Novel coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged in Wuhan, China, on December 31, 2019 [1]. The World Health Organization declared a COVID-19 pandemic on March 11, 2020. As of August 28th, 2022, SARS-CoV-2 had infected approximately 598 million individuals and caused 6.4 million deaths worldwide [2]. The first confirmed case in South Korea was reported on January 20, 2020, and as of September 6th, 2022, SARS-CoV-2 had infected approximately 23,706,477 individuals and caused 27,193 deaths in South Korea [3].

The COVID-19 pandemic has affected healthcare use rates globally. In South Korea, compared with the same period last year, the number of patients using healthcare because of respiratory infections, digestive or intestinal infections, and injury decreased by 51.9%, 31.3%, and 12.6%, respectively. Conversely, the number of patients with mood disorders increased by 7.1%. Preventive measures such as wearing masks, hand washing, and social distancing are presumed to have prompted these changes. In addition, the number of patients using a Korean medicine hospital decreased by 12.5%. This decrease is presumed to be due to a reluctance of healthcare use in the case of not urgent situations during the COVID-19 pandemic [4]. As such, COVID-19 had a significant impact on all outpatients, including first visit and revisit patients.

Facial nerve disorder (Koran standard classification of diseases, KCD G51) is a disease that occurs at a high proportion in Korean medicine, ranking 24th to 27th based on total Korean medicine costs over the past 10 years. The number of patients visiting Korean medical institutions because of facial nerve disorder (KCD G51) has decreased gradually over the past decade; however, the decrease was more rapid in 2020 when the COVID-19 pandemic occurred [5].

Several studies have suggested an association between COVID-19 and peripheral facial palsy (PFP). A higher occurrence of facial palsy was proposed during the COVID-19 pandemic than in the same period in the previous year [6]. Several cases of facial palsy after COVID-19 infection and facial nerve palsy as the initial clinical manifestations of COVID-19 infection have been reported [7-9]. However, various studies have proposed that COVID-19 and PFP are not associated, and several studies argued that insufficient evidence is available to attribute the increased prevalence of facial palsy to COVID-19 [10-12]. In addition, after the introduction of the COVID-19 vaccine, controversy occurred regarding whether an association was present between COVID-19 vaccination and PFP [13-19].

Altogether, changes in the use of health care services due to COVID-19 and the association between facial palsy and COVID-19 or the COVID-19 vaccine may have an influence on patients with facial palsy. A few studies have examined the use of Korean medicine after the COVID-19 pandemic. The Korea Institute of Oriental Medicine published the results of its survey titled “Utilization of Korean Medicine and Consumption of Korean Medicine” in 2020 [20]. Several studies reported the trends of patients visiting Korean medicine hospitals before and during the COVID-19 pandemic [21-23]. However, to the best of our knowledge, no previous study has investigated patients visiting a Korean medicine hospital for a single disease, including facial palsy.

This study aimed to analyze how the COVID-19 pandemic affected the use of a Korean medicine hospital by first-visit patients with PFP and to suggest future directions for facial palsy treatment in Korean medicine hospitals. First, we investigated whether a change occurred in the number of first-visit patients and in demographic characteristics in terms of age, sex, lesion site, and predisposing factors before and during COVID-19. Second, we determined if the distribution of disease phases differed before and during COVID-19; third, we investigated if residence locations differed before and during COVID-19, and fourth, we determined whether a change occurred in patient care before and during COVID-19.

1. Study individuals

A total of 2,381 first-time patients visited the Facial Palsy Center, Kyung Hee Korean Medicine Hospital from January 01, 2019 to December 31, 2021. A total of 2,310 first-time patients were included in this study, and data were extracted from their medical records. Since the first domestic confirmed case of COVID-19 occurred in January 2020, the data of patients visiting the Facial Palsy Center between January 1, 2019, and December 31 (i.e., before COVID-19); and between January 1, 2020, and December 31, 2021 (i.e., during COVID-19) were examined. For annual analyses to determine the tendencies of the data of the pre-COVID-19, first year, and second year of the outbreak period, the data of patients visiting the Facial Palsy Center in 2019 and from 2020 to 2021 were examined. Data of patients visiting the Facial Palsy Center in 2020 and 2021 were also analyzed to determine whether differences occurred between patient characteristics in the first and second years of the COVID-19 pandemic. For the annual analysis of predisposing factors, data were collected from acute patients whose predisposing factors were investigated.

2. Inclusion criteria

Patients with PFP (Bell’s palsy, Ramsay-Hunt syndrome, or sequelae of PFP) were included.

