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Table 3 Positive predictive value and sensitivity of IBD-related surgical procedure codes in the Swedish National Patient Register stratified by type of surgery and year

From: Validating surgical procedure codes for inflammatory bowel disease in the Swedish National Patient Register

CodesAbdominalPerianalOther IBD1966–19961997–2014Total
Code in chart6740578579164
Code in chart but missing in NPR243819
Code in NPR6836547880158
Code in NPR but missing in chart300123
Code in chart and NPR6536547778155
Correct code in chart and NPR6436537677153
Correct code in chart but false in NPR101112
PPV (95%CI)94.1 (88.7–98.6) 64/68100 (100–100) 36/3698.1 (93.1–100) 53/5497.4 (92.7–100) 76/7896.2 (92.9–100) 77/80 
Sensitivity (95%CI)97.0 (91.9–100) 65/6790.0 (81.8–100) 36/4094.7 (88.9–100) 54/5790.6 (84.6–100) 77/8598.7 (95.0–100) 78/79 
  1. CI Confidence interval, IBD Inflammatory bowel disease, NPR National patient register, PPV Positive predictive value Codes in the patient charts but missing in the NPR registered in 1996 or earlier consisted of six perianal procedure codes (KVÅ, 4999 - Other operation on anus or perianal tissue) and two abdominal procedure codes (KVÅ, 4642 - Ileocaecal resection; KVÅ, 4611 - Laparatomy and closure of a fistula to the bowel wall). One code registered in 1997 or later was missing (NOMESCO, JFH20 - Proctocolectomy with ileostomy)