was intrinsically correct. It was his diagnosis. He owned it, and it was his means of classifying this complex of clinical findings.
Interestingly, a similar assignment of diagnosis takes place in the clinical pathological conference, (CPC). The summary will refer to the clinicians’ diagnosis, the surgeon’s diagnosis, the Radiologist’s diagnosis or the pathologist’s diagnosis. Such is the ambiguity of the clinical findings in difficult cases. In the later, the pathologist’s autopsy findings generally win out.

HIV Testing


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USPSTF issues new draft recommendations on HIV screening. (from AMA morning rounds)

Draft recommendations on HIV screening from the US Preventive Services Task Force (USPSTF) received moderate coverage in print and online. Many experts and officials welcomed the guidelines, as they could potentially lead to earlier detection and treatment, as well as prevent more infections.
 
About time, Public Health is not what it use to be. If this had been done when the epidemic first started many people would still be alive and the epidemic would have moderated. What did happen was a politically correct lobby for non testing and anonymity for the infected.  Regulations specifically prevented diagnosis of HIV without patient consent. Hospitals were forced into universal precautions, which amounted to no isolation at all. Imagine a surgeon operating on patients without knowing the HIV status.

Saturday, November 17, 2012

A Fork in the Road


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Medicine, the profession struggles with its identity. Will we be physicians in the likes of the great scientist philosophers and humanists since Hippocrates? Or, will we succumb to the trend of commodifying the profession? It is clear that health care planners intend to move us in the direction of standardized care. The extent to which the profession restores its leadership, humanity and science will largely depend upon how it deals with the coming universality of computerized patient records.
Meaningful Use requirements for incentive pay under the Affordable Care Act and various agencies will mandate certain quality metrics in the Electronic Health Record. (EHR) Evidence of compliance may be required by the uniform claims submission process for reimbursement.[1] Programmers will likely build these metrics into the software developed by various vendors of the EHR. Doctors are familiar with Best Evidence and some of those treatment standards are already appearing in EHRs. A new feature will be Clinical Decision Support (CDS). Best Evidence largely deals with treatment protocols. CDC will deal mostly with diagnosis. What follows is a discussion about how the later, CDS, deals with differential diagnosis and the role of the physician in an electronic data environment.

The review of systems (ROS) and the differential diagnosis lie at the heart of the data processing that attempts to deal with these two intellectual processes. Each item in the ROS, signs and symptoms related by the patient, becomes critical data in the process to follow. The negative response is as significant as the positive -- maybe more. Each positive response, when confirmed by further questioning, evokes a list. The list is critical as well and might as well be indelibly imprinted behind each data point or on the mind of the physician. When completing the ROS, one then has a number of responses, each with its list of etiological possibilities. One or more diagnostic possibilities appearing on separate lists tend to point to the underlying problem and contribute to the establishment of a tentative differential.
Here is where statistics comes into play The coupling of signs and symptoms with a medical information database, can assure the clinician that he or she did not overlook the less obvious problem.  The more often a diagnosis appears on multiple lists and the more completely the signs and symptoms on the ROS fulfill the attributes of a diagnosis, the more likely you are on the right track. However, all overlapping signs and symptoms are not equal and many illnesses have similar symptoms. Furthermore, individual patients seem to have a limited range of symptoms to account for a wide range of possible illnesses. Patients also react to illness in a highly individualized way.

Ongoing and real-time statistical analysis of the differential diagnosis compared with outcomes can validate the initial list of possibilities. Thus the coupling together of patient data with the vast store of medical information, can assist the clinician with his or her interpretation of the data. Furthermore, the computer generated differential can focus statistically on the more likely candidate diagnoses. Database mining software can provide further relationships that the mind cannot grasp or that have not previously been observed.

