摘要：Objectives. We used recent data to reexamine whether the exclusion of adults from households with no telephone or only wireless phones may bias estimates derived from health-related telephone surveys. Methods . We calculated the difference between estimates for the full population of adults and estimates for adults with landline phones; data were from the 2007 National Health Interview Survey. Results . When data from landline telephone surveys were weighted to match demographic characteristics of the full population, bias was generally less than 2 percentage points (range = 0.1–2.4). However, among young adults and low-income adults, we found greater bias (range = 1.7–5.9) for estimates of health insurance, smoking, binge drinking, influenza vaccination, and having a usual place for care. Conclusions. From 2004 to 2007, the potential for noncoverage bias increased. Bias can be reduced through weighting adjustments. Therefore, telephone surveys limited to landline households may still be appropriate for health surveys of all adults and for surveys of subpopulations regarding health status. However, for some behavioral risk factors and health care service use indicators, caution is warranted when using landline surveys to draw inferences about young or low-income adults. In 2006, in this journal, we examined nationally representative survey data from 2004 and early 2005 to determine whether the exclusion of adults without landline telephones biased population-based estimates derived from health-related random-digit-dial telephone surveys. 1 Noncoverage bias is determined both by the magnitude of the difference between persons with and without landline telephones for the variable of interest and by the percentage of persons without landline telephones in the population of interest. 2 In 2004 and early 2005, only 7.2% of adults did not have landline telephones, and we concluded that “noncoverage is not presently a reason to reject the continued use of general population telephone surveys to help guide public health policy and program decisions.” 1 (p931) In less than 3 years, the percentage of adults without landline telephones more than doubled. In 2007, 13.5% of adults lived in households with only wireless telephones, and an additional 1.7% of adults lived in households without any telephone service. 3 Among certain subgroups, the percentage without landlines was even greater, reaching 30.6% for adults younger than 30 years and 21.6% for adults living in low-income households (defined as < 200% of the federal poverty level). Our previously published conclusion, that noncoverage bias is not a concern, 1 , 4 needed to be revisited. We therefore used more recent data to reexamine whether the exclusion of adults from households with no telephone or only wireless phones may bias estimates derived from health-related telephone surveys.
