Machine Learning to Assess the Prognostic Utility of Radiomic Features for In-hospital COVID-19 Mortality (preprint)

As portable chest X-rays are an efficient means of triaging emergent cases, their increased use has raised the question as to whether imaging carries additional prognostic utility for survival among patients with COVID-19. This study assessed the importance of known risk factors on in-hospital mortality and to investigate the predictive utility of radiomic texture features using various machine learning approaches. We detected incremental improvements in survival prognostication utilizing texture features derived from emergent chest X-rays, particularly among older patients or those with higher comorbidity burden. Important features included age, oxygen saturation, blood pressure, and certain comorbid conditions, as well as image features related to the intensity and variability of the pixel distribution. Thus, widely available chest X-rays, in conjunction with clinical information, may be predictive of survival outcomes of patients with COVID-19, especially older, sicker patients, and can aid in disease management by providing additional information.

The Heightened ‘Security Zone’ Function of Gated Communities during the COVID-19 Pandemic and the Changing Housing Market Dynamic: Evidence from Beijing, China

The ongoing COVID-19 pandemic has left a strong imprint on many aspects of urban life. Gated communities (GCs) in China are less commonly perceived as a negative and segregated urban form of community compared to other contexts, owing to their wide variety and relative openness. Yet, the enhanced security zone function and the popularity of GCs, along with the heightened segregation and exclusion effects, mean they are most likely to emerge in post-pandemic urban China because of the perceived effectiveness of GCs in preventing health risks by excluding outsiders during the pandemic. Drawing on empirical data from Beijing, this research presents strong evidence for a strengthened perceived ‘security zone’ effect of GCs during the pandemic. Given that rigid pandemic control measures were organized at the community level, a large-scale household survey in Beijing suggests that residents commonly recognise the effectiveness of GCs in security control and show a strong preference for GCs over open communities after the pandemic, even though there is a lack of direct evidence of reduced COVID-19 risk in GCs. The heightened perceived ‘security zone’ function of GCs has shown a significant impact on the housing market, evidenced by an increase of 2% in the housing prices for GCs, compared with those of open communities. The rising popularity of GCs is also evidenced by a significant increase in property viewings by potential homebuyers and smaller price discounts in actual transactions in gated communities vis-à-vis open communities. We argue that the rising risk-averse sentiment in the post-pandemic era has given rise to the popularity of GCs. This study provides timely and fresh insights into the changing meaning of GCs in post-pandemic China.

SARS-CoV-2 viral shedding characteristics and potential evidence for the priority for faecal specimen testing in diagnosis

This study aimed to identify the specimen type that has high positivity and its proper sampling time for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) testing to promote diagnostic efficiency. All SARS-CoV-2-infected patients with a laboratory-confirmed diagnosis in Zhoushan City were followed up for viral shedding in respiratory tract specimens and faecal samples. Positivity was analysed both qualitatively and quantitatively by proper statistical approaches with strong testing power. Viral shedding in respiratory tract and faecal specimens was prolonged to 45 and 40 days after the last exposure, respectively. The overall positive rate in respiratory tract specimens was low and relatively unstable, being higher in the early-to-mid stage than in the mid-to-late stage of the disease course. Compared with respiratory tract specimens, faecal samples had a higher viral load, higher overall positive rate, and more stable positivity in different disease courses and varied symptomatic status. Faecal specimens have the potential ability to surpass respiratory tract specimens in virus detection. Testing of faecal specimens in diagnosis, especially for identifying asymptomatic carriers, is recommended. Simultaneously, testing respiratory tract specimens at the early-to-mid stage is better than testing at the mid-to-late stage of the disease course. A relatively small sample size was noted, and statistical approaches were used to address it. Information was missing for both specimen types at different stages of the disease course due to censored data. Our research extends the observed viral shedding in both specimen types and highlights the importance of faecal specimen testing in SARS-CoV-2 diagnosis. Healthcare workers, patients, and the general public may all benefit from our study findings. Disposal of sewage from hospitals and residential areas should be performed cautiously because the virus sheds in faeces and can last for a long time.

Comprehensive Evaluation of COVID-19 Patient Short- and Long-term Outcomes: Disparities in Healthcare Utilization and Post-Hospitalization Outcomes (preprint)

BackgroundUnderstanding risk factors for short- and long-term COVID-19 outcomes have implications for current guidelines and practice. We study whether early identified risk factors for COVID-19 persist one year later and through varying disease progression trajectories. MethodsThis was a retrospective study of 6,731 COVID-19 patients presenting to Michigan Medicine between March 10, 2020 and March 10, 2021. We describe disease progression trajectories from diagnosis to potential hospital admission, discharge, readmission, or death. Outcomes pertained to all patients: rate of medical encounters, hospitalization-free survival, and overall survival, and hospitalized patients: discharge versus in-hospital death and readmission. Risk factors included patient age, sex, race, body mass index, and 29 comorbidity conditions. ResultsYounger, non-Black patients utilized healthcare resources at higher rates, while older, male, and Black patients had higher rates of hospitalization and mortality. Diabetes with complications, coagulopathy, fluid and electrolyte disorders, and blood loss anemia were risk factors for these outcomes. Diabetes with complications, coagulopathy, fluid and electrolyte disorders, and blood loss were associated with lower discharge and higher inpatient mortality rates. ConclusionsThis study found differences in healthcare utilization and adverse COVID-19 outcomes, as well as differing risk factors for short- and long-term outcomes throughout disease progression. These findings may inform providers in emergency departments or critical care settings of treatment priorities, empower healthcare stakeholders with effective disease management strategies, and aid health policy makers in optimizing allocations of medical resources.