Defibrillators use electric shocks to correct abnormal heartbeats that can lead to sudden death.

VOA: special.2010.08.17

There is very high certainty from well-designed trials that colon cancer screening, combined with effective follow-up and treatment of abnormal findings, reduces risk of colon cancer death by at least 35 percent and risk of getting colon cancer by 20 percent.

CNN: Are colonoscopies really necessary for people over 50?