TABLE 4

Number and Percentage of Participants Who Met the Tdap Dose VE Analysis Exclusion Criteria

Evaluation TypeTdap
Case, n = 438Control, n = 1256P
n%n%
Reasons for exclusion
 Vaccine history unknown204.5614.9.82
 Identified as pertussis case in surveillance data100.8
 Mis-administered DTaPa00.020.2.99
 Received >1 Tdap dose20.560.5.99
 Tdap given before 11 y of age4510.3937.4.06
 Tdap given before 2006b20.520.2.27
No. of excluded participants6615.116613.2.33
No. of participants included in overall VE evaluation37284.9109086.8
  • P values are derived from χ2 test unless cell numbers are <5 then Fisher’s exact test was used. If no participants matched the exclusion criteria or the P value was not determined the cell is blank.

  • a DTaP given outside of approved age range.

  • b Tdap was introduced in Vermont in 2006.