Table 4.

Measures of concordance for colorectal endoscopy use by Medicare claims, medical records, and self report

Data sources compared*Type of testTest use by source
Measures of concordance
Both sources (A)Non–gold only (B)Gold only (C)Neither source (D)Sensitivity (95% CI)Specificity (95% CI)PPV (95% CI)NPV (95% CI)Agreement (95% CI)κ (95% CI)
Claim to medical recordSigmoidoscopy7942643493 (87-98)91 (89-94)65 (57-74)99 (98-100)91 (89-94)0.72 (0.64-0.80)B
Colonoscopy180171135394 (91-98)95 (93-98)91 (87-95)97 (95-99)95 (93-97)0.89 (0.81-0.97)A
Endoscopy23022730297 (95-99)93 (90-96)91 (88-95)98 (96-99)95 (93-97)0.89 (0.81-0.98)A
Medical record to claimSigmoidoscopy7964243465 (57-74)99 (98-100)93 (87-98)91 (89-94)91 (89-94)0.72 (0.64-0.80)B
Colonoscopy180111735391 (87-95)97 (95-99)94 (91-98)95 (93-98)95 (93-97)0.89 (0.81-0.97)A
Endoscopy23072230291 (88-95)98 (96-99)97 (95-99)93 (90-96)95 (93-97)0.89 (0.81-0.98)A
Self report to medical recordSigmoidoscopy38903040356 (44-68)82 (78-85)30 (22-38)93 (91-95)79 (75-82)0.27 (0.20-0.35)D
Colonoscopy132845928669 (63-76)77 (73-82)61 (55-68)83 (79-87)75 (71-78)0.45 (0.37-0.53)C
Endoscopy1701116022074 (68-80)67 (61-72)61 (55-66)79 (74-83)70 (66-73)0.39 (0.31-0.47)D
Self-report to claimSigmoidoscopy47816337043 (33-52)82 (78-86)37 (28-45)85 (82-89)74 (71-78)0.23 (0.15-0.32)D
Colonoscopy136806128469 (62-75)78 (74-82)63 (57-69)82 (78-86)75 (71-78)0.46 (0.38-0.54)C
Endoscopy183986921173 (67-78)68 (63-73)65 (60-71)75 (70-80)70 (66-74)0.40 (0.32-0.49)D
  • NOTE: Concordance measures were assessed using the following formulas: Sensitivity = [A / (A + C)] × 100; Specificity = [D / (B + D)] × 100; PPV = [A / (A + B)] × 100; NPV = [D / (C + D)] × 100; Agreement = [(A + D) / (A + B + C + D)] × 100; κ = (percentage of agreement − percentage of expected agreement) / 1 − percentage of expected agreement, where expected agreement = {[(A + B) / (A + B + C + D)] × [(A + C) / (A + B + C + D)]} + [(C + D) / (A + B + C + D)] × [(B + D) / (A + B + C + D)] × 100.

    Abbreviations: 95% CI, 95% confidence interval; PPV, positive predictive value; NPV, negative predictive value.

  • * Comparisons are made using the second source listed as the “gold standard.”

  • Strength of agreement based on κ: A = 0.81-1.00 Almost Perfect. B = 0.61-0.80 Substantial. C = 0.41-0.60 Moderate. D = 0.21-0.40 Fair.