title: A comparison of UK primary care data with other national data sources for monitoring the prevalence of smoking during pregnancy.
abstract: BACKGROUND
  We aimed to assess the potential usefulness of primary care data in the UK for estimating smoking prevalence in pregnancy by comparing the primary care data estimates with those obtained from other data sources.
  
  
  METHODS
  In The Health Improvement Network (THIN) primary care database, we identified pregnant smokers using smoking information recorded during pregnancy. Where this information was missing, we used smoking information recorded prior to pregnancy. We compared annual smoking prevalence from 2000 to 2012 in THIN with measures from the Infant Feeding Survey (IFS), Smoking At Time of Delivery (SATOD), Child Health Systems Programme (CHSP) and Scottish Morbidity Record (SMR).
  
  
  RESULTS
  Smoking estimates from THIN data converged with estimates from other sources after 2004, though still do not agree completely. For example, in 2012 smoking prevalence at booking was 11.6% in THIN using data recorded only during pregnancy, compared with 19.6% in SMR data. However, the use of smoking data recorded up to 27 months before conception increased the THIN prevalence to 20.3%, improving the comparability.
  
  
  CONCLUSIONS
  Under-recording of smoking status during pregnancy results in unreliable prevalence estimates from primary care data and needs improvement. However, in the absence of gestational smoking data, the inclusion of pre-conception smoking records may increase the utility of primary care data. One strategy to improve gestational smoking status recording in primary care could be the inclusion of pregnancy in the Quality and Outcome's Framework as a condition for which smoking status and smoking cessation advice must be recorded electronically in patient records.
authors.affiliation: Division of Epidemiology and Public Health, University of Nottingham, Clinical Sciences Building, Nottingham City Hospital, Hucknall Road, Nottingham NG5 1PB, UK Division of Primary Care, University of Nottingham, Queen's Medical Centre, Nottingham NG7 2UH, UK.
authors.forename: Nafeesa N
authors.initials: NN
authors.lastname: Dhalwani
authors.affiliation: Division of Epidemiology and Public Health, University of Nottingham, Clinical Sciences Building, Nottingham City Hospital, Hucknall Road, Nottingham NG5 1PB, UK.
authors.forename: Laila J
authors.initials: LJ
authors.lastname: Tata
authors.affiliation: Division of Primary Care, University of Nottingham, Queen's Medical Centre, Nottingham NG7 2UH, UK.
authors.forename: Tim
authors.initials: T
authors.lastname: Coleman
authors.affiliation: Division of Epidemiology and Public Health, University of Nottingham, Clinical Sciences Building, Nottingham City Hospital, Hucknall Road, Nottingham NG5 1PB, UK.
authors.forename: Linda
authors.initials: L
authors.lastname: Fiaschi
authors.affiliation: Division of Epidemiology and Public Health, University of Nottingham, Clinical Sciences Building, Nottingham City Hospital, Hucknall Road, Nottingham NG5 1PB, UK.
authors.forename: Lisa
authors.initials: L
authors.lastname: Szatkowski
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D008875:Middle Aged; D011159:Population Surveillance / Q000379:methods; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology* / Q000523:psychology; D015995:Prevalence; D011320:Primary Health Care / Q000706:statistics & numerical data*; D012907:Smoking / Q000453:epidemiology*; D006113:United Kingdom / Q000453:epidemiology; D055815:Young Adult
keywords: pregnancy and childbirth disorders; primary care; smoking