A large body of evidence exists regarding associations between nurse staffing levels/nurse working environment, adverse patient outcomes (e.g., falls, hospital-acquired infections, pressure sores, mortality), and nurses’ wellbeing (e.g., risk of burnout) in general hospital wards (Cho et al., 2015, Lake et al., 2020, McHugh et al., 2021, Needleman et al., 2020). Although less often researched, similar observations have been made in the setting of intensive care units (ICUs) (Bruyneel et al., 2021b, Kester et al., 2021, Margadant et al., 2020, Rae et al., 2021). Unfinished care is an umbrella term encompassing several concepts (e.g., care left undone, missed care), that describe the situation in which nurses are forced to delay or omit necessary nursing care (Jones et al., 2015). Several scales exist to assess unfinished care and include several categories such as clinical care, communication with patients and families, and documenting nursing care. There have been indications from studies conducted in general hospital wards that unfinished nursing care plays a role in the associations between in-patient outcomes and nurse wellbeing (Ball et al., 2018, Bhatraju et al., 2020, Cho et al., 2020, Griffiths et al., 2018b).

It has been previously reported that unfinished nursing care occurred only infrequently in hospital wards during the COVID-19 pandemic (Labrague et al., 2022, Vogelsang et al., 2021). In contrast, a study of ICUs in Sweden reported an increase in unfinished nursing care in basic ICU care (Falk et al., 2022). Also, studies have reported an increased workload associated with the care of patients with COVID-19 in ICUs (Bruyneel et al., 2021a, Hoogendoorn et al., 2021). Therefore, it is of interest to assess the rates of unfinished nursing care in ICUs during the pandemic.

Several factors have been found to be associated with unfinished nursing care, including the work environment, staffing levels, and resource adequacy (Silva et al., 2020, Simonetti et al., 2022). Associations between a better working environment, adequate staffing levels for nurses, and lower levels of unfinished nursing care have already been demonstrated in ICUs (Chiappinotto et al., 2022, Duffy et al., 2018, Liu et al., 2016, Vincelette et al., 2022). Some studies have indicated a mediating role for unfinished nursing care in the relationship between nurse working environment (including nurse staffing levels) and adverse patient outcomes in the context of general hospital wards (Ball et al., 2018, Bruyneel et al., 2015). However, despite this evidence of the importance of unfinished nursing care and the analysis of risk factors, the underlying mechanisms are less well studied in the ICU setting.

Given the association between unfinished nursing care and adverse patient outcomes, nurses’ perceptions of the quality and safety of care are also relevant outcomes to study. Research has shown that these outcomes and nurses' general opinion of their work are connected (Bai et al., 2015). A study in the ICU showed that the perception of quality of care was associated with the work environment and, more specifically, with perceived staff adequacy and patient care (Stalpers et al., 2017). Furthermore, given the psycho-emotional impact of unfinished nursing care on nurses, the risk of burnout is also an important outcome to focus on (Piotrowska et al., 2022, Uchmanowicz et al., 2021).

This study focused on the prevalence of unfinished nursing care in the ICU given the potential high impact of COVID-19 on factors related to unfinished nursing care. A second objective of the study was to examine whether unfinished nursing care has a mediating role in the associations between nurse working environment, nurse-perceived quality of care, and risk of burnout among nurses. It was assumed that when problems in the work environment (with staffing and resource adequacy, in particular) occur, nurses are forced to leave necessary care undone, which jeopardizes both the quality of patient care and the wellbeing of nurses.