Patients, intervention, and outcomes
Using data from July 2010 to March 2018, we identified patients who were diagnosed with anaphylaxis and treated with intramuscular adrenaline on the day of admission. Patients with anaphylaxis were identified on the basis of the following ICD-10 codes: T78.0 (Anaphylactic shock due to adverse food reaction), T78.2 (Anaphylactic shock, unspecified), and T88.6 (Anaphylactic shock due to adverse effect of correct drug or medicament properly administered). We only assessed the initial hospitalization for patients who were hospitalized twice or more during the study period. We defined the glucocorticoids group as patients who received oral or intravenous glucocorticoids on the day of admission, the remaining patients comprising the control group.
The primary outcome was a biphasic reaction within 7 days of admission. We defined biphasic reaction as adrenaline re-use within 7 days from the date of admission. The secondary outcome was 7-day all-cause mortality.