Article review “for kim woods only”

Journal of Affective Disorders 290 (2021) 279–283

Available online 3 May 2021
0165-0327/© 2021 Published by Elsevier B.V.

Research paper

Impact of the COVID-19 pandemic on mental health service use among
psychiatric outpatients in a tertiary hospital

Jun Ho Seo a,c, Se Joo Kim a, Myeongjee Lee b, Jee In Kang a,*

a Institute of Behavioral Science in Medicine & Department of Psychiatry, Yonsei University College of Medicine, Yonsei-ro 50-1, Seodaemun-gu, Seoul, 03722, Republic
of Korea
b Biostatistics Collaboration Unit, Department of Biomedical Systems Informatics, Yonsei University College of Medicine, Seoul, Republic of Korea
c Graduate School, Yonsei University College of Medicine, Seoul, Republic of Korea

A R T I C L E I N F O

Keywords:
COVID-19
Mental health service use
Psychiatric disorder
Time-series analysis

A B S T R A C T

Background: The aim was to explore the impact of the COVID-19 pandemic on mental health service use ac-
cording to mental disorder diagnosis among psychiatric outpatients.
Methods: Psychiatric outpatient visits and patient diagnostic information were extracted from the EHR(electronic
health records) of a Korean tertiary hospital during 3 months of the COVID-19 pandemic and 3 months before the
COVID-19 outbreak. Visit rates of psychiatric outpatients according to primary psychiatric diagnosis category
before and after the COVID-19 pandemic were compared using an over-dispersed Poisson regression model. The
temporal associations between the number of daily outpatient visits and the daily number of newly confirmed
cases were examined by time-series analysis within each diagnosis category.
Results: Total daily outpatient visit rate was significantly reduced during the pandemic. Among the nine most
prevalent diagnosis categories, the daily visit rates for anxiety disorders, depressive disorders, and schizophrenia-
spectrum disorders were significantly reduced by about 29.8%, 14.8%, and 13.3% respectively. Time-series
analysis showed significant temporal correlations between the daily number of newly confirmed cases and the
daily visit rates for anxiety disorders and depressive disorders, whereas patients with schizophrenia-spectrum
disorders showed no significant temporal association.
Limitations: Potential confounding factors unrelated to the pandemic might have influenced the results.
Conclusions: The present findings suggest that patients with anxiety or depressive disorders may have concerns
regarding the spread of COVID-19, and may be more reluctant to visit psychiatry outpatient clinics. Delivery
strategies for mental healthcare services, such as telepsychiatry, would be helpful to enhance continuity of care
during the pandemic.

1. Introduction

South Korea was one of the first countries outside China to face a
major outbreak of coronavirus disease 2019 (COVID-19). The strong
infectivity of COVID-19 and rapid increase in the number of infected
people caused collective fear and health anxiety. In addition, the so-
cioeconomic impact of COVID-19 under robust quarantine and surveil-
lance has contributed to the development or exacerbation of various
psychiatric problems. (Tull et al., 2020; Becerra-García et al., 2020;
Verma and Mishra, 2020; Franchini et al., 2020; Brooks et al., 2020) An
updated meta-analysis of cross-sectional community-based studies be-
tween December 2019 and August 2020 during the COVID-19 pandemic

showed that anxiety in the general population increased 3-fold during
the COVID-19 pandemic (estimated overall prevalence of anxiety: 25%),
and that anxiety was associated with the initial or peak phase of the
outbreak and several risk factors, such as the female sex, younger age,
and social isolation. (Santabárbara et al., 2021) A more recent study
using a large electronic health record (EHR) showed that survivors of
COVID-19 were associated with an increased risk for psychiatric
sequelae, and a previous psychiatric diagnosis was independently
associated with an increased risk for COVID-19. (Taquet et al., 2021)
While the COVID-19 pandemic could increase psychological distress and
health anxiety, fear of contracting COVID-19 may increase a patient’s
reluctance to visit hospitals for appointments. (Bojdani et al., 2020; Yao

* Corresponding author.
E-mail address: [email protected] (J.I. Kang).

