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We discuss alternative estimators of the population total given a dual-frame random-digit-dial (RDD) telephone survey in which samples are selected from landline and cell phone sampling frames. The estimators are subject to sampling and nonsampling errors. To reduce sampling variability when an optimum balance of landline and cell phone samples is not feasible, we develop an application of shrinkage estimation. We demonstrate the implications for survey weighting of a differential nonresponse mechanism by telephone status. We illustrate these ideas using data from the National Immunization Survey-Child, a large dual-frame RDD telephone survey sponsored by the Centers for Disease Control and Prevention and conducted to measure the vaccination status of American children aged 19 to 35 months.

During the 2009 influenza A (H1N1) pandemic, there was an ongoing need to monitor 2009 H1N1 vaccination coverage at the national and state level to evaluate the vaccination campaign; thus, precise vaccination coverage estimates were needed in a timely fashion. The current objective is to describe and evaluate the methodology used to combine 2009 H1N1 vaccination coverage estimates from the Behavioral Risk Factor Surveillance System (BRFSS) and the National 2009 H1N1 Flu Survey (NHFS). H1N1 state level vaccination coverage estimates were combined by taking weighted averages of the BRFSS and NHFS estimates, with more weight given to the estimate with the larger effective sample size (sample size/design effect). The impact of the choice of weights was evaluated by comparing estimates when the design effect was removed from the weights. Combined vaccination coverage estimates for children generally fell midway between NHFS and BRFSS estimates because of larger NHFS sample sizes but smaller BRFSS design effects. Adult estimates were more closely weighted to BRFSS estimates because of larger BRFSS sample sizes. Combined standard errors were smaller than the survey-specific standard errors. When removing the design effect from the weights, the child combined estimates were more closely weighted to those from NHFS, resulting in larger standard errors. Adult combined estimates were similar regardless of choice of weight because of similar design effects across the two surveys. Combining estimates by weighting by the effective sample size allowed timely release of more precise estimates in all states during the 2009 H1N1 pandemic.

Background In April 2009, a novel influenza A virus emerged in the United States. By the end of July, influenza A (H1N1) 2009 monovalent (2009 H1N1) vaccine had been developed, licensed, and recommended by the Advisory Committee on Immunization Practices. Initial target groups for vaccination were identified and the first vaccine was publicly available in early October 2009. Objective This study examines socio-demographic differences in opinions about 2009 pandemic influenza A (H1N1) (pH1N1) and seasonal influenza disease and vaccines and the association with receipt of influenza vaccinations during the 2009–2010 influenza season. Changes in opinions over the course of the pH1N1 pandemic were also examined. Methods Data from the 2009 National H1N1 Flu Survey (NHFS) were analyzed. The NHFS was a CDC-sponsored telephone survey initiated in response to the 2009 pH1N1 pandemic to obtain weekly within-season estimates of vaccination coverage, opinions, and other information. Results Opinions about influenza vaccine and disease varied significantly by race/ethnicity, income, and education level. In multivariable logistic regression analysis, adjusted 2009 H1N1 vaccination coverage was most strongly associated with opinions about the effectiveness of the vaccine and personal risk of disease, varying from 7 to 11% among adults who believed the vaccine to have low effectiveness and themselves at low risk of influenza, to 50–53% among those who thought vaccine effectiveness to be high and themselves at high risk of influenza. Conclusion Improving communication about personal risk and the effectiveness of influenza vaccines may improve vaccination coverage. The findings of difference in opinions could be used to target communication.

To test the hypothesis that firefighter exposures may increase cancer risk, mortality rates were calculated for 3,066 San Francisco Fire Department firefighters employed between 1940 and 1970. Vital status was ascertained through 1982, and observed and expected rates, rate ratios (RR), and 95% confidence intervals (CI) were computed using United States death rates for comparison. The total number deceased (1,186) was less than expected and there were fewer cancer deaths than expected. However, there were significant excess numbers of deaths from esophageal cancer (12 observed, 6 expected), cirrhosis and other liver diseases (59 observed, 26 expected), and accidental falls (21 observed, 11 expected). There were 24 line-of-duty deaths, which were primarily due to vehicular injury, falls, and asphyxiation. Heart disease and respiratory disease deaths occurred significantly less often than expected. It was concluded that the increased risks of death from esophageal cancer and cirrhosis and other liver diseases may have been due to firefighter exposures, alcohol consumption, or interaction between alcohol and exposures. Because this was an older cohort and firefighter exposures have changed due to the increasing use of synthetic materials, it is recommended that the effects of modern-day exposures be further studied.