This study is part of an ongoing cohort study since 2007. A questionnaire survey administered by mail was conducted from October 1 to October 15, 2021. Subsequently, 498 older adults participated in this survey after attending a workshop project sponsored by the Ibaraki Prefecture in Japan. Participation in the study was voluntary and anonymous, and participants could withdraw from the study at any time. Approval for this research was obtained from the Research Review and Ethics Committee of the affiliated institution, and protection of personal information and research consent procedures were carried out in accordance with ethical regulations. The purpose and content of the study was explained to the participants in a written form, and they were considered to consent by filling out the survey.

The questionnaire included the Japanese version of the Fear of COVID-19 Scale (FCV-19S), the Lifestyle Satisfaction Scale, the Leisure Activity Scale for Contemporary Older Adults (LASCO), and the Japanese version of the Kessler Psychological Distress Scale-6 (K6). Scale details are outlined in the following section. Demographic information collected included participants' age, gender, marital status, and living situation, as well as self-rated health status (1, very good; 2, good; 3, somewhat poor; 4, poor), outpatient treatment, financial situation, and frequency of going out (less or more than once per week). The 301 participants who responded in person and had no missing variables in their responses were included in this analysis.

All analyses were performed using SPSS28.0 and Amos29.0 software. For each scale, a factor analysis was conducted to examine its structure and structural validity. In this factor analysis, items with factor loadings <0.4 were deleted, and Cronbach's alpha scores were also calculated to check for internal consistency. Correlation coefficients were then calculated to compute descriptive statistics and examine associations between variables. In addition, structural equation modeling was performed based on the hypothetical model created in this study. The following goodness-of-fit indices were used to evaluate the degree of fit: Tucker–Lewis index (TLI) > 0.90, comparative fit index (CFI) > 0.90, and root mean square error of approximation (RMSEA) <0.06 (28). The level of significance was set at p < 0.05.

Demographic information for the study participants is shown in Table 1. Participants include 301 older Japanese adults (23.6% male, 76.4% female) living in the Ibaraki prefecture, with a mean age of 76.7 ± 4.58 years; 76% of participants were married at the time of survey completion, and 82.3% lived with a cohabitant. Although 82.9% of participants had regular outpatient treatment, 87.7% reported their health status as relatively healthy. In addition, 83.6% of participants were financially comfortable, and 95% went out at least once a week. Of all participants, 47.0% lived in urban areas and 39.9% in rural areas.

We first conducted an exploratory factor analysis on each scale to examine the factor structure of the scales. For the FCV-19S, one item suspected of multicollinearity was deleted, and six items with one factor were used. Seven items from the LASCO with a factor loading of 0.4 or higher were retained. For the K6, six items with one factor were retained without deleting any item. All Cronbach's alpha scores are shown in Table 2. We then performed correlation analysis with the FCV-19S, Lifestyle Satisfaction Scale, LASCO, and K6; results are presented in Table 2. Correlations were found between all measures except the FCV-19 and LASCO.

Structural equation modeling was performed to examine the relationships among the variables (Figure 1). Goodness-of-fit indices were as follows: TLI = 0.936, CFI = 0.946, and RMSEA = 0.047, indicating an acceptable level of fit. Standardized coefficients showed a significant positive relationship between fear of COVID-19 and psychological distress (β = 0.33, p < 0.001) and lifestyle satisfaction and leisure activities (β = 0.35, p < 0.001). We further detected a significant negative relationship between fear of COVID-19 and lifestyle satisfaction (β = −0.23, p < 0.001) and between leisure activities and psychological distress (β = −0.33, p < 0.001).

In Japan, “the community-based integrated care system” has been established to enable older adults to live their own way in their own neighborhoods. This model promotes health and care prevention through social participation such as leisure activities (29). Indeed, prior research has reported that taking part in social activities decreases risk of functional impairment, maintains cognitive function, and decreases prevalence of depressive symptoms (30–32). Therefore, it is important for community-dwelling older adults to be encouraged to engage in social activities.

