title: Prediction of proximal advanced neoplasia: a comparison of four existing sigmoidoscopy-based strategies in a Chinese population.
abstract: OBJECTIVE
  To compare the performance of existing sigmoidoscopy-based strategies in predicting advanced proximal neoplasia (APN) in an asymptomatic Chinese cohort.
  
  
  METHODS
  We included all screening participants aged 50-70 years who received colonoscopy between 2008 and 2014 in Hong Kong. Sigmoidoscopy yield was estimated from the colonoscopic findings based on the: (1) UK flexible sigmoidoscopy; (2) Screening for COlon REctum (SCORE); (3) NORwegian Colorectal Cancer Prevention (NORCCAP) trials and (4) US clinical index based on age, gender and distal findings. The sensitivity, specificity, the number of subjects needed to screen (NNS) and the number of subjects needed to refer (NNR) for colonoscopy to detect one APN were evaluated. Binary logistic regression modelling identified the distal findings associated with APN.
  
  
  RESULTS
  From 5879 eligible subjects, 132 (2.2%) had APN. The US strategy achieved the highest sensitivity for APN detection (42.0%) and the UK criteria attained the highest specificity (96%). The US criteria led to the lowest NNS (92 vs 103-267) and the UK criteria required the least NNR (12 vs 16-21). Using the US strategy, the rates of APN detected were 1.4% (low-risk group), 2.2% (intermediate risk) and 5.9% (high risk). The c-statistics of the UK, SCORE, NORCCAP and the US criteria were 0.55±0.03; 0.59±0.03; 0.59±0.03 and 0.62±0.05 respectively.
  
  
  CONCLUSIONS
  The US criteria had the highest sensitivity for detection of APN and lowest NNS and the UK score had the highest specificity and the lowest NNR. The performance of all these four criteria to predict APN is limited, highlighting an urgent need to devise a novel APN prediction system for Asian subjects.
authors.affiliation: Institute of Digestive Disease, Chinese University of Hong Kong, Shatin, Hong Kong School of Public Health and Primary Care, Chinese University of Hong Kong, Shatin, Hong Kong.
authors.forename: Martin C S
authors.initials: MC
authors.lastname: Wong
authors.affiliation: Institute of Digestive Disease, Chinese University of Hong Kong, Shatin, Hong Kong.
authors.forename: Jessica Y L
authors.initials: JY
authors.lastname: Ching
authors.affiliation: Institute of Digestive Disease, Chinese University of Hong Kong, Shatin, Hong Kong Department of Medicine and Therapeutics, State Key laboratory of Digestive Diseases, LKS Institute of Health Science, Chinese University of Hong Kong.
authors.forename: Siew C
authors.initials: SC
authors.lastname: Ng
authors.affiliation: Institute of Digestive Disease, Chinese University of Hong Kong, Shatin, Hong Kong Department of Medicine and Therapeutics, State Key laboratory of Digestive Diseases, LKS Institute of Health Science, Chinese University of Hong Kong.
authors.forename: Sunny
authors.initials: S
authors.lastname: Wong
authors.affiliation: Institute of Digestive Disease, Chinese University of Hong Kong, Shatin, Hong Kong.
authors.forename: Victor C W
authors.initials: VC
authors.lastname: Chan
authors.affiliation: Institute of Digestive Disease, Chinese University of Hong Kong, Shatin, Hong Kong.
authors.forename: Jeffrey P
authors.initials: JP
authors.lastname: Shum
authors.affiliation: Institute of Digestive Disease, Chinese University of Hong Kong, Shatin, Hong Kong.
authors.forename: Thomas Y T
authors.initials: TY
authors.lastname: Lam
authors.affiliation: Institute of Digestive Disease, Chinese University of Hong Kong, Shatin, Hong Kong.
authors.forename: Arthur K C
authors.initials: AK
authors.lastname: Luk
authors.affiliation: Institute of Digestive Disease, Chinese University of Hong Kong, Shatin, Hong Kong.
authors.forename: Joseph J Y
authors.initials: JJ
authors.lastname: Sung
mesh_terms: D017677:Age Distribution; D000368:Aged; D003113:Colonoscopy / Q000379:methods; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000453:epidemiology / Q000473:pathology; D055088:Early Detection of Cancer / Q000379:methods*; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012017:Referral and Consultation / Q000706:statistics & numerical data; D012307:Risk Factors; D012680:Sensitivity and Specificity; D017678:Sex Distribution; D012812:Sigmoidoscopy / Q000379:methods*
keywords: COLORECTAL CANCER SCREENING