| Case definition | Source of data | No. (%) of patients | Measure† | Value (95% CI) | |||
|---|---|---|---|---|---|---|---|
| Administrative data | MRP data | ||||||
| Any 1 claim for outpatient dialysis | No | No | 2774 | (64.1) | Sensitivity | 77.0 | (74.7–79.2) |
| No | Yes | 315 | (7.4) | Specificity | 93.8 | (92.9–94.7) | |
| Yes | No | 183 | (4.2) | PPV | 85.2 | (83.2–87.2) | |
| Yes | Yes | 1053 | (24.4) | NPV | 89.8 | (88.7–90.9) | |
| Accuracy | 88.5 | (87.4–89.6) | |||||
| κ value | 0.73 | (0.70–0.75) | |||||
| Any 2 claims for outpatient dialysis | No | No | 2791 | (64.5) | Sensitivity | 74.6 | (72.3–76.9) |
| No | Yes | 347 | (8.0) | Specificity | 94.4 | (93.6–95.2) | |
| Yes | No | 166 | (3.8) | PPV | 86.0 | (84.0–88.0) | |
| Yes | Yes | 1021 | (23.6) | NPV | 88.9 | (87.8–90.0) | |
| Accuracy | 88.1 | (87.0–89.3) | |||||
| κ value | 0.72 | (0.69–0.74) | |||||
| Any 2 claims for outpatient dialysis at least 90 d apart | No | No | 2872 | (66.4) | Sensitivity | 64.8 | (62.2–67.3) |
| No | Yes | 482 | (11.1) | Specificity | 97.1 | (96.5–97.7) | |
| Yes | No | 85 | (2.0) | PPV | 91.2 | (89.5–93.0) | |
| Yes | Yes | 886 | (20.5) | NPV | 85.6 | (84.4–86.8) | |
| Accuracy | 86.9 | (85.8–88.0) | |||||
| κ value | 0.67 | (0.65–0.70) | |||||
| Any 2 claims for outpatient dialysis at least 90 d apart, with no gap greater than 21 d | No | No | 2883 | (66.7) | Sensitivity | 52.7 | (50.1–55.4) |
| No | Yes | 647 | (15.0) | Specificity | 97.5 | (96.9–98.1) | |
| Yes | No | 74 | (1.7) | PPV | 90.7 | (88.7–92.7) | |
| Yes | Yes | 721 | (16.7) | NPV | 81.7 | (80.4–83.0) | |
| Accuracy | 83.3 | (82.1–84.6) | |||||
| κ value | 0.57 | (0.54–0.59) | |||||
Note: CI = confidence interval, NPV = negative predictive value, PPV = positive predictive value. *Definitions are derived from those used in a study by Clement and colleagues.3 †All values are reported as percentages except for kappa values.