3. Exclusion criteria

Patients with non PFP (central facial palsy, traumatic facial nerve injury, Guillain–Barre syndrome, plastic surgery side effects, simple paresthesia, or simple angular deviation) were excluded.

4. Methods

This study was approved by the Institutional Review Board of Kyung Hee University Korean Medicine Hospital (IRB no: KOMCIRB 2022-01-001). The following data were collected from electronic medical records at Kyung Hee University Korean Medicine Hospital: First-visit date, sex (male and female), age groups (< 20, 20s–30s, 40s–50s, and > 60 years), lesion site (left and right), predisposing factors (fatigue and overwork, insomnia, stress, on a diet, exposure to severe temperature difference, viral disease, COVID-19 vaccination, and others), disease phase (acute, subacute, and chronic), residence (Seoul, Gyeonggi-do, Incheon, Hoseo, Gangwon-do, Yeongnam region, Honam region, Jeju-do, and foreign regions), hospital visit routes (no treatment before visit, only Western medicine treatment before visit, only Korean medicine treatment before visit, and Western and Korean medicine treatment before visit), and patient care (only outpatient care, both outpatient and inpatient care). The disease phases are classified into three phases: acute phase, the period within 7 days from onset; subacute phase, the period over 7 days and within 3 months from onset; and chronic phase, the period over 3 months.

5. Statistical analysis

Statistical analysis was performed using the Statistical Program for Social Science, ver. 28.0.0.0. for windows (IBM Co.). Chi-square test and Fisher’s exact test were used to compare the frequencies and proportions of categorical variables, respectively, between the groups of first-visit patients with PFP before and during the COVID-19 pandemic; annual analyses from 2019 to 2021 and from 2020 to 2021 were also conducted. Significance was set at p < 0.05.

1. Total number of patients by year

From January 1, 2019, to December 31, 2019, approximately 897 patients visited the Facial Palsy Center, Kung Hee University Korean Medicine Hospital. From January 1, 2020, to December 31, 2020, and from January 1, 2021, to December 31, 2021, 716 and 697 patients visited the hospital, respectively. The numbers of patients who visited the hospital in 2019, 2020, and 2021 are summarized in Fig. 1. The monthly numbers of first-visit patients are presented in Fig. 2 and show that the COVID-19 pandemic waves did not overlap with the periods of patient decline

Figure 1. The number of first-visit patients visiting Facial Palsy Center, Kyung Hee University Korean Medicine Hospital from 2019 to 2021.

Figure 2. The monthly number of first-visit patients visiting the Facial Palsy Center, Kyung Hee University Korean Medicine Hospital from 2019 to 2021 (vertical dotted line indicates the start of the COVID-19 in South Korea Shaded part indicates the 1st, 2nd, 3rd, and 4th wave of COVID-19 pandemic). COVID-19, coronavirus disease 2019.

2. Demographic characteristics

The demographic characteristics of patients before and during COVID-19 were compared as percentages. The proportion of female patients increased by 2.9%, from 51.5% to 54.4% during the COVID-19 pandemic, whereas the proportion of male patients decreased by 2.9%, from 48.5% to 45.6% during this time. The proportion of female patients increased by 1.7%, from 51.5% to 53.2% in 2020 compared with that in 2019, and by 2.3%, from 53.2% to 55.5% in 2021 compared with that in 2020. Conversely, the proportion of male patients decreased by 1.7%, from 48.5% to 46.8% in 2020 compared with that in 2019, and by 2.0%, from 46.8% to 44.5% in 2021 compared with that in 2020.

The ratio of patients < 20 years of age decreased by 1.4%, from 4.7% to 3.3%, and the ratio of those in their 20s–30s increased by 1.7%, from 23.4% to 25.1%. The proportion of those in their 40s–50s decreased by 4.4%, from 40.4% to 36.0%, and the proportion of those aged > 60 years increased by 4.2%, from 31.5% to 35.7%. The proportion of patients < 20 years of age continuously decreased by 1.3%, from 4.7% to 3.4% in 2020, compared with that in 2019, and by 0.2%, from 3.4% to 3.2% in 2021, compared with that in 2020. The proportion of patients in their 20s–30s increased by 3.3%, from 23.4% to 26.7% in 2020, compared with that in 2019, and decreased by 3.2%, from 26.7% to 23.5% in 2021, compared with that in 2020. The proportion of patients in their 40s–50s continuously decreased by 3.2%, from 40.4% to 37.2% in 2020, compared with that in 2019, and by 2.5%, from 37.2% to 34.7% in 2021, compared with that in 2020. The proportion of patients aged > 60 years increased by 1.3%, from 31.5% to 32.8% in 2020, compared with that in 2019, and increased by 5.8%, from 32.8% to 38.6% in 2021, compared with that in 2020 (Table 1).