Contents lists available at ScienceDirect

Journal of Affective Disorders

journal homepage: www.elsevier.com/locate/jad

https://doi.org/10.1016/j.jad.2021.04.070
Received 12 October 2020; Received in revised form 3 April 2021; Accepted 26 April 2021

Journal of Affective Disorders 290 (2021) 279–283

280

et al., 2020) According to data from a healthcare technology company
which included more than 1600 provider organizations of the United
States, a substantial cumulative reduction in outpatient visits across all
medical departments, including behavioral health, was reported over
the course of the pandemic in 2020. (Ateev Mehrotra et al., 2021) An
Italian study of a neurology outpatient clinic showed that 30% of pa-
tients suspended hospital treatments, mostly due to fear of COVID-19
infection. (Piano et al., 2020) In the field of psychiatry, another Italian
study reported a reduction in the total number of voluntary psychiatry
admissions in seven general hospitals of Lombardy after the COVID-19
outbreak. (Clerici et al., 2020) A recent report showed a decrease in
mental health emergency service utilization in a large German psychi-
atric hospital during the rapid rise of the COVID-19 pandemic. (Hoyer
et al., 2020) The fear or reluctance to visit hospitals in people with
pre-existing mental health problems could increase the risk of discon-
tinuation of mental healthcare service use and exacerbation of psychi-
atric problems. In particular, recent reports have revealed that older
patients with mental disorders missed their treatments considerably
after the COVID-19 outbreak. (Bojdani et al., 2020; Wong et al., 2020)
While studies on mental healthcare in the pandemic have been gradually
accumulated, (Rajkumar, 2020; Neelam et al., 2021; Sheridan Rains
et al., 2021) there has been no study regarding the impact of the
COVID-19 pandemic on the patients’ use of psychiatry outpatient ser-
vices by diagnoses until the present time of March 2021. Identifying the
types of mental disorder which are liable to discontinuation of mental
healthcare service use during a pandemic, such as COVID-19, would be
important to provide a basis for policymakers to plan appropriate de-
livery method and level of support for people with different mental
disorders.

We aimed to explore the impact of the COVID-19 outbreak on pat-
terns of mental health service use according to mental disorder diagnosis
among psychiatric outpatients in a tertiary general hospital in Korea.
Since telemedicine is still illegal in South Korea, a decrease in the
number of ambulatory visits would be a parameter that can reflect a
reduction in healthcare utilization. We examined the number of visits by
psychiatric outpatients according to psychiatric diagnosis over 3 months
(Mar 2020 – May 2020) during the COVID-19 pandemic compared to 3
months (Oct 2019 – Dec 2019) before the first confirmed case of COVID-
19 in Korea (Jan. 20, 2020) (https://covid19.who.int/table). In addi-
tion, we examined whether an increase or decrease in the number of
daily visits to psychiatric outpatient clinics were affected by the daily
number of newly confirmed cases of the COVID-19 using a Poisson
regression model with time series analysis.

2. Methods

Data source and study population

Data for daily outpatient visits to the Department of Psychiatry at
Severance Hospital, one of the largest tertiary general hospitals in Seoul,
were collected retrospectively through the electronic health record
(EHR) system. The research site hospital provides hospital-based mental
health service mostly through the outpatient clinic with no community
mental health teams. Data collected from Oct. 2019 to May 2020 were
chosen, as we defined the periods before and during the COVID-19
pandemic as Oct. 2019 to Dec. 2019 and Mar. 2020 to May 2020,
respectively. The first case of COVID-19 in South Korea was confirmed
on January 20, 2020, and the daily confirmed COVID-19 cases started to
exceed 100 from February 22, 2020. Visits to faculty members who
consistently worked during both periods were included, and visits to
faculty members who moved to a different workplace during either of
the two periods were excluded to control for confounding effects asso-
ciated with physician availability. Patients aged under 18 years were
excluded. Data were de-identified prior to use. The daily number of
confirmed COVID-19 cases in South Korea was obtained from the WHO
Coronavirus Disease Dashboard (https://covid19.who.int/table). This

study was approved by the Severance Hospital Institutional Review
Board.