Playing the percentage game, however, can be risky. An old adage states, “If you hear hoof beats in the hall, don’t think of zebras.” The Internist might ask, “Is there a circus in town?” The problem with rare diseases is that there are so many of them. Encountering a rare condition unexpectedly is a common occurrence. Adding further to the dilemma, the easy diagnosis often masks an underlying cause. Examples abound: Valvular Heart Disease, Shingles, Atrial Fibrillation, and Duodenal Ulcer to mention only a few of the more obvious ones all have underlying causes. Diagnosis is thus challenged on multiple levels. Physicians must peal away the layers of the diagnostic onion. Programing information technology to dig down to those multiple levels of scrutiny may be tricky indeed.
Some would advocate a process in which the computer and pre-defined procedures defined by best evidence as written by experts, take the prime role and relegate the physician to insuring the validity of the data points. The rationale to this approach lies in the frequency of diagnostic error and the never ending expansion of diagnostic and treatment procedures that do more harm than good costing more and more.

Others would say, we need to go back to the physician as the humanist and scientist of old with vast experience and ongoing medical education in a professionally structured society, dedicated to excellence. Today we are at a cross roads. The road to subordination, however, may have already been taken. Whichever path we follow, patient safety, access and consistent in depth handling of the data are primary. The differential diagnosis is critical to achieving anything like the health metrics of the rest of the industrial world. --- We are currently something like 37th in perinatal mortality and longevity.
Man thinks, the computer remembers. The physician’s mind does far better at complex judgment and interpretation than any computer to date. The mindful and highly experienced physician sees the above analysis and assembles a differential diagnosis with a scanning logic. Most physicians navigate a differential diagnosis quite well. The differential diagnosis, however, demands a high degree of commitment to the art, medical education and extensive exposure to most every form of disease. Our mind thinks and makes individualized judgments that the computer cannot. The computer on the other hand remembers and does statistics. We do not remember so well and we do not manage statistics well on a large database.[2]

For the statistical linkages between patient data and the proven diagnosis to be valid, they must be relevant to the patient. Do you depend on statistics developed on a national scale, an international scale or limited to a local population that might be more relative to the patient at hand? I say might be because each patient is a one of a kind individual. The only statistics that matter might very well be the patient's own genomics. The individual genome, despite the nail biting, is falling in price and will soon be ubiquitous. We need to be sure the tests are not sold like snake oil by bathers, naturopaths, charlatans and opportunists.

The psychological or psychiatric diagnosis proves elusive for the computer generated history, whereas, the physician may grasp it intuitively. A ROS with phases of the MMPI[3] covering all classes of behavioral and psychological issues could be helpful. The biggest mistake is to tell a patient, “It’s all in your head;” that’s not a diagnosis. Again the physician must dig down to an underlying cause. Be suspicious. Clinical interaction must continuously measure outcome and look for errors. --- It may be difficult to teach a computer to be suspicious.
The present day inconsistencies in both diagnosis and treatment have lead to a movement among health care planers to standardize care. Indeed there are many missed and wrong diagnoses.[4] Misses are almost inevitably due to omitting the ROS or ignoring one or two of the responses when they do not fit the assumption. Larry Weed[5], the inventor of the problem oriented record (POMR), insists that any positive, not accounted for by the diagnosis, belongs on the active problem list. Weed further advocates that the physician’s training is backwards and that he or she should be trained to exacting and standardized skill in history taking, examination and technical surgical skills while leaving the basic science and pathology to the experts delivered by computer but with the provider guiding the patient in making the decisions in a compassionate way. This supposes that information technology will provide the best diagnosis, the best evidence and the best treatment leaving the decisions largely to the patient. This sentiment is further advanced in John Wennberg’s book, Tracking Medicine.[6] In which he documents over treatment and inconsistent treatment demonstrating superior outcomes in regions of less intense and less specialized care.

