Strengths and limitations
We were able to compare an extensive set of patient and ED visit characteristics between patients with and without URVs. Although previous studies mentioned reasons for URVs in older adults, this is one of the few studies that investigated the frequencies of the different reasons for URVs in older adults [Some limitations, however, could be considered. The reasons for URVs were defined and categorized prior to the start of the study and based on explicit criteria, used in previous studies. However, the reasons for URVs were determined retrospectively. By having the URVs assessed by two independent researchers, we tried to comply with the classification criteria as much as possible. The Cohen’s kappa coefficient of 0.57, reflecting a moderate inter-rater reliability of the categorization system, may be a limitation.Furthermore, not all data about health determinants that are associated with hospital return were available. Finally, this study was conducted in two EDs of a non-academic hospital in the Netherlands. The findings may not be generalizable to all EDs. However, two studies, one conducted in a Dutch academic ED and one in two Australian large referral hospital EDs, reported comparable percentages of URVs for illness-related and patient-related reasons [