The impact of the nursing workforce on patient outcomes in intensive care

Introduction: Evidence from studies conducted mainly in the US and mainland Europe suggests that characteristics of the workforce, such as nurse patient ratios and workload (measured in a number of different ways) may be linked to variations in patient outcomes across health care settings (Carmel and Rowan 2001). Few studies have tested this relationship in the UK thus questions remain about whether we are justified in extrapolating evidence from studies conducted in very different health care systems. Objectives: To investigate whether characteristics of the nursing workforce affect patient mortality UK Intensive Care Units. Data: Patient data came from the case mix programme, Intensive Care National Audit and Research Centre (ICNARC), while information about the units came from a survey of all ICUs in England (Audit Comission 1998). The merged data set contained information on 43,859 patients in 69 units across England. ICNARC also supplied a risk adjustment variable to control for patient characteristics that are often the most important determinants of survival. Methods: Multivariate multilevel logistic regression. Findings: Higher numbers of direct care nurses and lower scores on measures of workload(proportion of occupied beds at the time the patient was admitted and mean daily transfers into the unit) were associated with lower mortality rates. Furthermore, the effect of the number of direct care nurses was greatest on the life chances of the patients who were most at risk of dying. Implications: This study has wide implications for workforce policy and planning because it shows that the size of the nursing workforce is associated with mortality (West et al 2006). Few studies have demonstrated this relationship in the UK. This study has a number of strengths and weaknesses and further research is required to determine whether this relationship between the nursing workforce and patient outcomes is causal.

Caking strength of granulated clay under frozen conditions

Transport of particulate clay occurs during some extremely cold weather conditions typically in the winter in the far North area. During the transport and temporary storage time, the clay may cake inside a rail or road wagon or in a silo, and consequently be difficult to be discharged from the containers. This paper studied caking strength of a granulated clay powder with a certain water moisture content of 18% for influences of temperature, packing stress and freezing time. The temperature tested was -5 oC, -10 oC and -20 oC. Because the clay powder may be packed at different bed depth, the study was undertaken across the packing stress range at 8.3 kPa (1 m bed depth), 25.0 kPa (3 m) and 75.0 kPa (9 m). Freezing time varied between 4 hours (transport) and 18 hours (overnight). During the tests, failure of caked materials was measured using a QTS texture analyzer and the caking strength of frozen samples was calculated. Influences on freeze caking of granular clay in storage or transport are discussed briefly. Some conclusions are made at the end of the paper,including recommendations for practical methods for mitigating these problems.