Accuracy of clinical prediction rules in peptic ulcer perforation: an observational study

Objective. The aim of the present study was to compare the ability of four clinical prediction rules to predict adverse outcome in perforated peptic ulcer (PPU): the Boey score, the American Society of Anesthesiologists (ASA) score, the Acute Physiology and Chronic Health Evaluation (APACHE) II score, and the sepsis score. Material and methods. Design: an observational multicenter study. Participants and settings: a total of 117 patients surgically treated for PPU between 1 January 2008 and 31 December 2009 in seven gastrointestinal departments in Denmark were included. Pregnant and breastfeeding women, non-surgically treated patients, patients with malignant ulcers, and patients with perforation of other organs were excluded. Primary outcome measure: 30-day mortality rate. Statistical analysis: the ability of four clinical prediction rules to distinguish survivors from non-survivors (discrimination ability) was evaluated by the area under the receiver operating characteristic curve (AUC), positive predictive values (PPVs), negative predictive values (NPVs), and adjusted relative risks. Results. Median age (range) was 70 years (25-92 years), 51% of the patients were females, and 73% of the patients had at least one co-existing disease. The 30-day mortality proportion was 17% (20/117). The AUCs: the Boey score, 0.63; the sepsis score, 0.69; the ASA score, 0.73; and the APACHE II score, 0.76. Overall, the PPVs of all four prediction rules were low and the NPVs high. Conclusions. The Boey score, the ASA score, the APACHE II score, and the sepsis score predict mortality poorly in patients with PPU.