Alcohol and Alcoholism, 2021, 1–7
doi: 10.1093/alcalc/agab019
Article
Downloaded from https://academic.oup.com/alcalc/advance-article/doi/10.1093/alcalc/agab… by Kent State University user on 02 April 2021
Article
Increases in Risky Drinking During the COVID-19
Pandemic Assessed via Longitudinal Cohort
Design: Associations With Racial Tensions,
Financial Distress, Psychological Distress
and Virus-Related Fears
William V. Lechner1 ,*, Natasha K. Sidhu1 , Jackson T. Jin1 ,
Ahmad A. Kittaneh1 , Kimberly R. Laurene2 , and Deric R. Kenne2
1
Department of Psychological Sciences, Kent State University, Kent, OH 44240, USA , and 2 Center for Public Policy &
Health Division of Mental Health & Substance Use, Kent State University, Kent, OH 44240, USA
*Corresponding author: Department of Psychological Sciences, Kent State University, 600 Hilltop Drive, Kent, OH 44240, USA.
Tel.: 330-672-2027; E-mail: wlechner@kent.edu
Received 19 December 2020; Revised 9 February 2021; Editorial Decision 2 March 2021; Accepted 2 March 2021
Abstract
Background: The COVID-19 pandemic has created disruptions to daily life resulting in wide-spread
unemployment and psychological distress. Recent studies have reported high rates of alcohol use
during this time; however, longitudinal data remain scarce and factors associated with increases
in high-risk drinking observed over time are unknown.
Aims: The current study examined changes in high-risk drinking patterns across four 7-day
observation periods, prior to and following a university wide campus closure. Additionally, factors
associated with changes in alcohol use patterns were examined including financial distress,
psychological distress, impact of racial tensions and virus-related fears.
Method: Students (N = 1001) in the Midwestern USA completed repeated assessments between
March and June 2020. Each survey included a timeline follow-back measure of alcohol use.
Pandemic-related distress spanning several factors was assessed at the final follow-up.
Results: Risky drinking patterns increased significantly over time. Overall, psychological distress
and impact of racial tensions were associated with higher rates of risky drinking, whereas COVID19-related fears were associated with lower rates. However, only financial-related distress was
associated with an increase in risky drinking patterns over time.
Conclusions: Increased risky drinking patterns observed in the current study may signal problems
that are likely to persist even after the direct impact of the COVID-19 pandemic on daily life
ends. Individuals experiencing financial distress may represent a particularly high-risk group.
Interventions targeting the cross-section of job loss, financial stress and problematic alcohol use
will be important to identify.
INTRODUCTION
The World Health Organization classified COVID-19 as a global
pandemic on 11 March 2020 (Organization WH, 2020). Public
health efforts to reduce the spread of the virus included closing
schools and businesses and enacting social distancing policies as
well as stay-at-home orders. The sudden onset of changes to daily
© The Author(s) 2021. Medical Council on Alcohol and Oxford University Press. All rights reserved.
1
2
the National Institute on Alcohol Abuse and Alcoholism (NIAAA) to
recommend against drinking beyond these limits (defined in measurements). Documenting changes in these high-risk drinking patterns
may provide valuable information on the resources needed to address
problems caused by the pandemic that may persist even after its initial
effects on daily life end. Lastly, this study examined the association
between changes in risky drinking and several factors attributed
specifically to the COVID-19 pandemic as well as the impact of
racial tensions during this time. Primary aims included (a) examining
changes in risky drinking patterns across four 7-day reporting periods
between 3 March 2020 and 2 June 2020 and (b) examining if
changes in risky drinking were related to four factors reported at
the third follow-up period including (i) COVID-19-related financial
loss, (ii) psychological distress caused by COVID-19, (iii) COVID-19related fears and (iv) racial tensions amid the pandemic. In addition
to COVID-19-related factors, we assessed the association between
changes in drinking patterns and the impact of racial tension due to
increasing concerns regarding racial issues in the USA. At the time of
this study, many societal events including several high-profile cases
of police violence against Black Americans (Nicole Dungca et al.,
2020) led to widespread protests against racial inequity and systemic
racism. We hypothesized (a) significant increases in risky drinking
across the assessment periods and (b) positive associations between
increased risky drinking and (i) COVID-19-related financial loss and
(ii) psychological distress caused by COVID-19. Due to the lack of
reporting in the literature on alcohol use during the pandemic in relation to the last two factors explored, (iii) virus-related fears and (iv)
racial tensions, we did not form a priori hypotheses on the direction
of these associations. Lastly, we included two exploratory models
examining the relationship between financial loss and changes in
risky drinking patterns, and psychological distress and changes in
risky drinking patterns as a function of gender, based on previous
observations that distress-related alcohol consumption may be more
prominent in women (Rodriguez et al., 2020).
METHODS
Participants and procedure
Participants were 1001 students at a large public university in Northeast Ohio who completed three surveys between March and June
2020. Participants were recruited through email to participate in
the study that consisted of self-report measures and retrospective
timeline follow-back (TLFB) assessment of alcohol use. Participants
completed the wave 1 assessment between 26 March and 6 April;
wave 2 assessment was completed between 29 April and 10 May and
wave 3 assessment was completed between 3 June and 14 June. Wave
1 included a retrospective timeline follow back assessment of alcohol
use in the week prior to and the week immediately following university campus closure due the COVID-19 pandemic. Campus closure
occurred on 10 March 2020 and included a student ban on entrance
to all academic buildings and transition to remote teaching. Waves
2 and 3 assessed alcohol use via retrospective timeline follow back
in the week prior to completion at each timepoint, respectively. The
initial recruitment email was sent on 26 March 2020 to all students
who were currently enrolled in spring semester (N = 33,280). A total
of 4276 students (response rate = 12.8%) responded to the wave 1
survey, and 3653 completed all outcome items assessed in the current
study. Wave 2 and 3 surveys were only sent to those who responded
to the wave 1 survey; of those, 1766 students (41.3%) completed the
wave 2 survey and 1390 students (32.5%) completed the third survey.
