States that have prohibited texting while driving reported fewer deaths than those without such policies in effect, according to a new study by the University of Alabama at Birmingham School of Public Health.

"Our results indicated that primary texting bans were significantly associated with a 3 percent reduction in traffic fatalities among all age groups, which equates to an average of 19 deaths prevented per year in states with such bans," Researcher Alva O. Ferdinand said in a statement.

"Primarily enforced texting laws that banned only young drivers from texting were the most effective at reducing deaths among the 15- to 21-year-old cohort, with an associated 11 percent reduction in traffic fatalities among this age group in states with such bans."

Ferdinand said that certain states have barred all drivers from texting while driving, while others have just forbidden this activity for young drivers. In some states, texting bans were accompanied with primary and secondary enforcements.

In primary enforcement, officers need not have another reason for stopping a vehicle like speeding or running a red light before citing a driver for texting while driving. But for the secondary enforcement, an officer must have another reason to stop a vehicle,.

According to the Centers for Disease Control and Prevention, nearly 31 percent of drivers in the United States, aged between 18-64 years, read or sent text or email messages while driving at least once in a month in 2011. During that same year, 387,000 people were injured and 3,331 people were killed in crashes involving a distracted driver.

In the study, the researchers analysed the impact of texting-while-driving on roadway crash fatalities. The researchers did not observe any reduction in traffic fatalities in states with secondarily enforced restrictions.

"We were a little surprised to see that primarily enforced texting bans were not associated with significant reductions in fatalities among those aged between 21 to 64 years, who are not considered to be young drivers," Ferdinand said.

The finding is published in the American Journal of Public Health.