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Table 5 2 by 2 table for the FOBT only, model only and a combined approach of FOBT positive plus risk positive at PPV 3% level (probability: 0.0168) for those with negative results

From: The use of electronic healthcare records for colorectal cancer screening referral decisions and risk prediction model development

 Diagnostic Positive: Record/diagnosis of CRC (over 2 year follow up)Diagnostic Negative: No record/diagnosis of CRC (over 2 year follow up)
CRCPolypTotalTotal
Index Test PositiveFOBT only n = 25,592158291449846
Model Only (negative population only, n = 24,297)1328411288
Combined n = 25,592 (positive result is either risk positive or FOBT positive)1713194902134
Index Test NegativeFOBT only n = 25,59216521938423,913
Model Only (negative population only, n = 24,297)15219134322,625
Combined n = 25,592 (positive result is either risk positive or FOBT positive)15219134322,625
  1. FOBT Only: Sensitivity 53.90%, Specificity 96.58%, PPV 34.67%, NPV 98.42%.
  2. Model Only: Sensitivity 10.68%, Specificity 94.61%, PPV 3.00%, NPV 98.51%.
  3. Combined (FOBT Positive or Risk Positive): Sensitivity 58.82%, Specificity 91.38%, PPV 18.67%, NPV 98.51%.