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life, fears about the implications of the virus on personal health,
employment and general uncertainty about the future led to observed
increases in psychological distress (Aylie et al., 2020; Filgueiras
and Stults-Kolehmainen, 2020; Smith et al., 2020). These necessary
public health measures also included negative consequences such as
limiting access to in-person social contact, mental health facilities and
physical health facilities as well as impeding individual livelihoods;
all of which are essential healthy coping mechanisms during times of
increased distress (Helliwell and Putnam, 2004; Penedo and Dahn,
2005; Diener and Ryan, 2009). Thus, the COVID-19 pandemic
created an environment in which unhealthy coping mechanisms, such
as problematic alcohol use, were likely to increase. Previous reports
have linked exposure to catastrophic societal events and natural
disasters to increased alcohol use (Morita et al., 2015; Locke et al.,
2020). Indeed, many reports have now demonstrated that alcohol
use has increased significantly since the beginning of the COVID-19
pandemic (Ahmed et al., 2020; Clay et al., 2020; Dumas et al., 2020;
Grigoletto et al., 2020; Kim et al., 2020; Lechner et al., 2020; Neill
et al., 2020; Pollard et al., 2020; Stanton et al., 2020; Tran et al.,
2020; Vanderbruggen et al., 2020; Wardell et al., 2020).
Several recent studies have reported changes in alcohol use during
the COVID-19 pandemic. Generally, studies report an increase in
alcohol use documented via cross-sectional design (Ahmed et al.,
2020; Clay et al., 2020; Dumas et al., 2020; Kim et al., 2020;
Lechner et al., 2020; Neill et al., 2020; Stanton et al., 2020; Tran
et al., 2020; Vanderbruggen et al., 2020; Wardell et al., 2020).
Three longitudinal studies have reported on alcohol use prior to
and during the COVID-19 pandemic. A study examining changes
in wastewater reported ‘decreased’ alcohol consumption after selfisolation measures were enforced in the district (Bade et al., 2020),
whereas two other longitudinal studies reported results in-line with
‘increases’ observed in cross-section. A national cohort study in the
USA reported increases in alcohol consumption from assessments
completed in April 2019 to April 2020 (Pollard et al., 2020), and a
second study reported increased emergency room visits due to alcohol
intoxication documented via chart review prior to and during the
pandemic (Grigoletto et al., 2020). In addition to examining changes
in alcohol use several studies have examined factors associated with
those changes including alcohol-related coping motives (Wardell
et al., 2020), inhibitory control (Clay et al., 2020), symptoms of anxiety or depression (Dumas et al., 2020; Lechner et al., 2020; Neill et al.,
2020; Rodriguez et al., 2020; Stanton et al., 2020; Tran et al., 2020;
Wardell et al., 2020), social connectedness (Lechner et al., 2020;
Wardell et al., 2020) and loss of job or income (Neill et al., 2020;
Vanderbruggen et al., 2020; Wardell et al., 2020), all documented
in cross-sectional analysis. While at least two studies demonstrate
longitudinally assessed increases in alcohol use following the COVID19 pandemic, these studies did not examine associations between
increased drinking and psychological or behavioral factors (Grigoletto et al., 2020; Pollard et al., 2020).
The current manuscript aimed to expand upon previous studies
by examining alcohol use at multiple timepoints in order to examine
longitudinal changes in drinking among a sample of college students
during the initial months of the COVID-19 pandemic. Furthermore,
the current study aimed to examine changes in high-risk drinking
patterns that have been linked to increased likelihood of developing
an Alcohol Use Disorder (Greenfield et al., 2014; Olsson et al., 2016;
Tavolacci et al., 2019). Previous research has shown that considering
both maximum drinks per drinking day and total number of drinks
per week are important determinants of risk for developing alcoholrelated problems (Greenfield et al., 2014), leading institutions such as
Alcohol and Alcoholism, 2021
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Alcohol and Alcoholism, 2021
Measures
Alcohol use (completed in waves 1–3) In order to provide insight to
changes in drinking patterns that could affect risk level for developing
an Alcohol Use Disorder or increase risk of chronic disease, the
NIAAA definition for exceeding low-risk drinking was utilized as
the primary outcome variable. As defined by NIAAA, for women,
low-risk drinking is no more than three standard drinks (SDs) on
any single day and no more than seven SDs per week. For men,
it is defined as no more than four SDs on any single day and no
more than 14 SDs per week (NIAAA, 2017). Two variables were
computed for each gender assigned at birth, based on these limits—
one for exceeding daily limits and one for exceeding weekly limits.
Those variables were collapsed into one binary variable indicating
that the participant had exceeded either daily or weekly drinking
limits in the given assessment week (0 = not exceeded, 1 = exceeded).
Patterns of drinking used to form the primary outcome variable were
garnered via the TLFB (Sobell et al., 1996), a well-validated calendar
assisted measure. Unfortunately, this classification method does not
account for gender identification outside of cisgender. A notation on
the need to improve classification methods for risky drinking based
on drinking patterns for individuals identifying as non-cisgender or
in transition is included in the discussion.
Financial distress due to COVID-19 (completed at wave 3) Three
items assessed financial distress specifically related to the COVID19 pandemic (Conway et al., 2020). Each item (e.g. ‘The coronavirus
(COVID-19) has impacted me negatively from a financial point of
view’ and ‘I have lost job-related income due to the coronavirus’) was
rated on a 7-point Likert-type scale ranging from 1 (strongly disagree)
to 7 (strongly agree). The total score was calculated by summing
three items and showed good reliability in this sample (Cronbach’s
alpha = 0.818).
Psychological distress due to COVID-19 (completed at wave 3)
Three items assessed psychological distress specifically related to
the COVID-19 pandemic (Conway et al., 2020). Each item (e.g. ‘I
have become depressed because of the coronavirus (COVID-19)’ and
‘The coronavirus outbreak has impacted my psychological health
negatively’) was rated on a 7-point Likert-type scale ranging from
1 (strongly disagree) to 7 (strongly agree). The total score was
calculated by summing the three items and showed good reliability
in this sample (Cronbach’s alpha = 0.850).