Table 1 . Proportion of demographic characteristics.

	Before COVID-19		During COVID-19
	2019		2020	2021	Sum (2020 + 2021)
Sex
Male	435 (48.5)		335 (46.8)	310 (44.5)	645 (45.6)
Female	462 (51.5)		381 (53.2)	387 (55.5)	768 (54.4)
Age
< 20	42 (4.7)		24 (3.4)	22 (3.2)	46 (3.3)
20s–30s	210 (23.4)		191 (26.7)	164 (23.5)	355 (25.1)
40s–50s	362 (40.4)		266 (37.2)	242 (34.7)	508 (36.0)
> 60	283 (31.5)		235 (32.8)	269 (38.6)	504 (35.7)
Lesion site
Left	468 (52.2)		350 (48.9)	351 (50.4)	701 (49.6)
Right	429 (47.8)		366 (51.1)	346 (49.6)	712 (50.4)

Values are presented as number (%)..

COVID-19, coronavirus disease 2019..

No difference was present between the proportion of left and right lesions, and no characteristic changes or tendencies were found (Table 1).

Fatigue and heavy workload were the most common predisposing factors in all years (63.3%, 58.2%, and 52.0% in 2019, 2020, and 2021, respectively), followed by stress (51.8%, 49.4%, and 45.8% in 2019, 2020, and 2021, respectively), and insomnia (46.6%, 44.9%, and 44.1% in 2019, 2020, and 2021, respectively). The proportions of viral diseases, such as common cold and enteritis, decreased during the COVID-19 pandemic (17.9%, 6.3%, and 1.8% in 2019, 2020, and 1.8%, respectively). Additionally, the category of COVID-19 vaccination was newly included in 2021. A total of 24 patients complained of PFP after COVID-19 vaccination (Table 2).

Table 2 . Proportion of predisposing factors.

	Before COVID-19		During COVID-19
	2019		2020	2021
Fatigue and overwork	198 (63.3)		184 (58.2)	118 (52.0)
Insomnia	146 (46.6)		142 (44.9)	100 (44.1)
Stress	162 (51.8)		156 (49.4)	104 (45.8)
On a diet	12 (3.8)		9 (2.8)	8 (3.5)
Exposure to severe temperature differences	66 (21.1)		43 (13.6)	35 (15.4)
Viral disease (e.g., common cold, enteritis)	56 (17.9)		20 (6.3)	4 (1.8)
Surgery and injury	14 (4.8)		9 (2.8)	7 (3.1)
COVID-19 vaccination	-		-	24 (10.6)
Others	2 (0.6)		6 (1.9)	15 (6.6)

Values are presented as number (%)..

COVID-19, coronavirus disease 2019; -, not applicable..

3. Disease phase distribution

The proportion of acute patients increased by 5.3%, from 48.7% before COVID-19 to 54.0% during the COVID-19 pandemic while the proportion of subacute patients decreased by 4.3%, from 36.5% to 32.2%, and the proportion of chronic patients decreased by 1.0%, from 14.8% to 13.8%. In 2019, patients with acute, subacute, and chronic conditions accounted for 48.7%, 36.5%, and 14.8% of the sample, respectively; in 2020, they accounted for 52.8%, 33.9%, and 13.8%; and in 2021, they accounted for 55.2%, 30.4%, and 14.2%, respectively (Table 3). A significant relationship was present between the presence of the COVID-19 pandemic (i.e., before and during) and the number of patients by disease phase according to chi-square analysis (p = 0.043). No relationship was present between the years from the COVID-19 pandemic (i.e., 1st and 2nd year of COVID-19 pandemic) and the number of patients by disease phase (p = 0.359).

Table 3 . Proportion of disease phase before and during COVID-19.

	Before COVID-19		During COVID-19			p-value
	2019		2020	2021	Sum (2020 + 2021)
Acute phase	437 (48.7)		378 (52.8)	385 (55.2)	763 (54.0)	0.043*
Subacute phase	327 (36.5)		243 (33.9)	212 (30.4)	455 (32.2)
Chronic phase	133 (14.8)		95 (13.3)	100 (14.3)	195 (13.8)

Values are presented as number (%)..

COVID-19, coronavirus disease 2019; PFP, peripheral facial palsy..

Chi-square test was used between the groups of first-visit patients with PFP before and during the COVID-19 pandemic..

*p < 0.05..

