The reasons hypoactive delirium is often overlooked

Gibbison et al. described delirium identification, prevention and management across ICUs in England, Wales and Northern Ireland 1. With a 93% response rate, this survey offers a clear national picture of current practice. In neurosurgery and surgical oncology, we often see how undetected delirium shapes long-term recovery and we commend the authors for producing a dataset that is highly relevant to daily care. One specific observation deserves closer examination, particularly because it can be addressed with the data already collected. In Table 2 1, confidence in the CAM-ICU tool was high for hyperactive delirium, with almost nine out of 10 respondents judging it accurate, yet barely half expressed the same confidence for hypoactive delirium. This gap is not surprising to those of us at the bedside 2. Hypoactive presentations are quieter, more insidious and often mistaken for fatigue or depression. What struck us, however, is that the survey results were presented in aggregate, without linking this diagnostic uncertainty to unit-level factors such as staff training, the professional role of the assessor or the presence of a delirium care package. These elements were captured elsewhere in the survey, and cross-tabulating them against the reported accuracy of CAM-ICU could reveal whether the lack of confidence stems from modifiable barriers rather than from limitations of the tool itself. It would be informative, for example, to know whether ICUs with structured and regular training report greater confidence in detecting hypoactive delirium, or whether nurses and physicians perceive its accuracy differently depending on their role 3. If a pattern emerged, this would suggest that targeted education or embedding CAM-ICU more firmly within a standardised care bundle could address the weakest point in detection directly. In our own experience, units that hold short, case-based teaching sessions and link the tool to a protocolised bundle tend to identify many more hypoactive cases than those relying solely on individual vigilance. This is important because hypoactive delirium is often the variant most strongly associated with poor outcomes yet remains the least visible. From a public health perspective, improving recognition of this subtype is not a narrow technical matter but a system issue. Early and confident detection can determine whether patients receive mobilisation, medication review or psychological support in time to influence their recovery 4. For older adults recovering from major neurosurgical or oncological procedures, the downstream effects on function and independence are profound. Exploring these links in the existing dataset could, therefore, help move the field from simply mapping practice variation to identifying levers for change. In conclusion, Gibbison et al. have delivered an important national benchmark. We believe a more detailed analysis of diagnostic confidence in relation to unit characteristics may help clarify the reasons for undetected cases of hypoactive delirium and inform strategies to address this issue. Such an approach would not only strengthen the translational impact of the present survey but also guide the development of practical, sustainable delirium care strategies across the health service.