Coronavirus-related fears (completed at wave 3) Three items
assessed general and health related fears associated with the COVID19 pandemic (Conway et al., 2020). Each item (e.g. ‘I am stressed
around other people because I worry I’ll catch the coronavirus
(COVID-19)’ and ‘I am afraid of the coronavirus’) was rated on
a 7-point Likert-type scale ranging from 1 (strongly disagree) to
7 (strongly agree). The total score was calculated by summing the
three items and showed good reliability in this sample (Cronbach’s
alpha = 0.881).
Impact of racial tensions and distress (completed at wave 3) Two
items were created by the authors to assess the impact of current
racial tensions amid the pandemic. The assessment period followed
soon after the death of George Floyd on 25 May, 2020, which
dominated media coverage and prompted protests around the USA.
Each item specifically references the death of George Floyd (i.e.
‘Current racial tensions related to the death of George Floyd have
impacted me negatively’ and ‘Current racial tensions related to the
death of George Floyd have caused a lot of anxiety/stress for me’)
and was rated on a 7-point Likert-type scale ranging from 1 (strongly
disagree) to 7 (strongly agree). The total score was calculated by
summing the two items and showed good reliability in this sample
(Cronbach’s alpha = 0.869).
Analytic strategy
Generalized estimating equations (GEE) were used to examine alcohol consumption reported across the four 7-day assessment periods,
with a binomial distribution, logit link and exchangeable working
correlation matrix specified. First, the main effect of time (0, 1, 2,
3) on drinking outcome (0 = did not exceed limit, 1 = exceeded
limit) was modeled. Next, the main effects of the four independent
variables were added to the model. The independent variables were
the scales detailed in the measurement section: (a) financial distress,
(b) psychological distress, (c) coronavirus-related fears and (d) impact
of racial tension. Finally, a model (Table 2) containing the main
effects of each independent variable as well as the four two-way
interactions between each variable and time was added in order
to examine associations between changes in drinking patterns and
each variable. Two exploratory models examined the effect of gender
on the relationship between psychological and financial distress and
risky drinking patterns, with hypotheses formed based on previously
published research (Rodriguez et al., 2020). These models included
all variables in the final model as well as a three-way interaction
between gender, psychological or financial distress (each modeled
separately) and time. Covariates were selected a priori based on the
extant alcohol use literature and included race: [White (0), Asian (1),
Black (2), multiracial (3) or other (4)]; age, gender: [male (0) female
(1)]; living environment: [with parent (0), my home/apartment (1),
other (2)]. Due to very small cell sizes for two racial groups (American
Indian or Alaskan Native and Native Hawaiian), these groups could
not be included in inferential analyses. For reporting within the
correlation table, race and living environment were recoded into
binary variables (race: white = 0, nonwhite = 1; living situation: with
parents = 0, my home/apt/other = 1). Risky drinking across weeks
was split into two variables (risky drinking in the 7-day observation
period prior to the pandemic-related school closure: 0 = did not
exceed low-risk limit, 1 = exceeded limits) and a second variable
combining the three 7-day observation periods following the closure
of the campus (0 = did not exceed at any point during the 3 weeks,
1 = exceeded limits in at least 1 week) for the correlation table.
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Only students completing all three surveys (n = 1001) are included
in the current analysis. In order to assess sensitivity to missing data, a
series of analyses were conducted for participants completing only
wave 1, waves 1 and 2 and waves 1 and 3. Results from these
sensitivity analyses were in the same direction and significance level
as the main results reported (see Supplementary Tables for results
of sensitivity analysis). The final sample was 83.1% females, 84.1%
non-Hispanic whites, and the mean age was 25.66 (SD = 8.66) years.
Demographics reported by the University registrar at the time of
study initiation were 63.4% females, 75.6% non-Hispanic whites;
thus, the current sample is skewed in assessing a greater proportion
of females and non-white Caucasians. Participants were told their
responses would be confidential and that the purpose of the survey
was to present a broad picture of student wellness. As an incentive,
participants were given the opportunity to enter a drawing to win
gift cards ranging from $20 to $100 at each of the three assessment
points.
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Alcohol and Alcoholism, 2021
Table 1. Descriptives and zero-order correlations
Correlations full sample (n = 1001)
M/N
SD/(%)
1
2
(1) Age
(2) Sex (female)
25.8
832
8.9
83.2%
−0.073
(3) Race binary (nonwhite)
(4) Living environment (home/apt)
(5) COVID financial
(6) COVID psychological distress
158
495
12.03
12.64
15.8%
49.5%
5.83
5.03
0.036
.451∗∗
−0.148∗∗
−0.139∗∗
(7) COVID fear
(8) COVID racial tension
(9) Risky drinking prior to closure
9.89
8.41
85
5.00
3.72
8.5%
0.041
−0.064∗
−0.025
−0.063
0.090∗∗
0.171∗∗
0.129∗∗
0.162∗∗
−0.042
−0.016
(10) Risky drinking after closure
233
23.3%
−0.012
0.045
3
4
0.073∗
0.025
−0.034
−0.077∗
−0.092∗∗
0.036
0.096∗∗
−0.063∗
−0.090∗∗
0.029
0.005
0.014
0.059
5
0.332∗∗
0.133∗∗
0.163∗∗
−0.020
0.074∗
6
7
8
0.417∗∗
0.394∗∗
0.078∗
0.076∗
0.426∗∗
−0.037
0.053
−0.015
0.050
9
0.392∗∗
∗ Denotes P < 0.05,
∗∗ Denotes P < 0.01.
