Table 2.
Positive predictive value, sensitivity and specificity of the Swedish National Patient register for IBD-related surgical procedure codes (n=258 patients)
| NPR | Chart review | |
|---|---|---|
| Patient chart positive for IBD-related surgery (n = 53 patients; N = 164 codes) |
Patient chart negative for IBD-related surgery (n = 205 patients) |
|
| Code for IBD-related surgery (Concordant code in NPR) | 155 (153) | 3 |
| No corresponding code for IBD-related surgery | 9 | 202 |
| Patients with no code in the NPR | 2 | |
| PPV (true positives, 95%CI) | 98.7 (96.3–100) 153/155 | |
| PPV (concordant codes, 95%CI) | 96.8 (93.9–99.1) 153/158 | |
| Sensitivity of the NPR (95%CI) | 94.5 (89.6–99.3) 155/164 | |
| Specificity of the NPR (95%CI) | 98.5 (97.6–100) 202/205 | |
CI Confidence interval, IBD Inflammatory bowel disease, NPR National patient register, PPV Positive predictive value PPV of true positives calculated from surgical procedure codes in the NPR present in the charts (n = 155) and codes confirmed by chart review. (n = 153). PPV of concordant codes calculated from all surgical procedure codes in the NPR (n = 158) and codes confirmed by chart review (n = 153)