Journal of Correctional Health Care - April 2023 - 143

Journal of Correctional Health Care
Volume 29, Number 2, 2023
ª The Author(s) 2023
DOI: 10.1089/jchc.21.10.0114
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RESEARCH ARTICLE
Pulse Oximetry Improves COVID-19 Screening Sensitivity
by Detecting Asymptomatic and Afebrile Infections
in a Case Control Study
Philip D. Kapatos, DPT, PT, GCS,1* and Steven L. Spoonemore, Jr., Dsc, DPT2
Abstract
SARS-CoV-2 has spread quickly despite the implementation of various strategies to limit the spread of the
disease. Current screening procedures are unable to detect asymptomatic infections. This study reports the
prevalence of abnormal vital signs among incarcerated individuals with asymptomatic infections and proposes
an enhanced screening algorithm that may detect asymptomatic infections. A case control study
used a retrospective electronic chart review of COVID-19 infected people and matched controls housed
in one Federal Bureau of Prisons institution. Data were collected on age, body mass index, medical history,
temperature, blood oxygen saturation (SpO2), and symptoms. Fifty-seven laboratory-confirmed COVID-19
infections and 81 confirmed controls were identified. Asymptomatic infections were present in 35/57 people
(61%) with a group minimum SpO2 94.4% (standard deviation [SD] 1.4) and a maximum oral temperature
of 99.19F(SD 0.36). An enhanced screening algorithm that uses pulse oximetry yields a sensitivity of
84.2%, 95% confidence interval [72.1-92.5]. Among asymptomatic people, there is a high prevalence of abnormal
SpO2 and temperature measurements. A screening algorithm that uses both of these measures can
detect asymptomatic infections with a low false positive rate.
Keywords: COVID-19, screening, hypoxemia, pulse oximetry, asymptomatic
Introduction
The SARS-CoV-2 virus was first identified in late 2019 and
led to a global pandemic early in 2020. The virus has a
number of unique characteristics that have allowed it to
spread quickly and widely. A person with COVID-19,
the disease caused by SARS-CoV-2, becomes infectious
on average about 2.3 days before symptom onset and
peaks at 0.7 days before symptoms begin (He et al., 2020).
Additionally, many infected people do not demonstrate
any symptoms, with reported prevalence estimates of
1Federal Bureau of Prisons, Federal Medical Center, Devens, Massachusetts, USA.
2Indian Health Services, Southcentral Foundation, Anchorage, Alaska, USA.
*Address correspondence to: Philip D. Kapatos, DPT, PT, GCS, Federal Bureau of Prisons, Federal Medical Center, 42 Patton Road, Devens, MA 01434, USA, Email:
Pkapatos@bop.gov
143
1.2%-96% (Epidemiology Working Group, 2020; So &
Smith, 2020). A recent systematic review and metaanalysis
placed the percentage of asymptomatic infections
at 40%-45% (Oran&Topol, 2020). This has led clinicians
and researchers to call attention to how much the spread of
the virus is being conducted by people with asymptomatic
infections (Gandhi et al., 2020; Lai et al., 2020).
Particularly interesting with regard to COVID-19 is a
pathologic condition termed ''silent hypoxia'' (Xie
et al., 2020). In one study reporting on chest computed

Journal of Correctional Health Care - April 2023

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