摘要：Objectives. We sought to determine whether the exclusion of adults without landline telephones may bias estimates derived from health-related telephone surveys. Methods. We took data from the 2004 and 2005 National Health Interview Survey and used logistic regression to compare the odds of behavioral risk factors and health care service use for adults with landline telephones to those for adults with only wireless telephones and adults without any telephone service. Results. When interviewed, 7.2% of adults, including those who did and did not have wireless telephones, did not have landline telephones. Relative to adults with landline telephones, adults without landline telephones had greater odds of smoking and being uninsured, and they had lower odds of having diabetes, having a usual place for medical care, and having received an influenza vaccination in the past year. Conclusions. As people substitute wireless telephones for landline telephones, the percentage of adults without landline telephones has increased significantly but is still low, which minimizes the bias resulting from their exclusion from telephone surveys. Bias greater than 1 percentage point is expected only for estimates of health insurance, smoking, binge drinking, having a usual place for care, and receiving an influenza vaccination. There were 158 million users of wireless (i.e., cellular, mobile) telephones in the United States in 2003. 1 That was approximately 1 wireless telephone for every 2 persons in the United States, and 46.6% of all US telephones were wireless. 1 Moreover, wireless telephones were used for 43% of all long-distance calls, and more minutes per person per month were logged on wireless telephones than on landline (i.e., wired, fixed) telephones. 2 , 3 It is perhaps not surprising, then, that some wireless telephone users have substituted a wireless telephone for their residential landline telephone. This wireless substitution has potential implications for the representativeness of most current random-digit-dialed (RDD) household telephone surveys because the sampling frames for these surveys have traditionally been limited to landline telephones. Noncoverage of households without landline telephones has always been a concern of telephone survey researchers, and several studies have been undertaken to examine the potential noncoverage bias in health-related telephone surveys. 4 – 7 These studies, conducted with data from 1998 or earlier, have demonstrated that noncoverage effects tend to be small in general population surveys of health risk indicators. With wireless substitution, however, the characteristics of the non–landline telephone population may be changing. Previously, adults living without a landline telephone usually did so because they could not afford a telephone. Now, a growing proportion of adults living without a landline telephone may have chosen to do so because of lifestyle preferences. We felt it was time to use the most recent national data available to revisit the relation between telephone ownership and health-related variables.
