Including cellphones in survey likely to increase reports of risky behavior, CDC finds

Adding cellphones to an annual telephone survey of health behaviors is likely to show an increase in some habits, such as cigarette smoking, the Centers for Disease Control and Prevention reported Thursday.

The 2011 edition of the Behavioral Risk Factor Surveillance System will include surveys from cellphone-only households for the first time, the CDC said. The agency has been studying adding the data since 2004.

The number of people who rely solely on a cellphone was estimated at 36.4 percent for the first half of 2011, according to the CDC. Those people are more likely to be younger and have lower education levels and lower incomes, the report said. Those groups are more likely to have a higher number of risk factors, such as smoking, heavy drinking and lack of physical activity, the CDC said.

The agency is trying to get the word out that higher levels of risk behaviors in the 2011 report probably do not represent an increase. The number of households without landlines will be about 11 percent in the survey, and that number is expected to rise to 20 percent in the 2012 survey, the CDC said.

The survey has also changed the way it weighs the data to more accurately reflect changes in individual variables, the agency said.