Marga Hoogendoorn

82 The beta coefficient represents the increase of NASA-Task Load Index when the factor increases with 1 point, thus a beta of 0.07 in the association between Nursing Activities Score and NASA-Task Load Index means that with every increase of 1 Nursing Activities Score point the NASA-Task Load Index increases with 0.07 points. The negative beta of -2.00 in the association between planned admission and NASA-Task Load Index means that in case of a planned admission the NASA-Task Load Index decreases with 2.0 points. We found a significant crude association between the objective workload with the Nursing Activities Score and perceived nursing workload with the NASA-Task Load Index (beta=0.07, p=0.01). However, after adjustment for confounders this association did not remain significant (beta=0.07, p=0.06). In our next models we analyzed the association between the different patient-, nurse-, and contextual factors and the NASA-Task Load Index. In the analysis of the association between the patient factors and the NASA-Task Load Index we found that the APACHE- IV Acute Physiology Score was significantly associated with the perceived workload, also after adjustment for confounders (beta= 0.03, p=0.02). Among the contextual factors, only the number of patients per nurse was associated with the perceived nursing workload (p<0.001), but after adjustment for confounders this association did not remain significant. Among the nursing factors, the type of nurse (certified or student nurse) was significantly associated with the perceived nursing workload, also after adjustment of confounders (beta= 4.56, p=0.03). Being a student nurse gives an increase of the NASA- Task Load Index with 4.56 points. This remained significant, even after adjustment for the fact that in practice student nurses were assigned to less complex patients than certified Intensive Care nurses. We found that student nurses have a lower mean Nursing Activities Score per nurse compared to certified Intensive Care nurses (66.2 versus 68.0). Also the maximum of Nursing Activities Score points per nurse was lower; 102 points for student nurses versus 158 points for certified Intensive Care nurses. D I SCUSS I ON This study showed that the objective nursing workloadmeasured by the Nursing Activities Score is not significantly associated with the perceived nursing workload of nurses. This result confirms the expectation that the time that is needed for patient care does not significantly influence the perceived nursing workload. Also the association between the number of patients per nurse and the perceived nursing workload remained not significant after analysis for confounding factors, i.e. the Nursing Activities Score. The results showed a lower mean Nursing Activities Score per patient in case of more than one patient per nurse compared to the mean score per patient in case of one patient per