Outpatient Management of Complex Bone and Joint Infections in an Ambulatory Setting

Introduction
Over 340 virtual hospital (VH) programs now operate across England, with a 60% increase between May 2022 and January 2023. Complex bone and joint infections (CBJIs) account for roughly 15% of Emergency Department caseload and disproportionately affect older adults, who face heightened risks from prolonged hospitalisation. Inpatient costs average £345/day. The Royal Berkshire Hospital established its Virtual Hospital in 2022 to provide outpatient monitoring and ambulatory treatment for CBJI patients. Given the paucity of data in this population, this study characterises demographics and outcomes under the Virtual Hospital CBJI pathway.

Methods
A retrospective analysis was conducted of all encounters under the CBJI pathway from the inception of the Virtual Hospital Unit until October 1, 2024 (n=128). Institutional approval was obtained for use of patient-level electronic records. Twenty-six encounters were excluded due to duplication (n=21) or failure to meet CBJI diagnostic criteria (n=5).

Results
Of 102 included patients, 40% were female and 60% male; median age was 65, with a substantial proportion of older adults. Mean inpatient admission was significantly shorter than subsequent virtual hospital admission (15 [95% CI 10–21] vs. 44 [95% CI 44–58] days; p<0.05), avoiding 1,563 bed-days and associated risks of prolonged admission in this age group. Treatment failure occurred in 11.7% (n=12). Staphylococcus aureus was the most common organism (58.3%, n=63). Adverse drug reactions occurred in 5% (n=5).

Conclusion
Virtual hospital management of CBJIs is associated with reduced hospitalisation duration and low treatment failure in the observed population, offering a valuable alternative to prolonged admission for older adults at risk of decline. Future work will develop a frailty-informed risk-stratification model to identify patients suitable for ambulatory care. Oral antibiotics with high bioavailability enable close monitoring, supporting safe, patient-centred care for older adults with CBJIs.