Letter to the Editor

This Letter to the Editor is in response to Smith et al.’s (2025) article, “Occupational Therapy Interventions and Early Engagement for Patients in Intensive Care: A Systematic Review.” We value the authors’ efforts to highlight occupational therapy’s role in intensive care unit (ICU) rehabilitation, and in this letter we aim to offer suggestions for future development with respect to the concept of early engagement. Although Weinreich et al.’s (2017) review provided an important early synthesis of occupational therapy in the ICU, it found limited differentiation between occupational therapy interventions and physical therapy interventions and highlighted a lack of occupational therapy–specific evidence. This underscores the relevance of Smith et al.’s (2025) updated analysis and the need to further clarify occupational therapy’s unique contributions.

Despite the existence of moderate evidence supporting occupational therapy interventions for activities of daily living (ADLs), physical rehabilitation, and cognition, there remains a knowledge gap regarding occupational therapy’s distinct contributions compared with other rehabilitation approaches, in particular physical therapy. Smith et al.’s (2025) research question—“What is the strength of empirical evidence for occupational therapy interventions related to early engagement in the ICU?”—effectively framed their investigation. However, how early engagement differs from broader rehabilitation strategies in terms of clinical impact remains unclear.

The absence of Level 1a evidence for occupational therapy’s role in ICU rehabilitation raises concerns about the strength of the current findings in guiding clinical decision making. This highlights a key question: To what extent does occupational therapy–specific early engagement improve ICU outcomes compared with conventional rehabilitation approaches? Addressing this question would strengthen the conceptual foundation of early engagement and clarify associated clinical implications.

Smith et al. (2025) classified the interventions and outcomes into three domains, excluding medical-based outcomes: (1) ADLs, (2) physical rehabilitation, and (3) cognition. This approach is consistent with occupational therapy practice, particularly with respect to early ICU engagement. However, each intervention may produce outcomes beyond its primary domain, warranting separate analyses of interventions and outcomes.

For example, Álvarez et al. (2017) reported improved functional independence; however, whether this was solely attributable to ADL retraining or involved a combination of interventions remains unclear. Categorizing interventions first, followed by systematically analyzing associated outcomes, including medical-based ones, may provide more meaningful insights.

This is particularly relevant for interventions that target delirium, a critical ICU-related outcome. Smith et al. (2025) acknowledged that Álvarez et al. (2017) found occupational therapy cognitive interventions associated with lower delirium incidence and duration. However, because these were delivered alongside ADL retraining and therapeutic exercise, determining which component was most influential is challenging. Nevertheless, this suggests that any single component, or their combination, was effective.

Therefore, rather than limiting outcome assessment to predetermined interventional domains, a more integrated analysis that captures all interventions and their diverse effects, including medical-based ones, would provide deeper insight into occupational therapy’s contributions to early ICU engagement.

Although excluding medical-based outcomes is consistent with Smith et al.’s (2025) occupational therapy–specific focus, ICU rehabilitation is inherently interdisciplinary. Occupational therapy interventions may influence broader medical indicators, such as length of ICU stay, readmission rates, and mortality. Given that early mobilization is associated with reduced ICU stay duration and improved survival, future research should explore whether occupational therapy– specific early engagement yields similar benefits.

Early engagement presents meaningful clinical implications, including mitigating ICU-acquired weakness, reducing delirium, and enhancing functional recovery. However, feasibility in real-world ICU settings remains challenging because of patient acuity, medical complexity, and interdisciplinary coordination. Smith et al. (2025) noted that many interventions were conducted within multidisciplinary programs, making it challenging to isolate occupational therapy–specific effects. Although interdisciplinary early mobility protocols, primarily nurse-led ones (e.g., Schallom et al., 2020), have proven successful, the development of occupational therapy–led models is a critical area for future research. Establishing occupational therapy–driven early engagement protocols would clarify the unique contributions of occupational therapy within ICU rehabilitation.

Smith et al. (2025) provided a valuable synthesis and laid the groundwork for research in early engagement. Their findings underscore the need for rigorous study designs to distinguish occupational therapy–specific contributions, refine the definition of early engagement, standardize intervention categorization, and incorporate both functional and medical-based outcomes to establish a stronger empirical foundation for occupational therapy in ICU care.

We encourage further exploration of occupational therapy– specific early engagement strategies in critical care settings.