Frontline healthcare workers are vital in delivering primary medical care and safeguarding the population against the coronavirus disease 2019 (COVID-19). Due to their critical role in various medical fields that induces a sense of responsibility, they may experience significant psychological stress.12 Nurses, particularly, are exposed to multiple tasks, such as administering tests and caring for infected patients. Their risk of contracting COVID-19 is significantly higher compared to other healthcare workers, which may lead to exposure to traumatic deaths, resulting in severe psychological issues.3

Hypochondriasis, also known as illness anxiety disorder, is a condition in which an excessive fear of being sick leads to anxiety, prompting an individual to avoid the perceived problem or repeatedly seek reassurances. Although seeking reassurance may temporarily reduce anxiety, the repetitive cycle of seeking reassurance and experiencing anxiety can lead to an excessive preoccupation with the perceived illness.456 The COVID-19 pandemic induced a fear of infections that prompted individuals to engage in reassurance-seeking behaviors such as constantly checking their bodily sensations, maintaining strict hand hygiene, or regularly monitoring news. However, excessively seeking reassurance can paradoxically increase anxiety. These reassurance-seeking behaviors can indicate an excessive preoccupation with illness in individuals concerned about their health or highly anxious about the virus. Most of these symptoms result from constant checking and the fear of contamination related to the COVID-19 pandemic. Additionally, measures such as wearing a mask and washing hands while effectively reducing the spread of infection may also increase preoccupation with the virus.

Previously, we observed that insomnia mediated the vicious cycle of viral anxiety, reassurance-seeking behavior, and hypochondriacal preoccupation with COVID-19 among the general population.7 Among the medical students, the influence of depression or viral anxiety on their preoccupation with COVID-19 was partially mediated by their reassurance-seeking behavior.8

In its simplest form, intolerance of uncertainty is the inability to tolerate the adverse response triggered by an absence of salient, pertinent, or sufficient information sustained by the associated perception of uncertainty. Intolerance of uncertainty has been associated with anxiety symptoms because of the way people respond to information when they are uncertain. Anxiety disorder development and maintenance are generally related to intolerance of uncertainty as a risk factor or cognitive vulnerability. Therefore, we hypothesize that intolerance of uncertainty and viral anxiety impact a vicious cycle of reassurance-seeking behaviors. COVID-19 pandemic researchers found that extreme intolerance of uncertainty induces anxiety, sleep problems, and depression, as well as behavior changes such as procrastination or emotional eating. Previously, we reported that intolerance of uncertainty among healthcare workers directly influenced their viral anxiety, and reassurance-seeking behavior and preoccupation with COVID-19 mediated this association.9 Reduced intolerance of uncertainty will, therefore, reduce viral anxiety by making it easier to predict and control.

Physical distancing also helps prevent viral transmission in this pandemic,10 which can be a double-edged sword. Psychological distress can occur if people adhere to physical distancing.11 However, as a healthcare worker, it can be an effective way to prevent the spread of infectious diseases.12 Consequently, healthcare professionals are forced to maintain physical distancing, which can also be stressful. Their adherence to physical distancing can be affected by intolerance of uncertainty,13 but little research has been done on how adherence to physical distancing affects or is affected by the preoccupation with COVID-19.

Intolerance of uncertainty or adherence to physical distancing during the pandemic may have contributed to more significant psychological distress among healthcare workers, especially frontline nursing professionals in the COVID-19 inpatient ward. Unlike other disasters, the victims of viral disasters transfer the infection to the healthcare workers at the hospital. Frontline nurses are equipped to care for patients despite poor protective equipment, overload, inadequate infection control, and pre-existing medical conditions. Consequently, they must prepare for risk, tolerate uncertainty, and adhere to physical distancing. It was previously reported that high-risk healthcare workers experienced more difficulty tolerating uncertainty than those in the low-burnout group and that could increase the healthcare workers’ ruminative thinking style.141516

The present study investigated whether preoccupation with COVID-19 was associated with reassurance-seeking behavior, viral anxiety, intolerance of uncertainty, or adherence to physical distancing, especially among frontline nursing professionals who worked in the COVID-19 inpatient ward. Furthermore, we tested whether adherence to physical distancing mediated the influence of intolerance of uncertainty on the vicious cycles of viral anxiety. We hypothesized that 1) reassurance-seeking behavior; 2) viral anxiety; 3) intolerance of uncertainty; and 4) adherence to physical distancing were positively associated with a preoccupation with COVID-19. We also hypothesized that adherence to physical distancing would, at least partially, mediate the relationship between intolerance of uncertainty and preoccupation with COVID-19 among the nursing professionals working in COVID-19 inpatients ward.

