Syncope and Presyncope as a Presenting Symptom or Discharge Diagnosis in the Emergency Department: An Administrative Data Validation Study.

Emergency department (ED) visits for syncope are common. Validation of ED administrative diagnostic coding for syncope is required before these codes can be used for health services research. We performed a retrospective multicentre chart review using a regional ED database in British Columbia. We identified adults who visited 1 of 3 high-volume urban EDs between 2010 and 2015. Cohort 1 included 350 ED visits for patients with a presenting complaint (PC) of syncope/presyncope, a discharge diagnosis (DD) of syncope and collapse, or both. Cohort 2 included 100 patients with ED visits with neither a PC of syncope/presyncope nor a DD of syncope and collapse. The reference standard was abstractor conclusion regarding syncope and presyncope ("definite/very likely" vs "possible" vs "unlikely" vs "absent") after structured review of ED medical records. We found that in cohort 1, syncope or presyncope were definite/very likely or possible in 96% of visits with a PC of syncope/presyncope and a DD of syncope and collapse. Syncope alone was definite/very likely in only 56% of visits. In cohort 2, syncope was definitely absent for 94% of patients. The reference standard showed excellent face validity and abstractor inter-rater agreement (Cohen κ > 0.80). Vital signs and orthostatic vital signs were not documented for 8% and 84% of visits, respectively. Our results suggest that a PC of syncope/presyncope combined with a DD of syncope and collapse is highly predictive of syncope or presyncope. These findings will inform design and interpretation of syncope health services research.