Widespread Cell-Phone Use Creates Mixed Signals for Health Researchers

There has been a lot of speculation, and growing concern, about the possible health effects of cell-phone use—ranging from questions about cell-phone safety and whether cell phones generate enough low-frequency radiation to cause cancer, to evidence that people who use their cell phones while driving are putting themselves and others at risk.

Now, according to a story in The Washington Post, it turns out that cell phones are posing another serious risk to human health, by preventing researchers and policymakers from getting the information they need to identify health problems and to make essential public health decisions.

People Who Use Only Cell Phones Pose Challenge for Health Researchers
Historically, federal health researchers have placed calls to U.S. households with conventional telephones to interview statistical samples of adults nationwide. That worked fine when the only people they were missing were those who lived in the fewer than 3 percent of U.S. households with no phones at all, but the increasing popularity of cell phones is changing that.

In the first half of 2008, 16 percent of American adults lived in households that use cell phones exclusively, according to the National Center for Health Statistics. That figure is up from 7 percent in 2005, and growing rapidly.

You would think that researchers could just extrapolate the data based on answers they receive from people they reach in the usual way, or include calls to cell-phone-only users along with their other calls, but it’s not that simple.

Some population groups—specifically young people, men and Hispanics—are more likely than others to forgo land lines in favor of cell phones, and studies have shown that people answer the same survey questions differently when they are talking to interviewers on a cell phone versus a conventional telephone. When people are talking on cell phones, they are often more candid about their lifestyle choices and more willing to admit negative behavior.

Gathering Data Over Cell Phones Takes More Time and Money
Interviewing cell-phone users also costs more and takes nearly twice as much time and effort as interviewing people who have conventional land lines. Scott Keeter, a polling expert at the Pew Research Center for the People and the Press, told The Washington Post that it takes about nine calls to working cell-phone numbers to get one completed survey, compared to five calls to working land-line numbers.

The cost of interviewing a cell-phone user is about 2.5 times greater than interviewing someone who uses a conventional telephone. Part of that comes from the increased labor costs of having to dial twice as many numbers for the same result, but surveyors have also started reimbursing cell-phone users for the minutes they use during the interview as an incentive to encourage more cell-phone users to participate.

Bottom line: Gathering reliable health and lifestyle data is never easy, and the rapid growth of cell-phone use is clearly adding another hurdle that researchers will have to consider and overcome as well as raising questions about the reliability of answers given during interviews conducted in more traditional ways. Despite these challenges, however, it is essential that researchers continue working to balance all of the variables and to produce the information that medical professionals and policymakers rely upon to help them safeguard public health.

Also Read:

• Cellphones' Growth Does a Number on Health Research -- The Washington Post
• How Safe are Cell Phones?
• Are Cell Phones and Microwave Radiation Really Unhealthy?
• Heavy Use of Mobile Phones Increases Cancer Risk, Study Finds
• FDA Questions Results of Study Linking Mobile Phones and Cancer
• How to Recycle Your Old Cell Phone