Skill mix and the effectiveness of nursing care.

Abstract

The objective of the study was to examine the links between inputs into the process of nursing, in particular, the skill mix of nursing staff and the outputs of nursing in terms of the quality and outcome of care. The review of literature revealed several ambiguities and conceptual problems at the measurement level which needed to be clarified prior to data collection itself. The overall objectives of the project were: - To develop and field test measures for monitoring the quality and outcome of nursing care. - To identify the major input and process variables which need to be taken into account in monitoring the impact of nursing skill mix. - To investigate the links between skill mixes and the quality and outcome of the care provided. - To relate the full costs of different skill mixes to both the quality of care and to the outcomes for patients of that care. The research design was discussed extensively with senior nurse managers and research nurses. It was decided to focus extensively on a professional assessment of the delivery of nursing care: the patients’ perceptions, although acknowledged to be very important, were therefore excluded. The design focused on those aspects of care which were almost totally within the control of nurses. A case study approach was adopted, data being collected in 15 acute medical or surgical wards at seven hospital sites by qualified nurses trained as observers by the research teams. The sample of hospitals and wards was chosen within the constraints of gaining permitted access but, while not being statistically representative of all hospital wards in England and Wales, ensured that a wide variation in contrasting styles of ward structures and nursing organisation was covered. Thus both Nightingale and nuclear wards were selected, some with primary nursing, some with patient allocation and some with team nursing; the choice of hospitals included both district general and teaching hospitals in both rural and urban areas throughout the country. Instruments were devised and field tested by the research team before the main study. In particular, a set of event-based outcome measures were devised to complement the measure of process quality. The data were analysed at three levels. Firstly, at the level of patient/nurse interaction; secondly, at the level of the observation session (the two-hour observation of interactions between nurses and patients) and thirdly, at the ward level. The measurement of skill mix followed two main approaches. One was by grade predominance – where the ratings recorded at the interaction level referred to one grade (the predominant grade) more than any other grade. Secondly, a grade mix index was developed by allocating scores of 1-6 to each grade (Learner = 1, F/G Grade = 6) involved in an interaction and weighting the score by the number of grades involved. In general, the main results of several analyses can be summarised by saying that grade mix had an effect on the quality of care in so far as the quality of care was better the higher the grade (and skill) of the nurses who provided it, but that the variation in the quality of care between different grades of staff was reduced when higher graded staff worked in combination with lower graded staff. These results were robust as far as this study was concerned, they occurred in different approaches to measuring skill mix and from analysing the data at different levels of aggregation. At the ward level better outcomes were also associated with greater proportions of staff in Grade D and above independently of the effect of quality. Several methodological improvements are suggested as a result of the study both in terms of the criteria for choosing and designing instruments and in terms of augmenting the usefulness of both the Qualpacs instrument and the event-based outcome measures. Finally, the results have been related to current debates about staff and skill substitution and the use of support staff. The variations in both quality and outcome with higher grade staff suggest that investment in employing qualified staff, providing post-qualification training and developing effective methods of organising nursing appeared to pay dividends in the delivery of good quality patient care.