Marga Hoogendoorn

131 Our research showed that the Nursing Activities Score (NAS) performed best for measuring nursing workload and quantification of nursing staff. Earlier validation with time measurements showed that NAS was able to explain 81% of the nursing activities 2 . The interrater reliability of the NAS however showed variable results (Kappa 0.02 – 0.69) with low results for the categories with an estimation of the amount of time spent by the nurse in this activity (e.g. present at bedside and observation for two hours or more) 3,4 . An evaluation of the face validity and content validity also showed that the estimation of time could lead to either an overestimation or underestimation of the needed nursing time 5 . In our study with time and motion techniques we found an overestimation of the workload as measured with NAS. A possible explanation could be the differences in validation techniques. Where the NAS was originally developed with the work-sampling approach obtained by multi moment recordings, we used a time-and-motion technique in our study 2 . Due to those findings, it is important to focus on further validation and if needed recalibration of the NAS, because of the increasing use of nursing workload systems in the substantiation of nursing staff requirements 1 . Our research also showed that it is important to focus not only on the objective nursing workload as measured with those tools but also take the perceived workload into consideration. However, although a first analysis of the crude association between the NAS and the NASA-TLX showed a significant association, the association did not remain significant after adjustment for confounders. Clearly, this aspect of workload needs further investigation. Nevertheless, it appears that the severity of patient illness and the graduation level of the nurse are significant associated with the perceived workload. Planning nursing staff should therefore be based on the Nursing Activities Score, the patient illness and graduation level of the nurse. Another important perspective we added in our research is the satisfaction of the nurses with their workload. Both in the literature and in nursing practice the terms ‘high workload’ or ‘low workload’ are used. But until now we could not find any description on how these qualifications translate into the satisfaction of the nurses with their work done. With our research we connected the measured objective and perceived workload with the satisfaction of nurses with their workload. Furthermore, from this point of view it is important to focus on an optimum NAS per nurse. The NAS is originally developed and validated with the suggestion that the effort of one nurse corresponds with 100 NAS points 2 . This was however never validated as an optimumNAS per nurse. Different studies from all over the world showed that the mean NAS per nurse per shift can differ from 44.5 in Spain up to 101.8 in Norway 6-9 . Our study showed that nurses are most satisfied about the workload when the NAS is around 80 NAS points per nurse. Satisfaction of the nurse is however only a parameter from the nurses’ point of view. Earlier research