Pertussis in Pregnancy Safety (PIPS) Study

Study type

• Study type:
  Non-interventional study
• Scope of the study:
  Assessment of risk minimisation measure implementation or effectiveness

Non-interventional study

• Non-interventional study design:
  Cohort

  Other
• Non-interventional study design, other:
  Intensive monitoring schemes

Study drug and medical condition

• Anatomical Therapeutic Chemical (ATC) code:
  (J07AJ52) pertussis, purified antigen, combinations with toxoids

  pertussis, purified antigen, combinations with toxoids

Population studied

• Age groups:
  • Preterm newborn infants (0 – 27 days)
  • Term newborn infants (0 – 27 days)
  • Infants and toddlers (28 days – 23 months)
• Special population of interest:
  Pregnant women
• Estimated number of subjects:
  325000

Study design details

• Main study objective:
  To evaluate health outcomes for pregnant women and their infants following administration of Tdap (pertussis-containing vaccine) during pregnancy.
• Outcomes:
  Adverse Events following administration of pertussis vaccine (Tdap) during pregnancy, The difference in hospital-related outcomes of those vaccinated or not with Tdap during pregnancy in all NZ women pregnant between 2009 & 2013.The difference in birth outcomes and hospital-related outcomes of infants born to mothers vaccinated or not with Tdap during pregnancy in all NZ women pregnant between 2009 & 2013.
• Data analysis plan:
  Logistic regression will estimate odds ratios for the risk for (specific) adverse events for mothers and infants in vaccine exposed and unexposed groups. Age, ethnicity and socioeconomic deprivation and season for hospital admission will be included as additional explanatory variables. Each person will only be counted once for each hospitalisation, the primary diagnosis and repeat admissions for the same episode will be removed, including transfers from one hospital to another.For diagnosis where individuals may have multiple admissions for different occurrences and the outcome is a count, Poisson regression will be used with testing and adjustment for overdispersion where required.The temporal relationship between onset of events and vaccination will be presented including distribution where appropriate.Serious adverse events will be reported as detailed clinical cases.To analyse the effect of Tdap on still births we will perform a survival analysis.