title: Quantification of risk factors for herpes zoster: population based case-control study.
abstract: OBJECTIVE
  To quantify the effects of possible risk factors for herpes zoster at different ages.
  
  
  METHODS
  Case-control study.
  
  
  METHODS
  UK Clinical Practice Research Datalink primary care data.
  
  
  METHODS
  144 959 adults diagnosed with zoster between 2000 and 2011; 549,336 age, sex, and practice matched controls.
  
  
  METHODS
  Conditional logistic regression was used to generate adjusted odds ratios to estimate the strength of association of each potential risk factor with zoster and assess effect modification by age.
  
  
  RESULTS
  The median age of the cases and controls was 62 years. Factors associated with increased risk of zoster included rheumatoid arthritis (3111 (2.1%) v 8029 (1.5%); adjusted odds ratio 1.46, 99% confidence interval 1.38 to 1.55), inflammatory bowel disease (1851 (1.3%) v 5118 (0.9%); 1.36, 1.26 to 1.46), chronic obstructive pulmonary disease (6815 (4.7%) v 20 201 (3.7%); 1.32, 1.27 to 1.37), asthma (10 243 (7.1%) v 31 865 (5.8%); 1.21, 1.17 to 1.25), chronic kidney disease (8724 (6.0%) v 29 437 (5.4%); 1.14, 1.09 to 1.18), and depression (6830 (4.7%) v 22 052 (4.0%); 1.15, 1.10 to 1.20). Type 1, but not type 2, diabetes showed some association with zoster (adjusted odds ratio 1.27, 1.07 to 1.50). The relative effects of many assessed risk factors were larger in younger patients. Patients with severely immunosuppressive conditions were at greatest risk of zoster-for example, patients with lymphoma (adjusted odds ratio 3.90, 3.21 to 4.74) and myeloma (2.16, 1.84 to 2.53), who are not eligible for zoster vaccination.
  
  
  CONCLUSIONS
  A range of conditions were associated with increased risk of zoster. In general, the increased risk was proportionally greater in younger age groups. Current vaccines are contraindicated in people at the greatest risk of zoster, highlighting the need for alternative risk reduction strategies in these groups.
authors.affiliation: Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK harriet.forbes@lshtm.ac.uk.
authors.forename: Harriet J
authors.initials: HJ
authors.lastname: Forbes
authors.affiliation: Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK.
authors.forename: Krishnan
authors.initials: K
authors.lastname: Bhaskaran
authors.affiliation: Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK.
authors.forename: Sara L
authors.initials: SL
authors.lastname: Thomas
authors.affiliation: Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK.
authors.forename: Liam
authors.initials: L
authors.lastname: Smeeth
authors.affiliation: Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK.
authors.forename: Tim
authors.initials: T
authors.lastname: Clayton
authors.affiliation: Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK.
authors.forename: Sinéad M
authors.initials: SM
authors.lastname: Langan
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000150:complications; D001327:Autoimmune Diseases / Q000150:complications* / Q000453:epidemiology / Q000276:immunology; D016022:Case-Control Studies; D003863:Depression / Q000150:complications; D048909:Diabetes Complications; D005260:Female; D006562:Herpes Zoster / Q000453:epidemiology / Q000209:etiology* / Q000276:immunology / Q000517:prevention & control; D053061:Herpes Zoster Vaccine; D006801:Humans; D007114:Immunization; D016867:Immunocompromised Host / Q000276:immunology; D015212:Inflammatory Bowel Diseases / Q000150:complications; D016015:Logistic Models; D008180:Lupus Erythematosus, Systemic / Q000150:complications; D008297:Male; D008875:Middle Aged; D050177:Overweight / Q000150:complications; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications; D051436:Renal Insufficiency, Chronic / Q000150:complications; D012307:Risk Factors; D006113:United Kingdom
chemical_list: D053061:Herpes Zoster Vaccine