Search

Objectives: To examine the effect on estimated levels of health conditions produced from large-scale surveys, when either list-wise respondent deletion or standard demographic item-level imputation is employed. To assess the degree to which further bias reduction results from the inclusion of correlated ancillary variables in the item imputation process., Design: Large cross-sectional (US level) household survey., Participants: 218 726 US adults (18 years and older) in the 2006 Behavioral Risk Factor Surveillance System Survey. This survey is the largest US telephone survey conducted by the Centers for Disease Control and Prevention., Primary and Secondary Outcome Measures: Estimated rates of severe depression among US adults., Results: The use of list-wise respondent deletion and/or demographic imputation results in the underestimation of severe depression among adults in the USA. List-wise deletion produces underestimates of 9% (8.7% vs 9.5%). Demographic imputation produces underestimates of 7% (8.9% vs 9.5%). Both of these differences are significant at the 0.05 level., Conclusion: The use of list-wise deletion and/or demographic-only imputation may produce significant distortion in estimating national levels of certain health conditions.

To meet challenges arising from increasing rates of noncoverage in US landline-based telephone samples due to cell-phone-only households, the Behavioral Risk Factor Surveillance System (BRFSS) expanded a traditional landline-based random digit dialing survey to a dual-frame survey of landline and cell phone numbers. In 2008, a survey of adults with cell phones only was conducted in parallel with an ongoing landline-based health survey in 18 states. The authors used the optimal approach to allocate samples into landline and cell-phone-only strata and used a new approach to weighting state-level landline and cell phone samples. They developed logistic models for each of 16 health indicators to examine whether exclusion of adults with cell phones only affected estimates after adjustment for demographic characteristics. The extents of the potential biases in landline telephone surveys that exclude cell phones were estimated. Biases resulting from exclusion of adults with cell phones only from the landline-based survey were found for 9 out of the 16 health indicators. Because landline noncoverage rates for adults with cell phones only continue to increase, these biases are likely to increase. Use of a dual-frame survey of landline and cell phone numbers assisted the BRFSS efforts in obtaining valid, reliable, and representative data., (Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health 2011.)

Use of random-digit dialing (RDD) for conducting health surveys is increasingly problematic because of declining participation rates and eroding frame coverage. Alternative survey modes and sampling frames may improve response rates and increase the validity of survey estimates. In a 2005 pilot study conducted in six states as part of the Behavioral Risk Factor Surveillance System, the authors administered a mail survey to selected household members sampled from addresses in a US Postal Service database. The authors compared estimates based on data from the completed mail surveys (n = 3,010) with those from the Behavioral Risk Factor Surveillance System telephone surveys (n = 18,780). The mail survey data appeared reasonably complete, and estimates based on data from the two survey modes were largely equivalent. Differences found, such as differences in the estimated prevalences of binge drinking (mail = 20.3%, telephone = 13.1%) or behaviors linked to human immunodeficiency virus transmission (mail = 7.1%, telephone = 4.2%), were consistent with previous research showing that, for questions about sensitive behaviors, self-administered surveys generally produce higher estimates than interviewer-administered surveys. The mail survey also provided access to cell-phone-only households and households without telephones, which cannot be reached by means of standard RDD surveys.

The National Immunization Survey (NIS) was designed to measure vaccination coverage estimates for the US, the 50 states, and selected urban areas for children ages 19-35 months. The NIS includes a random-digit-dialed telephone survey and a provider record check study. Data are weighted to account for the sample design and to reduce nonresponse and non-coverage biases in order to improve vaccination coverage estimates. Adjustments are made for biases resulting from nonresponse and nontelephone households, and estimation procedures are used to reduce measurement bias. The NIS coverage estimates represent all US children, not just children living in households with telephones. NIS estimates are highly comparable to vaccination estimates derived from the National Health Interview Survey. The NIS allows comparisons between states and urban areas over time and is used to evaluate current and new vaccination strategies.

Objectives: This study was done to assess progress in hepatitis B vaccination of children from 1994 through 1997., Methods: We used data from the National Immunization Survey (NIS), a random-digit-dialed telephone survey that includes a mail survey to verify vaccination providers' records. The NIS is conducted in 78 geographic areas (50 states and 28 selected urban areas) in the United States., Results: A total of 32,433 household interviews were completed in the 1997 NIS. An estimated 83.7% of children aged 19 to 35 months received 3 or more doses of hepatitis B vaccine. Coverage with 3 doses was greater (86.7%) among children in states that had day care entry requirements for hepatitis B vaccination than among children in states without such requirements (83.0%) and was greater among children from families with incomes at or above the poverty level (85.0%) than among children below the poverty level (80.6%). Hepatitis B vaccination of children increased from 1994 through 1996, from 41% to 84%, but coverage reached a constant level of 84% to 85% in 1996/97., Conclusion: Although substantial progress has been made in fully vaccinating children against hepatitis B, greater efforts are needed to ensure that all infants receive 3 doses of hepatitis B vaccine.