RESULTS
DISCUSSION
Bivariate correlations, means and standard deviations for all variables included in analyses are listed in Table 1; descriptive reporting
for groups (e.g. race, living situation) contained within collapsed
variables in Table 1 follows. In the week prior to campus closure,
8.5% (n = 85) participants reported drinking patterns that exceeded
low risk drinking guidelines. That percentage was higher (12.6%,
n = 126) in the week following campus closure and remained higher
at each follow-up assessment (11.9%, n = 119; and 12.1%, n = 121),
respectively. The majority of the sample identified as white (84.2%)
and also included individuals identifying as Asian (3.0%), Black
or African American (3.5%), multiracial (2.9%), Native Hawaiian
(0.1%) or a racial group not listed (6.3%). A slight majority of the
sample reported living at their home or apartment (49.5%), followed
by those who were living with their parent(s) or guardian (48.8%) or
other living environment (1.6%) following campus closure.
The main effect of time on risky drinking was significant;
risky drinking increased following the baseline assessment period
[b = 0.452, 95% confidence interval (CI) = 0.218, 0.685, P < 0.001]
and remained at an increased level at each of the follow-up assessments (b = 0.395, 95% CI = 0.144, 0.645, P = 0.002; b = 0.404,
95% CI = 0.165, 0.643, P = 0.001) (Supplemental Table 1). Changes
in risky drinking after the baseline assessment (between the second,
third and fourth 7-day observation periods) were nonsignificant.
Significant main effects (examined prior to the final model that
included interaction terms) indicated that higher psychological distress associated with COVID-19, and higher impact of racial tensions
since the pandemic were associated with increased likelihood of risky
drinking overall (b = 0.039, 95% CI = 0.003, 0.074, P = 0.031)
and (b = 0.049, 95% CI = 0.004, 0.094, P = 0.032), respectively
(Supplemental Table 1). Conversely, endorsement of fears related
to the COVID-19 virus was associated with less risky drinking
overall (b = −0.047, 95% CI = −0.079, −0.016, P = 0.003).
The final model, which included all four two-way interactions
between independent variables and time, demonstrated that only
financial distress since the COVID-19 pandemic was associated with
increased risky drinking over time (b = 0.020, 95% CI = 0.006,
0.035, P = 0.006) (Table 2). Exploratory analyses examining
differences in gender in terms of the association between financial
distress, psychological distress and changes in risky drinking did not
reveal significant effects (b = −0.010, 95% CI = −0.042, 0.022,
P = 0.556) and (b = −0.013, 95% CI = −0.022, 0.047, P = 0.472),
respectively.
In this longitudinal study of alcohol consumption assessed at four
time points from 4 March 2020 through 2 June 2020, we observed
a significant increase in risky drinking patterns. Risky drinking
increased in the week following campus closure and remained significantly elevated in the two follow-up assessment periods. Additionally,
we observed several factors to be associated with risky drinking
overall, including psychological distress, fears related to COVID19 and impact of racial tensions. However, only loss of income or
employment-related distress due to the pandemic was associated with
an increase in risky drinking across the four reporting periods.
The current results align with some but not all findings reported
in previous studies examining factors related to alcohol use during
the COVID-19 pandemic. Specifically, several studies reported associations between alcohol use during the pandemic and depressive
symptoms or broader indices of psychological distress (Dumas et al.,
2020; Lechner et al., 2020; Neill et al., 2020; Rodriguez et al., 2020;
Stanton et al., 2020; Tran et al., 2020; Wardell et al., 2020). The
current study observed an association between psychological distress
due to the pandemic and risky drinking overall but did not find
an association between changes in risky drinking over time related
with this factor. Discrepancies may be due to differences in the
assessment of psychological distress, measurement of alcohol use and
study design. Specifically, the current study asked questions directly
related to changes in depressive symptoms or psychological wellbeing related to the pandemic, whereas most previous studies have
focused on assessing psychological symptoms in general. Additionally, this is the first study, to our knowledge, to examine factors associated with changes in patterns of risky drinking at multiple timepoints
during the COVID-19 pandemic, other indices of alcohol use or
cross-sectional assessment may produce different results. The general
finding of higher levels of risky drinking overall being associated with
psychological distress is in line with past literature examining the
relationships between these variables (e.g. Bott et al., 2005). Current
findings regarding the association between financial or employmentrelated distress and increased alcohol use are in line with reporting
in several previous studies (Neill et al., 2020; Vanderbruggen et al.,
2020; Wardell et al., 2020). The current findings expand the literature
by demonstrating this association within a longitudinal cohort design
and specifically in relation to changes in risky drinking patterns
rather than other indices of alcohol use. Additionally, this is the first
study, to our knowledge, to document an association between the
impact of racial tensions and increased risky drinking overall during
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Scale
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Alcohol and Alcoholism, 2021
Table 2. GEEs: factors associated with risky drinking across four timepoints
Parameter
Std. error
Lower (95%Wald CI)
Upper (95% Wald CI)
P
−2.52
−0.008
−0.028
0.018
0.514
0.009
0.130
0.211
−3.53
−0.027
−0.283
−0.395
−1.51
0.011
0.226
0.432
0.000
0.393
0.827
0.931
−0.820
−1.83
−0.110
−0.521
0.540
0.652
0.418
0.385
−1.87
−3.11
−0.930
−1.27
0.230
−0.551
0.709
0.235
0.129
0.005
0.791
0.177
0.452
−0.071
−0.045
0.084
−0.064
0.038
0.020
−0.016
0.006
0.005
0.168
0.527
0.023
0.029
0.025
0.036
0.007
0.008
0.008
0.011
0.123
−1.11
−0.090
0.026
−0.114
−0.033
0.006
−0.034
−0.010
−0.017
0.782
0.963
0.001
0.143
−0.015
0.108
0.035
0.001
0.022
0.027
0.007
0.893
0.055
0.005
0.011
0.298
0.006
0.064
0.472
0.651
the COVID-19 pandemic. While we did not observe an association
between racial tension and changes in risky drinking patterns over
time, this finding should be explored in future studies, particularly
given limitations of the current sample. Specifically, the ability to
examine associations between racial tension and changes in risky
drinking among black participants was significantly limited due to
small sample size for the group (3.5%, n = 35). In general, black
participants were less likely to demonstrate risky drinking patterns
as compared with white participants (b = −1.88, P = 0.006) and
reported higher impact of racial tension (mean difference = 3.06,
P < 0.001) as compared with white participants. This general finding
that black participants drank less than their white counterparts
aligns with previous research conducted prior to the 2020 pandemic
(Zapolski et al., 2014). Future studies designed to examine coping
mechanisms associated with racial tension and adequately powered
to examine racial group differences will provide highly valuable
contributions to the literature.
