quiz 4 Flashcards
According to the majority of research discussed in class, a number of cognitive biases are consistent with what error(s) when estimating probability in medicine?
Question 1 Answer
a.
Underestimation of pretest probability and over-reliance on numeracy skills that were less common in previous medical curricula
b.
Failure to assume an attitude that would be both more scientific and more cautious: that a patient has a disease until proven otherwise
c.
Underestimation of the value of chest radiography both for ruling in and ruling out pneumonia
d.
Overestimation of disease probability both before tests are administered and after the results of testing are received
d.
Overestimation of disease probability both before tests are administered and after the results of testing are received
An intern completes a patient intake and is convinced that the patient they’ve seen has a rare disease, because “the symptoms match perfectly!” What should the intern’s supervisor be most concerned that the intern is doing?
Question 2 Answer
a.
Completing only a patient history and not doing enough physical exams or ordering enough lab tests to get a more holistic picture of the patient case
b.
Substituting judgments of how similar a disease is to the stereotypical presentation of that disease for judgments of the probability of disease
c.
Failing to consider aspects of the patient such as their habits and personality, which should steer the intern’s diagnostic opinion in another direction
d.
Not taking enough time to think and to do research to find an even better diagnostic match for this patient’s signs and symptoms
b.
Substituting judgments of how similar a disease is to the stereotypical presentation of that disease for judgments of the probability of disease
You are discussing a patient case with your colleagues at the teaching clinic and voice uncertainty about the probability that your patient with joint pain has Disease X
Ariana points out that patients with joint pain are diagnosed with Disease X 14% of the time in a primary care setting
Bradley mentions that 60-70% of patients with Disease X have joint pain similar to what your patient described to you
Carla claims that the prevalence of Disease X in Canada is 1-2% of the population, according to recent statistics
Danaka adds that government statistics on the lifetime prevalence of Disease X in Canadians is 30%
Assuming all of them are correct, which is the best to use for a pretest probability?
Question 3 Answer
a.
30%
b.
1-2%
c.
14%
d.
60-70%
NOT B, D
A patient describes her headaches as “all over” her head. They are accompanied by nausea and occasional vomiting which can occur first thing in the morning. She has been feeling tired lately and has been making more mistakes at work.
Thinking of differentials, you consider the following facts:
These are some of the classic symptoms of a brain tumor
Headaches occur in about 50% of patients with brain tumors
Cognitive dysfunction occurs in about 35% of patients with brain tumors
In general practice, one study found that 0.1% of people presenting with headache had primary brain tumors
Which option is closest to the most reasonable pretest probability that this patient has a brain tumor?
Question 4 Answer
a.
25%
b.
50%
c.
90%
d.
1%
d.
1%
Which of the following would make for the best reference class for use in estimating a pretest probability?
Question 5 Answer
a.
Government statistics on the yearly incidence of a disease in the population of which your patient is a member
b.
World Health Organization data on the global disease prevalence for the condition you are considering
c.
Research on the eventual diagnosis a group of patients received after presenting with a complaint similar to your patient’s
d.
Lifetime prevalence of a disease in a population with demographics similar to your patient’s from a reputable source
c.
Research on the eventual diagnosis a group of patients received after presenting with a complaint similar to your patient’s
