Why does rule out testing feel so good? Because it's WIN-WIN. I showed you the 4-Box representation. Now let me show you a real life example.
A 17 year old female is seen in the emergency room with a chief complaint of asthma dyspnea and shortness of breath. Thus begins the rule out testing.
Step 1: Vital signs
- Blood pressure 127/54. No hypertension. No hypotension causes to be concerned about. This fact narrows the scope and severity of disease immediately.
- Heart rate 78. The absence of tachycardia and bradycardia narrow the scope and severity of disease immediately.
- Respiratory rate 36. Somewhat concerning. An elevated respiratory rate (normal is 12) helps the doctor exclude many conditions (narcotic overdose) and puts others higher in the differential (anxiety, pulmonary embolism, asthma, pneumonia, bronchitis, heart failure, pain)
- Temperature normal. A normal temperature excludes many conditions and narrow the diagnosis.
- Oxygen saturation 97% on room air. This is highly encouraging and narrows the scope of diagnosis as well.
By evaluating nothing more than a set of vital signs, the doctor has narrowed their differential diagnosis to a likely probability disease states by excluding many more. Vital signs tell us everything about the acuity and severity of the disease state.
Step I: Chief complaint: "I'm short of breath". When doctors hear a chief complaint it can often pinpoint a diagnosis or offer clues for what to search for. Then the history begins.
Step II: History of present illness (HPI): We are taught as medical students to take a thorough history. As a medical student during my internal medicine rotation, I would often spend an hour or more taking just the history. A fact that can frustrate crusty nurses without the patience for medical education. Great history taking is ingrained into our minds as students. It involves asking hundreds of questions to pinpoint the complaints. Character, onset, location, duration, what makes it better, what makes it worse, other associated signs or symptoms. These are the questions of HPI.
In this case above the shortness of breath (character) started at 8 am abruptly (onset) after her boyfriend broke up with her by text message, and is constant (duration). Nothing makes it better or worse. Associated with headache and tingling in the hands and legs.
The clues of the HPI can generate further clues and questions to ask. They can broaden or narrow the differential diagnosis. This is where a great deal of rule out testing is accomplished.
The only cost of this 'rule out testing' is physician's time.
Step III: Past Medical Family and Social History:
Here we learn whether there is a personal history of pulmonary emboli or anxiety and depression. We learn if there are any congenital heart conditions. Any smoking. Any drug use. Any diabetes or heart failure history. We learn whether mom has ever had any second trimester miscarriages or if clots run in the family. We learn if our patient is on birth control pills or taking other thrombogenic medications. We can learn a lot from step III. In this case, we learn she is on birth control pills and she's a smoker and her mother had a venous embolism in her 20's. And she just got back from a trip to Europe. This is where a great amount of rule out testing is accomplished.
The only cost of this 'rule out testing' is the physician's time.
Step IV: Review of systems
Here we ask about all the other organ systems. We try to find out if anything else is going on. Headaches? Fevers? Chills? Sweats? Sore throat? Dizzy? Chest Pain? Palpitations? Cough? Hemoptysis? Abdominal pain? Diarrhea? Dysuria? Hematuria? Hematochezia? Rash? Swollen or painful joints?
This is the organ system questionnaire where we try to gather a wealth of information and try to tie it all together. Here we learn from our patient that she has a long standing history of anxiety and depression. We learn she came to the emergency room three times in the last two years with shortness of breath, each time after her boyfriend broke up with her. This is where a great amount of rule out testing is accomplished.
The only cost of this 'rule out testing' is the physician's time.
Step V: Physical Exam
This is where your physician is supposed to examine you from head to toe. You can learn a lot from the exam. Is there throat exudate? Is there wheezing? An S3 or S4? Murmur? Does the chest wall expand and contract in a symmetric fashion? Is there JVD present? How about lymphadenopathy? How about abdominal pain? Rash? Swollen or painful legs? This is where a great amount of rule out testing is accomplished.
The only cost of this 'rule out testing' is the physician's time.
Up to this point, our rule out testing has all been shouldered on the back of the physician's skill set and the time required of them to accomplish it. It's all based the doctors ability to ask the right questions and examine the right organ systems. What do we have so far? Here is my summary:
A 17 year old seen three times previously in the ED with shortness of breath, each time after her boyfriend broke up with her. She has normal vital signs except for a rapid respiratory rate. Her medical history suggests a long standing history of anxiety and depression. She is otherwise healthy except she smokes, takes birth control pills and her mother had a history of a blood clot in her early 20's. Plus she just came back from a long trip to Europe. She complains of numbness and tingling in her extremities. Her exam does not suggest any evidence of asthma or heart failure. Her exam has no suggestion of any abnormalities.