Variables

We collected the following data for each visit: patient age, date and
day of visit, psychiatric diagnoses, and whether each diagnosis was
definite or putative. Then we selected only one primary definite psy-
chiatric diagnosis per visit in the order of priority. All primary diagnoses
by the International Classification of Diseases 10th revision (ICD-10: F0.
x-F9.x) were categorized into clinically distinct groups. The following
nine diagnosis groups were selected as the most prevalent among adult
psychiatric outpatients at the tertiary hospital:

“Neurocognitive disorders, delirium, and other organic mental dis-
orders (F0.x),” “Schizophrenia spectrum disorders (F2.x),” “Bipolar
disorders (F30.x, F31.x),” “Depressive disorders (F32.x-F39.x),” “Anxi-
ety disorders (F40.x, F41.x),” “Obsessive-compulsive disorders (OCD)
(F42.x),” “Stress-related disorders (F43.x),” “Somatoform disorders
(F45.x),” and “Sleep-related disorders (F51.x, G47.x).”

The primary variable was set as the daily number of visits.

Analytical procedures

We first investigated whether daily outpatient visit rates to the
department of psychiatry were affected by COVID-19. To compare the
daily number of outpatient visits during the two periods, before and
during the COVID-19 pandemic, we used a Poisson regression model of
the observed daily number of outpatient visits and the logarithm of daily
session number was included as an offset. As overdispersion was
observed in the Poisson model, we adjusted for the day of the week and a
overdispersion parameter. The overdispersion parameter was estimated
using the Pearson’s Chi-squared statistic. We performed subgroup
analysis by psychiatric disorder group in the same way. In addition,
since sex and age are important variables that can influence risk
perception of the COVID-19 pandemic and unwillingness to visit
healthcare service, (Bojdani et al., 2020; Wong et al., 2020; Mehra et al.,
2020; Liu et al., 2020; Banerjee, 2020) the effect of sex and age was
examined. In the analysis by age groups, subjects were divided into three
age groups; young age group (18 to 35 years old), middle age group (36
to 55 years old), and old age group (56 years old or more). We deter-
mined the age boundaries according to a previous Korean psychiatric
study. (Kim and Yoon, 2018)

We then investigated the short-term effects of new daily confirmed
COVID-19 cases on psychiatric outpatient clinic visits by time-series
analysis using an overdispersed Poisson regression model for those
psychiatric disorders with significant changes. By averaging the new
daily COVID-19 cases leading up to and including the day of the visit, we
constructed cumulative lag variables, lag3, lag7, and lag14, to examine
the association. We adjusted for the day of the week as a covariate.

The SAS version 9.4 (SAS Institute, Cry, NC) was used for statistical
analyses. A two-sided P-value less than 0.05 was considered statistically
significant and the Bonferroni-adjusted method was used for the mul-
tiple comparisons.

3. Results

The total daily outpatient visit rate, or the number of visits per day,
during the period from March 1, 2020 to May 31, 2020 (n = 12,119,
mean age, 47.8 years; 59.9% female) was reduced by about 13.1%,
compared to the visit rate from October 1, 2019 to December 31, 2019
(n = 14,053, mean age, 48.3 years; 61.0% female). This reduction was
statistically significant after adjustment for confounders including the
daily session number of psychiatric outpatient clinics and the number of
working days during each period. In addition, reduction in the total
daily outpatient visit rate was observed in both males (RR = 0.900) and
females (RR=0.849) (Figure S1). In the analysis by age groups, the

J.H. Seo et al.

Journal of Affective Disorders 290 (2021) 279–283

281

reduction was also found in all the three age groups, and the reduction
was observed to be larger in the old age group compared to young age
group (RRs in young, middle, and old age group, 0.919, 0.876, and
0.824, respectively) (Figure S1).

