Marga Hoogendoorn

94 opportunity to comment on the workload or the questionnaire in a free text field. During and after the shift the researcher was available for questions about the Nursing Activities Score and the questionnaires. STAT I ST I CAL ANALYSES We used univariate logistic regression analysis with nursing workload satisfaction divided into two categories: not satisfied (0 – 5) and satisfied (6 – 10) as the outcome variable. The independent variables, the Nursing Activities Score and the overall workload NASA- TLX score, were divided into quintiles, using the first quintile as the reference value. For our secondary analyses we used as independent variables each of the six subscales of the NASA-TLX divided into four categories: very low (<40), low (40 – 50), high (60 - 70) and very high ( ≥ 70) with very low as the reference value. We used the Odds Ratio (OR) and the 95%-Confidence Interval (CI) to determine if the association between workload satisfaction and objective or perceived workload is statistically significant (confidence interval does not include 1) or not significant (confidence interval does include 1). All analyses were performed using the R statistical environment (version 3.6.1) (R Foundation for Statistical Computing, Vienna, Austria). RESULTS During the study period we collected NASA-TLX data from 229 nurses in 226 different shifts of 8 different hospitals. During these shifts, the ICU nurses were taking car for 389 different patients. Eight patients missed NAS-data and were excluded. The data of two nurses were excluded because of a missing satisfaction rate. Therefore, finally we included 381 patients, 227 nurses and 226 shifts. Table 1 shows the baseline characteristics of the included patients, nurses, type of hospitals and type of shifts. The median Nursing Activities Score per nurse, the objective nursing workload, was 69.6 (IQR 49.3 – 80.5) with a minimum of 20.6 points per nurse and a maximum of 134 points per nurse. The overall perceived workload based on NASA-TLX per nurse was 43.3 (IQR 30-50) with a minimum sum-score of 33 and a maximum score of 75. Overall, the nurses were satisfied with the workload with a median satisfaction rate of 8 on a scale of 0 till 10 (IQR 6 – 8) (see Table 2). Thirteen nurses took the opportunity to leave free text in the questionnaire. Those comments can be found in the last row in table 2.