The impact of remote home monitoring of people with COVID-19 using pulse oximetry: a national population and observational study
Authors: Sherlaw-Johnson Chris , Georghiou Theo , Morris Steve , Crellin Nadia E , Litchfield Ian , Massou Efthalia , Sidhu Manbinder S , Tomini Sonila M , Vindrola-Padros Cecilia , Walton Holly , Fulop Naomi 
Published: December 2021

AbstractBackgroundRemote home monitoring of people testing positive for COVID-19 using pulse oximetry was implemented across England during the Winter of 2020/21 to identify falling blood oxygen saturation levels at an early stage. This was hypothesised to enable earlier hospital admission, reduce the need for intensive care and improve survival. This study is an evaluation of the clinical effectiveness of the pre-hospital monitoring programme, COVID oximetry @home (CO@h).MethodsWe analysed relationships at a geographical area level between the extent to which people aged 65 or over were enrolled onto the programme and outcomes over the period between November 2020 to February 2021FindingsFor every 10% increase in coverage of the programme, mortality was reduced by 2% (95% confidence interval: -4% to 1%), admissions increased by 3% (-1% to 7%), in-hospital mortality fell by 3% (-8% to 3%) and lengths of stay increased by 1·8% (-1·2% to 4·9%). None of these results are statistically significant.InterpretationThere are several possible explanations for our findings. One is that the CO@h did not have the hypothesised impact. Another is that the low rates of enrolment and incomplete data in many areas reduced the chances of detecting any impact that may have existed. Also, CO@h has been implemented in many different ways across the country and these may have had varying levels of effect.FundingThis is independent research funded by the National Institute for Health Research, Health Services & Delivery Research programme (RSET Project no. 16/138/17; BRACE Project no. 16/138/31) and NHSEI. NJF is an NIHR Senior Investigator. The views expressed in this publication are those of the authors and not necessarily those of the National Institute for Health Research or the Department of Health and Social Care.Research in ContextEvidence before this studyExisting evidence before this study and the search strategy used to obtain this evidence has been published previously by the authors in a systematic review. Previous quantitative studies have assessed remote oximetry monitoring services for COVID-19 patients mostly at individual sites and focussed on their safety. However, their effectiveness has been little studied. This may reflect the challenges of identifying reliable counterfactuals during a rapidly evolving pandemic.Added value of this studyThis study is part of a wider mixed methods evaluation that followed the rapid implementation of remote monitoring across the English NHS during the Winter of 2020/21. It adds to the evidence of the effectiveness of such programmes at a national level.Implications of the available evidenceThere is some existing evidence that remote monitoring of COVID-19 patients can be locally effective although we have not been able to replicate such findings at a wider level. Missing data and lower coverage of the service than expected may have influenced our results, and the effectiveness of some local programmes could have been lost among the analysis of national data. Future implementation requires better data collection strategies which could be focussed within fewer local areas, and effective learning from areas that have achieved better population coverage.