title: Illness patterns prior to diagnosis of lymphoma: analysis of UK medical records.
abstract: BACKGROUND
  Increased understanding of the relationship between lymphomas and co-morbidities is likely to provide valuable insights into the natural history of these disorders.
  
  
  METHODS
  761 cases with lymphoma (310 diffuse large B-cell [DLBCL]; 226 follicular [FL]; and 225 Hodgkin [HL]) and 761 unaffected age and sex matched controls were recruited and their histories of infection and non-infection diagnoses in primary care records were compared using negative binomial regression.
  
  
  RESULTS
  No differences were observed between the infectious illness patterns of DLBCL and FL cases and their matched controls over the 15 years preceding lymphoma diagnosis. A marked excess of infectious illness episodes was recorded for HL cases compared to their controls; evident at least a decade prior to HL diagnosis. For non-infectious consultations an excess of case over control visits emerged 4-6 years before DLBCL and FL diagnosis; no specific co-morbidity associations were found. No case-control differences for non-infectious conditions were apparent for HL.
  
  
  CONCLUSIONS
  There are substantial variations in patterns of illness prior to diagnosis of the three lymphoma subtypes examined. The excess of infectious diagnoses prior to HL may point to underlying immune abnormality, but there was no suggestion of this for DLBCL and FL where a generalized excess of non-infectious conditions was evident.
authors.affiliation: Epidemiology and Genetics Unit, Department of Health Sciences, University of York, Heslington, York, UK. simon.crouch@egu.york.ac.uk
authors.forename: Simon
authors.initials: S
authors.lastname: Crouch
authors.forename: Jill
authors.initials: J
authors.lastname: Simpson
authors.forename: Pat
authors.initials: P
authors.lastname: Ansell
authors.forename: Eleanor
authors.initials: E
authors.lastname: Kane
authors.forename: Debra
authors.initials: D
authors.lastname: Howell
authors.forename: Alex
authors.initials: A
authors.lastname: Smith
authors.forename: Rob
authors.initials: R
authors.lastname: Newton
authors.forename: Andrew
authors.initials: A
authors.lastname: Jack
authors.forename: Eve
authors.initials: E
authors.lastname: Roman
mesh_terms: D015897:Comorbidity; D005260:Female; D006801:Humans; D008223:Lymphoma / Q000175:diagnosis* / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D006113:United Kingdom / Q000453:epidemiology