Table 2.
Positive Predictive Value of Combined Case Definitions for Identifying Cases of Cerebral Venous Sinus Thrombosis
| Case Definitions (ICD-10-CM Codes) | TP, n | FP, n | PPV, % (95% CI) |
|---|---|---|---|
| G08, I636, I676 | |||
| G08 or I636 or I676 as primary diagnosis | 70 | 4 | 94.6 (86.7–98.5) |
| G08 or I636 or I676 as primary or secondary diagnosis | 115 | 11 | 91.3 (84.9–95.6) |
| G08 or I636 or I676 as primary, secondary, or tertiary diagnosis | 137 | 13 | 91.3 (85.6–95.3) |
| G08 or I636 or I676 in any field of diagnosis | 165 | 17 | 90.7 (85.5–94.5) |
| G08, I636, I676, I629 | |||
| G08 or I636 or I676 or I629 as primary diagnosis | 71 | 78 | 47.7 (39.4–56.0) |
| G08 or I636 or I676 or I629 as primary or secondary diagnosis | 117 | 136 | 46.3 (40.0–52.6) |
| G08 or I636 or I676 or I629 as primary, secondary, or tertiary diagnosis | 138 | 168 | 45.1 (39.4–50.9) |
| G08 or I636 or I676 or I629 in any field of diagnosis | 166 | 214 | 43.7 (38.6–48.8) |
Note: Seven cases have simultaneous coding with G08, I636, I676, or I629 in any field of diagnosis.
Abbreviations: TP, true positive; FP, false positive; ICD-10-CM, International Classification of Diseases, 10th Revision, Clinical Modification; PPV, positive predictive value; CI, confidence interval.