background Measuring instruments are mostly of western origin. The question is whether such instruments are just as suitable for use with patients from non-western countries as they are for those from western countries.
aim To obtain insight into the conditions which measuring instruments should in theory satisfy if they are to be used transculturally and to assess the usefulness of western instruments when applied by Dutch psychiatrists to immigrants to the Netherlands.
method The equivalence concept - in other words the degree of correspondence between conceptual meanings and methods of applying instruments in different cultures - is analysed with the help of the literature and other (informal) sources of information.
results Five aspects of equivalence are described and discussed: (1) semantic-; (2) content-; (3) construct- and conceptual-; (4) criterion-; and (5) technical-equivalence.
conclusion Equivalence between measuring instruments is a complicated matter. Very little work has been done in this field in the Netherlands. Guidance is given on steps that can be taken to bring about equivalence.