Among the nine most frequent diagnosis groups, the relative risks
(RRs) were statistically significant in the “schizophrenia spectrum dis-
orders” group, “anxiety disorders” group, and “depressive disorders”
group, while the other six groups showed no statistically significant
changes between the two periods (Table 1). The “anxiety disorders”
group showed the greatest reduction in the visit rate of 29.8%. Findings
and detailed statistics from the subgroup analyses by sex or age groups
in the “schizophrenia spectrum disorders” group, “anxiety disorders”
group, and “depressive disorders” group are presented in Supplementary
materials (Table S1, S2).

Among the three diagnosis groups that were shown to be signifi-
cantly affected after the pandemic, the “anxiety disorders” group and
“depressive disorders” group showed a significant temporal association
between the daily outpatient visits and the daily number of newly
confirmed cases of COVID-19. Outpatient visits among the “anxiety
disorders” group decreased by an average of about 5.8% during lag 3
days, 5.5% during lag 7 days, and 5.7% during lag 14 days per 100-case
daily increase in the newly confirmed COVID-19 cases. For depressive
disorders, a 100-case daily increase in newly confirmed cases corre-
sponded to a 4.0% decrease (lag3), 3.9% decrease (lag7), and 4.6%
decrease (lag14) in visit rates. On the other hand, the “schizophrenia
spectrum disorders” group did not show any significant temporal asso-
ciation with the daily increase in newly confirmed cases (Table 2). Fig. 1
shows the trend lines of daily outpatient visits corresponding to the
trend lines of daily confirmed COVID-19 cases in the “anxiety disorders”
group and “depressive disorders” group.

4. Discussion

To the best of our knowledge, this is the first study to investigate the
effect of the COVID-19 pandemic on mental healthcare service use of
outpatients according to psychiatric diagnoses. The present study

showed significant decreases in psychiatric outpatient visit rates during
the COVID-19 outbreak, in particular for anxiety disorders, depressive
disorders, and schizophrenia-spectrum disorders. Our findings suggest
that outpatients with mental health problems had poorer access to
appropriate psychiatric care during the COVID-19 pandemic. Since the
pandemic could increase the risk of psychiatric problems and exacerbate
mental health conditions, (Zhou et al., 2020; Huang and Zhao, 2020;
Frank et al., 2020) the actual reduction rates in mental health service use
may be even larger than those shown in the present results. Therefore,
unmet clinical needs related to psychiatric problems under viral out-
breaks like COVID-19 are a critical concern, and strategies are needed to
enhance continuity of mental healthcare and improve delivery to mental
healthcare services.

In particular, in a time-series analysis, significant temporal correla-
tions were found between the daily number of newly confirmed cases of
COVID-19 and daily visit rates among outpatients with anxiety disorders
and depressive disorders. Among anxiety disorders, a 100-case daily
increase in new confirmed cases corresponded to a 5.8% decrease (lag3)
and 5.5% decrease (lag7) in the visit rates. These results indicate that
patients with anxiety or depressive disorders tended to have more sen-
sitive responses to changes in the risk of viral infection and were
reluctant to seek mental healthcare services, possibly due to concerns
regarding the spread of COVID-19 in healthcare settings. In addition,
individuals with anxiety-related disorders are more frightened about
COVID-19 infection and more likely to self-isolate than those without
mental disorders. (Asmundson et al., 2020) Since those with excessive
worry, contamination fear, and health anxiety tend to engage in avoi-
dant behaviors, anxious or depressive patients may even become
housebound. (Asmundson and Taylor, 2020; Taylor and Asmundson,
2020) In addition to patient-related factors, various other factors, such
as operational changes related to the pandemic, could contribute to the
findings of reduced ambulatory visits. Since remote healthcare services
are prohibited under the Korean medical regulations, the reduction of
in-person psychiatric outpatient visits in the present Korean study is
unlikely to be related to alternative healthcare service use of telemedi-
cine. A possible explanation is that the patients may utilize primary
hospital near their homes transiently under social distancing guidelines.
Another explanation is that psychiatrists may have prescribed medica-
tions for longer durations at the preceding appointment to avoid over-
crowding in hospitals or due to concerns of potential travel restriction,
although South Korea has not enforced travel restriction in the
COVID-19 pandemic.

