TABLE 3

Risk of Pertussis Among Adolescents and Teenagers According to Tdap Receipt and Vaccines Received During the First 2 y of Life, January 2010 to December 2011

Vaccine Type During First 2 Years of LifeReceived TdapPCR-Positive Cases Compared WithOR95% CIP Value
4 DTaP versus 4 DTwPNoPCR-negative controlsa9.921.31–75.31.027
KPNC-matched controlsb16.282.26–117.49.006
YesPCR-negative controlsa4.851.92–12.21<.001
KPNC-matched controlsb4.741.99–11.32<.001
  • a Conditional logistic regression stratified by calendar time, and including covariates to adjust for gender, race or ethnic group, and medical clinic. The model for each Tdap subgroup deleted 1 observation for PCR-negative controls because of missing covariate data.

  • b Conditional logistic regression stratified by calendar time, gender, race or ethnic group, and medical clinic.