Arguably, we should do the thinking and follow a strategy in which the computer remembers the data and the physician exercises judgement based on the individual patient and that patient’s choices. The physician concentrates on the science, the judgment and the art of medicine. Bring the patient to the fore of decision making. The computer tracks lists and analyses statistically on a real-time basis. Embrace the benefits of HIT and CDS. Retain control of the data, however, at all costs. Let the computer couple your precise clinical data with the vast store of medical terminology, nosology, and the salient features of each. The value here is in not missing something and not getting stuck in a wrong assumption. The analysis should present to the physician a credible preliminary differential. With or without assisted memory and coupling to the vast store of medical knowledge, the ROS is key to patient safety and care. Without extensive branching logic, though, the computer administrated ROS may create variable data. We have all experienced the patient responding differently on different occasions, to different physicians or to the nurse. I think the responsibility for securing a valid database remains with the physician. Less experienced clerical questioners may fail to elicit valid data.
Physicians and Medical Schools struggle with a conflict between physicians in the classic role of science, art, diagnosis and a newly proposed role in which the physician practices in a role subordinate to the computer, algorithms, protocols, check lists and the authors of Best Evidence.

At the heart of the conflict lie the complex process of diagnosis and the choice of individual treatment. To meaningfully apply the dictate of Best Evidence, one needs the right diagnosis. We suggest that the best application of computers, statistics will be achieved when the computer applies its faultless memory and capacity for data with dynamic real-time statistical analysis, not on mass populations, but on the internal data at hand. This strategy provides data more relevant to the individual patient and keeps the physician in control of the data. The strategy also leaves the physician and the patient with the choices, the judgment and the mindfulness of that data. The physician thinks, the patient participates, the computer remembers.

Yogi Berra once famously said, "When you come to a fork in the road, take it!" As a profession, we should have it both ways, the physicians science and art plus the computers memory.


[1] Agencies include: Health and Human Services (HHS), National Institution of Health (NIH), Centers for Medicaid and Medicare Services (CMS), Insurance companies, and regional Health Information Exchanges (HIE),
[2] We do need to take into account the computer’s future capabilities, however. So far the computer does not think, but IBM's Watkins comes close.
 [3] Minnesota Multiphasic Inventory
[4] The American Journal of Medicine, Vol 121, (5A) May, 2008
“Overconfidence as a cause of Diagnostic Error in Medicine,”  ES BERNER & Mark L. Graber, M.D. American Journal of Medicine, 2008 Vol 121 S2-S23
[5] Medicine in Denial, Lawrence L. Weed and Lincoln Weed April 2011, Amazon
[6] Tracking Medicine, John Wennberg, 2011, Amazon

Friday, November 9, 2012

Wrong Diagnosis


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 All the best evidence protocols are worthless in the face of the wrong diagnosis. With the efforts to standardize medical treatment, reduce costs and enhance patient safety, planners pay little attention to missed or wrong diagnosis. Disease in my formal medical training was defined as a maladaptation to the environment, and at some level, indeed it is. Medical science and the physician’s art define the causes of that maladaptation as a diagnosis or syndrome. Unfortunately many diseases have common signs and symptoms. The body has a limited number of ways to respond to disease and there are so many diseases and syndromes – more than we can remember.  The identification of a diagnosis, therefore, may be uncertain at best.[1]  

Two thousand four hundred and fifty years ago Hippocrates confronted the challenge of diagnosis with terms meticulously describing the manifestations of disease. His precise descriptions and inductive reasoning lead to the abandonment from mythology in diagnosis and from the concept of disease as a punishment by the gods. His diagnosis was correct in that it was a precise description of its effect.

Today, however, with far greater knowledge of pathophysiology we struggle with identifying the cause of our patients’ problems. We try to identify the diagnosis in order to relate a treatment plan that is safe and yields a prognosis favorable to the patient.  What is the problem? With what little research there is on wrong diagnosis and missed diagnosis, we find up to a 20% error rate. Autopsy findings prove error rates much higher. In some cases, such as pulmonary embolism or aortic aneurism, the error rate runs as high as 60%[2] Outpatient ENT errors run high as well and most hospital admissions for pneumonia are signed out as community acquired pneumonia unidentified.

