Better Diagnosis Series: Differential Diagnosis

[Guest guest]

Good Morning!

 

This week I have put together a series of different articles based on

helping all of us to know and understand the components in a

diagnosis and tools that may help in determining a proper and

affective way in determining the facts.

 

 

Better Diagnosis Series: Differential Diagnosis

 

I would like to thank the Center for Health Evidence for this great

research.

 

 

Differential Diagnosis

 

When we are ill we present with one or more symptoms. These symptoms

prompt the practitioner to gather information through family history

and physical examination, identifying clinical findings that suggest

explanations for the symptom(s).

 

Differential diagnosis is the method by which the practitioner

evaluates the possible causes of a patient's clinical findings before

making a final diagnosis. [2] [3] Experienced practitioner often

gather information and group together findings into a summarized

pattern, based on body location or organ system involvement

 

We consider these clincial findings, [3] [4] and include problems of

biologic, psychologic or sociologic origin. [5] It is for these

clincial findings, rather than for the final diagnosis, that the

practitioner selects a patient's differential diagnosis.

 

When considering a patient's differential diagnosis, the practitioner

is selective, considering first those disorders that are

more likely a possibility and treating the most prevelant first.

 

The practitioner's single best explanation for the patient's clinical

problem(s) can be termed the `working diagnosis'. A few other

possiblities, termed `active alternatives' , may be worth considering

further at the time of initial work-up, because of their likelihood,

seriousness, if undiagnosed and untreated, or responsiveness to

treatment.

 

Additional causes of the clinical problem(s), termed `other

hypotheses', may be too unlikely to consider at the time of initial

diagnostic work-up, but remain possible and could be considered

further if the working diagnosis and active alternatives are

later disproved.

 

Using this framework for the patient, selecting a patient-specific

differential diagnosis has implications for both diagnostic testing

and initial therapy. For the leading hypothesis, the practitioner may

choose to confirm the diagnosis, using a highly specific test with

a high likelihood ratio for a positive result. [10] [11]

 

The practitioner may start initial therapy for both the working

diagnosis and for one or more of the active alternatives, depending

on circumstances.

 

Keep in mind that selecting a patient's differential diagnosis

includes a combination of symptoms, looking at over all patterns and

then discovering from your intake, which other factors play a role in

the present disorder.

 

 

Andrew Pacholyk, MS, L.Ac.

Peacefulmind.com

Therapies for healing

mind, body, spirit

 

 

 

References:

 

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palpitations.

Am J Med 1996; 100: 138-148.

 

2. Sox HC, Blatt MA, Higgins MC, Marton KI. Medical Decision Making

Butterworth,

Boston, 1988.

 

3. Barondess JA, Carpenter CCJ, Eds. Differential Diagnosis,

Philadelphia, Lea &

Febiger, 1994.

 

4. Glass RD. Diagnosis: A Brief Introduction, Melbourne, Oxford

University

Press, 1996.

 

5. Engel GL. The need for a new medical model: a challenge for

biomedicine.

Science 1977; 196: 129-136.

 

6. Laupacis A, Wells G, Richardson WS, Tugwell P, for the Evidence-

Based

Medicine Working Group. Users' guides to the medical literature: V.

How to use

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Working

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9. Dans AL, Dans LF, Guyatt GH, Richardson S, for the Evidence-Based

Medicine

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10. Jaeschke R, Guyatt GH, Sackett DL, for the Evidence-Based

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11. Jaeschke R, Guyatt GH, Sackett DL, for the Evidence-Based

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article about

a diagnostic test. B. What are the results and will they help me in

caring for

my patients? JAMA 1994; 271: 703 -707.

 

12. Pauker SG, Kassirer JP. The threshold approach to clinical

decision making.

N Engl J Med 1980; 302: 1109 - 1117.

 

13. Tversky A, Kahneman D. Judgment under uncertainty: heuristics and

biases.

Science 1974; 185: 1124-1131.

 

14. Dawson NV, Arkes HR. Systematic errors in medical decision

making: judgment

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15. Kassirer JP, Kopelman RI. Cognitive errors in diagnosis:

instantiation,

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16. Richardson WS. " Where do pre-test probabilities come from? " [EBM

Note]

Evidence Based Medicine (in press).

 

17. Guyatt GH, Patterson C, Ali M, Singer J, Levine M, Turpie I,

Meyer R.

Diagnosis of iron deficiency anemia in the elderly Am J Med 1990; 88:

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