Marga Hoogendoorn

14 quality registry. NICEwas founded in 1996 by a group of intensivists in the Netherlands for the purpose of benchmarking ICU data in order to monitor and improve quality of Dutch ICU care 48,49 . The minimal dataset of this registry contains among others demographic, physiological and diagnostic data, ICU, and hospital length of stay and mortality of all patients admitted to a Dutch ICU. Since 2016, all Dutch ICUs participate in the NICE registry. This year, 2021, we celebrate the 25 th anniversary of NICE. Besides participating with the minimal dataset, an ICU can choose to participate in other optional data modules. One of these optional modules is the capacity module, available since 2017, in which data about workload are processed. Since the start in 2017, eleven hospitals currently collect data for the capacity module and the number of participants is growing. The capacity module contains specific nursing information and was therefore developed in cooperation with the Dutch Society of ICU nurses, the V&VN-IC 50 . This dataset contains among others, NAS data. All separate interventions of the NAS, with the corresponding score, are collected and from these the total NAS score per patient is calculated. The capacity module also contains the number of ICU nurses per shift and per unit, classified as student or graduated ICU nurse. The NAS data are collected by ICU nurses at the end of each shift. The NICE registry provides both an online monitoring and analyses tool as well as annual benchmark reports with data of individual hospitals compared to the other participating hospitals. For this thesis, we used data from both the minimal dataset and the capacity module. 1 . 4 IMPACT OF COV I D Doing research on nursing workload in a period when the COVID-19 pandemic imposed a global burden on healthcare resources gave a unique opportunity to assess the effects of this problem on nursing workload. During this pandemic it became soon apparent that the COVID-19 patients had a huge impact on the ICU nursing workload. Also in the Netherlands the ICU nursing workload was considered high by ICU nurses as indicated in a survey among ICU nurses 51 . During this COVID-19 pandemic, the impact of a persistent high workload on the work satisfaction and mental health of ICU nurses became clear 52 . The experience of a new patient category with an unknown disease and the complexity of the nursing care in a setting with a high risk of infection caused overall a high nursing workload 53,54 . On top of the increase of nursing workload per patient, nurses were also confronted with an increase in the number of patients they had to take care for 55 .