title: Risk of invasive pneumococcal disease in people admitted to hospital with selected immune-mediated diseases: record linkage cohort analyses.
abstract: BACKGROUND
  Invasive pneumococcal disease is a serious infection, and it is an important cause of morbidity and mortality in certain groups of 'at-risk' people. Those considered 'at-risk' in the UK include very young children, people aged 65 years and older and people with certain serious chronic diseases, asplenia or immunosuppression. There is little evidence about whether people with immune-mediated diseases are at increased risk of pneumococcal disease and therefore may benefit from pneumococcal vaccination.
  
  
  METHODS
  Retrospective cohort studies, using linked hospital data, from the longstanding Oxford Record Linkage Study (1963-2008) and from recent English national linked Hospital Episode Statistics (1999-2008); analysis of whether people with immune-mediated diseases are more likely than others to be admitted to hospital for pneumococcal disease; calculation of rate ratio for pneumococcal disease in cohorts with immune-mediated disease compared with control cohorts.
  
  
  RESULTS
  There were elevated rate ratios for many of the immune-mediated diseases, for example, Addison's disease in England 3.8 (95% CI 3.4 to 4.2), autoimmune haemolytic anaemia 4.9 (4.4 to 5.3), Crohn's disease 2.2 (2.1 to 2.3), diabetes mellitus 3.7 (3.4 to 4.1), multiple sclerosis 3.7 (3.5 to 3.8), myxoedema 1.60 (1.58 to 1.63), pernicious anaemia 1.74 (1.66 to 1.83), primary biliary cirrhosis 3.3 (2.9 to 3.7), polyarteritis nodosa 5.0 (4.0 to 6.0), rheumatoid arthritis 2.47 (2.41 to 2.52), scleroderma 4.2 (3.8 to 4.7), Sjogren's syndrome 3.2 (2.9 to 3.5) and systemic lupus erythematosus 5.0 (4.6 to 5.4). Findings in the Oxford and all England data sets were similar.
  
  
  CONCLUSIONS
  People admitted to hospital with immune-mediated diseases are at higher risk than those with invasive pneumococcal disease. Vaccination should be considered in this group of patients.
authors.affiliation: Unit of Health-Care Epidemiology, Department of Public Health, University of Oxford, Oxford, UK.
authors.forename: Clare J
authors.initials: CJ
authors.lastname: Wotton
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Goldacre
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D004739:England / Q000453:epidemiology; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D007154:Immune System Diseases / Q000150:complications* / Q000453:epidemiology; D008297:Male; D008498:Medical Record Linkage; D011008:Pneumococcal Infections / Q000453:epidemiology / Q000209:etiology* / Q000276:immunology; D022242:Pneumococcal Vaccines / Q000008:administration & dosage; D012189:Retrospective Studies; D012307:Risk Factors; D017678:Sex Distribution; D014611:Vaccination
chemical_list: D022242:Pneumococcal Vaccines