The 'afternoon effect' as a proxy for systemic vulnerabilities in surgical care.
Journal
Anaesthesia
Journal Volume
81
Journal Issue
5
Start Page
749
End Page
750
ISSN
1365-2044
Date Issued
2026-05
Author(s)
Abstract
We read with interest the article by Sim et al. [1], which showed poorer postoperative outcomes among patients whose surgery began later in the day. Beyond circadian and fatigue-related explanations, we suggest that this ‘afternoon effect’ functions as a proxy for deeper systemic vulnerabilities, particularly within East Asian healthcare systems. An implicit hierarchical culture often shapes surgical scheduling in academic centres. Senior surgeons and their most complex cases are typically prioritised for the morning lists, while afternoon lists are populated by less experienced teams or lower-acuity cases. Moreover, morning sessions often feature fixed surgeon–anaesthetist pairings, a configuration shown to be associated with fewer postoperative complications [2]. This systemic pattern may not only introduce unmeasured differences in case complexity and team familiarity but also interact with operational constraints. One example is ICU bed availability, which often delays high-risk cases to later hours. These structural factors may create a persistent time-of-day gradient in peri-operative risk that statistical adjustment cannot resolve in full. As the day progresses, the cumulative effects of scheduling inefficiencies and resource constraints often translate into heightened production pressure [3]. Afternoon surgery lists can be compressed by morning case overruns and limited hospital bed turnover. Under such pressure, teams may face operational compromises such as reassigning cases to different operating theatres or modifying team composition, resulting in unfamiliar surgeon–anaesthetist pairings. This ‘team fluidity’ erodes the efficiencies of established specialist teams, increasing both communication overhead and cognitive load, thereby amplifying the systemic risks already inherent to late-day surgery. The immediate postoperative phase for patients finishing surgery in the late afternoon is structurally disadvantaged. These patients are transferred to wards during the evening handover to the night shift. This is a period characterised by reduced staffing, limited supervision and more limited access to senior clinicians [4]. During night shifts, nurse staffing is typically reduced by half, effectively doubling the number of patients each nurse must care for, thereby increasing workload and cognitive strain [5]. This aligns with the authors' discussion of limited specialist availability during night hours, which disrupts continuity of care. Such temporal disparities in resources heighten the risk of delayed recognition of clinical deterioration, a central mechanism underlying ‘failure to rescue’ events. The association reported by Sim et al. may represent the endpoint of a cumulative, system-level risk cascade, beginning with scheduling hierarchies, compounded by intra-operative team fluidity under production pressure and culminating in a resource-limited postoperative environment. While optimising surgical scheduling is a valid goal, a more fundamental response is required. Future quality improvement initiatives should aim to strengthen organisational resilience across the entire peri-operative pathway, mitigating these predictable, time-of-day-dependent vulnerabilities to ensure a consistent standard of patient safety around the clock.
Type
letter