Marga Hoogendoorn

13 explained with the NAS, whereas the TISS was only representing 43% of the total nursing time 35 . The NAS was originally developed to measure the nursing workload per day but it has also been validated for the use per shift 36 . More than 15 years after development, the NAS is used all over the world for measuring nursing workload 37 . However, some studies showed that scoring NAS is subject to differences in interpretation of the scoring rules which can ultimately lead to differences in the NAS-score and subsequently lead to differences in the calculated need for nursing staff 38-40 . Given these considerations, the increasing use of the NAS and the importance of the results for ICU management it is relevant to re-evaluate the validity of this instrument in the current ICU practice in the Dutch ICU setting. 1.2.2 Quantif ication of the perceived nursing workload Beside the time needed for the interventions, it is also important to quantify the perceived impact of this time on the nurse. Thirty minutes support and care for the patient and his or her family can weight more in terms of perceived workload than thirty minutes of administrative tasks surrounding discharge of a patient to the ward. The NASA-Task Load Index (TLX) is a questionnaire originally developed to measure the perceived workload in the National Aeronautics and Space Administration (NASA) but also validated in other settings, including health care systems 41,42 . It is commonly used to measure the perceived workload in health care 23,43,44 . Earlier research has shown that a perceived high workload is associated with job (dis)satisfaction and nurse burnout 27,45 . It is therefore important to focus on this aspect of the nursing workload. This final impact of nursing workload on a nurse is determined by both the objective and the perceived workload. The relation between objective and perceived workload is unclear, as is also the perception of this workload for the nurse. When is a nurse satisfied with his or her workload? When is it high? Or low? To our knowledge, it is unknown what nurses themselves consider a high or low workload, how this is related to nurses’ satisfaction and which factors influence satisfaction. To keep the nurse motivated and satisfied and prevent nurses from developing a burnout, we feel that we also have to take their perception on an optimal workload into account 46,47 . 1 . 3 NAT I ONAL I NTENS I VE CARE EVALUAT I ON Managers should be able to benchmark the workload of their ICU with other ICUs, to support the process of decision making on capacity planning. For this thesis, we used data on workload gathered and processed by the National Intensive Care Evaluation (NICE)