Abstract
This paper reports the results of a project aimed at decreasing the use of, and costs associated with, the practice of using care assistants to provide one-toone observation or ‘specialling' in five acute adult medical and surgical wards at a North Island hospital. Education sessions were provided to staff to prompt better management of patients receiving this level of observation. Using a timeseries design, a retrospective study was completed for the six months pre- and six months post-intervention (staff education). Data were collected and analysed on all patients in the five acute wards who had required ‘specialling' during the specified twelve-month period. Results showed that following the intervention there had been a reduction in the incidence and duration of ‘specialling,' and a halving of costs associated with this practice. The findings have implications for patient management and cost effectiveness. Incident statistics were not retrospectively reviewed in this study.

Keywords
Specialling, care assistants, cost, education

Introduction
In the health sector, evaluation of interventions is necessary for a range of reasons, including to decide resource allocation and to improve professionals' knowledge and decisions (Ovretveit, 1998; Owen, 1999). In many instances changes in practice are initiated without evaluation of the effectiveness of the intervention in relation to the purpose of the intervention. This article reports on the retrospective evaluation of an education intervention that was undertaken in a North Island hospital, the purpose of which was to reduce costs and to improve assessment of patient needs. The retrospective evaluation was undertaken to answer questions ...cont.