title: Identification of patients at risk for colorectal cancer in primary care: an explorative study with routine healthcare data.
abstract: BACKGROUND
  Early diagnosis of colorectal cancer (CRC) is likely to reduce burden of disease and improve treatment success. Estimation of the individual patient risk for CRC diagnostic determinants in a primary care setting has not been very successful as yet. The aim of our study is to improve prediction of CRC in patients selected for colonoscopy in the primary healthcare setting using readily available routine healthcare data.
  
  
  METHODS
  A cross-sectional study was carried out in the Julius General Practitioners' Network database. Patients referred for colonoscopy by their general practitioner (GP) between 2007 and 2012 were selected. We evaluated the association between long-term registered patient characteristics, symptoms and conditions, and colonoscopy test results with multivariable logistic regression.
  
  
  RESULTS
  Two per cent (2787/140 000) of the patients between 30 and 85 years were found to be newly referred for colonoscopy by their GP, of whom 57 (2%) were diagnosed with CRC. Age 50 years or over, hypertension and the absence of preceding consultations for abdominal pain were independent predictors for CRC and/or high-risk adenomas, with an area under the curve of 0.65.
  
  
  CONCLUSIONS
  Three factors in routine care data combined might prove valuable in future strategies to improve the prediction of CRC risk in primary care. Improvement in quality and availability of routine care data for research and risk stratification is needed to optimize its usability for prediction purposes in daily practice.
  
  
  CONCLUSIONS
  Only referring patients at the highest risk for colonoscopy by the GP could decrease superfluous colonoscopies.
authors.affiliation: aJulius Center for Health Sciences and Primary Care bDepartment of Gastroenterology, University Medical Center Utrecht, Utrecht cDepartment of Computer Science, VU University Amsterdam, Amsterdam dDepartment of Public Health and Primary Care, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Nynke R
authors.initials: NR
authors.lastname: Koning
authors.forename: Leon M G
authors.initials: LM
authors.lastname: Moons
authors.forename: Frederike L
authors.initials: FL
authors.lastname: Büchner
authors.forename: Charles W
authors.initials: CW
authors.lastname: Helsper
authors.forename: Annette
authors.initials: A
authors.lastname: Ten Teije
authors.forename: Mattijs E
authors.initials: ME
authors.lastname: Numans
mesh_terms: D000236:Adenoma / Q000175:diagnosis / Q000453:epidemiology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000453:epidemiology; D003430:Cross-Sectional Studies; D055088:Early Detection of Cancer / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D017063:Outcome Assessment, Health Care; D015995:Prevalence; D011320:Primary Health Care / Q000379:methods*; D012017:Referral and Consultation / Q000706:statistics & numerical data; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors