Marga Hoogendoorn

73 I NTRODUCT I ON High levels of workload with a low number of patients per nurse are common in the Intensive Care Unit , due to a high complexity and intensity of patient care. The high workload in combination with a shortage of highly educated Intensive Care nurses increases the risk of burn-out in Intensive Care nurses 1 . The number of patients per nurses, defined as the Nurse : Patient ratio has proven to be associated with quality of care and the outcome of critically ill patients 2,3 . A low Nurse : Patient-ratio is related to an increase in both patient morbidity and mortality 4,5 . However, recent research showed that workload per nurse, and not the number of patients per nurse, was associated with in-hospital mortality 6 . Therefore, it is more important to focus on the workload per nurse than the number of patients per nurse. Several systems have been developed to measure nursing workload in Intensive Care Units 7 . One of the most accepted and widely used systems is the Nursing Activities Score (appendix 2). The Nursing Activities Score was developed in 2003 as an instrument to categorize the nursing activities in patient care in Intensive Care and the average time consumption of those activities 8 . It has been used in different countries all over the world as a tool for planning nursing capacity in daily practice 9 . Because of the use of a fixed number of points representing the needed time per activity, we use the term ‘objective workload’ for the workload measured by Nursing Activities Score. Although Nursing Activities Score objectively measures the nursing time needed to take care for each Intensive Care patient, e.g. one hour bedside care, it does not take the emotional or perceived workload into account. This is, however, an important factor of the nursing workload 10 . One hour bedside care for a dying young patient with a sepsis and hemodynamic instability due to multi-organ failure will weigh more in terms of perceived workload for a nurse than one hour bedside care for a patient after planned cardiac surgery with hemodynamic instability. The impact of taking care for these complex patients can also be different depending on the expertise of a nurse. Research has shown that a perceived high workload is associated with nurse burnout and job (dis)satisfaction 11,12 . Therefore, in capacity planning it seems to be important to use the objective workload, but also the workload as perceived by the nurse. The NASA-Task Load Index is a validated questionnaire originally developed to measure the perceived workload in the National Aeronautics and Space Administration (NASA) 13 (appendix 4). This six-item scale represents six aspects of workload: mental, physical, and temporal demand, effort, performance and frustration. The NASA Task Load Index has been shown to be reliable and is also the most commonly used system for the measurement of the