Critically ill adults admitted to the intensive care units (ICUs) often have difficulty self-reporting pain due to intubation and undergoing sedation (Gélinas, 2016; Herr et al., 2019). Pain may be unrecognized or undertreated, especially among those unable to self-report (Herr et al., 2019; Randen et al., 2013). Unrelieved pain could lead to poor recovery, prolonged ICU stay, and increased mortality (Georgiou et al., 2015; Herr et al., 2019).

Research on pain assessment practices for critically ill adults unable to self-report requires further investigation (Kerbage et al., 2021). Optimal pain control and clinical healthcare outcomes rely heavily on critical care nurses' pain assessment and management practices (Damico et al., 2018; Herr et al., 2019; Olsen et al., 2016). Studies of critical care nurses' pain healthcare practices conducted outside of Asia indicate that nurses are less likely to use pain assessment tools for patients unable to self-report than for those who can (Rose et al., 2011, Rose et al., 2012; Younis, 2021).

Barriers to effective pain practices include the inability to self-report and medical instability (Hamdan et al., 2022; Rababa et al., 2021; Rose et al., 2011; van der Woude et al., 2016). Facilitators of effective pain practices include management of pain as an institutional priority, availability of pain assessment tools and management guidelines, communication about pain among healthcare providers during handovers, and appropriate pain prescriptions (Deldar et al., 2018; Hamdan et al., 2022; Kizza & Muliira, 2015; Rababa et al., 2021; Rose et al., 2011, Rose et al., 2012; Subramanian et al., 2012; van der Woude et al., 2016). Other factors associated with critical care nurses' pain assessment practices include characteristics of the ICU (e.g. lack of surgical patients, heavy workload); nurses' years of clinical experience or professional clinical competency level, education or training received (Damico et al., 2020; Deldar et al., 2018; Hamdan, 2019; Hamdan et al., 2022; Kizza & Muliira, 2015; Rababa et al., 2021; Rose et al., 2011; van der Woude et al., 2016; Wang & Tsai, 2010); attitude toward pain; attitude toward or control over administration of pain relief medication; and familiarity with pain assessment tools and management guidelines (Deldar et al., 2018; Hamdan, 2019; Kizza & Muliira, 2015; Rababa et al., 2021; Rose et al., 2012; Subramanian et al., 2012; Wang & Tsai, 2010).

For critically ill adults unable to self-report, nurses' utilization of behavioral pain assessment tools is essential as this promotes accurate and consistent measurement of pain, enhances effective communication of pain assessment results between healthcare providers, initiates optimal pain management, and improves healthcare quality. Exploring the modifiable factors associated with nurses' pain assessment practices is crucial because they can influence holistic quality improvement processes that promote optimal pain control. Implementing a systematic approach to pain assessment can result in more frequent documentation of pain assessment and more efficient pain management (Damico et al., 2018). However, the implementation of appropriate pain assessment-related interventions is challenged by multiple factors. These may include nurse- and institution-related factors (Georgiou et al., 2015; Hamadeh et al., 2024).

Critically ill adults are often intubated and ventilated, unconscious or highly unstable so that effective communication of symptoms such as pain is extremely challenging. Therefore, it is important to explore nurse- and institution-related modifiable factors associated with nurses' utilization frequency of behavioral pain assessment tools for this specific population. This study aimed to investigate the nurse- and institution-related factors associated with critical care nurses' often and routine utilization of behavioral pain assessment tools for critically ill adults unable to self-report. Identifying modifiable factors that influence pain assessment practices can help institution policy makers and nurse leaders develop and implement appropriate interventions and interprofessional educational programs that enhance pain management for critically ill adults.