The following table or figure may be downloaded to PowerPoint for personal use in teaching and presentations. This feature is available to all subscribers to the journal.

You MUST read and follow the guidelines at Request to Reproduce AJR Content if you are distributing or using AJR content beyond academic use (limited distribution, non-revenue producing, or educational purposes).

(Downloading may take up to 30 seconds.
If the slide opens in your browser, select File -> Save As to save it.)

Fig. 1. —Diagram shows individual's time line from birth to death. Preclinical phase of disease begins with onset and ends when signs and symptoms appear. Clinical phase begins with onset of signs and symptoms. Detectable preclinical phase (DPCP) is interval of time during preclinical phase when disease is detectable by test. Lead time is interval of time from disease detection to appearance of signs and symptoms. For screening to be effective, critical point (CP) must occur during DPCP. (Adapted from [5])