Hypothesis-Driven History Taking
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Objective

This module has been developed to teach First Year Medical Students the process of clinical reasoning
and how to take a medical history using a hypothesis-driven approach that emphasizes pattern recognition.
 

What's at Stake

Stritch School of Medicine seeks to train students to be both astute clinicians and compassionate care-givers.

This Hypothesis-Driven History-Taking Project aims to accelerate the process by which medical students achieve
proficiency in clinical reasoning, as well as skillfulness in their history taking abilities.

Context

Over the past century the defining paradigm for health care has gradually shifted from a provider-centered model
to a patient-centered approach. Some practitioners, however, have resisted this shift, believing that "patient-centered
medicine" means "giving over control" to patients.

What patient centered medicine actually calls for is recognizing the unique competence and perspectives of both
physician and patient with the ultimate goal being service to patients and their well-being.

Evidence suggests that such a patient-centered approach, particularly as it has helped to strengthen the physician-patient
relationship, can have a favorable impact on patient satisfaction, health outcomes, compliance, and even malpractice claims.

The literature, however, also suggests that one of the barriers to effective communication between physician and patient,
are physician behaviors that too narrowly focus on diagnosis and treatment at the expense of empathy, patient education,
and building trust.

Quality medical care, today, demands that clinicians be proficient in communication and relational skills as well as in their
diagnostic acumen!

Physicians must recognize their need to be astute diagnosticians operating effectively within the richer and more nuanced
bio-psycho-social-spiritual model that now defines the physician-patient relationship.

But these abilities are not "factory-installed equipment" in aspiring clinicians -- they must be learned, nurtured and developed.

This module on Hypothesis Driven History Taking, therefore, seeks to expose students, early in their training, while they are learning
the value of Patient Centered Medicine, to the process of clinical reasoning.

We believe that doing so will not only strengthen and accelerate the students' acquisition of clinical skills, but it will foster these
abilities in a patient-centered framework.

 

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Taking A Patient History.
 

The medical interview is now seen as an opportunity for a clinician to accomplish three goals:

• Gather information         (relevant to patients' concerns and to clinical diagnoses)

• Establish relationship    (showing empathy and developing trust while attending to patient's concerns)

• Educate the patient       (empowering patients in appropriate ways to care for themselves)

Clinicians today must be agile in their ability to fulfill their diagnostic responsibilities as they simultenously work to
build an empathetic, caring relationship with their patients.

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Centering on the Patient 

Both physician and patient are under pressure from the pace and demands of carrying our their respective responsibilities.

Some clinicians believe that there is not sufficient time to be both "diagnostic" and "empathetic."

A study by Beckman and Frankel showed that physicians, eager to arrive at a clinical diagnosis, would interrupt a patient within
18 seconds of the patient's beginning to speak.
 
They found that patients rarely continued to express their true concerns once they were interrupted.

They also found that when patients were allowed to express all their concerns at the onset of the interview, no more than 150 seconds were needed.
Beckman HB, Frankel RM, The effect of physician behavior on the collection of data. Ann Intern Med 2001;134:1079-1085
 

(That's less than four minutes!)

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What lesson do we take from this?
Interrupting the patient with cardinal questions before allowing the patient to speak may actually work against a physician's time efficiency.
 

Model Example of Patient Centered Interview
 

"Once all concerns have have been expressed, the physician and patient can set an agenda for the current visit and then arrange for subsequent visits to address less pressing issues."

"After the patient has expressed all concerns and an agenda has been set, the physician can explore the most urgent concerns or problems. The physician should allow the patient to tell their story and guide the patient in the process by using open-ended phrases."
Barrier PA, Two words to Improve Physician-Patient Communication: "What Else?" Mayo Clinic Proc. 2003;78:211-214

Q: "Tell Me More About That..."  (open ended)

The physician should revert to specific or closed questions only after the patient has had the opportunity to fully speak their concerns and tell the story of what they have been experiencing.