4. Distribution of residence locations

The proportion of visits by residents in Seoul increased from 53.6% to 57.4% after the COVID-19 outbreak. The proportion of patients visiting from all regions except Seoul and Honam decreased during COVID-19. The proportions of patients visiting from Seoul were the highest in all years (53.6%, 57.4%, and 57.4% in 2019, 2020, and 2021, respectively), followed by those living in Gyeonggi (30.4%, 29.9%, and 29.3% in 2019, 2020, and 2021, respectively) (Table 4). A significant relationship was present between the presence of the COVID-19 pandemic (i.e., before and during) and the number of patients by location of residence according to the chi-square analysis (p = 0.003). No relationship was present between the years from the COVID-19 pandemic (i.e., 1st and 2nd year of COVID-19 pandemic) and the number of patients by location of residence.

Table 4 . Proportion of residence locations before and during COVID-19.

	Before COVID-19		During COVID-19			p-value
	2019		2020	2021	Sum (2020 + 2021)
Seoul	481 (53.6)		411 (57.4)	400 (57.4)	811 (57.4)	0.003*
Geonggi	273 (30.4)		214 (29.9)	204 (29.3)	418 (29.6)
Incheon	32 (3.6)		22 (3.1)	23 (3.3)	45 (3.2)
Ho-seo	21 (2.3)		18 (2.5)	17 (2.4)	35 (2.5)
Gangwon	27 (3.0)		17 (2.4)	22 (3.2)	39 (2.8)
Yeongnam	33 (3.7)		15 (2.1)	16 (2.3)	31 (2.2)
Honam	15 (1.7)		18 (2.5)	13 (1.9)	31 (2.2)
Jeju	7 (0.8)		1 (0.1)	2 (0.3)	3 (0.2)
Foreign region	8 (0.9)		0 (0)	0 (0)	0 (0)
Total	897		716	697	1,413

Values are presented as number (%) or number only..

COVID-19, coronavirus disease 2019; PFP, peripheral facial palsy..

Chi-square test was used between the groups of first-visit patients with PFP before and during the COVID-19 pandemic..

*p < 0.05..

5. Distribution of hospital visit routes

Before COVID-19, 41.2%, 38.6%, 11.4%, and 8.8% of patients visited the hospital after only Western medicine treatment, after both Western and Korean medicine treatments, after only Korean medicine treatment, and after no treatment, respectively, whereas during the COVID-19 pandemic, these respective proportions were 43.6%, 38.6%, 10.3%, and 7.5% of patients. For patient visits to the Korean medicine hospital in 2019, 2020, and 2021, 41.2%, 44.4%, and 42.8% of patients visited after only Western medicine treatment, respectively; 38.6%, 36.2%, and 41.2% of patients visited after both Western and Korean medicine treatments, respectively; 11.4%, 10.8%, and 9.8% of patients visited after only Korean medicine treatment, respectively; and 8.8%, 8.7%, and 6.3% of patients visited after no treatment, respectively.

In all years, the proportion of hospital visits after only Western medicine treatment was the highest, followed by visits after both Western and Korean medicine treatments, after only Korean medicine treatment, and after no treatment (Table 5). No significant relationship was present between the presence of the COVID-19 pandemic (i.e., before and during) and the number of patients by hospital visit route. No relationship was present between the years from the COVID-19 pandemic (i.e., 1st and 2nd year of COVID-19 pandemic) and the number of patients by hospital visit route.

Table 5 . Proportion of hospital visit routes before and during COVID-19.

	Before COVID-19		During COVID-19			p-value
	2019		2020	2021	Sum (2020 + 2021)
After no treatment	79 (8.8)		62 (8.7)	44 (6.4)	106 (7.5)	0.277
After only Western medicine treatment	370 (41.2)		318 (44.4)	298 (42.8)	616 (43.6)
After only Korean medicine treatment	102 (11.4)		77 (10.8)	68 (9.8)	145 (10.3)
After Western and Korean medicine treatments	346 (38.6)		259 (36.2)	287 (41.2)	546 (38.6)
Total	897		716	697	1,413

Values are presented as number (%) or number only..

COVID-19, coronavirus disease 2019; PFP, peripheral facial palsy..

Chi-square test was used between the groups of first-visit patients with PFP before and during the COVID-19 pandemic..