On the other hand, while visit rates to mental healthcare services
among outpatients with schizophrenia-spectrum disorders were signif-
icantly reduced after the COVID-19 outbreak compared to before the
outbreak, their daily visit rates showed no significant temporal associ-
ation with the daily number of newly confirmed cases of COVID-19. The
different results between the psychosis group and neurosis group of
anxiety and depression suggest that the decrease in mental healthcare
service use seen in schizophrenic patients might be associated with
reasons other than fear or health anxiety related to viral spread. Under
the unique situation created by the COVID-19 pandemic, decreased
casual contacts might have burdened schizophrenia-spectrum disorder
patients with decreased social support and changes in routine,
increasing their risk of symptom aggravation or social isolation, which
might in turn have led them to disengage from treatments. (Kozloff
et al., 2020; Fonseca et al., 2020; Yang et al., 2012; Sendt et al., 2015)

Unlike our expectation, patients with OCD did not show a significant
reduction in visit rates during the pandemic. Previous studies reported
that people with OCD were affected by worsening of the COVID-19
pandemic and exhibited clinical worsening or relapse of their OCD
symptoms. (Davide et al., 2020; Fineberg et al., 2020; Benatti et al.,
2020) While some people with aggravation of OCD symptoms could
have increased avoidance behaviors, others may have exhibited a
greater need for medication revision, reassurance, and treatment. In
addition, the impact on OCD may be different according to the type of

Table 1
Comparison of psychiatry outpatient clinic visit rates between
2019.10.1–2019.12.31 and 2020.3.1–2020.5.31 by Poisson regression (refer-
ence period: 2019.10.1–2019.12.31).

Diagnosis group Visits
(Oct.-
Dec.
2019)

Visits
(March-
May
2020)

RR 95%CI P-value

Total 14,053 12,119 0.869 0.831–0.908 <0.0001**
Neurocognitive

disorders,
delirium, and
other organic
mental disorders

1000 878 0.889 0.791–0.999 0.048

Schizophrenia-
spectrum
disorders

3261 2783 0.867 0.807–0.932 <0.0001**

Depressive
disorders

2879 2440 0.852 0.787–0.923 <0.0001**

Bipolar disorders 1583 1548 1.008 0.936–1.085 0.837
Anxiety disorders 1481 1051 0.702 0.632–0.780 <0.0001**
Obsessive-

compulsive
disorders

624 579 0.918 0.796–1.060 0.243

Stress-related
disorders

828 746 0.908 0.809–1.020 0.104

Somatoform
disorders

677 581 0.860 0.759–0.974 0.018

Sleep-related
disorders

978 902 0.904 0.824–0.992 0.033

RR, relative risk; CI, confidence interval; *p<0.005; **p<0.0001; overdispersion
adjusted.

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282

symptom dimension during the pandemic; for example, subgroups with
contamination symptoms could be more affected and reluctant to visit
hospitals due to the fear of possible contamination. (Benatti et al., 2020)
Different illness behaviors and symptom types may partially explain the
lack of significant reduction in mental health outpatient services in
different diagnosis groups. In addition, limited statistical power related
to small sample sizes in certain groups may have led to a false negative
result. Considering their nominal significance shown in the groups of
somatoform disorders or sleep-related disorders, this warrants further
investigation, despite the results not having survived the Bonferroni
correction. Further studies with larger sample sizes are required to un-
derstand how illness behaviors and seeking healthcare services are
affected by individual factors among specific mental health conditions,
including fear of viral spread, health anxiety, unemployment, and social
isolation in response to the COVID-19 pandemic.