Q: "You say that you have back pain, can you show me where?" (getting specific)

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Cardinal Questions
These questions are essential to understanding a problem; but they should be asked ONLY
after first allowing the patient initial time to tell, in their own words, about their concerns.

A good clinician requires detailed information to reach an accurate diagnosis.

But, as we have just discussed, a good clinician today recognizes that their inquiry into "the specifics"
is best pursued after allowing the patient to speak and after setting the agenda of prioritized concerns.

Once this has been accomplished, a patient not only understands, but expects that their physician
must seek out the details.  

A skillful clinician listens carefully for the information they need as they allow the patient to speak.

In order to get a clear picture of the patients experience, a physician needs answers to the following
cardinal questions:                                                            

Q: What is the Problem? (Pain, Discomfort, Concern, etc)

Q: What does it feel like? (Quality)

Q: How severe is it? (Intensity)

Q: Where is it Located? (Location of Pain, Discomfort, etc)

Q: When did it Begin? (Onset)

Q: What brings it On? What Makes it Worse? (Aggravating factors)

Q: What Makes it Better? (Alleviating factors)

Q: Does It Go Anywhere Else? (Radiation pattern)

Q: Are there any other Symptoms you are having? (Associated symptoms)
 

The physician may get much of this information by simply listening as the patient speaks; when necessary the physician
should ask the patient the above questions, or ask for clarification if the patient has been vague in their description.

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  Hypothesis Driven History   

Taking a skillful history, however, is about more than simply asking the cardinal questions.

A skillful clinician is listening to what the patient is saying, and trying to fit the information into a recognizable pattern known as a "diagnosis."
 

The Hypothesis Driven History reflects the importance of "pattern recognition" in clinical diagnostic reasoning. An experienced
and skilled clinician recognizes the "clustering" and "association" of symptoms, signs and test results which are often expressed
in a pattern. (Pattern recognition).

As part of the process of pattern recognition, a skilled clinician is always interpreting from among the "pertinent positive" and "pertinent negative"
symptoms in the history (as well as on the physical exam).

We shall come back to this, but first let's take a look at the process of human knowing, doing so through the lens of a clinician...
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Clinical Reasoning

The Process
Diagnostic reasoning can be understood as a cognitive process that moves through the following steps:  Experiencing  /  Understanding  /  Judging  / Deciding  /  Acting

                                       This is a continually recycling process!

                                That's why clinicians must make rounds each day!    

 
The Steps 

1. Experience
    Clinical reasoning can take as its 'starting point' any of a variety of 'experiences'
    (i.e. Patient history, physical exam findings, lab results, radiologic findings, biopsy reports).
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2. Understanding
    We then move from the experience to understanding by drawing upon categories of intelligibility --
    those disease conditions that form the list of explanatory possibilities or 'diagnoses'.
    
    We call this part of categorical understanding --differential diagnosis.
   
    This is the second step in the process -- it is our attempt to understand what may be going on with a
     patient!  
     
     A good clinician is someone who reads enough to learn about all the possible causes to explain a
     process.
     
     Since not all diagnostic possibilities (or categories of understanding) are equally adequate or relevant 
     explanations, our attempt to understand must ultimately be confirmed and the final
     diagnosis determined.
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3. Judgment
   To do this we must exercise judgment --to determine which among our list of possibilities is the most
     plausible explanation.   
   
    We do this by weighing evidence.   

    Judgment is the process of weighing evidence. (Hence the need for evidence-based medicine --EBM).

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4. Decision
   Judgment leads us to a final decision. In deciding, we move from differential diagnosis to final diagnosis.

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5. Action
   Reaching a decision then moves us forward into action (either further diagnostic investigation or therapy)
    on behalf  of the patient.  "We don't know simply to know, we know so that we can act!"
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Diagnostic Thinking

To summarize, clinical reasoning is a cognitive process -- one that conforms to those epistemological mechanisms
by which we come to knowledge and proceed to appropriate action.

