Characterising adverse events in postdischarge high-risk patients with 6-month follow-up in a Korean tertiary hospital: a retrospective cohort study.

objectivesThis study aimed to examine adverse event occurrences in outpatient care settings and healthcare utilisation after discharge and to identify the characteristics of patients at high risk of safety issues during the care transition from the hospital to their homes. In addition, the performance of outpatient triggers for the detection of adverse events was explored.

designA retrospective cohort study using hospital medical record reviews over 6 months postdischarge.

settingA tertiary teaching hospital in South Korea.

participantsA total of 746 adult patient medical records mainly including patients potentially at high risk of adverse events were analysed, comprising 5439 outpatient visits. PRIMARY OUTCOME MEASURE: Occurrence of adverse events.

resultsApproximately 14.2% of patients experienced at least one adverse event within 6 months postdischarge. Medication-related (84.2%) and surgical/procedural (13.2%) events were common. Most events were mild in severity and assessed as unpreventable. Patients who experienced adverse events had significantly more all-cause re-hospitalisations, emergency room visits and outpatient clinic visits. No difference was found in mortality. Controlling for other variables, multiple logistic regression analysis showed that patients who are overweight (OR=0.48, 95% CI 0.25 to 0.90), with circulatory system diseases (OR=0.38, 95% CI 0.15 to 0.96) and with a National Early Warning Score 2 (NEWS2) ≥2 at discharge (OR=0.26, 95% CI 0.12 to 0.54) were less likely to experience adverse events. Those with admissions via emergency rooms or day-surgery centres (OR=1.98, 95% CI 1.18 to 3.32), in medical departments (OR=1.93, 95% CI 1.15 to 3.23), with a diagnosis of cancer (OR=2.03, 95% CI 1.14 to 3.62) and longer hospital stays (OR=1.07, 95% CI 1.02 to 1.11) were more likely to experience adverse events postdischarge. Outpatient triggers with relatively high performance included 'constipation with narcotics/calcium channel blockers', 'abrupt medication discontinuation', 'rash' and 'white blood cell count <3000/mm³'.

conclusionsApproximately 14% of patients, mainly comprising high-risk patients, experienced adverse events postdischarge, with more emergency room visits and all-cause re-hospitalisations. Patients experiencing adverse events were characterised by body mass index, type of admission route, clinical department, medical diagnosis, length of hospital stay and NEWS2. Patient and caregiver participation in the monitoring and reporting of adverse events should be encouraged to improve postdischarge patient safety. The use of triggers to detect potential patient safety problems is recommended.