In our case series of 19 COVID-19 patients, post-hospitalization home oxygen treatment and mobile-based monitoring facilitated early hospitalization of hypoxemic patients during the Omicron wave of the COVID-19 pandemic. This resulted in some relief to the overwhelmed healthcare as well as significant saving of healthcare expenditure.
Home monitoring of COVID-19 patients has been applied in different settings and in different ways; pre-hospitalization or post-hospitalization, with or without oxygen treatment, symptom-based or vital signs based [6,7,8,9,10,11,12,13,14,15].
Safety of a similar post-hospitalization monitoring program supporting home oxygen treatment was also established in a cohort of 73 COVID-19 patients from Paris, France, in the first three months of the pandemic when the wild type was the dominant variant of SARS-CoV-2 [9]. In a retrospective study of a virtual ward in 2021 in the United Kingdom, 3/44 patients discharged with an oxygen concentrator were readmitted and 1/44 died [10].
With high uncertainty how the Omicron wave would affect healthcare in Finland, we anticipated on the possibility of high numbers of prolonged hospitalizations. Indeed, the number of hospitalized patients has been high throughout the year 2022. A total of 1 124 195 confirmed or probable COVID-19 cases and a total of 8 238 new inpatient episodes due to COVID-19 in secondary care [3] were registered in Finland in 2022, while a much larger proportion remained undiagnosed after testing policy was adjusted due to restricted diagnostic capacity [3, 16].
The main objectives of the implementation of our program were to increase flexibility of the healthcare service, to reduce the number of hospitalized COVID-19 patients and to relieve workload at a critical phase of the pandemic. With 210.5 prevented hospitalization days, mostly around the early peak of the Omicron wave, this goal was achieved. Similarly, home oxygen treatment was associated with 6.4 ± 3.2 days reduction of hospital admission in patients who were discharged with oxygen therapy in comparison to the hospital protocol according to a cohort study of 320 COVID-19 patients from the Netherlands, until May 2021, likely including mainly wild-type and alpha variants cases [11]. In a study performed in California, United States, in 2021, a remote patient monitoring program was associated with a shorter length of hospital stay in the intervention group of 75 patients in comparison to a control group (median 4.8 versus 6.1 days; p = 0.03) [12]. However, in a randomized controlled trial, including 62 patients, only a small, non-significant difference of 1.6 hospital-free days was observed in favor of the intervention group [13]. Several factors may contribute to the difference between their findings and ours. In their intervention group, mean duration of home oxygen treatment was only 6.7 days after randomization, which suggests differences in severity of COVID-19 in patients selected for remote treatment, or in substantial differences in treatment regimes. Remote monitoring may also result in slower tapering of oxygen and possibly overestimation of prevented hospital days in our study. Furthermore, the investigators of that study found that in their study setting, early discharge disseminated to their control group, as these patients had also been informed about the intervention.
In our study, only few patients were enrolled in the later phase of the Omicron wave, as the patient population and the clinical picture of hospitalized COVID-19 patients changed to a more aged patient group with a phenotype without severe lung involvement. This was potentially due to age-dependent immunity dynamics upon vaccination and/or previous exposure to COVID-19 [3, 16]. This raises the question if there is any large-scale need for home oxygen treatment for future COVID-19 patients.
Even though our study population was rather small, the savings were significant due to prevented hospitalization days, on average 7,605 euro per patient. In Ireland, ambulatory monitoring protocol was applied in a cohort of 502 COVID-19 patients with a cost–benefit estimates ranging from net costs to health service of €142,000 to net savings of €27,883 depending on admission rate to home monitoring during the first months of the pandemic [14]. Similarly to our study, post-hospitalization home oxygen treatment was found to be both safe and economically beneficial in a Dutch study consisting of 49 COVID-19 patients [15]. In that study, the potential reduction in hospital days was 616 days in total or 12.6 days per patient and the estimated costs avoided were €146,736. Readmission rate was 12%.
Cost–benefit of post-hospitalization monitoring of COVID-19 patients may depend on several factors, such as the selection of patients, epidemiologic aspects, local and national healthcare costs as well as costs related to development and utilization of the monitoring programs. Furthermore, the costs analysis depended on projected discharge dates, based on clinical parameters as reported by the patient via the application. The estimation of reduction in hospitalization may be inaccurate, and hospitalization itself may also predispose to complications such as nosocomial infections [17]. Therefore, the cost–benefit evaluation should be interpreted with caution and cannot be generalized. However, even with uncertainty about the exact amount saved, our findings strongly indicate that post-hospitalization monitoring of hypoxemic COVID-19 is economically beneficial. Moreover, financial costs and financial benefits may be prone to multiple disturbing factors. The financing model may require modification in order to optimize the utilization of hospitalization-reducing telemedicine programs.
Apart from the benefits of home treatment, the program also has its limitations. For instance, the utility of application-based monitoring can be limited by poor technical or language skills and may thereby cause inequity in received healthcare. In some cases, the patients were provided with a tablet (iPad) to allow the involvement of family members or home care nurses in the use of the application while preserving the patients’ privacy. Furthermore, even though home treatment may relieve the burden of hospitalized patients, implementation of a new working tool and preparing and educating of patients for monitoring may require extra effort and time from the treating staff and increase the experienced working load.
Our study has some limitations. First, only a modest number of patients were enrolled in our program. Therefore, the risk of clinical deterioration and other safety issues may be underestimated. The small sample size may also lead to under- or overestimation of costs. Second, our data cannot be generalized due to several specific aspects mentioned in the previous paragraph. Costs of hospitalization may differ significantly between countries, which hampers comparison of hospitalization costs at the international level [18]. Third, as previously discussed, retrospective estimation of reduction of the length of hospital stay is rather insecure. Prospective, randomized studies are practically challenging in rapidly evolving epidemics with acute need of saving human resources and are still limited by the impossibility of blinding. Fourth, this study was not designed to evaluate the possible limitations of the program mentioned above. Nevertheless, we feel that our study contributes to the evidence that remote oxygen treatment and monitoring of COVID-19 patients can be safely performed and can be highly cost-effective.
Future studies and reports are needed to address whether remote home oxygen treatment and monitoring remains beneficial during the later phase of the epidemic and to evaluate whether these programs can safely be applied in other conditions, such as pneumonia of different etiologies, exacerbation of chronic pulmonary conditions, and pulmonary embolism. Furthermore, the prevalence of persisting symptoms of patients enrolled in such programs could be assessed, preferably in prospective studies, as a large proportion of hospitalized COVID-19 patients report persisting symptoms. Thus, we think that a randomized trial on rapid discharge supported by remote monitoring with or without oxygen treatment could be feasible in respiratory infections beyond COVID-19.