Those mechanisms are:  Experiencing  /  Understanding  /  Judging  / Deciding  /  Acting

Each of the steps in this process has a corresponding 'virtue' that makes the process most effective:

BEWARE! 
Failure to perform any of the steps properly, skews the successive steps in the whole process!
A good clinician must take seriously ALL the steps in the process that make up clinical reasoning...

If I haven't ATTENTIVELY examined the patient, or reviewed at the lab results I may miss important initial information 

If I don't read enough pathology or learn about disease states, I will not be an INTELLIGENT diagnostician -"beware of the physician with a single diagnosis." 

If I don't weigh evidence in a careful and REASONABLE fashion I will be inaccurate in my diagnostic judgment

Having weighed the evidence, I am RESPONSIBLE for making a final decision and communicating my working diagnosis

Once I have decided the cause of the problem, I must implement my treatment, acting in a proper, proportionate, ethical and PROFESSIONAL fashion

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This process applies no matter what experience serves as the starting or entry point...

 

Three Examples:
(to demonstrate different starting points in the process of clinical reasoning)

The Is... (Experience)	What could it be? (Understanding)	What tells me what it is? (Judging)	What it is... (Deciding)	What I do now? (Action)
Symptom: Chest pain	Angina? Biliary Colic? Aortic Dissection? Esophageal Reflux?	+EKG? +GB Ultrasound? +Abdominal CT scan? +EGD (Upper endoscopy)	Final Dx? (depends on the evidence generated by the tests)	Heart Catheterization? Cholecystectomy? Vascular Surgery? Acid blocking Rx?
EKG finding: ST segment elevation	Ischemia, heart attack? Benign J point elevation? Pericarditis?	Troponin levels Healthy, muscular male no risk factors Friction Rub,	Final Dx?	Urgent Heart Catheterization Reassure patient re: normal variant. Rx with anti-inflammatory
Lab Report: Blood Culture growing Gram + cocci	Bacteremia? Contaminant?	Await Bacterial Species identification How many bottles positive ?	Bacteremia? Contamininat?	Start Antibiotic Rx Ignore, if contaminant!

    Hypothesis Driven History Taking            

A hypothesis-driven-history is derived when a clinician elicits a history by not only
asking the Cardinal Questions, but, in addition, inquiring about and interpreting the
"pertinent positive" and "pertinent negative" elements in the history.

Since this is a process of "pattern recognition," doing this well requires knowing
about what "associates" with what and in what "patterns."

The process of pattern recognition takes time and experience to master.
It requires knowledge of pathology and physiology, but we shall begin now by
relying on memorization of profiles to help introduce you to this process and
allow you to begin making pattern associations as you take a history from a patient.
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Lets Get Started...

To allow you an opportunity to take a hypothesis-driven history we will
explore two clinical problems -- chest pain and back pain --each of which
has a differential diagnosis list with associated "pertinent positive" elements.

Studying/learning the pattern of pertinent elements for each potential diagnosis
for a given complaint will allow you to begin to conduct a patient history guided
by your hypothesis of possible causes with their associated clinical symptoms.

Consider the following two problems, their potential causes,
and the pertinent positive findings associated with each.

Problem	Possible Cause	Possible Cause	Possible Cause	Possible Cause
1.Chest pain
	Heart Pain    Angina Pectoris	Stomach Pain    Gastritis or Reflux esophagitis	Chest Wall Pain       Costochondritis	Lung Pain        Pleuritis
Cardinal Questions	Pertinent Positive	Pertinent Positive	Pertinent Positive	Pertinent Positive
Type of Pain	"Pressure", "discomfort"	"Burning"	"Soreness"	"Grabbing/catching"
Aggravating	Exercise, or exertion	Spicy foods, alcohol	Movement	Breathing deeply
Alleviating	Resting	Antacids	Sit quietly	Shallow breaths
Radiation	Arm, shoulders, jaw,	Pit of stomach	No radiation	No radiation
Associated Symptoms	Short of breath, fatigue	Belching, nausea, sour taste	Feel fine	Cough, Shortness of breath, fever