This study has limitations that are important to consider when
interpreting results. The degree that the present findings may generalize to other populations and or events is limited by several factors.
Data for the current study were collected from university students,
during the COVID-19 pandemic. Different populations as well as
events that are different from the COVID-19 pandemic may produce
different results. It is important to note that while the analysis
included changes in patterns of high-risk drinking previously associated with increased risk for Alcohol Use Disorder, the current results
are not capable of providing information on changes in actual risk.
Additionally, although the measure of psychological distress used in
the current analysis specified distress related to the pandemic, it is
also likely tapping into general psychological distress. Disentangling
these sources of distress would require assessment of psychological
functioning prior to the campus closure, which we do not have for
this sample. Moreover, all measurements associated with changes in
alcohol use were assessed at the third wave only. Research examining
changes in both alcohol use and changes in these measurements over
time would significantly improve the study design. The response rate
(12.9%) and high percentage of female Caucasian students limits
the generalizability of these results despite covariation for gender
and race. It is also important to consider the potential influence of
seasonal variation and or secular trends in drinking behavior that
are not accounted for within the current study. Future research is
needed to continue to track and monitor alcohol use as the pandemic
progresses as well as examine the utility of remote technologies to
deliver empirically supported strategies for alcohol use reduction (e.g.
Riper et al., 2011). As noted, studies that include samples capable
of providing adequate power to detect differences between majority
and minority groups on several factors examined in the current study
will provide crucial contributions to the literature in this area. This
study was also limited in that it relied on assessing drinking patterns
as assessed by gender assigned at birth. This method only allows for
classification of drinking risk for cisgender individuals. Additionally,
the main outcome variable was assessed via retrospective timeline
follow-back self-report; while this method has been well validated, it
is subject to limitations inherent to self-report measures.
In conclusion, the current study presents novel information on
changes in risky drinking patterns during the COVID-19 pandemic.
Examining changes in drinking associated with increased risk of
developing an Alcohol Use Disorder provides valuable information for universities and other public health institutions to use in
preparation for addressing long-term consequences of the pandemic.
Whereas the current results do not include a clinical assessment of
Alcohol Use Disorder, they may provide a more sensitive assessment
of changes in drinking that could lead to functional impairments
if they are not adequately addressed. Additionally, these findings
suggest that individuals experiencing financial distress may represent
a particularly high-risk group. Given the current unprecedented levels
of unemployment in the USA caused by the pandemic (Allegretto
and Liedtke, 2020; Organization IL, 2020), it will be imperative
to identify interventions that consider the cross-section of job loss,
financial stress and problematic alcohol use.
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Intercept
Age
Time (week)
Gender (female)
Race (referent = white)
Asian
Black or African American
Multiracial
Another race
Living (referent = w/parent or guardian)
At my home/apt
Other
Financial distress
Psychological distress
COVID-19 fear
Racial tension
Financial distress by time
Psychological distress by time
COVID-19 fear by time
Racial tension by time
b
6
SUPPLEMENTARY MATERIAL
Supplementary material is available at Alcohol and Alcoholism online.
CONFLICT OF INTEREST STATEMENT
None declared.
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REFERENCES
Alcohol and Alcoholism, 2021
Clinical Infectious Diseases
ViewpointS
Muge Cevik,1 Julia L. Marcus,2 Caroline Buckee,3 and Tara C. Smith4
1
Division of Infection and Global Health Research, School of Medicine, University of St Andrews, St Andrews, United Kingdom, 2Department of Population Medicine, Harvard Medical School and
Harvard Pilgrim Health Care Institute, Boston, Massachusetts, USA, 3Center for Communicable Disease Dynamics, Harvard T. H. Chan School of Public Health, Boston, Massachusetts, USA, and
4
College of Public Health, Kent State University, Kent, Ohio, USA
It is generally agreed that striking a balance between resuming economic and social activities and keeping the effective reproductive
number (R0) below 1 using nonpharmaceutical interventions is an important goal until and even after effective vaccines become
available. Therefore, the need remains to understand how the virus is transmitted in order to identify high-risk environments and activities that disproportionately contribute to its spread so that effective preventative measures could be put in place. Contact tracing
and household studies, in particular, provide robust evidence about the parameters of transmission. In this Viewpoint, we discuss
the available evidence from large-scale, well-conducted contact-tracing studies from across the world and argue that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission dynamics should inform policy decisions about mitigation strategies
for targeted interventions according to the needs of the society by directing attention to the settings, activities, and socioeconomic
factors associated with the highest risks of transmission.
Keywords. COVID-19; coronavirus; SARS-CoV-2; novel coronavirus; transmission.
Since coronavirus disease 2019 (COVID-19) was first described
in December 2019, we have witnessed widespread implementation of local and national restrictions in many areas of the
world and social, health, and economic devastation due to direct and indirect impact of the pandemic. It is generally agreed
that striking a balance between resuming economic and social
activities and keeping the effective reproductive number (R0)
below 1 using nonpharmaceutical interventions is an important
goal until and even after effective vaccines become available.
Achieving this balance requires an understanding of how the
virus is spread. There is also a need to identify the structural
factors that contribute to transmission, a particular concern
considering the already stark health disparities driven by socioeconomic and racial/ethnic inequities in our societies.
An understanding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission dynamics can inform
policy decisions by directing attention to the settings and activities that confer the highest risk of transmission and understanding of the intersection between poverty, household
crowding, and COVID-19. This understanding will allow policymakers and public health practitioners to shape the best
strategy and preventative measures and inform the public about
Received 11 June 2020; editorial decision 15 September 2020; published online 23 September
2020.
Correspondence: M. Cevik, Division of Infection and Global Health Research, School of
Medicine, University of St Andrews, Fife, KY16 9TF UK (mc349@st-andrews.ac.uk).