So what do we do? Up to this point the history and physical examination has been one giant rule out test. In the absence of positive findings on history and exam, the negative findings are just as important to help guide your differential. In this case the patient's history has been narrowed down to two possibilities:
Is this a panic attack or is this a pulmonary embolism? She has a classic history of anxiety, a previous history of similar attacks under similar circumstances and stable vital signs. BUT, she has multiple risk factors for pulmonary embolism, despite her normal vital signs. Could this be a panic attack? Could this be a pulmonary embolism? Could it be both? The answer to all three questions is yes.
Now, that our history and physical are complete, the question becomes, do you as a physician have enough information to make a diagnosis of one or the other with high probability of success and low probability of a bad outcome? Do you have the confidence to make the diagnosis and feel good about it, without any other information? In all likelihood, because of your fear of being sued for failure to diagnose, the answer is no. Is there a guideline or a protocol to help you make your decision? No there is not. There is only your your skills as a physician, a skill that holds little chance of holding up to the standards of today's technology.
This is where rule out testing feels so good.
Do you send the patient home with a diagnosis of panic attack and follow up with her doctor? Or do you pursue further testing for pulmonary embolism? That is the million dollar question. And let me answer it for you. Our current system is set up to pursue the diagnosis of exclusion without regards to cost. And here's why. Doctors act out of fear. Patients respond out of the comfort of knowing. And in both situations, neither is personally held responsible for for the cost of their desires. We pay for it through higher premiums. We will pay for it through higher taxes. The patient is immune from the immediate cost of feel good medicine. The doctor is immune from the fear of not knowing. A fear that is driven to spend other peoples money to prevent a bad outcome.
Look at my four box theory on Testing vs Outcomes. The physician will always want to stay on the top line. Because that's where the lawyers work for food. That's where they feel good. And that's where the patients feel good. That's why rule out testing feels so good.
Let's go back and look at our example above. What are the options for this doctors plan? There are only two:
- Make a diagnosis of panic attack based on her hyperventilating, numbness, rapid respiratory rate and her previous history of similar episodes under similar circumstances and send her home without any blood work, xrays or other objective technological data.
- Pursue further rule out testing for pulmonary embolism based on her recent travel history, her smoking, her birth control pill usage, her positive family history of blood clots and her rapid respiratory rate, despite the lack of tachycardia, hypoxemia, chest pain, leg swelling or other classic findings for pulmonary embolism.
The threshold for further testing, no matter how low the probability, lies in the perceived urgency of the situation. A blood clot, while usually not life threatening, can be. But then again, many conditions can be life threatening, at the long end of the tail. The problem with probabilities is that eventually you get it wrong. And you don't want to be the doctor holding the bag, when your probabilities fail you. If you didn't do everything in the way of rule out testing, and a bad outcome happens, you land in the last box of my four box theory: No Test and Bad Outcome. And that is the box physicians fear the most. Not because they did something wrong, but because of the perception that they did something wrong. As a result, when in doubt, you order the test. And you let someone else pay for it while the patient and doctor gets piece of mind.
It's the perfect finance system to encourage lots of blood work, lots of xrays, lots of surgeries, lots of procedures and lots of expensive technology as well as lots of expensive cover your ass protocols that add lots of expense with little in return. We place doctors in control of other peoples money and then establish irrational expectations and standards of care for them to spend it. The #1 rule for doctors is to avoid the No Test with Bad Outcome scenario. It trumps everything else we do. And it's a fear driven mentality. A fear based on getting sued, not losing a lawsuit. The suit itself is the fear.
This patient, a 17 year old hyperventilating after losing her boyfriend, will probably get lab work, she'll get an IV, perhaps with the use of a vein light, she'll get a d-dimer and even if it's negative, she'll get either a V/Q scan or a CT scan of her lungs looking for a pulmonary embolism. Even though all the data points to a high probability of anxiety, because of the possibility of a pulmonary embolism based on history, the failure to diagnose this potentially life threatening or disabling condition has a high probability of landing the physician in box four where it's LOSE-LOSE.
It's just easier to order the test and feel good about it. And complain when your premiums rise another 10% next year.