Problem	Possible Cause	Possible Cause	Possible Cause	Possible Cause
2.Back pain
	Spine Pain    Herniated lumbar disc	Kidney Pain    Kidney stone, kidney infection	Pancreas pain       Pancreatitis	Skin Pain        Herpes Zoster "Shingles"
Cardinal Questions	Pertinent Positive	Pertinent Positive	Pertinent Positive	Pertinent Positive
Type of Pain	Aching	Sharp, comes and goes	Deep boring pain	Burning
Aggravating	Bending, cough, sneeze	Just comes on own	Eating, drinking	Always there
Alleviating	Curl Up, knees flexed	Just goes on own	Lean Forward	Nothing
Associated Symptoms	Tingling, numbness foot	Nausea, vomiting, can't void	Vomiting, Not hungry	Skin Rash, blisters
Radiation	Down leg	Groin	Stomach and back	Around my side

Review and commit to memory these summary profiles for the two problems (Chest Pain, Back Pain)
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To make things simple, consider the following profile summaries:

Chest Pain Profiles:

Back Pain Profiles:                 

In conclusion...
 You are asked to memorize the above profiles so that when you are asked to interview a standardized patient who presents with either chest pain or back pain you can:

     1.  Allow the patient to tell you about what they are experiencing.

 
        2.  Elicit the history (for either chest pain or back pain) driven by your awareness of the possible causes for
             chest or back pain so that you can listen for, ask about  and interpret the "pattern" of pertinent positive
             elements.

        3.  Explain to the patient what you think might be going on before you leave the room to "speak to
             your attending." 
 

      
    
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  Self Assessment Questions
                                                         Choose the single best right answer.
                                                         Answers for these questions can be found at the bottom of the page.
 

1. Patient Centered Medicine emphasizes:
          
             a.    Making a speedy diagnosis
             b.    Allowing the patient to feel heard and understood
             c.    Ordering as few tests as necessary
             d.    Giving control to the patient
 

2. The Medical Interview should accomplish which of the following?
 
             a. Gathering information
             b. Building relationship and trust
             c. Educating the patient
             d. All of the above

3. Allowing the patient to tell their story takes too long. A good clinician
    proceeds directly to asking the questions they need to make a diagnosis.

             a. True
             b. False
 

4. A good clinician should begin the history:

            a. Getting to the details
            b. Asking open ended questions
            c. Finding out when the complaint began
            d. Setting time limits on the discussion
           

5.  The Hypothesis Driven History:
           
            a. Is based on what the patient believes is going on
            b. Collects information first, then comes to a diagnosis
            c. Takes advantage of the process of pattern recognition
            d. Allows the patient to set the priorities

6.  Clinical reasoning is a process involving which of the following phenomena?

            a. An experience
            b. Understanding
            c. Judging
            d. Deciding
            e. All of the above

7.   Success in clinical reasoning requires which of the following virtues

            a. Properly attending to the patient and laboratory results
            b. Skill in generating a differential diagnostic list
            c. Carefully weighing all the pertinent information
            d. All of the above

8.  Shortchanging any of the steps in the process of clinical reasoning can adversely
     influence subsequent steps.

            a. True
            b. False
 

9. The process of clinical reasoning is a continually recycling process.

           a. True
           b. False


10. The Hypothesis Driven History relies upon a clinician's awareness of:

           a. The single cause of a given problem
           b. The pertinent symptoms that are associated with a given cause
           c. The results of all lab tests
           d. All of the above

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Answers:

  1. b    2. d    3. b    4. b    5. c    6. e    7. d    8. a    9. a    10. b

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