The Centers for Disease Control and Prevention (CDC) have released preliminary results from the National Health Interview Survey taken from July through December 2007. The survey is primarily intended to confidentially gather health-related information from the non-institutionalized U.S. civilian population as a data source to guide public health and policy decision-making. Over the years, the survey has asked participants whether they can be re-contacted, and beginning in 2003 the survey began including questions about whether a family’s telephone number was a traditional landline.
Preliminary results from the July-December 2007 survey indicate that almost one in six (15.8 percent) of American homes were relying solely on mobile phones for their telephone service. Additionally, more than one in eight U.S. homes (13.1 percent) received almost all their calls on a mobile phone even if they had a landline.
The new figures represent a 2 percent growth in the number of mobile-only homes since the first half of 2007. The survey also found that roughly one third of respondents under 30 years of age only use cell phones, and that low-income respondents were more likely to be cell-only than more affluent participants. Further, respondents who only use cell phones are more likely to be living with unrelated roommates, be renters rather than home owners, and are more likely to be Hispanic or African American than white. The survey also found that homes with both landlines and mobile phones tend to have completed higher levels of education.
The findings could have an impact on survey and telephone polling organizations, who historically call only landline numbers when conducting phone surveys. The growing mobile-only segment of the U.S. population—and significant demographic trends within it—will likely force national polling organizations to rethink their sampling methodologies.
The survey also found that about two percent of U.S. households have no telephone at all.