This study had several limitations. First, potential confounding fac-
tors unrelated to the COVID-19 pandemic, including seasonal variation,
might have influenced the changes in outpatient visit rates between the
periods before and during the COVID-19 outbreak. Second, since this
was a retrospective study with all data obtained solely from EHR and
with no psychometric assessment tools, we cannot confirm which factors
changed the visit rates during the pandemic. Third, since we classified
the ICD-10 codes from clinician’s primary psychiatric diagnosis on EHR
system, without using a structured interview, into nine diagnostic cat-
egories, unmeasured diagnostic factors such as comorbid psychiatric
disorders and medical diseases may bias the results of treatment
compliance and dropout rates. Lastly, the present findings should not be
generalized, as the results are only based on data from a tertiary hos-
pital. This study should be replicated in other settings, such as in diverse
regions with different disease prevalence and in different countries with

various institutional and cultural backgrounds. Since the ongoing
COVID-19 pandemic could further increase social isolation, unemploy-
ment, and financial distress, which are common risk factors of discon-
tinuation of outpatient psychiatric treatment, (Minamisawa et al., 2016;
Henzen et al., 2016; Khazaie et al., 2013) the long-term effects of the
COVID-19 pandemic on mental health service use should be
investigated.

5. Conclusion

In summary, we investigated the impact of the COVID-19 pandemic
on psychiatry outpatient clinic use in a tertiary hospital according to
psychiatric diagnosis. The “anxiety disorders” group, “depressive dis-
orders” group and “schizophrenia-spectrum disorders” group showed
significant reductions in mental health service use during the COVID-19
pandemic. In addition, while the visit rates of the “anxiety disorders”
group and “depressive disorders” group were significantly affected by
the daily number of newly confirmed cases, that of the “schizophrenia-
spectrum disorders” group was not. The present findings suggest that
outpatients with psychiatric disorders such as anxiety or depression may
have more concerns regarding the spread of COVID-19, and may be
more reluctant to visit psychiatry outpatient clinics during a pandemic.
Under the pandemic situation, introduction of other service delivery
methods, such as telepsychiatry, should be considered.

Contributor

Authors Jee In Kang and Jun Ho Seo designed the study and Jun Ho
Seo collected the data. Author Myeongjee Lee performed the statistical
analyses. Authors Jun Ho Seo, Se Joo Kim and Jee In Kang interpreted

Table 2
Changes in outpatient visits per 100-case increase in the number of new daily confirmed cases of COVID-19.

lag3 (3 days) lag7 (7 days) Lag 14 (14 days)
RR 95% CI P-value RR 95% CI P-value RR 95% CI P-value

Total 0.956 0.938–0.974 <0.0001** 0.955 0.937–0.974 <0.0001** 0.950 0.930–0.970 <0.0001**
Schizophrenia-spectrum disorders 0.987 0.955–1.020 0.4290 0.986 0.952–1.021 0.4220 0.989 0.951–1.028 0.5617
Depressive disorders 0.960 0.932–0.991 0.0112* 0.961 0.931–0.992 0.0135* 0.954 0.921–0.989 0.0093*
Anxiety disorders 0.942 0.908–0.978 0.0017* 0.945 0.910–0.982 0.0037* 0.943 0.903–0.984 0.0074*

RR, relative risk; CI, confidence interval.
* p<0.0167.
** p<0.0001; overdispersion adjusted.

Fig. 1. Trend in the number of new daily confirmed cases (solid line) and daily outpatient visits (dotted line) during the COVID-19 pandemic.

J.H. Seo et al.

Journal of Affective Disorders 290 (2021) 279–283

283

the findings, and Jun Ho Seo and Jee In Kang prepared the main
manuscript. All authors contributed to and have approved the final
manuscript.

Role of funding source

This work was supported by the National Research Foundation of
Korea (NRF) grant funded by the Korean government (NRF-
2019R1A2C1084611). The funding source did not have any influence on
the study design, data collection, analysis and interpretation of data,
writing of the report, and the decision to submit the article for
publication.

Declaration of Competing Interest

The authors declare that they have no conflict of interest.

Acknowledgements

There is no acknowledgement.

Supplementary materials

Supplementary material associated with this article can be found, in
the online version, at doi:10.1016/j.jad.2021.04.070.

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