title: Cumulative incidence of lumbar disc diseases leading to hospitalization up to the age of 28 years.
abstract: METHODS
  A cohort study of 12,000 persons with a follow-up period ranging from birth to the age of 28 years.
  
  
  OBJECTIVE
  To determine the cumulative incidence of lumbar disc disease leading to hospitalization in a well-defined geographic population, with special emphasis on age of onset and differences between the genders and among disease categories.
  
  
  BACKGROUND
  There are few published reports on low back pain in adolescence, and most of them are cross-sectional in design.
  
  
  METHODS
  The Finnish National Hospital Discharge Register was used to identify all possible cases of lumbar disc disease. Copies of all hospital records regarding the diagnosis and course of the disease were collected and the hospitalizations were classified into three categories: 1) confirmed herniated nucleus pulposus (HNP), 2) unconfirmed HNP (sciatica symptoms without visible herniation), and 3) other low back diseases. The patients were classified according to the highest category of diagnosis achieved by each.
  
  
  RESULTS
  Symptomatic low back pain leading to hospitalization first appeared around the age of 15 years, and the incidence rose more sharply from the age of 19, especially in men with other low back diseases. Men were hospitalized more than twice as often as women.
  
  
  CONCLUSIONS
  Lumbar disc diseases leading to hospitalization begin early.
authors.affiliation: Department of Public Health Science and General Practice, University of Oulu, Finland. paavo.zitting@oulu.fi
authors.forename: P
authors.initials: P
authors.lastname: Zitting
authors.forename: P
authors.initials: P
authors.lastname: Rantakallio
authors.forename: H
authors.initials: H
authors.lastname: Vanharanta
mesh_terms: D000328:Adult; D017668:Age of Onset; D015331:Cohort Studies; D005260:Female; D005387:Finland / Q000453:epidemiology; D005500:Follow-Up Studies; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D007403:Intervertebral Disc; D007405:Intervertebral Disc Displacement / Q000453:epidemiology; D008159:Lumbar Vertebrae; D008297:Male; D013122:Spinal Diseases / Q000453:epidemiology*; D013997:Time Factors