Intro to Diagnostic

Question 1

Discuss the common reasons to obtain diagnostic studies

Answer 1

1. Screening for subclinical diagnosis in asymptomatic individuals
2. Confirm diagnosis in a symptomatic individual

• Rule in primary diagnosis and/or
• Rule out differential diagnoses
• 14 y/o female with left wrist pain after falling on the outstretched hand

3.Management of known medical condition

• Assess response to therapeutic intervention
• 43 y/o male with hyperlipidemia (↑ Total cholesterol, ↑ LDL cholesterol and ↓ HDL cholesterol) started on a statin medication 3 months ago

4.Personalized medicine (Genelex / GeneSight)

• •Targeted medication therapy
• •Pharmacogenetic tools → prescribing antidepressants

Question 2

Describe the criteria for screening diagnostic studies

Answer 2

1. Population characteristics
   
   • prevalence of disease
   • compliant with tests and treatments
2. Disease characteristics
   
   • morbidity and mortality
   • Effective and acceptable treatment
   • Pre-symptomatic period detectable
   • Improved outcome from early treatment
3. Test characteristics
   
   • Good sensitivity and specificity
   • Low cost and low risk*
   • Test available and practical

Question 3

Outline the considerations a clinician must address before ordering diagnostic studies.

Answer 3

• Can the primary diagnosis be ruled in with a high level of certainty without the test?
• Can you be certain that life-threatening diagnoses are not present without the test?
• Will the test help to establish a diagnosis, affect a treatment decision or help predict a prognosis?
• What relevant results could this test provide?
• If the results are positive (abnormal) what will I do?
• If the results are negative (normal) what will I do?
• Is this the least invasive and least costly means of getting the necessary information?