In-hospital bed occupancy and the emergency department - effects on decisions about the level of care

Abstract: Background: Emergency Department (ED) overcrowding occurs when the need for ED services outstrips available resources. Causes have been divided into input, throughput, and output factors, of which the last appear to be the most influential. Unavailability of inpatient beds (so-called “access block,” or “hospital crowding”) impairs ED output and is associated with increased waiting times in the ED, especially for patients awaiting hospital admission (“boarding”). Access block has also been suspected to induce an admission-bias, causing only the sickest patients to be admitted to hospital when hospital beds are scarce. The aim of this thesis was to evaluate whether access block affected the prioritization of the level of care in ED patients so that patients were less likely to be admitted to a hospital bed at times of access block than otherwise. Part V addressed whether more patients were triaged out of the ED at times of access block. Methods: In Part I, the proportion of hospital admissions among 118,668 visits to the ED, at a 420-bed emergency hospital in Region Skåne, Sweden, was compared across different levels of access block (measured as strata of in-hospital bed occupancy). Multivariate models were constructed to adjust for the effects of known confounders. In Part II, the appropriateness of ED discharges was addressed by comparing the proportion of unplanned 72h revisits to the ED across different levels of access block, for the 81,878 cases treated and released from the ED at index. In Part III, the outcomes evaluated in Parts I and II were addressed for 19,620 ED visits due to acute abdominal pain. Part IV was performed analogously to Part III, but for 12,223 ED visits due to chest pain. In Part V, the permeability of an ED front-end facility that triages patients of perceived low acuity out of the ED was compared across different levels of access block, for 37,129 visits to the facility. Results: In Part I, a negative association between access block and the probability of inpatient admission was observed (OR 0.67–0.81 at occupancy >105%, compared to at occupancy <95%), implying that patients were less likely to be admitted to the hospital at times of access block. Part II revealed no association between access block and the 72h revisit rate. The association detected in Part I remained for the study populations addressed in Parts III/IV. No association between access block and the 72h revisit rate was observed in patients with acute abdominal pain, but a negative association between the two was observed in patients with chest pain. ED length of stay in patients who were treated and released from the ED increased at times of access block, in Parts III/IV. Conclusion: ED patients were less likely to be admitted to a hospital bed at times of access block than otherwise, at the study site. The lack of an association with the 72h revisit rate could be interpreted as that the practice is safe, but since it fails to take into account rare, but fatal, outcomes such as mortality, future studies should address more granular patient outcomes and specific subgroups. Cost-effectiveness analysis could help to evaluate the viability of managing certain conditions in the ED as compared to in inpatient wards.