Doctors aren't washing their hands as thoroughly as they should be

A new study shows health care providers are twice as likely to comply with hand-hygiene guidelines if they know they're being watched.

Researchers studied doctors in the infection prevention department at Santa Clara Valley Medical Center in San Jose, California, over the course of six months.

SEE ALSO: Singer Grimmie dies after Orlando shooting, suspect dead

ABC reports that doctors who knew they were being watched by infection prevention nurses adhered to washing guidelines 57 percent of the time. But doctors who were unaware they were being watched by anonymous volunteers had a compliance rate of only 22 percent.

This is a textbook example of the Hawthorne Effect, which states that people change their behavior when they know they're under observation.

EXPLORE MORE: Donald Trump still insists Don King endorsed him, despite King's denial

Study authors say "unknown observers should be used to get the most accurate hand hygiene data."
Accurate data is important: The World Health Organization recognizes hands as a major infection risk — and this study is just the latest to show they probably aren't washed as thoroughly as you'd think.

The organization reports average compliance with hand-sanitation guidelines sits at 38.7 percent. The Centers for Disease Control and Prevention finds a 40 percent average.

RELATED: US News top recommended health products:

This video includes clips from The Centers for Disease Control and Prevention and World Health Organization.