title: Deep vein thrombosis in primary care: possible malignancy?
abstract: BACKGROUND
  The increased prevalence of unrecognised malignancy in patients with deep vein thrombosis (DVT) has been well established in secondary care settings. However, data from primary care settings, needed to tailor the diagnostic workup, are lacking.
  
  
  OBJECTIVE
  To quantify the prevalence of unrecognised malignancy in primary care patients who have been diagnosed with DVT.
  
  
  METHODS
  Prospective follow-up study.
  
  
  METHODS
  All primary care physicians affiliated/associated with a non-teaching hospital in a geographically circumscribed region participated in the study.
  
  
  METHODS
  A total of 430 consecutive patients without known malignancy, but with proven DVT were included in the study and compared with a control group of 442 primary care patients, matched according to age and sex. Previously unrecognised, occult malignancy was considered present if a new malignancy was diagnosed within 2 years following DVT diagnosis (DVT group) or inclusion in the control group. Patients with DVT were categorised in to those with unprovoked idiopathic DVT and those with risk factors for DVT (that is, secondary DVT).
  
  
  RESULTS
  During the 2-year follow-up period, a new malignancy was diagnosed 3.6 times more often in patients with idiopathic DVT than in the control group (2-year incidence: 7.4% and 2.0%, respectively). The incidence in patients with secondary DVT was 2.6%; only slightly higher than in control patients.
  
  
  CONCLUSIONS
  Unrecognised malignancies are more common in both primary and secondary care patients with DVT than in the general population. In particular, patients with idiopathic DVT are at risk and they could benefit from individualised case-finding to detect malignancy.
authors.affiliation: Julius Center for Health Sciences and Primary care, University Medical Center Utrecht, The Netherlands. R.Oudega@knmg.nl
authors.forename: Ruud
authors.initials: R
authors.lastname: Oudega
authors.forename: Karel G M
authors.initials: KG
authors.lastname: Moons
authors.forename: H
authors.initials: H
authors.lastname: Karel Nieuwenhuis
authors.forename: Fred L
authors.initials: FL
authors.lastname: van Nierop
authors.forename: Arno W
authors.initials: AW
authors.lastname: Hoes
mesh_terms: D016022:Case-Control Studies; D005194:Family Practice; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications / Q000175:diagnosis* / Q000453:epidemiology; D009426:Netherlands / Q000453:epidemiology; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D020246:Venous Thrombosis / Q000150:complications* / Q000188:drug therapy / Q000453:epidemiology