Table 2.
Validity of 19 selected variables recorded in the Western Denmark Cardiac Computed Tomography Registry during 2008–2012 using medical record review as reference standard
| True positive | False negative | False positive | True negative | PPV, % (95% CI)
|
NPV, % (95% CI)
|
|||||
|---|---|---|---|---|---|---|---|---|---|---|
| Available data | Worst-case scenarioa | Best-case scenarioa | Available data | Worst-case scenarioa | Best-case scenarioa | |||||
| Medical history data | 361 | 13 | 18 | 1,359 | 95.3 (92.6–97.0) | 89.1 (85.7–91.8) | 95.6 (93.1–97.2) | 99.1 (98.4–99.5) | 96.2 (95.1–97.1) | 99.1 (98.4–99.5) |
| Family history of premature CAD | 74 | 3 | 9 | 119 | 89.2 (80.7–94.2) | 76.3 (66.9–83.7) | 90.7 (83.3–95.0) | 97.5 (93.0–99.2) | 95.2 (89.9–97.8) | 97.6 (93.2–97.8) |
| Current lipid-lowering therapy | 74 | 1 | 2 | 143 | 97.4 (90.9–99.3) | 93.7 (86.0–97.3) | 97.5 (91.2–99.3) | 99.3 (96.2–99.9) | 96.6 (92.3–98.6) | 99.0 (96.3–99.9) |
| Current medical treatment for hypertension | 77 | 3 | 4 | 135 | 95.1 (88.0–98.1) | 91.7 (83.8–95.9) | 95.2 (88.4–98.1) | 97.8 (93.8–99.3) | 94.4 (89.4–97.1) | 97.9 (94.0–99.3) |
| Smoking status (current/former) | 122 | 3 | 2 | 89 | 98.4 (94.3–99.6) | 93.9 (88.3–96.9) | 98.5 (94.6–99.6) | 96.7 (90.9–99.9) | 90.8 (83.5–95.1) | 96.9 (91.4–99.0) |
| Diabetes | 13 | 1 | 1 | 206 | 92.9 (66.5–98.7) | 92.9 (66.5–98.7) | 92.9 (66.5–98.7) | 99.5 (97.3–99.9) | 96.7 (93.4–98.8) | 99.5 (97.4–99.9) |
| Previous PCI | 0 | 0 | 0 | 223 | – | – | – | 100 (98.3–100) | 97.4 (94.4–98.8) | 100 (98.4–100) |
| Previous cardiac surgery | 1 | 2 | 0 | 221 | 100 (20.6–100) | 100 (20.6–100) | 100 (20.6–100) | 99.1 (97.5–99.9) | 96.5 (93.3–98.2) | 99.1 (96.9–99.8) |
| Previous myocardial infarction | 0 | 0 | 0 | 223 | – | – | – | 100 (98.3–100) | 97.8 (95.0–99.1) | 100 (98.3–100) |
| Procedure datab | 2,185 | – | 62 | – | 97.2 (96.5–97.8) | 84.8 (83.4–86.2) | 97.6 (96.9–98.1) | – | – | – |
| Coronary CTA indication (angina/equivalent) | 250 | – | – | – | 100 (98.5–100) | 100 (98.5–100) | 100 (98.5–100) | – | – | – |
| Date of procedure | 243 | – | 7 | – | 93.6 (94.3–96.6) | 93.6 (94.3–96.6) | 93.6 (94.3–96.6) | – | – | – |
| Height | 73 | – | 2 | – | 97.3 (90.8–99.3) | 33.5 (27.6–40.0) | 99.1 (96.7–99.8) | – | – | – |
| Weight | 75 | – | 1 | – | 98.7 (92.9–99.8) | 34.4 (28.4–40.9) | 99.5 (97.5–99.9) | – | – | – |
| Type of CT scanner | 243 | – | 6 | – | 97.6 (94.8–98.9) | 95.5 (92.1–97.5) | 95.5 (92.1–97.5) | – | – | – |
| Kilo-electron volt | 232 | – | 11 | – | 95.5 (92.1–97.5) | 94.7 (91.1–96.9) | 95.5 (92.1–97.5) | – | – | – |
| Radiation dose | 222 | – | 5 | – | 97.8 (95.0–99.1) | 96.5 (93.3–98.2) | 97.8 (95.0–99.1) | – | – | – |
| Contrast volume | 210 | – | 6 | – | 97.2 (94.1–98.7) | 86.4 (81.5–90.2) | 97.5 (94.7–98.9) | – | – | – |
| CACS result | 220 | – | 4 | – | 96.2 (95.5–99.3) | 94.8 (91.2–97.0) | 98.3 (95.7–99.3) | – | – | – |
| Coronary CTA result | 227 | – | 9 | – | 95.0 (92.9–98.0) | 94.6 (91.0–96.8) | 96.3 (93.0–98.0) | – | – | – |
| Consequence of the coronary CTA results | 190 | – | 11 | – | 94.5 (90.5–96.9) | 94.5 (90.5–96.9) | 94.5 (90.5–96.9) | – | – | – |
Notes: The study sample consisted of 250 randomly selected symptomatic patients who underwent coronary CTA at three university and two nonuniversity cardiac centers in Western Denmark. Patients with missing information in the registry or medical records were not included in the analyses.
Worst- and best-case scenarios were calculated assuming that none or all of the missing values in the medical files confirmed the registry data;
the procedure data variables comprise continuous variables and categorical variables with more than two levels. For these variables, PPV was calculated from the proportion of exact matches on the corresponding scale (yes/no).
Abbreviations: CACS, coronary artery calcium scoring; CAD, coronary artery disease; CI, confidence interval; CT, computed tomography; CTA, computed tomography angiography; NPV, negative predictive value; PCI, percutaneous coronary intervention; PPV, positive predictive value.