Many causes lead us to submit an erroneous diagnosis. Perhaps the greatest problem is the number of layers of cause and effect that we deal with. Is it a gross diagnosis or a tissue diagnosis or tomorrow a bio-molecular diagnosis – even genomic?  Is it left lower quadrant pain, a left ovarian mass, a corpus lutein cyst, a seromucinous cyst adenocarcinoma and if the later, what proteinomic predisposition?

Autopsy has gone out of style. Two hundred years ago Marie Francois Bichat wrote over his autopsy room in Paris, “Death comes to the Aid of the Living.” The abandonment of autopsy must be economic. Maybe insurance companies refused to pay for it. Patient’s families have always objected. The hospital does not want the responsibility. The pathologist finds it a low marginal return activity. For whatever reason, autopsy -- except for forensics -- seems a lost art. We find clinical pathological conference and morbidity and mortality conference replaced by the x-ray conference. With the abandonment of autopsy we have lost the gold standard for definitive diagnosis.

The CAT scan has replaced the autopsy in an intellectual sense, and that is all wrong. The CAT scan is expensive, far more so than an autopsy and is by no means definitive at the tissue, cellular and molecular level. Although X-ray conferences are contemporary, and bring together multiple specialties and the diagnostic suggestions of the group, they still may still fail to yield the right answer. CAT scans done extensively in place of careful differential diagnosis and basic cognitive disciplines cost the patient and the health care system enormously. With an initial wrong presumption the addition of added unnecessary tests and procedures lead to decreased patient satisfaction, safety and poorer outcomes. --- “First, do no harm!”

Patients are different. There molecular biology may be as varied as their noses. Statistically derived presumptions, may fail to account for geography, ethnicity or individual circumstances. Additionally, the physician may decline to write a diagnosis that may cause the patient to be ineligible for insurance, induction into the military or some other sensitive job such as hospital privileges for a doctor or class I medical for an airline pilot. These are usually minor omissions, but together they deny any meaningful analysis of a database based on the diagnosis.

Our very regulations seeking standardized care may cause a more insidious error rate based on the diagnostic requirement for laboratory or other diagnostic studies. The same may apply to treatment plans – a treatment looking for a diagnosis. A similar diagnostic distortion occurs, when the diagnosis is altered or selected for reimbursement purposes. Hopefully these alterations are harmless to the patient, but in some context can lead to a wrong presumption in a future event that misses a lifesaving solution.

Overconfidence, assumption, snap diagnosis and omission of essential parts of the history and physical contribute to errors as well.[3] We do not keep statistics on wrong diagnosis, but the trial lawyers do, and they can tell us something.  Graber et al chronicle the size of the missed diagnosis problem which results in between 40,000 and 80,000 deaths a year in the US. The problem may actually be greater.[4]

Cognitive scenarios as presented by primary care specialty boards, the review of systems together with listening to the patient, a complete history and physical at least for the organ system involved will go far. But the association of findings with the vast number of possibilities suggested by these findings presents a challenge to the clinician. It is a challenge that medical schools can meet with appropriate lists, current terminology and criteria for diagnosis  -- most of all a vigorous CME program. Johns Hopkins will hold a conference on wrong diagnosis this month.[5]



[1] Delaney; Munro: Diagnostic difficulty and error in primary care; Family Practice 2008; 25 (6) 400-413
 
[2] Berner, Graber; Overconfidence as a cause of diagnostic error in medicine; Am J Med 2008;121: S2-S23
 
[3] Bringing Diagnosis Into the Quality and Safety Equations; Graber ML; Wachter RM, Cassel CK. JAMA. 2012; 308(12): 1211-1212.
 