Regarding the proportions of visits by disease phase, the proportion of patients visiting the hospital after no treatment in all phases consistently decreased. The proportion of patients in the acute phase visiting the hospital after no treatment decreased from 15.1% to 14.6% compared with that in 2019 and from 14.6% to 10.9% in 2021 compared with that in 2020. The proportion of patients in the subacute phase visiting the hospital after no treatment decreased from 1.8% to 1.6% compared with that in 2019 and from 1.6% to 0.9% in 2021 compared with that in 2020. The proportion of patients in the chronic phase visiting the hospital after no treatment decreased from 5.3% to 3.2%, compared with that in 2019, and from 3.2% to 0.0% in 2021, compared with that in 2020 (Tables 6–8). In patients stratified by disease phase, no relationship was present between the presence of the COVID-19 pandemic (i.e., before and during) and the number of patients by hospital visit route.

Table 6 . Proportion of hospital visit routes before and during COVID-19 in acute patients.

	Before COVID-19		During COVID-19			p-value
	2019		2020	2021	Sum (2020 + 2021)
After no treatment	66 (15.1)		55 (14.6)	42 (10.9)	97 (12.7)	0.190
After only Western medicine treatment	216 (49.4)		212 (56.1)	213 (55.3)	425 (55.7)
After only Korean medicine treatment	60 (13.7)		45 (11.9)	42 (10.9)	87 (11.4)
After Western and Korean medicine treatments	95 (21.7)		66 (17.5)	88 (22.9)	154 (20.2)
Total	437		378	385	763

Values are presented as number (%) or number only..

COVID-19, coronavirus disease 2019; PFP, peripheral facial palsy..

Chi-square test was used between the groups of first-visit patients with PFP before and during the COVID-19 pandemic..

6. Distribution of patient care

The proportion of patients receiving only outpatient treatments increased by 12.8% from 57.2% to 70.0%, and the proportion of those receiving both outpatient and inpatient treatment decreased by 12.8% from 42.8% to 30.0% during the COVID-19 pandemic. The proportion of patients receiving only outpatient treatments increased by 7.9% from 57.2% to 65.1% in 2020, compared with that in 2019, and by 9.7% from 65.1% 74.8% in 2021, compared with that in 2020. The proportion of patients receiving both outpatient and inpatient treatment decreased by 7.9%, from 42.8% to 34.9% in 2020, compared with that in 2019, and by 9.7%, from 34.9% to 25.2% in 2021, compared with that in 2020 (Table 9). A significant relationship was present between the presence of the COVID-19 pandemic (i.e., before and during) and the number of patients treated by patient care (p = 0.003). Furthermore, a significant relationship was present between the time from COVID-19 (i.e., 2020 and 2021) and the number of patients by patient care (p = 0.016).

Table 7 . Proportion of hospital visit routes before and during COVID-19 in subacute patients.

	Before COVID-19		During COVID-19			p-value
	2019		2020	2021	Sum (2020 + 2021)
After no treatment	6 (1.8)		4 (1.6)	2 (0.9)	6 (1.3)	0.136
After only Western medicine treatment	130 (39.8)		93 (38.3)	72 (34.0)	165 (36.3)
After only Korean medicine treatment	24 (7.3)		10 (4.1)	10 (4.7)	20 (4.4)
After Western and Korean medicine treatments	167 (51.1)		136 (56.0)	128 (60.4)	264 (58.0)
Total	327		243	212	455

Values are presented as number (%) or number only..

COVID-19, coronavirus disease 2019; PFP, peripheral facial palsy..

Chi-square test was used between the groups of first-visit patients with PFP before and during the COVID-19 pandemic..

Table 8 . Proportion of hospital visit routes before and during COVID-19 in chronic patients.

	Before COVID-19		During COVID-19			p-value
	2019		2020	2021	Sum (2020 + 2021)
After no treatment	7 (5.3)		3 (3.2)	0 (0)	3 (1.5)	0.091
After only Western medicine treatment	24 (18.0)		13 (13.7)	13 (13.0)	26 (13.3)
After only Korean medicine treatment	18 (13.5)		22 (23.2)	16 (16.0)	38 (19.5)
After Western and Korean medicine treatments	84 (63.2)		57 (60.0)	71 (71.0)	128 (65.6)
Total	133		95	100	195

Values are presented as number (%) or number only..

COVID-19, coronavirus disease 2019; PFP, peripheral facial palsy..

Chi-square test was used between the groups of first-visit patients with PFP before and during the COVID-19 pandemic..

Table 9 . Proportion of patient care before and during COVID-19.

	Before COVID-19		During COVID-19			p-value
	2019		2020	2021	Sum (2020 + 2021)
Only outpatient treatment	250 (57.2)		246 (65.1)	288 (74.8)	534 (70.0)	0.003*
Outpatient and inpatient treatment	187 (42.8)		132 (34.9)	97 (25.2)	229 (30.0)
Total	437		378	385	763

Values are presented as number (%) or number only..

