The study population comprised women who were born between 1 st September 1990 and 29th February 1992 who were resident in Wales on 1 st April 2012. These women would have been offered HPV vaccination as part of the catch-up campaign, and invited for routine cervical screening between 1st September 2010 and 29th February 2012 as they turned 20 years of age, or after moving into Wales. The Centre for Improvements in Population Health through e-Records (CIPHeR) has established the Secure Anonymised

Information Linkage (SAIL) databank, which brings together and anonymously links a wide range of person-based data [17]. This databank includes existing routinely collected datasets such as the selleck Welsh Demographic Service (all people registered with a Welsh or English General Practitioner), Cervical Screening Wales (CSW) (data from a population based national screening programme

[18]) and the National Community Child Health Database (NCCHD) (child health records of children who since 1987 have been born, treated (including vaccination status) or resident in Wales [19]). Using these linked datasets we identified all women resident in Wales on 1st April 2012 within the cohort birth range, 1st September 1990 to 29th February 1992. HPV vaccination data (number of doses and dates administered) were extracted from both the CSW and NCCHD ATM Kinase Inhibitor mouse databases and triangulated to give a complete vaccination history for the cohort of women. Data on cervical screening uptake and clinical outcome were obtained from the CSW databases. Data on birth characteristics of the women such as maternal age at birth, gestational age at birth and childhood vaccination status (for any childhood vaccinations as per the recommended Sodium butyrate schedule for immunisations in the UK) were extracted from the NCCHD. Data on quintile of social deprivation was based on Townsend score calculated using data from the 2001 Census, based on the woman’s area of residence on April 1st 2012. All analyses were carried out using SPSS v19. Univariate binary logistic regression was used to describe the association between each variable (quintile of social deprivation, maternal age at birth, gestational age at birth, childhood

vaccination) and (i) HPV vaccination uptake, (ii) cervical screening uptake and (iii) cervical screening abnormality. Multivariate binary logistic regression was used to obtain odds ratios for the association between HPV vaccination uptake and cervical screening uptake, adjusted for the variables listed above. Women were categorised as having been partially HPV vaccinated if only 1 or 2 of the recommended 3 doses were recorded, and fully HPV vaccinated if 3 or more doses were recorded. Childhood vaccination was defined as any childhood vaccination recorded on the NCCHD database (excluding HPV vaccination). A cervical screening cytological abnormality was defined as a result of borderline changes, mild/moderate/severe dyskaryosis or worse.