A total of 256 participants were included in this study, which consisted over 90% female (N = 240, 93.8%) participants, who worked for an average of 6.7 ± 5.9 years. Almost all of the participants (N = 245, 96.5%) were on a working time shift. 42.2% were quarantined for COVID-19 infection and all of them experienced patient deaths associated with COVID-19 infection. Less than 15% (N = 38, 14.9%) reported psychiatric difficulties. Table 1 lists the mean scores of the rating scales used in this study.

Significant correlations were observed in Pearson’s correlation analysis. Age was associated with OCS (r = −0.12, P < 0.05) and adherence to physical distancing (r = 0.27, P < 0.01). The OCS score was significantly correlated with CRBS (r = 0.70, P < 0.01), FCV-19S (r = 0.65, P < 0.01), IUS-12 (r = 0.30, P < 0.01), and adherence to physical distancing (r = 0.28, P < 0.01). CRBS was significantly correlated with FCV-19S, IUS-12, and adherence to physical distancing (P < 0.01). FCV-19S was related to IUS-12 and adherence to physical distancing (r = 0.26, P < 0.01 in both scales). Adherence to physical distancing only correlated with IUS-12 (r = 0.21, P < 0.01; Table 2).

To explore the parameters that could predict the obsession with COVID-19, linear regression analysis was performed. Age (β = −0.07, P = 0.002), CRBS (β = 0.35, P < 0.001), and FCV-19S (β = 0.24, P < 0.001) could predict obsession with COVID-19 (Adjusted R² = 0.60, F = 78.1, P < 0.001; Table 3).

Mediation analysis showed that the indirect pathway from intolerance of uncertainty to (independent variable) reassurance seeking or viral anxiety (mediator) to preoccupation with COVID-19 (dependent variable) was significant but mediated by adherence to physical distancing in the indirect pathway, which was not significant (Table 4). This pathway found that reassurance-seeking and viral anxiety would mediate the effect of intolerance of uncertainty on the preoccupation with COVID-19 (Fig. 1).

In this study, we found that our hypotheses were supported, as we observed positive correlations between preoccupation with COVID-19 among frontline nursing professionals and 1) coronavirus-related reassurance-seeking behavior (Hypothesis 1); 2) viral anxiety (Hypothesis 2); 3) intolerance of uncertainty (Hypothesis 3); and 4) adherence to physical distancing (Hypothesis 4). However, our hypothesis that adherence to physical distancing mediated the association between intolerance of uncertainty and preoccupation with COVID-19 (Hypothesis 5) was not supported. Instead, the association was found to be mediated by viral anxiety and reassurance-seeking behavior.

Existing literature have found evidence that intolerance of uncertainty relates to other psychological problems. Intolerance of uncertainty could be related to obsessions or compulsions, and understanding this would help manage anxiety disorder.26 Additionally, intolerance of uncertainty plays a role in individuals experiencing anxiety disorders such as hypochondriacal issues. In our previous study, conducted among healthcare workers during the COVID-19 pandemic, we observed that the intolerance of uncertainty was significantly correlated with an obsession with COVID-19.27 The present study observed the association between the intolerance of uncertainty and obsession with COVID-19 among nursing professionals who work in COVID-19 inpatient units.

A high proportion of participants in this study experienced being quarantined (42.2%) or infected (38.4%). Isolation ward nurses’ frequency of exposure to COVID-19 is much higher than that of the general population owing to the nature of the job. Nurses caring for infected patients in isolation wards are more concerned about infection. Research on coronavirus is still ongoing, and there is uncertainty about its mutation. The uncertainty of the new virus can cause more fear among people with higher anxiety.2829 This uncertainty of the new virus provokes more anxiety for frontline medical workers and makes them act more obsessively toward COVID-19. Previous research has shown that anxiety in infectious diseases negatively correlates with performance.30 Therefore, intervention regarding frontline nurses’ anxiety is vital for effective patient management.

