lyall d., hawley c. & scott k. (2004) Journal of Advanced Nursing 46(4), 390–394 Nurses’ Observation Scale for Inpatient Evaluation: reliability update The Nurses’ Observation Scale for Inpatient Evaluation is a 30-item scale designed in 1965 for behavioural and observational rating of psychiatric inpatients. This paper reports a re-evaluation of the Nurses’ Observation Scale for Inpatient Evaluation carried out to confirm that it remains reliable in a modern United Kingdom (UK) setting. The scale is a joint-rated one and we tested the degree of agreement between two individual raters and not, as in previous studies, between two pairs of raters. A total of 100 patients were each rated by two nurses, and a least-squares simple regression model was used to describe the average level of agreement between the pairs of ratings. The correlation in total scale scores was 0·76 ( F = 136, P < 0·0001). The correlations for Negative and Positive Factors were 0·68 ( P < 0·001) and 0·75 ( P < 0·001), respectively. This study has shown that the Nurses’ Observation Scale for Inpatient Evaluation retains satisfactory inter-rater reliability with current clinical populations, and we suggest that it remains a useful tool for everyday clinical practice and a basis for meaningful communication between staff about patient status. [ABSTRACT FROM AUTHOR]