Clinical Decision Making

Chapter 2 Clinical Decision Making

Clinical Case Problem 1 A Third-Year Medical Student Who Wants to Know How to Think

A third-year medical student asks you to teach her the secrets of clinical decision making, or how you think when you approach and treat a patient. You agree to take her to see a patient in the emergency department. After you talk with the patient, you ask the student to describe everything she has seen and heard. You carefully note that she has missed approximately half of what happened in the conversation between you and the patient and even more in the physical examination.

Select the best answer to the following questions

1. This case represents a problem with which step(s) of the clinical decision making process?

a. cue acquisition

b. hypothesis formation

c. the search process

d. all of the above

e. none of the above

2. The most common problem related to clinical decision making by practicing physicians is

a. not formulating enough hypotheses

b. not formulating the correct hypotheses

c. not attending to all the patient-relevant cues

d. not knowing the prevalence of the condition

e. not using time appropriately in treatment plans

3. The student returns with you to the office and sees a patient on her own initially to gather historical and physical examination data, which she then presents to you. After seeing the patient, she is absolutely convinced the patient has a particular diagnosis. You take her with you to see the patient, and you obtain more historical information and examine the patient. As you ask her questions about her reasoning, she proceeds to ignore a whole variety of things that do not support her original diagnostic hypothesis. She has made which of the following errors in clinical decision making?

a. failure to acquire a cue

b. failure to generate hypotheses

c. premature closure

d. all of the above

e. none of the above

Clinical Case Problem 2 A 25-Year-Old Medical Student Who Is Having Anxiety Regarding His Upcoming Epidemiology Examination

A 25-year-old medical student comes to your office in a state of extreme anxiety manifested by palpitations and sweating throughout the previous week. He tells you he is scheduled to have a clinical epidemiology examination in 24 hours.

On physical examination, his blood pressure is 120/70 mm Hg, pulse is 90 beats per minute and regular, and respirations are 24 per minute. His physical examination is normal. You order a thyroid-stimulating hormone test to exclude hyperthyroidism. You explain to him that given the low prevalence of thyroid disease in his age group and the higher prevalence of anxiety in his medical school population of students, the test’s negative predictive value will be helpful. He looks confused and more anxious.

In an attempt to deal with his symptoms, you decide to spend some time tutoring the student in basic epidemiologic concepts. You begin by explaining the basics of a 2 × 2 table that relates positive and negative test results to the presence or absence of disease in a specific population (Table 2-1).

Table 2-1 Relationship Between Test A and Disease B

	Disease B Present	Disease B Absent
Test A result positive	30	50
Test A result negative	10	80

Use the data from Table 2-1 for questions 4 to 9.

Consider the data in Table 2-2 illustrating the prevalence of disease X in various populations. On the basis of this information about disease prevalence and assuming the sensitivity of test A for disease X is 80% and the specificity of test A for disease X is 90%, answer questions 10 to 13.

Table 2-2 Prevalence of Disease X in Certain Populations

Setting	Prevalence (Cases/100,000)
General population	50
Women, ≥50 years	500
Women, ≥65 years, with a suspicious finding on clinical examination	40,000

To answer question 14, consider the data in Table 2-3 regarding the sensitivity and specificity in the diagnosis of diabetes mellitus in the population.

14. Given that the data are correct, if the sensitivity of the test for a given blood glucose level is 36%, which of the following would be the most likely value for specificity?

15. The validity of a test is best defined as which of the following?

a. the reliability of the test

b. the reproducibility of the test

c. the variation in the test results

d. the degree to which the results of a measurement correspond to the true state of the phenomenon

e. the degree of biologic variation of the test

16. Which of the following terms is synonymous with the term reliability?

a. reproducibility

17. Which of the following is not a measure of central tendency?

d. standard deviation

e. none; all of the above are measures of central tendency Gaussian distribution

Table 2-3 Sensitivity and Specificity of Blood Glucose Levels in the Diagnosis of Diabetes Mellitus

Blood Glucose Levels 2 Hours after Eating	Sensitivity	Specificity
>140 mg/100 (7.8 mmol/L)	57%	99.4%

Consider the following experimental data: In a trial of the effect of reducing multiple risk factors on the subsequent incidence of coronary artery disease, high-risk patients were selected for study. Elevated blood pressure was one of the risk factors for people to be considered. People were screened for inclusion in the study on three consecutive visits. Blood pressures at those visits, before any therapeutic interventions were undertaken, were as listed in Table 2-4. Use the data in Table 2-4 to answer question 18.

Table 2-4 Blood Pressure Readings versus Visit Number

Visit Number	Mean Diastolic Blood Pressure (mm Hg)
1	99.2
2	91.2
3	90.7

Consider the following experimental data: A population of heavy smokers (men smoking more than 50 cigarettes per day) are divided into two groups and observed for a period of 10 years.

Use the data from Table 2-5 to answer question 19.

Tags: Swansons Family Medicine Review

Oct 1, 2016 | Posted by admin in GENERAL SURGERY | Comments Off

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