Text messaging can help smokers quit the habit, according to an international study.
A review of four trials conducted in New Zealand, Britain and Norway, found that programs to help people stop smoking that included text-messaged advice doubled the chances that smokers would be able to kick the habit for up to a year.
The trials, involving 2,600 smokers, used text messages as a way to give smokers daily advice and encouragement and also offered support when quitters needed it the most.
If they found themselves craving nicotine, for example, they could text "crave" to the program and get immediate advice on what to do.
"We know that stopping smoking can be really difficult and most people take several attempts to quit successfully," researcher Robyn Whittaker from the University of Auckland in New Zealand told Reuters Health.
"It is important to be able to offer lots of different options for extra support."
Two of the studies looked at programs that only involved text messages, finding that the service doubled the odds that smokers would quit over six weeks.
The other two studies focused on a program in Norway that used text messages, e-mails and a dedicated Web site. It found that smokers who used the program were twice as likely to report abstinence for up to one year.
The findings appeared in the Cochrane Library, a publication of the international research organization the Cochrane Collaboration.
However the studies found the majority of smokers taking part in the studies did not succeed in quitting, regardless of whether they had text-message help.
One of the programs in the study, called Txt2Quit, is running in New Zealand, with government funding, and automatically sends users two to three text messages per day shortly before a designated "quit date," and for one month afterwards.
A recent review of people who took part in the program's first year found that one-third did not smoke four weeks after their quit date. That figure dropped to 16 per cent after 22 weeks.
Whittaker said it is estimated that only about 5 per cent of smokers are able to kick the habit without any help.
But text messages could serve as one more tool in the smoking-cessation arsenal and may be effective for some people because they can get help when cravings strike.
"The frequent messages can also act as a good reminder and motivation to keep going," Whittaker said.