In this study, viral anxiety and reassurance-seeking behavior mediated the influence of adherence to physical distancing on obsession with COVID-19. Our previous study observed that intolerance of uncertainty directly influenced their viral anxiety, and reassurance-seeking behavior and obsession with COVID-19 mediated this association.27 We confirmed that intolerance of uncertainty might influence the vicious cycle of viral anxiety, reassurance-seeking behavior, and hypochondriacal preoccupation with COVID-19, even among nursing professionals working in COVID-19 inpatient units. As shown in this study, intolerance of uncertainty has direct and indirect effects through mediation on psychological distress in many ways on COVID-19 healthcare workers.3132 According to a prior study, it can also influence adherence to physical distancing. Moreover, intolerance of uncertainty is reported to have a mediation effect on the fear of COVID-19 toward positivity.33

However, in this study, we observe that adherence to physical distancing did not mediate the influence of intolerance of uncertainty on obsession with COVID-19, contrary to our expectations. Consistent with our previous study conducted among healthcare workers,13 we observed that intolerance of uncertainty directly influenced adherence to physical distancing. However, compliance with physical distancing did not mediate the influence of intolerance of uncertainty on the preoccupation with COVID-19. First, due to the peculiarity of a group of nurses working in the COVID-19 ward, the mediation effect on obsession with COVID-19 may have been insignificant. If the intolerance of uncertainty is more prominent, there is a higher possibility that physical distancing is better followed. However, nurses in the COVID-19 ward are likely to observe social distancing appropriately. This may be related to their professionalism or their working guidelines, or they simply may be overwhelmed with fear and anxiety during the pandemic.34

Second, distancing phobia is a double-edged sword.35 It may be a result of the ambivalence of physical distancing. Thus, it is necessary to distinguish between physical distancing and social distancing phobia. Physical distancing reflects various situations; in this context, physical distancing is a double-edged sword.35 Maintaining good physical distancing can reduce the probability of viral infection, thereby reducing anxiety about viral infection. However, maintaining physical distance can also cause considerable anxiety about virus infection. Previous research on nursing students revealed that those who felt anxious about being infected with COVID-19 tended to adhere to physical distancing.36 Additionally, since the social connection due to physical distancing is weakened and isolated, depression or anxiety may increase. People may also be anxious about social distancing phobia, fear of getting close to others. The mediating effect may not have been well revealed as various attributes are mixed. The COVID-19 pandemic forced many healthcare workers to work in a COVID-19 inpatient ward without adequate training to cope with the pressures. When stressed by environmental factors, they may use negative psychological coping strategies such as hypochondriasis, which can negatively affect their jobs and social lives.3738

The limitations of this study include the potential for bias in the responses collected through a self-reported, web-based questionnaire. The decision to collect participants’ responses online was made due to the ongoing pandemic and the desire to prevent the transmission of the virus. However, this data collection method may have introduced bias into the results. Further, this study was conducted only at one hospital located in Seoul, implying that the findings cannot be generalized to other locations or populations. The study also did not classify the participants as patient-facing, contact, or frontline healthcare workers, which could have provided valuable information about how the pandemic affected these groups. Furthermore, the study participants were considered clinically vulnerable or living with family or friends who would be regarded as clinically vulnerable, which might have influenced the results. Therefore, the results may not represent the general population or be generalizable to other groups. Given that this study was conducted approximately 2 years after the onset of the pandemic, it may be challenging to accurately capture the participants’ psychological state during the acute phase of the pandemic. This limitation could have affected the ability to confirm the mediating effect definitively.

In conclusion, the study found that preoccupation with COVID-19 among frontline nursing professionals was positively correlated with reassurance-seeking behavior, viral anxiety, intolerance of uncertainty, and adherence to physical distancing. However, the data did not support the hypothesis that compliance with physical distancing would mediate the association between intolerance of uncertainty and preoccupation with COVID-19. Instead, the association was found to be mediated by viral anxiety and reassurance-seeking behavior. These findings provide important insights into the psychological effects of the COVID-19 pandemic on frontline nursing professionals and can inform interventions to support their well-being. It can help reduce anxiety if accurate information is quickly delivered to frontline medical staff as a top priority and can prevent excessive immersion. Additionally, it is essential to deploy medical staff who can cope with infectious diseases on-site and sufficiently train and educate them before deployment to avoid exhaustion. This is also an important aspect that should be considered. The study also highlights the need for organizations to provide resources and support to help mitigate the psychological stress of working during a pandemic on their employees. From the early stages of infectious disease, a psychological support team for medical staff responding to the disease should be established, and periodic evaluations should be conducted to identify high-risk groups. Additionally, sufficient rest time should be provided to prevent excessive distress, and methods for promoting physical and psychological recovery should be taught.