CMS100 - Week 1 Intro Lec

what are the three broad parts of the diagnostic process

what are the more detailed steps of the diagnostic process? what are the components within each step?

1. obtain info from patient

• history taking + patient-centred interviewing

2. consider what may be going in and what info is still needed to take action

• illness scripts

• differential diagnosis

• probability

• evidence

• testing thresholds

• treatment thresholds

3. get this info

• history taking + patient-centred interviewing + physical exams

4. take appropriate action

• testing thresholds

• treatment thresholds

• probability

• evidence

what is history-taking? what does it include? what is the relevant vocabulary

• questions asked of a patient - high diagnostic value

• includes items like different aspects of pt’s concerns + their meds + past medical history + family history + social history

• relevant vocab - symptom: a disease manifestation reported by the patient, this info is often charted as subjective notes (i.e. sore throat, muscle pain)

what is patient-centred interviewing? why is it important?

• Focuses on:

  • Patient’s ideas

  • Feelings/fears

  • Impact on functioning

  • Expectations

• Why important?

  • Illness ≠ just symptoms (context matters)

  • Understanding emotional/personal factors → better clinician

  • Letting patient express concerns is therapeutic

what are physical exams? what does it include? what is the relevant vocabulary

• inspection, auscultation (listening), percussion (tapping body parts), palpation and other maneuvers to gather further info

• relevant vocab - sign: a manifestation of a disease that the clinician perceives, often charted as objective notes (i.e. high temp, skin rash)

what is a differential diagnosis? why is it so important? what is the relevant vocabulary?

• a list of conditions that are candidates for explaining a pt’s concerns

• one’s first though about what condition the pt has is subject to bias and especially for beginners, too often wrong

  • relevant vocab - premature closure: failing to consider reasonable alternatives after initial diagnosis

what are illness scripts?

• in expert clinicians, clinically-relevant memory is accessed in patterns termed “illness scripts”

• this knowledge has a relatively consistent structure, which includes predisposing conditions, clinical features, and mechanism of illness

how is it encouraged that illness scripts explicitly be created?

• create disease illness scripts to learn + to compare and contrast conditions - building a standard template for each disease

• create patient illness scripts to match against disease patterns and generate a differential diagnosis

what is probability from a clinical standpoint?

• how likely different conditions are - helps to make decisions about what to do

• we must constantly update probability estimates as more information is obtained

what is evidence from a clinical standpoint?

• information that helps us update our estimates of probabilities

• gathered from the pt history, physical exam, and further testing

what well-represents the value of a piece of evidence?

• likelihood ratio

  • calculating this tells you how to update estimations of probability; rarely done in practice

what are testing and treatment thresholds? why do we need them?

• thresholds are probability cutoffs beyond which a clinician takes action or stops gathering information

• becuase we will never achieve 100% certainty that a patient does or does not have a condition