COVID-19, coronavirus disease 2019; PFP, peripheral facial palsy..

Chi-square test was used between the groups of first-visit patients with PFP before and during the COVID-19 pandemic..

*p < 0.05..

Facial nerve palsy is a disease that mainly causes palsy of the affected facial muscles due to facial nerve damage and is associated with symptoms such as reduced saliva secretion, subsequent pain, hearing irritation, and loss of unilateral taste [24]. The most common cause of acute PFP is Bell’s palsy, and other etiologies include viral infection (herpes zoster virus, human immunodeficiency virus), Guillain–Barre syndrome, head or ear trauma, and temporal bone fracture [25]. The timing of treatment is critical for the therapeutic response to acute PFP. The most important treatment for Bell’s palsy is to reduce the number of nerve fibers in the Wallerian degeneration state between approximately 2 and 14 days to help recovery of facial nerves. In Western medicine, early treatment with prednisolone significantly improves the chances of recovery [26]. In Korean medicine, acupuncture, herbal medicine, herbal acupuncture, and physical therapy are conducted to help quick recovery [27].

Regarding health service use in South Korea after the COVID-19 pandemic, the proportion of patients using Korean medicine decreased by 12.5% compared with the same period last year [4]. The number of patients who visited Korean medical institutions for facial nerve disorder (KCD G51) had decreased gradually over the past decade but decreased rapidly in 2020 when the COVID-19 pandemic occurred [5]. This change in health service use is presumed to be due to new variations such as wearing masks, washing hands, social distancing, and concerns over COVID-19 infection in the hospital.

First-visit patients refer to patients who have never been treated by a doctor in the same department at the same medical institution for the corresponding disease [28]. Unlike revisit patients, first-visit patients have not previously experienced the medical service of a hospital, especially human factors such as skills, kindness, and detailed explanations of medical staff. Accordingly, they choose hospitals considering physical factors, such as medical equipment, rest areas or convenience facilities, cleanliness of the environment, and parking spaces, accessibility factors such as the location of the hospital, and efficiency factors such as waiting time, convenience of treatment procedure, and collaborative practice [29].

In this study, we aimed to determine whether the COVID-19 pandemic affected the characteristics of first-visit patients with PFP who visited a Korean medicine hospital. The reason for limiting patients to first-visit patients is to observe the differences in health service use after COVID-19, excluding patient loyalty and trust from existing experiences in hospitals and medical staff. In addition, because early treatment of PFP is critical, we attempted to confirm the specificity of the disease in first-time patients. Since the pandemic started in South Korea in January 2020, data were divided into those before and during the COVID-19 pandemic as of 2020. Annual analyses were conducted to determine the tendencies of the data of the pre-COVID-19, first, and second years of the outbreak period and differences between patient characteristics in the first and second years of the COVID-19 pandemic.

A total of 2,310 first-time patients visited the Facial Palsy Center, Kyung Hee University Korean Medicine Hospital for PFP from January 1, 2019, to December 31, 2021, and 897, 716, and 697 people visited the center in 2019, 2020, and 2021, respectively. From 2019 to 2020, the number of patients decreased by 20.2%, and from 2020 to 2021, this decreased by 2.7%. This decrease was particularly high between 2019 and 2020, possibly owing to a decrease in medical care use after the COVID-19 outbreak. Large decreases were recorded in the number of patients using Korean medicine (decreased by 12.5%) after the outbreak of COVID-19 [4]. For example the number of first-time patients visiting the Department of Acupuncture and Moxibustion at the Korean medicine hospital in Daejeon decreased by 15.2% [21]. We also demonstrated that the series of COVID-19 waves did not overlap with the timing of decline in patient numbers by month.

Overall, before COVID-19, the proportion of female patients was similar to that of male patients. Similarly, a previous study showed no difference in the incidence of PFP by sex [30]. During COVID-19, the proportion of female patients showed a persistent increase with time. Conversely, the proportion of male patients persistently decreased. This is contrary to the results of a previous study that reported that the use of medical services by women decreased during the COVID-19 pandemic [31]. In this study, the sex of first-visit patients with PFP during COVID-19 had no significant effect.

The proportion of patients aged < 20 years and in their 40s–50s persistently decreased, and that of patients aged > 60 years persistently increased during COVID-19. Patients in their 40s–50s accounted for the highest proportion in 2019 and 2020; however, those aged > 60 years accounted for the highest proportion in 2021. This result is consistent with the results of a previous study showing that the use of medical services by those aged ≤ 18 years and those in their 20s–40s decreased significantly during the COVID-19 pandemic, whereas the utilization rate of patients aged ≥ 60 years decreased slightly [32]. This result can be attributed to several complex factors, such as the tendency of older adults to maintain medical care use despite the pandemic, underestimation of subjective health conditions, and an increase in the population aged > 65 years every year [22,33].

