title: Vaccinations and childhood type 1 diabetes mellitus: a meta-analysis of observational studies.
abstract: OBJECTIVE
  The aim of this study was to investigate the association between routine vaccinations and the risk of childhood type 1 diabetes mellitus by systematically reviewing the published literature and performing meta-analyses where possible.
  
  
  METHODS
  A comprehensive literature search was performed of MEDLINE and EMBASE to identify all studies that compared vaccination rates in children who subsequently developed type 1 diabetes mellitus and in control children. ORs and 95% CIs were obtained from published reports or derived from individual patient data and then combined using a random effects meta-analysis.
  
  
  RESULTS
  In total, 23 studies investigating 16 vaccinations met the inclusion criteria. Eleven of these contributed to meta-analyses which included data from between 359 and 11,828 childhood diabetes cases. Overall, there was no evidence to suggest an association between any of the childhood vaccinations investigated and type 1 diabetes mellitus. The pooled ORs ranged from 0.58 (95% CI 0.24, 1.40) for the measles, mumps and rubella (MMR) vaccination in five studies up to 1.04 (95% CI 0.94, 1.14) for the haemophilus influenza B (HiB) vaccination in 11 studies. Significant heterogeneity was present in most of the pooled analyses, but was markedly reduced when analyses were restricted to study reports with high methodology quality scores. Neither this restriction by quality nor the original authors' adjustments for potential confounding made a substantial difference to the pooled ORs.
  
  
  CONCLUSIONS
  This study provides no evidence of an association between routine vaccinations and childhood type 1 diabetes.
authors.affiliation: UKCRC Centre of Excellence for Public Health NI, Queen's University Belfast, Belfast, UK.|Centre for Public Health, Queen's University Belfast, Grosvenor Road, Belfast, BT12 6BJ, UK.
authors.forename: Eileen
authors.initials: E
authors.lastname: Morgan
authors.affiliation: UKCRC Centre of Excellence for Public Health NI, Queen's University Belfast, Belfast, UK.|Centre for Statistical Science and Operational Research, Queen's University Belfast, Belfast, UK.
authors.forename: Sophia R
authors.initials: SR
authors.lastname: Halliday
authors.affiliation: Centre for Public Health, Queen's University Belfast, Grosvenor Road, Belfast, BT12 6BJ, UK.
authors.forename: Gemma R
authors.initials: GR
authors.lastname: Campbell
authors.affiliation: Centre for Public Health, Queen's University Belfast, Grosvenor Road, Belfast, BT12 6BJ, UK.
authors.forename: Chris R
authors.initials: CR
authors.lastname: Cardwell
authors.affiliation: UKCRC Centre of Excellence for Public Health NI, Queen's University Belfast, Belfast, UK. c.patterson@qub.ac.uk.|Centre for Public Health, Queen's University Belfast, Grosvenor Road, Belfast, BT12 6BJ, UK. c.patterson@qub.ac.uk.
authors.forename: Chris C
authors.initials: CC
authors.lastname: Patterson
mesh_terms: D019433:Chickenpox Vaccine / Q000627:therapeutic use; D002648:Child; D003922:Diabetes Mellitus, Type 1 / Q000453:epidemiology* / Q000276:immunology; D004675:Encephalitis, Tick-Borne / Q000453:epidemiology / Q000517:prevention & control; D017325:Hepatitis B Vaccines / Q000627:therapeutic use; D006801:Humans; D007252:Influenza Vaccines / Q000627:therapeutic use; D022542:Measles-Mumps-Rubella Vaccine / Q000627:therapeutic use; D008587:Meningitis, Viral / Q000453:epidemiology / Q000517:prevention & control; D064887:Observational Studies as Topic / Q000706:statistics & numerical data; D010567:Pertussis Vaccine / Q000627:therapeutic use; D012307:Risk Factors; D012900:Smallpox Vaccine / Q000627:therapeutic use; D014611:Vaccination / Q000009:adverse effects / Q000706:statistics & numerical data*; D017778:Vaccines, Combined / Q000627:therapeutic use
chemical_list: D019433:Chickenpox Vaccine; D017325:Hepatitis B Vaccines; D007252:Influenza Vaccines; D022542:Measles-Mumps-Rubella Vaccine; D010567:Pertussis Vaccine; D012900:Smallpox Vaccine; D017778:Vaccines, Combined; C050102:measles, mumps, rubella, varicella vaccine
keywords: Epidemiology; Meta-analysis; Type 1 diabetes; Vaccinations