Goals and tools

At the end of this module, you will be able to:

• Make sensitivity and specificity more clinically useful
• Distinguish between tests that rule-in and rule-out disease
• Interpret likelihood ratios in the care of patients

There are two more advanced topics for the calculator on your belt/pocket protector crowd:

• Apply likelihood ratios at the bedside
• Interpret and use "ROC curves", a tool to help you compare diagnostic tests

As you work through this module, please have the following three articles available:

• Bush B, Shaw S, Cleary P, Delbanco T, Aronson MD.  Screening for alcohol abuse using the CAGE questionnaire.  Am J Med 1987; 82: 231-5
• Williams JW, Simel DL, Roberts L, Samsa GP.  Clinical evaluation for sinusitis:  making the diagnosis by history and physical examination.  Ann Intern Med 1992;  117:  705-10
• Davie AP, Caruana FL, Sutherland GR and McMurray JJV. Assessing diagnosis in heart failure: which features are any use? Quart J Med 1997; 90:335-339

Since a few calculations are involved, you may want to have a calculator ready, or use Start | Programs | Accessories | Calculator to use the calculator in Windows '95 or '98.