Marga Hoogendoorn

74 perceived workload in different settings, including health care 10,14-16 . Because of the use of a scale representing the experienced impact of work on the nurses, we use from now on the term ‘perceived workload’ for the workload as measured with NASA-Task Load Index. Although it is increasingly common to use the Nursing Activities Score in Intensive Cares for measuring nursing workload and planning nursing resources, less is known about to what extent this objective workload is related to perceived workload, and which other factors are potentially of influence on the perceived workload. We found one study from Hoonakker et al. (2015) 10 that analyzed the association between NASA-Task Load Index and factors such as kind of shift and Nurse to Patient ratio but not for patient factors. The aim of our study is to assess the association between the objective nursing workload measured by Nursing Activities Score and the perceived nursing workload measured with NASA-Task Load Index, and identify patient, nurse, and contextual factors (e.g. kind of shift) associated with the perceived nursing workload. METHODS Study design We measured the objective nursing workload and the perceived workload in a prospective cohort study between October 1 st 2016 and November 30 th 2017. Dutch Intensive Cares with an existing workload registry or an intention to participate in a workload registry were approached to participate in this study on a voluntary basis. Objective nursing workload The Nursing Activities Score, used for the objective nursing workload, represents a total of 23 nursing activities in direct and indirect patient care (e.g. hygiene procedures, mobilization and positioning, care of artificial airways, administration tasks) (appendix 2). Each activity is translated into a score, between 1.2 and 32.0 points, representing the time needed to fulfill this activity. A total score of 100 Nursing Activities Score -points has been defined equally to the time spend by 1 Fulltime-equivalent nurse per shift 8 . Research has shown that the Nursing Activities Score explains 59 - 81% of the actual nursing time 8,17 . The interrater reliability of the Nursing Activities Score showed variable results (Kappa 0.02 – 0.69), with low results for the items with an estimated time by nurses (i.e. two hours for administration), to substantial results for the other items 24 . The Nursing Activities Score is collected by nurses at the end of the shift. For this study we used the total sum