Clinical Infectious Diseases® 2020;XX(XX):1–6
© The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society
of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.
DOI: 10.1093/cid/ciaa1442
transmission risk. Epidemiological investigations including
contact-tracing studies and outbreak investigations conducted
so far across the world already provide crucial information
about the probability of infection in close contacts and various
environments. We argue that health authorities should use the
large-scale, well-conducted contact-tracing studies and observations from across the world to date in their risk assessment
and mitigation strategies. This article summarizes current
knowledge about transmission dynamics and discusses recommendations that could prevent infections by focusing on factors
associated with risk of transmission.
FACTORS INFLUENCING TRANSMISSION DYNAMICS
Emerging data suggest that risk of transmission depends on
several factors, including contact pattern, host-related infectivity/susceptibility pattern, environment, and socioeconomic
factors (Figure 1). We will discuss the emerging evidence relating to each of these aspects of transmission.
Contact Pattern
Contact-tracing studies provide early evidence that sustained
close contact drives the majority of infections and clusters. For
instance, living with the case, family/friend gatherings, dining,
or traveling on public transport were found to have a higher risk
for transmission than market shopping or brief (<10 minutes)
community encounters [1–3]. While people are more likely to
recall and disclose close and household contacts, and it is easier
for tracers to identify the source, household studies provide important information about the contact patterns and activities
VIEWPOINTS • cid 2020:XX (XX XXXX) • 1
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Severe Acute Respiratory Syndrome Coronavirus 2 (SARSCoV-2) Transmission Dynamics Should Inform Policy
Indoor/Outdoor
Venlaon
Long term care facilies
Environment
Host
factors
Contact
paern
Age
Infecousness
Severity of illness
Host defence factors
Socio-economic
factors
Poverty
Job insecurity
Prolonged working hours
Household crowding
Figure 1. Factors influencing transmission dynamics. Transmission depends on several factors, including contact pattern (duration of contact, gathering, proximity,
activity), environment (outdoor, indoor, ventilation), host-related infectivity/susceptibility pattern (ie, viral load in relation to disease course, severity of illness, age), and socioeconomic factors (ie, crowded housing, job insecurity, poverty). Virus infectivity and differences between other viruses and host immune factors are not discussed in this
review. (This figure was created by the authors based on available literature about SARS-CoV-2 transmission dynamics.) Abbreviation: SARS-CoV-2, severe acute respiratory
syndrome coronavirus 2.
associated with higher attack rates. Close contacts with the
highest risk of transmission are typically friends, household
members, and extended family, with a secondary attack rate that
ranges from 4% to 35% [1, 4–8]. In the same household, higher
attack rates are observed among spouses compared with the rest
of the household [8]. A systematic review including 5 studies
based on relationship demonstrated that household SAR (secondary attack rate) to spouses (43.4%; 95% confidence interval
[CI], 27.1–59.6%) was significantly higher than to other relationships (18.3%; 95% CI, 10.4–26.2%) [8]. Similar results were
observed in the USS Theodora Roosevelt outbreak in which
those sharing the same sleeping space had a higher risk of being
infected [9]. In addition, the attack rate has shown to be higher
when the index case is isolated in the same room with the rest
of the household or when the household members have daily
close contact with the index case [10, 11]. Transmission is significantly reduced when the index case is isolated away from the
family, or preventative measures such as social distancing, hand
hygiene, disinfection, and use of face masks at home are applied
[10, 11]. In a study of an outbreak in the largest meat-processing
plant in Germany, while the universal point of potential contact among all cases was the workplace, positive rates were
statistically significant for a single shared apartment, shared
2 • cid 2020:XX (XX XXXX) • VIEWPOINTS
bedroom, and associated carpool [12]. These findings suggest
that sleeping in the same room or sharing the same sleeping
space and increased contact frequency constitute a high risk of
transmission.
Large clusters have been observed in family, friend, and workcolleague gatherings including weddings and birthday parties [13,
14]. Other examples include gatherings in pubs, church services,
and close business meetings [14–17]. These findings suggest that
group activities pose a higher risk of transmission. In non–household contact-tracing studies, dining together or engaging in group
activities such as board games have been found to be a high risk
for transmission as well [18]. In the same household, frequent
daily contact with the index case and dining in close proximity
have been associated with increased attack rates [10, 11].
Large, long-term-care facilities such as nursing homes and
homeless shelters have seen increased rates of infection, in part
because of patterns of contact among staff and residents. In
nursing home outbreak investigations from the Netherlands,
Boston, and London, multiple viral genomes were identified,
suggesting multiple introductions to the facility leading to infections among residents [19–21]. In an investigation of 17
nursing homes that implemented voluntary staff confinement
with residents, including 794 staff members and 1250 residents
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Proximity to index case
Time of contact
Duraon of exposure
Contact frequency
Acvity
Host Factors
Contact tracing and outbreak investigations suggest that many
people with SARS-CoV-2 either do not contribute to onward
transmission or have minimal potential to do so [6, 17], and
a large number of secondary cases are often caused by a small
number of infected patients. While this may also be due to contact pattern and environmental factors, host factors strongly influence this variation; individual variation in infectiousness is
an expected feature of superspreading events.
Timing of the contact with an index case is key in transmission dynamics as it relates to the infectiousness of the index case.
In a systematic review of studies published up to 6 June 2020,
we found that viral load peaks early in the disease course, with
the highest viral loads observed from symptom onset to day 5,
indicating a high level of infectiousness during this period [23]
(Figure 2). Supporting these findings, transmission events are
estimated to occur in a short window, likely a few days prior to
and following symptom onset [4, 23]. For example, a contacttracing study that followed up 2761 contacts of 100 confirmed
COVID-19 cases demonstrated that infection risk was higher
if the exposure occurred within the first 5 days after symptom
onset, with no secondary cases documented after this point [4].
