Marga Hoogendoorn

11 1 . 1 I NTRODUCT I ON The Intensive Care Unit (ICU) in a hospital delivers labor-intensive services to critically ill patients requiring a high amount of care. Due to their critical illness, the ICU patient is in need for monitoring and use of modalities for organ support, and therefore specialized nursing care 1,2 . The Dutch Quality Standard Organization of Intensive Care defines an ICU patient as “a patient with one or more critically endangered or impaired vital signs, where continuous monitoring is necessary, and treatment of a potentially reversible condition can lead to recovery of vital signs’ 3 . This complex ICU patient requires special nursing care. Due to the complex care the ICU nurses provide they can take care for only a limited number of patients. The number of patients per nurse on an ICU does generally not exceed the number of three, or as usually stated the patients per nurse ratio is not exceeding 3 : 1 2- 4 . On top of that, the ICU nurse has a higher autonomy in decision making and action, compared to the general ward nurse 5-8 . Due to the complex and specific care the nursing staff consists mainly of certified ICU nurses. The resulting high need for specialized nursing capacity is also the main reason why ICU care is expensive 9 . The costs for nursing staff comprise about 40% of the total ICU costs 10,11 . In most West European countries, there exist currently a shortage of specialized ICU nurses 12,13 . Given the shortage of ICU nurses it is important to keep nurses motivated and satisfied with their job. Both understaffing and overstaffing is an undesirable situation which can lead to job dissatisfaction. Understaffing increases the risk for burn-out and overstaffing the risk for bore-out 14,15 . Therefore, nursing resources should be deployed as efficiently as possible. From a managerial as well as financial point of view, it is important to have access to valid and reliable instruments to quantify the need for nursing staff to avoid understaffing as well as overstaffing. 1 . 2 NURS I NG WORKLOAD A common way to quantify the need for nursing staff is by quantifying the amount of work that is to be done by the nurses. The most used method to quantify the amount of work is to determine the number of patients a nurse has to take care of 16 . However, this is a crude measure and more important than the number of patients per nurse is the amount of work those patients actually require. The amount of time needed to perform those patient care activities is dependent on several factors, e.g. the degree of patient dependency, the complexity of the illness of the patient or the skills of the ICU nurse 17-19 . The sum of all