Predictors of Tetanus-Diphtheria-Acellular Pertussis Vaccination Among Adults Receiving Tetanus Vaccine in the United States: Data From the 2008 National Health Interview Survey

Background. The incidence of pertussis in the United States has been increasing. Adult vaccination is important to reduce disease burden and prevent transmission to infants at high risk of complications. The tetanus-diphtheria-acellular pertussis (Tdap) vaccine has been available in the United States since 2005 and is indicated as a one-time replacement for the routine tetanus-diphtheria (Td) booster. However, among adults receiving tetanus vaccination, only about half receive Tdap. Purpose. To identify predictors of adult Tdap vaccination among individuals who receive tetanus vaccine. Methods. National Health Interview Survey data from 2008 were analyzed in 2011. Respondents were 18 to 64 years old, received tetanus vaccination during 2005-2008, and were aware if it contained pertussis. Predictors of Tdap vaccination were identified with multivariate logistic regression using procedures for complex survey methods. Results. Overall, 51.1% of respondents received Tdap. Vaccination was less likely for those 50 to 64 years old compared with those 18 to 24 years old (odds ratio [OR] = 0.61, 95% confidence interval [CI] = 0.38-0.96). Some college education was associated with higher odds of vaccination compared with lower education levels (OR = 1.55, 95% CI = 1.16-2.07). Having 2 to 3 office visits (OR = 2.01, 95% CI = 1.32-3.06) or 4 to 9 office visits (OR = 1.60, 95% CI = 1.06-2.42) in the previous year increased the odds of vaccination compared with no visits. Individuals with functional limitation due to illness had lower odds compared with no limitation (OR = 0.70, 95% CI = 0.54-0.91). Conclusions. In 2008, 51.1% of adult Td vaccinations included pertussis, suggesting continued efforts to remove barriers are needed. Interventions should target older, functionally impaired, and educationally disadvantaged populations.