Comparison | Aggregate Sensitivity, p1__{hat} (x_{1}/n_{1}) | Aggregate Sensitivity, p2<__{hat} (x_{2}/n_{2}) | Z Statistic^{a} | P |
---|---|---|---|---|

Part A or B (1) versus Part A alone (2), all events, ±30-d ascertainment window | 90.9% (160/176) | 82.4% (145/176) | 2.35 | 0.009^{b} |

Part A or B (1) versusPart B alone (2), all events, ±30-d ascertainment window | 90.9% (160/176) | 84.6% (149/176) | 1.79 | 0.037^{b} |

Procedures (1) versus diagnoses (2), Part A or B claims, up to ±90-d ascertainment window | 100% (40/40) | 91.2% (124/136) | 1.95 | 0.05^{c} |

Claims ascertainment window up to ±90 d (1) versus ±30 d (2), using Part A or B claims | ||||

all events | 93.2% (164/176) | 90.9% (160/176) | 0.79 | 0.22^{b} |

atrial fibrillation and venous thromboembolism | 96.0% (48/50) | 90.0% (45/50) | 1.18 | 0.12^{b} |

all other events | 92.1% (116/126) | 91.3% (115/126) | 0.22 | 0.41^{b} |

Adapted “Hebert method” (1) versus Part A or B claims (2) for diagnoses | 88.2% (120/136) | 89.0% (121/136) | −0.19 | 0.43^{b} |

↵

^{a}Z = (p_{1}__{hat}− p_{2}__{hat})/{[p_{p_hat}(1 − p_{p}__{hat})]^{1/2}*[(1/n_{1}) + (1/n_{2})]^{1/2}}, wherein the proportions compared are p_{1}__{hat}= (x_{1}/n_{1}) and p_{2}__{hat}= (x_{2}/n_{2}), and p_{p}__{hat}= (x_{1}+ x_{2}/n_{1}+ n_{2}). Z >1.645 is significant at*P*< 0.05 when using a one-tailed test. Z >1.960 is significant at*P*< 0.05 when using a two-tailed test.↵

^{b}Hypotheses with only one possible direction of difference were examined with a one-tailed test. Specifically, the addition of claims data for event ascertainment by inclusion of both Medicare parts or by an expanded capture window could increase sensitivity or produce no change but not reduce sensitivity; the requirement for additional confirmatory diagnosis claims could reduce or not alter sensitivity achieved with single claims but not increase sensitivity.↵

^{c}The difference in sensitivity between procedures and diagnoses was examined with a more conservative two-tailed test.