Table 4.
Validity of the Diagnostic Codes for IBD, CD and UC in the NPR Using Department Specialization as Criteria, Including Abdominal Surgical Departments as Specialized Departments of Gastroenterology
| Diagnosis Department Specialization |
No. of Cases According to NPR with at Least One Registration | No. of Confirmed Cases | PPV (95% CI) |
|---|---|---|---|
| Including MC as IBD casea Departments of internal medicine, surgery or gastroenterology Other/unknown |
266 |
210 |
0.79 (0.74–0.84) |
|
11 |
7 |
0.64 (0.31–0.89) |
|
| Excluding MC as caseb Departments of internal medicine, surgery or gastroenterology Other/unknown |
266 |
154 |
0.58 (0.52–0.64) |
|
11 |
7 |
0.64 (0.31–0.89) |
|
| CD Departments of internal medicine, surgery or gastroenterology Other/unknown |
56 |
28 |
0.50 (0.36–0.64) |
|
5 |
3 |
0.60 (0.15–0.95) |
|
| UC Departments of internal medicine, surgery or gastroenterology Other/unknown |
210 |
113 |
0.54 (0.47–0.67) |
|
6 |
4 |
0.67 (0.22–0.96) |
Notes: a Using patients with CD, UC, IBDu and MC in the patient records as cases.
bUsing patients with CD, UC and IBDu in the records as cases.
Abbreviations: NPR, the Danish National Patient Registry; IBD, inflammatory bowel disease; CD, Crohn’s disease; UC, ulcerative colitis; IBDu, undifferentiated IBD; MC, microscopic colitis; PPV, positive predictive value; CI, confidence interval.