This understanding indicates that viral dose plays an important
role in transmission dynamics. In contrast, higher viral loads in
severe acute respiratory syndrome coronavirus (SARS-CoV-1)
and Middle East respiratory syndrome coronavirus (MERSCoV) were identified in the second week after symptom onset,
suggesting that patients had viral load peak after hospitalization
[23]. Therefore, early viral load peak also explains efficient community SARS-CoV-2 spread in contrast to SARS-CoV-1 and
MERS-CoV, during which community spread was put under
control; however, nosocomial spread was an important feature
of the outbreaks. In contrast, during COVID-19, only a small
number of hospital-based outbreaks have been reported so far,
which may be due to a downtrend in viral load levels later in the
disease course [23, 24].
Symptoms and severity of illness appear to influence transmission dynamics as well. People with symptoms appear to have
a higher secondary attack rate compared with presymptomatic
and asymptomatic index cases (those who develop no symptoms
Figure 2. SARS-CoV-2 viral load dynamics and period of infectiousness. Incubation period (time from exposure to symptom onset) of 6 days (2–21 days), peak viral load
levels documented from day 0 (symptom onset) to day 5, infectious period starts before symptom onset up to 10 days (this may be extended in patients with severe illness),
and RNA shedding continues for a prolonged period of time but culturable virus has been identified up to day 9 of illness. (This figure was created by the authors on Biorender,
https://biorender.com based on available literature about SARS-CoV-2 viral load dynamics.) Abbreviations: max, maximum; PCR, polymerase chain reaction; SARS-CoV-2,
severe acute respiratory syndrome coronavirus 2.
VIEWPOINTS • cid 2020:XX (XX XXXX) • 3
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in France, staff confining themselves to a single facility for a
weeklong period was associated with decreased outbreaks in
these facilities [22].
These findings emphasize that contact patterns, including the
duration of contact, contact frequency, proximity to index case,
and types of activities, influence transmission risk, highlighting
the need for tailored prevention strategies for different settings.
Environment
Transmission risk is not one-dimensional and contact patterns
also depend on the setting of the encounter. Findings from
contact-tracing studies in Japan suggest an 18.7-fold higher risk
of transmission indoors compared with outdoor environments
[28]. These findings are in keeping with our understanding
about transmission patterns of respiratory viral infections.
While outdoor settings usually have lower risk, prolonged contact in an enclosed setting can lead to increased risk of transmission. Especially when combined with environmental factors
such as poor ventilation and crowding this may lead to further
increases in attack rates. Epidemiological studies so far support
this knowledge. SARS-CoV-2 is much more efficiently spread
in enclosed and crowded environments. The largest outbreaks
from across the world are reported in long-term-care facilities
such as nursing homes, homeless shelters, prisons, and also
workplaces including meat-packing plants and factories, where
many people spend several hours working together, dining and
sharing communal spaces [12, 14]. A study in 6 London care
homes experiencing SARS-CoV-2 outbreaks identified a high
proportion of residents (39.8%) and staff (20.9%) who tested
positive for SARS-CoV-2 [20]. Among 408 individuals residing
at a large homeless shelter in Boston, 36% of those tested were
found to be positive [16]. Although it is much harder to obtain data from incarcerated populations, the largest clusters of
cases observed in the United States have all been associated with
4 • cid 2020:XX (XX XXXX) • VIEWPOINTS
prisons or jails, suggesting a high attack rate in these institutional settings [29]. Social distancing is the opposite of incarceration, and overcrowding, poor sanitation and ventilation, and
inadequate healthcare contribute to the disproportionate rates
of infections seen in prisons and jails, which demonstrates the
larger pattern of the health disparities in our societies.
Socioeconomic Factors and Racial/Ethnic Disparities
Global figures suggest that there is a strong association between
socioeconomic deprivation, race/ethnicity, and a higher risk of
infection and death from COVID-19 [30, 31]. People facing the
greatest socioeconomic deprivation experience a higher risk
of household and occupational exposure to SARS-CoV-2, and
existing poor health leads to more severe outcomes if infected
[32]. People with lower-paid and public-facing occupations are
often classified as essential workers who must work outside
the home and may travel to work on public transport. Indeed,
in New York City, higher cumulative infection rates were observed in neighborhoods that continued to engage in mobility
behaviors consistent with commuting for work [33]. These occupations often involve greater social mixing and greater exposure risk due to prolonged working hours, resulting in reduced
ability to practice social distancing among low-income families
[34]. In addition, households in socioeconomically deprived
areas are more likely to be overcrowded, increasing the risk of
transmission within the household. Black, Hispanic, and other
marginalized, racial/ethnic, and migrant groups have also been
shown to be at greater risk of infection, severe disease, and
death from COVID-19 [31, 35–37]. These increased risks are
also likely due to socioeconomic conditions that increase the
risk of transmission, inequitable access to adequate healthcare,
and higher rates of comorbidities due to adverse living and
working conditions and structural racism. It is not surprising
that the largest outbreaks are observed in meat-packing plants,
and most commonly exposed occupations include nurses, taxi
and bus drivers, and factory workers [31]. These disparities
also shape the strong geographic heterogeneities observed in
the burden of cases and deaths—for example, across the United
States and the United Kingdom [31, 38]. These findings support
the hypothesis that the COVID-19 pandemic is strongly shaped
by structural inequities that drive household and occupational
risks, emphasizing the need to tailor effective control and recovery measures for these disadvantaged communities proportionate to their greater needs and vulnerabilities.
Large Clusters and Superspreading Events
Clusters have become a prominent characteristic of SARSCoV-2, which distinguishes it from seasonal influenza [14, 17].
