Perioperative Nursing Workload, Missed Safety-Critical Care and Near-Miss Events: A Prospective Study Guided by the Donabedian Structure-Process-Outcome Model

Background and Rationale: Perioperative care is a safety-critical setting characterized by high cognitive demand, time pressure, concurrent tasks, and frequent workflow interruptions. Operating room nurses perform multiple safety-critical care duties within the same clinical workflow, including patient and procedure verification, safe positioning, surgical counts, specimen/label verification, equipment preparation, normothermia maintenance, handoff, and documentation. Missed nursing care has been defined in the nursing literature as any required aspect of patient care that is omitted, either in part or in total, or substantially delayed (Kalisch, Landstrom, & Hinshaw, 2009). Recent literature calls for mechanism-focused research that moves beyond prevalence estimates of missed care toward understanding why care is missed and what outcomes result (Palese, 2026). Studies examining the perioperative setting through direct, procedure-level observation remain limited. While workflow interruptions and perceived workload have been linked to missed nursing care (Liu et al., 2026), it remains unclear which specific safety-critical perioperative nursing duties are most likely to be delayed or omitted under high workload, and whether this translates into near-miss or process-deviation events. This study addresses workload using both a subjective self-report tool (NASA-TLX) and directly observed objective indicators (interruptions, task-switching, concurrent duties, procedure duration, shift timing, and equipment/supply shortages).

Conceptual Model: The study's conceptual model integrates the Donabedian structure-process-outcome framework with the missed nursing care literature: perioperative workload and workflow interruptions represent exposures related to the care environment (structure); missed/delayed safety-critical perioperative nursing care represents the proximal care process; and near-miss/process-deviation events represent the safety outcome. The pre-specified pathway is: workload and interruptions to missed/delayed safety-critical care to near-miss/process-deviation events. A distinguishing feature of this design is that missed nursing care is measured through direct, procedure-level observation of applicable safety-critical tasks rather than retrospective, general self-report, allowing nurse-level perceived workload, procedure-level objective workload, and directly observed care process to be linked within the same multilevel data structure.

Aims and Research Questions: The primary aim is to examine the relationship between perioperative nursing workload and procedure-level missed/delayed safety-critical nursing care. Secondary aims are to evaluate the relationship between missed/delayed safety-critical care and near-miss/process-deviation events, to determine the independent contribution of objective workload indicators, and, if a sufficient number of near-miss events is reached, to exploratorily examine whether missed safety-critical care mediates part of the relationship between workload and near-miss/process-deviation events. Research questions: (1) What are perioperative nurses' procedure-level perceived and objective workload levels? (2) How frequently are safety-critical perioperative nursing duties delayed or omitted, and which duties are most affected? (3) Is higher perceived and objective perioperative workload independently associated with a higher Missed Safety-Critical Care Index? (4) Is missed/delayed safety-critical care associated with the occurrence of near-miss/process-deviation events? (5) If a sufficient number of near-miss events is reached, does missed/delayed safety-critical care explain part of the relationship between workload and near-miss/process-deviation events?

Hypotheses: H1 (primary): As perioperative nursing workload increases, the rate of missed/delayed safety-critical care at the procedure level will increase. H1a: A higher Missed Safety-Critical Care Index will be associated with an increased likelihood of near-miss/process-deviation events. H1b (exploratory): If a sufficient number of events is reached, missed/delayed safety-critical care will explain part of the relationship between perioperative workload and near-miss/process-deviation events.

Setting and Design: This is a single-center, prospective, analytic observational study conducted in the operating rooms of Agri Training and Research Hospital. Routine clinical practice will not be altered, and the researchers will not intervene in clinical decisions, team task allocation, surgical technique, or patient care. Data collection is planned to take place over approximately 8-12 weeks between October 2026 and December 2026, following institutional and ethics committee approval. The unit of analysis is the surgical procedure; because the same nurse may be observed across multiple procedures, the data have a clustered structure with procedures nested within nurses, which will be accounted for using appropriate multilevel models.