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Thursday, November 1, 2012

Misdiagnosis


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A review of the literature published in the Green Journal[1] Table1 lists diagnostic errors by clinical condition from various studies. Striking among them, ruptured abdominal aortic aneurysm was missed 61% and dissecting thoracic aneurysm 35% of the time. The radiologist missed breast cancer on the mammogram 21% of the time. The initial diagnosis of bipolar disorder was wrong 69% of the time. Among patients with fatal pulmonary embolism, the diagnosis was unsuspected 55% of the time. Psoriatic arthritis was missed or wrong 39% of the time. Amazingly, the machine EKG missed atrial fibrillation in 35% of the tracings and the reviewing clinician failed to pick it up in 24% of those.
In my own observation, misdiagnosis is rampant among less threatening clinical conditions especially those offered from outside of the relevant specialty among specialists, as well as the more unusual conditions encountered by primary care physicians. It is not uncommon to misdiagnose various forms of sinus disorder, otitis and respiratory disease. Pneumonia too, while recognized as such often lacks a credible etiology -- due in part to less scrupulous sputum collection and identification by microbiology. With a multitude of causes, pneumonia may be diagnosed by circumstance such as community-acquired pneumonia and treated with a high percentage antibiotic for the so-called community acquired condition.

Trial lawyers claim that the first physician misdiagnoses cancer 45% of the time -- probably not an overstatement.
Medicine is both an art and a science. Some physicians lean so to the side of art that they lay claim to the diagnosis itself. When they “make a diagnosis,” that diagnosis is laid in stone. The treatment, whether appropriate or not, is credited with the success whilst the body cures itself with or in spite of the treatment. So much is the body’s responsiveness to caring, faith and encouragement that the placebo effect is real. Thus, the patient’s response reinforces the physician’s self-confidence and further obscures misdiagnosis.

Then too, there is the right treatment for the wrong diagnosis, often developed over time based on experience, the outcome may be quite effective – or just an accident. Was this how a drug for Parkinson’s came to be effective for influenza, how an anti tuberculosis drug became effective for depression, or how a depression medication came to be effective for pain.
Diagnosis too is like an amoeba; it changes with passing specialties, fashion and even science. Current medical terminology changes as if with the weather, placing a slightly or even a profoundly different slant on the basic concept of pathophysiology and today a new understanding of the basics of disease through advances in molecular biology.

I’ve made the point now so often that is a cliché to add the distortion in diagnostic records produced by insurance clerks. Seeking to submit only the diagnosis that claims processors will accept for reimbursement, the insurance database bears little relationship to the actual doctor’s notes. Furthermore, the ICDMA consistently leagues behind current terminology. Whereas ICDA makes room for acute, sub acute and chronic, it makes little provision for differential diagnosis, presumptive, working or established diagnosis. One can write 3 or 4 digit codes and state the diagnosis simply as chest pain without specific cause or abdominal pain the same way, but in the wisdom of the reimbursement system, a 4 digit code does not garner reimbursement or authorization for further testing. Expediency thus codifies the wrong diagnosis in the accumulated database of medicare, medicaid and other third party claims processing agencies.
A further distortion results from the physician’s reluctance to saddle the patient with a diagnosis, which might cause the patient to lose insurance coverage. The same applies to a prior condition. Sometimes the physician may downplay a frightening diagnosis pending further counseling with the patient. In another case, the physician may avoid the true diagnosis to protect the patient’s confidentiality when a family member or others view or co-pay the insurance claim.
Unfortunately health care planers and even public health base medical policy on this vast corrupted pool of diagnostic data.

Diagnostic errors in hospitals account for 17% of adverse events and 10.5% of adverse events resulted from misdiagnosis.[2] Given that 15% of the time the clinician lists the wrong initial diagnosis, clinical decision support (CDS) – elsewhere called computer decision support system (CDSS) -- makes a lot of sense. While CDS finds its way into most commercial vender based electronic health records (EHR) and internally programed institutional EHRs, very few include diagnostic decision support beyond facilitating the problem list. Wright, Sittig and Ash et al, in the Journal of Informatics (AMIA) list taxonomy of 53 CDS front-end applications taken from a survey of seven selected vendors and four institutions. Only three provide any diagnostic support. Most CDS applications focus on medications, orders, incompatibilities and treatment protocols based on “best evidence.” Obviously, the best treatment protocol applied to a wrong diagnosis does more harm than good. If the clinician lists all of the possibilities as in a differential diagnosis, the list will likely contain the right diagnosis. It then becomes a process of selection and elimination. The final answer may still be in dispute at autopsy but there will be fewer misstatements along the way and a far more credible database. CDS can provide a differential diagnosis along with statical probabilities based on the patient data available. If the CDS contains the criteria for diagnosis and the patient meats that criteria, then the clinician will likely be on the right track. The human mind under the best of circumstances struggles with both memory and statistics. In no way can a computer replace the judgment, the intuition, and the wisdom of a well-educated and experienced physician, but well written database applications can remember it all unerringly, and apply statistical interpretation. Furthermore, to an even higher level of accuracy, the relational database can internally improve its statistical interpretation based on later proven diagnosis and or outcome. Ongoing analysis of internal data amounts to a simple artificial intelligence, but not of the human variety. Therefore, CDS acts as a complement to clinical thinking, not a replacement and an ongoing source of continuing medical education. (CME)

