Marga Hoogendoorn

134 7. 4 STRENGTH AND WEAKNESSES A strength of our work is that we performed a thorough evaluation of the available nursing workload systems. Based on the results of this evaluation we concluded that the NAS is a well performing and the most used system. Therefore, we used the NAS in our consecutive studies. A clear advantage of the use of NAS for our research was that NAS has been used in many international and multicenter studies. This enabled comparing the findings of our research with findings in other studies. Another strength is the use of a time-and-motion technique for the validation study. The time-and-motion technique is considered as the best measure for time measurements 12 . The NAS is originally developed with the work-sampling approach obtained by multi moment recordings, whereas we used in our study the time-and-motion technique for validation 2 . The time-and-motion technique provides a more accurate estimate which makes the validation reliable. A strength is also the use of different perspectives on nursing workload: the objective workload as measured by a validated tool like NAS, the perceived nursing workload as measured by a validated tool such as the NASA-TLX, and finally the association of both perspectives with the satisfaction of nurses with this workload. We realize that conducting a study on nursing workload in which we ask the ICU nurse to complete additional questionnaires is precarious from a workload perspective. However, with the use of the existing data registry with data on workload and patient factors we were able to reduce the extra work to only the NASA-TLX questionnaire and the satisfaction rate. The use of this existing registry also made it possible to conduct research on workload during the COVID-pandemic on a relatively short notice. The results of our study on nursing workload during the COVID-pandemic places this thesis about workload in the current timeline. It also shows that with an existing nursing workload registry it is possible to respond quickly in current or future dynamics affecting nursing workload. Nevertheless, like every research there are also some weaknesses to take into consideration. Comparing the number of ICUs included in our study with other studies using data from the NICE registry the number of ICUs is relatively low. Although the eight included ICUs were diverse in size and representative to Dutch ICUs regarding hospital type and geographical location, the number of included ICUs is still low. In addition, in the COVID study data of six ICUs were included. The other ICUs were not able to collect