The distribution of the location of lesions did not exhibit any tendencies or characteristic changes (left or right) before and during COVID-19. The number of patients stratified by the location of lesions (left or right) was similar from 2019 to 2021, indicating that data was unaffected by the right and left concept in Korean medicine, such as the “men-left-woman-right” theory where disease in men mainly appears on the left and disease in women mainly appears on the right, and the “left-blood-right-qi” theory where the left side of the human body is supervised by qi, and the right side of the human body is supervised by blood.

Analysis of the distribution of predisposing factors by year among patients in the acute phase revealed that fatigue and heavy workload were the most common factors in all years, followed by stress and insomnia. Unlike previous surveys that showed that the psychology of stress, depression, and anxiety increased because of COVID-19, the proportion of psychological factors such as stress or insomnia did not increase. Characteristically, the proportions of viral diseases, such as common cold and enteritis, plummeted during the COVID-19 pandemic [31]. This result corresponds to that in a previous survey on public health care use where the number of patients with common cold and influenza decreased after wearing masks during the COVID-19 pandemic [4]. In addition, the category of COVID-19 vaccination was newly included in 2021. A total of 24 patients complained of PFP after COVID-19 vaccination. No cases of COVID-19 as a predisposing factor for facial palsy were found because patients could not visit a Korean medicine hospital in the acute phase of COVID-19 owing to self-isolation or hospitalization at Western hospitals.

In our study, the acute phase was defined as within 7 days after onset, the subacute phase was defined as > 7 days and within 3 months after onset, and the chronic phase was defined as > 3 months after onset [34]. As the number of patients with various viral infections significantly decreased because of preventive measures during COVID-19, we aimed to confirm whether the proportion of patients in the acute phase decreased. During the COVID-19 pandemic, the proportions of patients in the acute, subacute, and chronic phases increased from 48.7% to 54.0%, decreased from 36.5% to 32.2%, and decreased from 14.8% to 13.8%, respectively, compared with the proportions before the pandemic. The proportion of patients in the acute phase continuously increased, indicating that the decrease in viral infection had no effect. Given that the proportion of patients in the acute phase continued to increase, we can assume that the perception that the number of patients in the acute phase that needed to visit a hospital as soon as possible for treatment continuously increased regardless of the pandemic situation. Conversely the proportion of patients in the subacute and chronic phases decreased, possibly due to a decrease in medical care use for non-urgent cases during the COVID-19 period [4]. The decrease in patients in the chronic phase was smaller than that in the subacute phase. This is presumed to be because of the tendency of chronic patients who have sequelae of facial palsy after moderate or severe facial nerve damage to visit higher institutions after receiving treatment at primary medical institutions. Analysis of the proportion of patients by disease phase revealed a significant relationship between the presence of the COVID-19 pandemic (i.e., before and during) and the number of patients stratified by disease phase (p = 0.043).

To determine whether a change in the regional distribution of patients visiting the hospital occurred after social distancing, an analysis of patient residences was conducted. The proportion of residents in Seoul increased from 53.6% to 57.4% during the COVID-19 pandemic. The proportion of patients visiting from most regions decreased during COVID-19. This seems to be related to the tendency to avoid long-distance visits because of social distancing. In addition, a significant relationship was present between the presence of the COVID-19 pandemic (i.e., before and during) and the number of patients stratified by residence (p = 0.003).

From 2019 to 2021 in all years, the proportion of hospital visits after only Western medicine treatment was the highest, followed by visits after both Western and Korean medicine treatments, after only Korean medicine treatment, and after no treatment. No significant change occurred in the order of the proportion of hospital visit routes regardless of COVID-19. Furthermore, no significant relationship was present between the presence of the COVID-19 pandemic (i.e., before and during) and the number of patients stratified by hospital visit. Characteristically, the proportion of patients visiting the hospital after no treatment in all phases consistently decreased. In particular, the proportion of patients in the acute phase visiting the hospital after no treatment decreased from 15.1% to 14.6% compared with that in 2019 and from 14.6% to 10.9% in 2021 compared with that in 2020. It can be assumed that the perception that patients with facial palsy in the acute phase should receive necessary treatment within an appropriate time is improving despite the COVID-19 pandemic situation. The standard treatment, which recommends taking steroids within 3 days of the onset of PFP, may have been the main cause of such results [35].

