Marga Hoogendoorn

130 increase of the perceived nursing workload. In chapter 5 it became clear that both the objective and perceived nursing workload are associated with the satisfaction of nurses regarding their workload. This study showed that ICU nurses are most satisfied with their workload when the NAS is around 80 points in total per nurse per shift. Furthermore, a high perceived nursing workload (especially the mental and physical part) as measured with the NASA-TLX, was significant associated with how satisfied ICU nurses were with the nursing workload. This study also showed that nurses are not satisfied with both a very high objective or perceived nursing workload or a low objective or perceived nursing workload. Thus, this study showed us that there is an optimum point in nursing workload regarding the satisfaction of ICU nurses with their workload. 3. What is the impact of COVID-19 on the ICU nursing workload? While most of the data used for this thesis were collected before March 2020, we were also able to perform one study on data of six hospitals during the COVID-19 pandemic. The analyses described in chapter 6 have learned us that the COVID-19 pandemic had a significant impact on the ICU nursing workload. Firstly, this was caused by a significant higher NAS of the COVID-19 patients compared to the other ICU patients. Secondly, during the COVID-19 period the number of patients per nurse was higher compared to the same period in 2019 without COVID-19. This was caused by a high number of admissions of COVID-19 patients in combination with a long length of stay on the ICU. The combination of a higher NAS per patient and an increase of the number of patients per nurse led to a significant higher NAS per nurse during the COVID-19 period. 7. 2 D I SCUSS I ON OF MA I N F I ND I NGS Our research showed that nursing workload and the substantiation of nursing staff requirements on the ICU has a long history of interest. Although the evidence for the substantiation of nursing staff requirements with workload scoring systems is limited, new workload systems have been developed over the years. Those findings are confirmed in a recent review of literature related to nurse staffing methods and tools 1 . This research also concluded that it is important to focus on learning more about the use of existing tools rather than developing new tools. Because of the rapid developments in critical care, it may be necessary to incorporate new treatment modalities and new ways of nursing care. It is therefore important to focus on further validation or calibration of existing systems.