Instruments to measure complexity of care based on nursing workload in intensive care units: A systematic review

To establish an evidence-based recommendation on the use of validated scoring systems that measure nursing workload in relation to the complexity of care in adult Intensive Care Units. A systematic review based on the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) was conducted (PROSPERO registration: CRD42021251272). We searched for validation studies until July 2023 using the bibliographic databases CINAHL, Scopus, Pubmed, WOS, Cochrane Database, SCIELO, Cuiden and Cuidatge. Reference selection and data extraction was performed by two independent reviewers. The assessment of risk of bias was performed using QUADAS-2 and the overall quality according to COSMIN and GRADE approach. We included 22 articles identifying 10 different scoring systems. Reliability, criterion validity and hypothesis testing were the most frequently measurement properties reported. The NAS was the only tool to demonstrate a Class A recommendation (the best performing instrument). NAS is the best currently available scoring system to assess complexity of care from nursing workload in ICU. However, it barely met the criteria for a class A recommendation. Future efforts should be made to develop, evaluate, and implement new systems based on innovative approaches such as intensity or complexity of care. The results facilitate decision making as it establishes a ranking of which instruments are recommended, promising or not recommended to measure the nursing workload in the intensive care units.