title: Decompression illness treated in Denmark 1999-2013.
abstract: BACKGROUND
  The incidence, diver characteristics and symptomatology of decompression illness (DCI) in Denmark has not been assessed since 1982, and the presence of long-term residual symptoms among divers receiving hyperbaric oxygen therapy in Denmark has never been estimated to our knowledge.
  
  
  METHODS
  We undertook a retrospective study of the incidence and characteristics of DCI cases in Denmark for the period of 1999 to 2013. Medical records and voluntary questionnaires were reviewed, extracting data on age, gender, weight, height, diver certification level, diving experience, number of previous dives, type of diving, initial type of hyperbaric treatment and DCI symptoms. Trend in annual case numbers was evaluated using run chart analysis and Spearman's correlation. Age, height, weight, and BMI were evaluated using linear regression. The presence of long-term residual symptoms was investigated by phone interviewing the subgroup of divers treated in 2009 and 2010.
  
  
  RESULTS
  Two-hundred-and-five DCI cases were identified. The average annual case load was 14 with no significant trend during the study period (P = 0.081). Nor did we find any trend in age, weight, height or BMI. The most frequent symptoms were paraesthesia (50%), pain (42%) and vertigo (40%). Thirteen out of the subgroup of 30 divers had residual symptoms at discharge from hospital, and six out of 24 of these divers had residual symptoms at the time of follow-up.
  
  
  CONCLUSIONS
  We observed a more than ten-fold increase in DCI-cases since the period 1966-1980. In the subgroup of divers treated in 2009/2010, a quarter had long-term residual symptoms as assessed by telephone interview, which is in keeping with the international literature, but still a reminder that DCI can have life-long consequences.
authors.affiliation: Hyperbaric Medicine Centre, Department of Anaesthesiology, Centre of Head and Orthopaedics, University Hospital of Copenhagen, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen Ø, Denmark, christiansjuhl@hotmail.com.
authors.forename: Christian
authors.initials: C
authors.lastname: Svendsen Juhl
authors.affiliation: Hyperbaric Medicine Centre, Department of Anaesthesiology, Centre of Head and Orthopaedics, University Hospital of Copenhagen, Rigshospitalet, Copenhagen, Denmark.
authors.forename: Morten
authors.initials: M
authors.lastname: Hedetoft
authors.affiliation: Hyperbaric Medicine Centre, Department of Anaesthesiology, Centre of Head and Orthopaedics, University Hospital of Copenhagen, Rigshospitalet, Copenhagen, Denmark.
authors.forename: Daniel
authors.initials: D
authors.lastname: Bidstrup
authors.affiliation: Hyperbaric Medicine Centre, Department of Anaesthesiology, Centre of Head and Orthopaedics, University Hospital of Copenhagen, Rigshospitalet, Copenhagen, Denmark.
authors.forename: Erik Christian
authors.initials: EC
authors.lastname: Jansen
authors.affiliation: Hyperbaric Medicine Centre, Department of Anaesthesiology, Centre of Head and Orthopaedics, University Hospital of Copenhagen, Rigshospitalet, Copenhagen, Denmark.
authors.forename: Ole
authors.initials: O
authors.lastname: Hyldegaard
mesh_terms: D000328:Adult; D000367:Age Factors; D001827:Body Height; D015992:Body Mass Index; D001835:Body Weight; D002568:Certification; D003665:Decompression Sickness / Q000150:complications / Q000453:epidemiology / Q000628:therapy*; D003718:Denmark / Q000453:epidemiology; D004242:Diving / Q000009:adverse effects* / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D006931:Hyperbaric Oxygenation / Q000706:statistics & numerical data*; D015994:Incidence; D016014:Linear Models; D008297:Male; D010146:Pain / Q000453:epidemiology; D010292:Paresthesia / Q000453:epidemiology; D012189:Retrospective Studies; D011795:Surveys and Questionnaires; D063189:Symptom Assessment; D014717:Vertigo / Q000453:epidemiology
keywords: Decompression sickness; diving incidents; hyperbaric oxygen therapy; outcome; recompression