The impact of post-hospital remote monitoring of COVID-19 patients using pulse oximetry: a national observational study using hospital activity data
Authors: Georghiou Theo , Sherlaw-Johnson Chris , Massou Efthalia , Morris Stephen , Crellin Nadia E , Herlitz Lauren , Sidhu Manbinder S , Tomini Sonila M , Vindrola-Padros Cecilia , Walton Holly , Fulop Naomi J 
Published: January 2022

AbstractBackgroundThere was a national roll out of ‘COVID Virtual Wards’ (CVW) during England’s second COVID-19 wave (Autumn 2020 – Spring 2021). These services used remote pulse oximetry monitoring for COVID-19 patients following discharge from hospital. A key aim was to enable rapid detection of patient deterioration. It was anticipated that the services would support early discharge and avoid readmissions, reducing pressure on beds. This study is an evaluation of the impact of the CVW services on hospital activity.MethodsUsing retrospective patient-level hospital admissions data, we built multivariate models to analyse the relationship between the implementation of CVW services and hospital activity outcomes: length of COVID-19 related stays and subsequent COVID-19 readmissions within 28 days. We used data from more than 98% of recorded COVID-19 hospital stays in England, where the patient was discharged alive between mid-August 2020 and late February 2021.FindingsWe found a longer length of stay for COVID-19 patients discharged from hospitals where a CVW was available, when compared to patients discharged from hospitals where there was no CVW (adjusted IRR 1·05, 95% CI 1·01 to 1·09). We found no evidence of a relationship between the availability of CVW and subsequent rates of readmission for COVID-19 (adjusted OR 0·95, 95% CI 0·89 to 1·02).InterpretationWe found no evidence of early discharges or reduced readmissions associated with the roll out of COVID Virtual Wards across England. Our analysis made pragmatic use of national-scale hospital data, but it is possible that a lack of specific data (for example, on which patients were enrolled) may have meant that true impacts, especially at a local level, were not ultimately discernible.FundingThis is independent research funded by the National Institute for Health Research, Health Services & Delivery Research programme and NHSEI.Research in contextEvidence before this studyPost-hospital virtual wards have been found to have a positive impact on patient outcomes when focussed on patients with specific diseases, for example those with heart disease. There has been less evidence of impact for more heterogenous groups of patients. While these services have been rolled out at scale in England, there has been little evidence thus far that post-hospital virtual wards (using pulse oximetry monitoring) have helped to reduce the length of stay of hospitalised COVID-19 patients, or rates of subsequent readmissions for COVID-19.Added value of this studyThis national-scale study provides evidence that the rollout of post-hospital discharge virtual ward services for COVID-19 patients in England did not reduce lengths of stay in hospital, or rates of readmission.Implications of all the available evidenceWhile there is currently an absence of evidence of positive impacts for COVID-19 patients discharged to a virtual ward, our study emphasises the need for quality data to be collected as part of future service implementation.