The STRATA Study: Structural Antecedents of Tdap Administration in Obstetrical Practices in the Midwestern United States

Abstract

Every year in the United States, young infants die from pertussis. The incidence of pertussis among infants exceeds that of all other age groups. Protection is only available if the mother receives the tetanus, diphtheria, and acellular pertussis (Tdap) vaccine during pregnancy, providing passive immunity to the infant. Infants with pertussis whose mothers received Tdap during pregnancy have a significantly lower risk of hospitalization, intubation, and death. Despite the evidence of their effectiveness, maternal Tdap vaccination rates remain suboptimal. Reasons for stagnant Tdap vaccination rates are complex and multi factorial. Evidence suggests that a recommendation from a provider and availability of the vaccine are the strongest indicators of vaccine receipt among pregnant women. However, not all obstetrical providers offer the Tdap vaccine on site. The structure and processes of vaccine programs within obstetrical practices in the U.S. is unknown, and this lack of understanding limits our ability to improve outcomes for young infants. The purpose of this STRATA (Structural Antecedents of Tdap Administration) study was to understand the existing structure of vaccine programs in obstetrical practices through the discovery of structural antecedents and processes that facilitate onsite Tdap administration. Framed within Donabedian’s Structure-Process Outcome Quality of Care Model, a cross-sectional survey was conducted among rural and urban/suburban obstetrical practices in the Midwestern U.S. Fifty obstetrical practices in four states participated. Ninety percent (n = 45) of practices provided Tdap on-site, and those that did not referred patients elsewhere for the vaccine, possibly indicating that more practices are following maternal vaccine recommendations than in the past. The results of this study suggest that several structural elements are antecedents to on-site Tdap administration, including administering other types of vaccines on-site, having a vaccine storage unit on-site, having an advanced registered nurse practitioner or physician assistant deliver care, having standing orders for vaccine administration, and having staff trained to assess vaccine history. The limitations of the study include its small sample size, lack of diversity of the sample, and low response rate. Additional research with a larger sample of practices from other regions of the U.S. is recommended. Collection of scale/continuous level data in future research would allow for more robust statistical tests, such as factor and correlational analyses.