Diagnosis is like an onion, it has many layers. Changing patterns of cause and effect, a long and complex history and the patient’s adaptations both emotionally and physically yield hidden layers. The problem list helps as in problem oriented charting. Still not universally used, it at least provides a list of the elements. Sir Wm. Osler, professor of medicine at the U of Pennsylvania, 1884, Johns Hopkins, 1888, Oxford 1905[3] and the acknowledged father of modern internal medicine, suggested that the physician, in dealing with multiple problems not subscribe multiple diagnoses but rather look for an underlying cause. He also suggested that the physician’s primary role was convincing patients to take fewer medicines; hardly in keeping with today’s `Medicine Wagon` cornucopia of expensive drugs.
Most planners and non-clinicians miss the degree to which diagnosis, treatment and medical knowledge change over time, like an amoeba moving this way and that sometimes rapidly and other times slowly. The changes come with new knowledge, with current fashion and with genomic reinterpretation of the pathophysiology itself.  Furthermore, patients vary greatly as individuals. Geographical regions, even small ones, experience significantly different epidemiological and environmental problems.

Aggregating all of the known diagnoses and syndromes in the World into one database with criteria presents a formidable task. It would have not have been attempted just a few years ago due to limitations in storage capacity. That limitation no longer exists. Accumulating such an open source universal database for diagnostic CDS may go a long way in improving diagnostic accuracy. However, health care institutions and vendors may avoid incorporating a resource sensitive volume of material into their database system.
There are many reasons for the problem of diagnostic inaccuracy.  As mentioned one is the changing criteria and understanding of the etiology of disease with advances in genomics proteinomics and micro-molecular biology. Other problems result from the insurance clerk’s attempt to list a diagnosis compatible with the requirements for testing and or reimbursement. Another results from the snap diagnosis associated with high throughput, efficiencies insisted upon by profit-motivated management. There must be some significant reasons for the dismal ranking of US medicine compared with the rest of the world. Not to beat a dead horse, but a ranking of 36th in infant mortality implies something more than mal distribution of providers and over-treatment. I submit that diagnostic CDS will go a long way towards closing the gap.
Table 1Diagnostic Error Rates from the literature[4]

Tuberculosis / Autopsy                                       50%
Pulmonary Embolism                                           55%
Aortic Aneurism                                                   61%       
Sub Arachnoid Hemorrhage                              30%
Breast Cancer / Mammogram                            21%
Bipolar Disorder                                                   69%
Appendicitis                                                          18%
Cancer Path                  2-9% GYN;   5-12% non-GYN     
Endometriosis                                                       18%
Psoriatic Arthritis / Standard Patient                39%
Atrial Fibrillation / EKG Machine                       35%
Infant Botulism                                                     50%
Diabetes Mellitus                                                 18%
Chest XR by / ER                                                   18%

                               

 



[1] The American Journal of Medicine, vol 121 (5A), May 2008
 
1 Over Confidence as a Cause of Diagnostic Error in Medicine, E.S. Berner & Mark L Graber, m.d. American Journal of Medicine, 2008, Vol 121 S2—S23