Marga Hoogendoorn

76 Nursing Activities Score with a data definition according the updated guidelines 25 , and the sum-score of the Nursing Activities Score per patient as collected by the Intensive Care nurse at the end of the shift. From the eight hospitals participating in our study, five hospitals participated in the optional nursing capacity-module of the National Intensive Care Evaluation. For the three hospitals not participating in the nursing capacity-module, the nurses were trained in the Nursing Activities Score and collected Nursing Activities Score data at the end of the shift on a paper form. Data about type of shift, number of nurses per patient, education level, and years of experience of the nurse were collected on the same digital form as the NASA-Task Load Index. Data preparation For the analysis of the Nursing Activities Score we included the total score per nurse per shift. We used the cumulative Nursing Activities Score in case of more than one patient per nurse. For the analysis of t patient factors, we included the APACHE-IV Acute Physiology Score, in case of more than one patient per nurse we used a cumulative APACHE-IV Acute Physiology Score of all the patients the nurse took care for during that shift. We believe that a younger age can affect the perceived nursing workload as treating young severely ill people might be emotionally stressful, therefore we indicated whether the treated patient was younger than 45 years. We also indicated whether the treated patient was 80 years or older. In case of more than one patient per nurse we used the cumulative number of patients younger than 45 years and the cumulative number of patients of 80 years or older. The number of comorbidities per patient was evaluated in the analysis. In case of more than one patient per nurse we used the cumulative score of the comorbidities of all the patients the nurse had to take care for during that shift. For the analysis of the body mass index as a patient factor we categorized the results in an index of < 30 (not obese) or ³ 30 (obese) according to the categorization of the World Health Organization 22 . In case of more than one patient per nurse we used the cumulative number of patients with a body mass index of 30 or higher. For the analysis of type of admission as a patient factor we categorized type of admission in two categories: planned or unplanned admission. We added a category ‘both planned and unplanned admissions’ for nurses with more than one patient covering both types of admissions. We also adjusted our model for day of admission or discharge versus days in between.