PT - JOURNAL ARTICLE AU - Émond, Marcel AU - Guimont, Chantal AU - Chauny, Jean-Marc AU - Daoust, Raoul AU - Bergeron, Éric AU - Vanier, Laurent AU - Moore, Lynne AU - Plourde, Miville AU - Kuimi, Batomen AU - Boucher, Valérie AU - Allain-Boulé, Nadine AU - Le Sage, Natalie TI - Clinical prediction rule for delayed hemothorax after minor thoracic injury: a multicentre derivation and validation study AID - 10.9778/cmajo.20160096 DP - 2017 Apr 01 TA - CMAJ Open PG - E444--E453 VI - 5 IP - 2 4099 - http://www.cmajopen.ca/content/5/2/E444.short 4100 - http://www.cmajopen.ca/content/5/2/E444.full AB - Background: About 75% of patients with minor thoracic injury are discharged after an emergency department visit. However, complications such as delayed hemothorax can occur. We sought to derive and validate a clinical decision rule to predict hemothorax in patients discharged from the emergency department. Methods: We conducted a 6-year prospective cohort study in 4 university-affiliated emergency departments. Patients aged 16 years or older presenting with a minor thoracic injury were assessed at 5 time points (initial visit and 7, 14, 30 and 90 d after the injury). Radiologists' reports were reviewed for the presence of hemothorax. We used log-binomial regression models to identify predictors of hemothorax. Results: A total of 1382 patients were included: 830 in the derivation phase and 552 in the validation phase. Of these, 151 (10.9%) had hemothorax at the 14-day follow-up. Patients 65 years of age or older represented 25.3% (210/830) and 23.7% (131/552) of the derivation and validation cohorts, respectively. The final clinical decision rule included a combination of age (> 70 yr, 2 points; 45-70 yr, 1 point), fracture of any high to mid thorax rib (ribs 3-9, 2 points) and presence of 3 or more rib fractures (1 point). Twenty (30.8%) of the 65 high-risk patients (score ≥ 4) experienced hemothorax during the follow-up period. The clinical decision rule had a high specificity (90.7%, 95% confidence interval 87.7%-93.1%) in this high-risk group, thus guiding appropriate post-emergency care.Interpretation: One patient out of every 10 presented with delayed hemothorax after discharge from the emergency department. Implementation of this validated clinical decision rule for minor thoracic injury could guide emergency discharge plans.