This paper describes the development and testing of a European version of t
he Appropriateness Evaulation Protocol (AEP). It stemmed from the original
U.S. version and the multiple adaptations and modifications made previously
and separately by researchers in European countries. The group was particu
larly concerned with developing a common list of reasons for inappropriate
admissions and days of stay, since the principal goal was to enable an unde
rstanding of inappropriate hospital use and potential solutions within loca
l health and social care systems. Developing a common EU-AEP included sever
al steps. First, each national instrument was translated from the national
language to English. These back translations were compared with each other
and with the US-AEP. A working group analyzed the content of the lists of r
easons published in the literature and proposed a novel conceptual approach
. On the basis of workshop discussions, a draft of a common European versio
n was circulated to each participant for agreement. In the EU-AEP, the clin
ical criteria for the appropriateness of admission include 10 related to pa
tient condition and five to clinical services. The criteria for the appropr
iateness of days of care include 10 covering medical services, six for life
support/nursing services, and eight related to patient condition. The prop
osed core list of reasons of inappropriateness distinguish clearly between
two concepts: a) the level of care required by the patient; and b) the reas
on why this level of care was not used. The first list would thus refer to
the nature of resources and facilities required, while the second would foc
us more on the efficient organization of those resources. A validated Europ
ean tool to assess inappropriate hospital admissions and hospital days of s
tay and their causes might be used to assess the need for resources for inp
atient care as well as for outpatient care. Assessing the reasons for inade
quacies might lead also to the examination of organizational questions. Fin
ally, a common tool allows comparisons between countries concerning the fre
quency of inappropriate admissions and days of stay and their reasons in re
lation to the different organizations of health care across Europe.