JMIR Publications

ABSTRACT

Background:

Patient monitoring is indispensable in any operating room or intensive care unit to follow the patient’s current health state based on measured physiological parameters. Reducing workload helps to free cognitive resources and thus affects human performance, which ultimately improves the quality of care. Out of many methods to assess perceived workload, the NASA-Task Load indeX (NASA-TLX) provides the most widely accepted tool. However, only a few studies have investigated the validity of the NASA-TLX in the health care sector.

Objective:

This study aimed to validate the raw NASA-TLX in patient monitoring tasks by investigating its correspondence with expected lower and higher workload situations and its robustness against non-workload related covariates. Furthermore, we compared workload scores of conventional patient monitoring with the newly developed visualization technologies “Visual Patient” and “Visual Clot” to further understand the interaction of these technologies regarding perceived workload.

Methods:

In this meta-analysis, we evaluated raw NASA-TLX scores after performing patient monitoring tasks collected during four different investigator-initiated, computer-based, prospective, multicenter studies conducted in three hospitals with high standard of care in central Europe. In these already published studies, we simplified conventional patient monitoring by creating two new situation awareness-oriented information transfer technologies called Visual Patient and Visual Clot. As participants, we included resident and staff physicians, and nurse anesthetists with completed specialization qualification. We analyzed the raw NASA-TLX scores by fitting mixed linear regression models, and univariate models with different covariates.

Results:

We assessed a total of 1160 raw NASA-TLX questionnaires after performing specific patient monitoring tasks. Good test performance and higher self-rated diagnostic confidence correlated significantly with lower raw NASA-TLX scores and its sub scores (P<.0001 respectively). Staff physicians rated significantly lower workload scores than residents (P=.0012), whereas nurse anesthetists did not show any difference in the same comparison (P=.83). Standardized distraction resulted in higher rated total raw NASA-TLX scores (P<.001) and sub scores. There was no gender difference regarding perceived workload (P=.26). The new visualization technologies Visual Patient and Visual Clot resulted in significantly lower total raw NASA-TLX scores and all sub scores when compared to conventional monitoring (P<.0001 respectively).

Conclusions:

This study validates the raw NASA-TLX workload assessment tool for patient monitoring tasks. Assumed workload reducing factors such as good test performance, high confidence, job experience, higher hierarchical job positions and the new monitoring visualization technologies Visual Patient and Visual Clot all correlated with decreased perceived workload. The NASA-TLX was robust against non-workload associated factors such as gender. Further research should focus on its applicability in clinical routine.