Table 1

Summary of descriptive characteristics of cohort
Unvaccinated Vaccinated, Any dose Vaccinated, 1 dose Vaccinated, 2 doses Completely vaccinated, 3 doses
Number of observations 14,085 24,871 1,422 2,268 21,151
Mean age in 2007 16.1 (± 1.0) 16.0 (± 1.0)* 16.0 (± 1.0) 16.0 (± 1.0)# 16.0 (± 1.0)
Mean age at first screen 18.5 (± 1.4) 18.5 (± 1.3)# 18.1 (± 1.5)# 18.1 (± 1.5)# 18.6 (± 1.3)
Mean age at entry to cohort 19.0 (± 1.4) 19.0 (± 1.3) 18.7 (± 1.3)# 18.7 (± 1.3)# 19.0 (± 1.2)#
Age in 2007 (years)
≤14 1,446 (10.3%) 2,567 (10.3%) 163 (11.5%) 271 (11.9%)* 2,131 (10.1%)
15 2,434 (17.3%) 4,480 (18.0%) 262 (18.4%) 470 (20.7%)# 3,743 (17.7%)
16 4,125 (29.3%) 7,419 (29.8%) 372 (26.2%)+ 628 (27.7%) 6,413 (30.3%)*
17 6,080 (43.2%) 10,405 (41.8%)+ 625 (44.0%) 899 (39.6%)+ 8,864 (41.9%)*
Remoteness area3
Major cities 10,019 (71.8%) 16,608 (66.8%)# 955 (67.2%)# 1,477 (65.1%)# 14,154 (67.0%)#
Inner regional 3,250 (23.3%) 6,858 (27.6%)# 383 (26.9%)# 642 (28.3%)# 5,826 (27.6%)#
Outer regional 681 (4.9%) 1,380 (5.6%)+ 83 (5.8%) 147 (6.5%)# 1,149 (5.4%)+
Remote 6 (0.0%) 14 (0.1%) 1 (0.1%) 2 (0.1%) 11 (0.1%)
Socioeconomic status4
1 (lowest) 2,551 (18.4%) 3,830 (15.5%)# 278 (19.6%) 401 (17.7%) 3,147 (14.9%)#
2 2,833 (20.4%) 4,741 (19.1%)+ 336 (23.7%)+ 497 (22.0%)* 3,899 (18.5%)#
3 2,713 (19.6%) 4,463 (18.0%)# 262 (18.5%) 444 (19.7%) 3,754 (17.8%)#
4 3,195 (23.1%) 6,340 (25.6%)# 302 (21.3%) 572 25.3%)+ 5,461 (25.9%)#
5 (highest) 2,571 (18.6%) 5,399 (21.8%)# 240 (16.9%) 346 (15.3%)# 4,804 (22.8%)#
Age at first screen (years)
≤14 105 (0.7%) 114 (0.5%)# 13 (0.9%) 30 (1.3%)+ 71 (0.3%)#
15 to 17 2,831 (20.1%) 4,840 (19.5%) 436 (30.7%)# 624 (27.5%)# 3,775 (17.8%)#
18+ 11,149 (79.2%) 19,917 (80.1%)* 973 (68.4%)# 1,614 (71.2%)# 17,305 (81.8%)#
Screening history
Screening before 1 April 2007 244 (1.7%) 385 (1.5%) 52 (3.7%)# 74 (3.3%)# 257 (1.2%)#
First screen after 1 April 2007 13,841 (98.3%) 24,486 (98.5%) 1,370 (96.3%)# 2,194 (96.7%)# 20,894 (98.8%)#
Age commenced vaccination (years)
≤13 591 (2.4%) 19 (1.3%)! 63 (2.8%) 509 (2.4%)
14 to 15 9,609 (38.6%) 318 (22.4%)$ 756 (33.3%)$ 8,526 (40.3%)
16 to 17 13,519 (54.4%) 679 (47.7%)$ 1,159 (51.1%)$ 11,665 (55.2%)
18+ 1,152 (4.6%) 406 (28.6%)$ 290 (12.8%)$ 451 (2.1%)
Year entered cohort
2007 632 (4.5%) 497 (2.0%)# 46 (3.2%)* 52 (2.3%)# 398 (1.9%)#
2008 1,114 (7.9%) 2,140 (8.6%)* 188 (13.2%)# 248 (10.9%)# 1,701 (8.0%)
2009 2,350 (16.7%) 4,924 (19.8%)# 357 (25.1%)# 577 (25.4%)# 3,982 (18.8%)#
2010 3,981 (28.3%) 7,375 (29.7%)+ 403 (28.3%) 607 (26.8%) 6,361 (30.1%)#
2011 6,008 (42.7%) 9,935 (39.9%)# 428 (30.1%)# 784 (34.6%)# 8,709 (41.2%)+
Cytological abnormalities diagnosed on entry into cohort5
Negative 11,444 (82.7%) 19,661 (85.4%)# 911 (80.5%)# 1,579 (84.1%)# 17,148 (85.7%)
Low-grade 1,817 (13.1%) 2,488 (10.8%)# 169 (14.9%) 230 (12.2%)# 2,086 (10.4%)#
High-grade
Possible 111 (0.8%) 146 (0.7%)* 8 (0.7%) 15 (0.8%) 123 (0.6%)*
Definite 97 (0.7%) 132 (0.6%)* 12 (1.1%) 12 (0.6%) 108 (0.5%)*
Endocervical 1 (0.0%) 4 (0.0%) 0 (0.0%) 0 (0.0%) 4 (0.0%)

1Count is of women; “unvaccinated” refers to women screened who did not receive any dose of HPV vaccine; “completely vaccinated” refers to women who were clinically completely vaccinated with three doses of HPV vaccine.

2Entry into the cohort was at first Pap test, or 1 April 2007 if screened before this date.

3Women were allocated to a remoteness area based on their postcode of usual residence, according to the Australian Standard Geographic Classification (ASGC) for 2006. Missing data on 140 women excluded.

4Women were allocated to a socioeconomic status (SES) groups based on their postcode of usual residence, according to the Australian Bureau of Statistics Socio-Economic Indexes for Areas (SEIFA) Index of Relative Socio-Economic Disadvantage [17]. Missing data on 320 women excluded.

5Missing data on 2,079 women excluded.

*P-value P ≤0.05 (reference group unvaccinated women).

+P-value ≤0.01 (reference group unvaccinated women).

#P-value ≤0.001 (reference group unvaccinated women).

$P-value ≤0.001 (reference group fully vaccinated women). Note any dose group not compared.

!P-value ≤0.01 (reference group fully vaccinated women). Note any dose group not compared.

Gertig et al.

Gertig et al. BMC Medicine 2013 11:227   doi:10.1186/1741-7015-11-227

Open Data