Table 1

 Published definitions of frequent users of EDs

*Minimum attendances per year unless otherwise stated.
Lucas and Sanford4USA2 in the previous month or 4 in the previous year
Zuckerman and Shen13USA3
Genell Andren and Rosenqvist2Sweden4
Hansagi et al7Sweden4
Olsson and Hansagi8Sweden4
Byrne et al11Ireland4
Sun et al12USA4
Mandelberg et al1USA5
Williams et al9UK7
Kne et al3USA11
Chan and Ovens10Canada12
Lynch and Greave5UK6 in 6 months
Pope et al6CanadaSeveral attendances and potential for heavy future use