To determine whether the COVID-19 pandemic changed the types of patient care among patients in the acute phase, we investigated the proportion of patients who received only outpatient treatment and patients who received outpatient and inpatient treatment in the Korean medicine hospital. The medical staff of the Facial Palsy Center, Kyung Hee University Korean Medicine Hospital routinely explain and recommend inpatient treatment for first-visit patients with facial palsy in the acute phase to recover as much information as possible and minimize the after effects at the beginning of the disease. During the COVID-19 pandemic, the existing explanation was maintained, but an explanation was added that hospitalization is possible after negative results of the COVID-19 test are obtained; thus, hospitalization is not possible on the day of the first visit. The proportion of patients who received both outpatient and inpatient treatment persistently decreased, but the proportion of patients who received only outpatient treatment persistently increased during COVID-19. This decrease is similar to that in a previous study, where the number of people visiting medical institutions for admissions decreased during the COVID-19 outbreak [36]. Several complex factors may have played a role in this process. In the early days of the COVID-19 epidemic in South Korea, the pandemic spread rapidly in medical and living facilities [37]. Moreover, inpatients experienced higher levels of anxiety about infection than outpatients [36]. In addition, although facial palsy hinders the quality of life and affects social life, it is not a life-threatening condition [38]. The requirement of having to take a COVID-19 test before hospitalization and the inability to be hospitalized on the day of the first visit may have affected the results. A significant relationship was present between the presence of the COVID-19 pandemic (i.e., before and during) and the number of patients who received only outpatient treatment (Kyung Hee University Korean Medicine Hospital) (p = 0.003). Furthermore, a significant relationship was present between the time from COVID-19 (i.e., 2020 and 2021) and the number of patients by patient care (p = 0.016). Unlike other analyzed items, a difference was present between the first and second years of COVID-19. The prolonged COVID-19 pandemic appears to have continuously affected the type of patient care.

The significance of this study is that it evaluated the proportions of first-visit patients with PFP who visited a Korean medicine hospital before and during the COVID-19 pandemic for three years. We identified several characteristics of healthcare use among first-visit patients with PFP during the COVID-19 pandemic. The number of first-visit patients in the acute and chronic phases decreased in 2020, when the pandemic occurred, but then increased in 2021, which was the second year of the pandemic. This indicates that first-visit patients in both acute and chronic phases prefer Korean medicine treatment. Considering that the number of first-visit patients visiting the hospital after no treatment or visiting the hospital after only Korean medicine treatment continued to decrease, it is necessary to actively encourage collaborative practice between Western and Korean medicine because patients do not expect to treat their symptoms only with Korean medicine. More than 60% of first-visit patients in the chronic phase visited the hospital after Western and Korean medicine treatments, suggesting the need for differentiated treatment options for chronic patients. COVID-19 vaccination was included as a predisposing factor in 2021; therefore, further studies are needed regarding the relationship between facial palsy and COVID-19 vaccination. In the event of an infectious disease, such as COVID-19, intensive outpatient treatment can be expanded. Patients who develop facial palsy after being confirmed with COVID-19 cannot receive Korean medicine treatment during quarantine; therefore, protocols need to be devised for patients in quarantine to receive Korean medical treatment. Personal hygiene can be used as a preventive strategy given that the number of patients with viral diseases decreased sharply during the COVID-19 pandemic. This study may serve as a reference for policy decision making and research on PFP.

This study has some limitations. The research period ended on December 31, 2021, at the end of the COVID-19 outbreak. Only data from one department at a single Korean medicine hospital were analyzed in this study, and therefore, the results cannot be generalized to all Korean medicine hospitals. As patients infected with COVID-19 could not visit Korean medical institutions during the initial quarantine period, the analysis of patients with facial palsy due to COVID-19 was limited.

We analyzed the electronic medical records of 2,310 patients with PFP who first visited the Facial Palsy Center, Kyung Hee University Korean Medicine Hospital from January 1, 2019, to December 31, 2021. We found several differences in the characteristics of first-visit patients with PFP during the COVID-19 pandemic in terms of demographic characteristics, disease phase, residence locations, and patient care.

Conceptualization: YL, YSK. Data curation: YL. Formal analysis: YL. Investigation: YL. Methodology: YL, YSK. Project administration: YL, SL. Resources: YL. Software: YL. Supervision: YSK. Validation: YL. Visualization: YL, SL. Writing – original draft: YL. Writing – review & editing: SL, YSK.

The authors have no conflicts of interest to declare.

None.

This study was approved by the Institutional Review Board of Kyung Hee University Korean Medicine Hospital (IRB no: KOMCIRB 2022-01-001).