The use of single-case experimental designs to evaluate nursing interventions for individual clients.

Nurses are increasingly called upon to devise interventions for individual clients. These interventions must be effective for the purpose for which they are designed if they are to be considered appropriate for the client for whom they were devised. Single-case research methodology offers the practising nurse an easy to use strategy for assessing the efficacy of individualised interventions, with the controls of an experimental design and the flexibility required for use in applied settings. This paper describes the basic principles underlying the use of these designs and illustrates their application in assessing the efficacy of interventions with individual clients.