This emphasises that large clusters and superspreading events
may be the driver of the majority of infections, just as they were
for SARS-CoV-1 in 2002–2003 [39, 40]. For instance, during the
2003 SARS-CoV-1 outbreak, over 70% of infections were linked
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throughout the illness) [18]. While asymptomatic patients can
transmit the virus to others, the findings from 9 studies in a systematic review, including studies published up to 3 July 2020,
found secondary attack rates of 0% to 2.8%, compared with secondary attack rates of 0.7% to 16.2% in symptomatic cases in
the same studies, suggesting asymptomatic index cases transmit
to fewer secondary cases [18]. Another systematic review that
included studies published up to 10 June 2020 similarly found a
reduced risk of transmission for asymptomatic versus symptomatic cases (.35; 95% CI, .10–1.27) and presymptomatic versus
symptomatic cases (.63; 95% CI, .18–2.26) [25]. There are also
differences in attack rates based on symptom severity. In the
Zhang et al [26] study the secondary attack rate was 3.5% for
those with mild symptoms, 5.7% for those with moderate symptoms, and 4.5% for those with severe symptoms (based on the
China Centers for Disease Control guidelines). In a contacttracing study, contacts of severe cases were more likely to develop severe infections themselves [4].
Virus transmission is also affected by a number of other host
factors, including host defense mechanisms and age. Current
synthesis of the literature demonstrates significantly lower
susceptibility to infection for children aged under 10 years
compared with adults given the same exposure, and elevated
susceptibility to infection in adults aged over 60 years compared
with younger or middle-aged adults [27].
RECOMMENDATIONS
Increased risk of transmission in deprived areas and among
people in low-paid jobs suggests that poverty and household
crowding need to be addressed with interventions that go beyond guidance on social distancing, hand hygiene, and mask
use. Previous research suggests that, although social distancing
during the 2009 H1N1 swine flu pandemic was effective in reducing infections, this effect was most pronounced in households with greater socioeconomic advantage. Similar findings
are emerging for COVID-19, with the ability to practice social
distancing strongly differentiated by county and household income [34]. The disproportionate impact of COVID-19 on
households living in poverty and the racial and ethnic disparities observed in many countries emphasize the need to urgently
address these inequities that directly impact health outcomes.
This includes social and income protection and support to ensure low-paid, nonsalaried, and zero-hours contract workers can
afford to follow isolation and quarantine recommendations; provision of protective equipment for workplaces and community
settings; appropriate return-to-work guidelines; and testing and
opportunities for isolation outside of the home to protect those
still at work.
Second, knowing which contacts and settings confer the
highest risk for transmission can help direct contact-tracing
and testing efforts to increase the efficiency of mitigation strategies. Early viral load peak in the disease course indicates
that preventing onward transmission requires immediate selfisolation with symptom onset, prompt testing, and results with
a 24- to 48-hour turnaround time, and robust contact tracing.
In many countries, people with symptoms access testing late
in the disease course, by which time they may have had multiple contacts while in the most infectious period. While selfisolation with symptoms is crucial, 75% of those with symptoms
and their contacts in the United Kingdom reported not fully
self-isolating [44]. While presymptomatic transmission likely
contributes to a fraction of onward transmission, over half of
transmission is caused by those with symptoms, especially in
the first few days after symptom onset. These findings suggest
that messages should prioritize isolation practice, and policies
should include supported isolation and quarantine.
Third, policymakers and health experts can help the public
differentiate between lower-risk and higher-risk activities and
environments and public health messages could convey a spectrum of risk to the public to support engagement in alternatives for safer interaction, such as in outdoor settings. Without
clear public health communication about risk, individuals may
fixate on unlikely sources of transmission—such as outdoor activities—while undervaluing higher-risk settings, such as family
and friend gatherings and indoor settings. Enhancing community awareness about risk can also encourage symptomatic persons and contacts of ill persons to isolate or self-quarantine to
prevent ongoing transmission.
Finally, because crowded indoor spaces and gatherings likely
will continue to be the driver of transmission, public health
strategies will be needed to mitigate transmission in these settings (eg, nursing homes, prisons and jails, shelters, and meatpacking plants), such as personal protective equipment and
routine testing to identify infected individuals early in the disease course. As part of the pandemic response we may need
to consider fundamentally redesigning these settings, including
improved ventilation, just as improved sanitation was a response to cholera. Such strategies should be adopted in settings
where large outbreaks and superspreading events have been
identified by contact-tracing studies.
While modeling studies and computer simulations could contribute to our understanding of transmission dynamics and aerodynamics of droplets, contact-tracing studies provide real-life
transmission dynamics and individual and structural factors associated with SARS-CoV-2 transmission, which are essential to
shape our public health plans, mitigate superspreading events,
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to superspreading events in Hong Kong and Singapore [39].
Hallmarks for superspreading events include a combination of
factors, typically a highly infectious individual(s) gathered with
other individuals in enclosed and crowded environments [14,
17]. There have been several superspreading events reported so
far. For example, an outbreak investigation from China identified that 24 out of 67 passengers were infected during a 50-minute return bus journey, which was linked to an index case who
was symptomatic the day before the trip. In contrast, during the
event, only 6 people were infected, all of whom were in close
contact with the same index case [41]. In Washington State, a
mildly symptomatic index case attended a choir practice (the
practice was 2.5 hours), and out of 61 persons, 32 confirmed
and 20 probable secondary COVID-19 cases occurred with an
attack rate of 53.3% to 86.7% [42]. While these superspreading
events occur, the frequency of these events and whether they are
caused by a single index case are unclear. The modeling suggests
that several independent introductions might be needed before a COVID-19 outbreak eventually takes off, meaning often
these large outbreaks occur when multiple infected persons are
introduced to the environment, as shown in the nursing home
investigation [43]. Other large outbreaks are reported in night
clubs, karaoke bars, and pubs [14, 17], which may be related to
crowding, leading to multiple introductions into the same setting as seen in nursing home investigations. These findings and
observations suggest that contact-tracing investigations need to
be combined with phylogenetic analysis to understand the settings and activities most likely to yield a superspreading event
to inform preventative measures.
and control the current pandemic. Further understanding of
transmission dynamics is also critical to developing policy recommendations for reopening businesses, primary and secondary schools, and universities.
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Notes
Financial support. J. L. M. is supported in part by the US National
Institute of Allergy and Infectious Diseases (grant number K01 AI122853).
Potential conflicts of interest. J. L. M. has consulted for Kaiser Permanente
Northern California on a research grant from Gilead Sciences. All other authors report no potential conflicts. All authors have submitted the ICMJE
Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed.
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