Participants of this study included older adults in a resident-participating long-term care-prevention project. The mean age was 76.7 years, and the majority of participants were older than 75. The male/female ratio was 76.4%, with more females. In general, women are more likely to participate in care-prevention activities in the community, and this group was classified as active, with 95% of participants going out at least once a week. Study participants were gathered from various regions throughout the prefecture and are considered representative of community-dwelling older adults.

We found that fear of COVID-19 had a positive effect on psychological distress; that is, a stronger fear of COVID-19 led to increased psychological distress. Since March 2020, the lives of older adults have changed drastically relative to before the COVID-19 pandemic (33), resulting in various psychological problems. For example, fear and anxiety about contracting COVID-19 can have a significant impact on the mental health of older adults (34–36). Previous studies have similarly reported that fear of COVID-19 affects mental health. We note that our study was conducted in October 2021, approximately 1.5 years after the outbreak of SARS-CoV-2. Therefore, it is clear that fear of COVID-19 has a long-term impact on psychological distress. Another published study noted short-term effects on psychological wellbeing in the early stages of the COVID-19 pandemic, as well as long-term effects due to a prolonged period of self-restraint (37). Thus, our findings are similar to those reported in previous studies and support our hypothesis that fear of COVID-19 affects psychological distress.

Because of their vulnerability and susceptibility to severe illness due to SARS-CoV-2 infection, older individuals have been asked to refrain from or limit their activities. Although these restrictions serve as important infection-prevention measures, prolonged self-restraints result in lifestyle changes and reduce opportunities for leisure and social activities. This new normal to prevent viral infection has had profound social, psychological, and physical effects. In particular, the negative impact of restricted leisure activities on mental health has been noted in several published studies (16, 38). Given that leisure activities are important for maintaining lifestyle satisfaction and good physical and mental health in older adults (39), there are also concerns about prolonged self-restraint leading to increased frailty, a condition referred to as Corona-Frailty (40). These observations highlight the need to comprehensively relationships among these factors in older adults.

This study is novel in that it revealed a comprehensive association between variables, rather than the one-to-one associations previously examined. Notably, we found that fear of COVID-19 affected psychological distress through effects on lifestyle satisfaction and engagement in leisure activities. Thus, these results suggest that fear of COVID-19 increases psychological distress by disrupting lifestyle and restricting engagement in leisure activities. Previous studies have noted a one-to-one association between fear of COVID-19 and psychological distress (35) and between engagement in leisure activities and mental health (16). However, a comprehensive association between fear of COVID-19 and psychological distress via lifestyle satisfaction and engagement in leisure activities is a new finding.

Restrictions associated with the new normal are required to reduce transmission during an infectious pandemic, such as COVID-19. However, given the ongoing nature of the pandemic, social activities for older adults have been restricted for a long period of time, and it has been difficult for these individuals to establish a new normal. Previous studies have reported many limitations for older adults in the wake of COVID-19, including those affecting leisure and social activities and interpersonal interactions (41–43). Results from this study suggest that failure to establish a new lifestyle that includes social and leisure activities will adversely affect the mental health of older individuals. Even before the COVID-19 pandemic, it was known that social and leisure activities are important for healthy living among older adults (30). Our results are consistent with these findings and suggest that safe social activities are important to prevent deterioration of mental health during the COVID-19 pandemic.

The results of this study suggest that improving lifestyle satisfaction and engagement in leisure activities may prevent psychological distress among older adults. Thus, for those who have a strong fear of COVID-19, it is likely that psychological distress could be improved by providing support increase lifestyle satisfaction and enable engagement in safe leisure activities. Since 2020, the spread of SARS-CoV-2 has necessitated self-restraint and limitations in social interactions to prevent infection, and as a result, the lives of older adults have changed drastically. In response, there is increasing concern about the decline in physical and mental functions of older adults, with various reports describing Corona-Frailty (44–46) and a separate report claiming that fear of COVID-19 increases the risk of frailty in older adults (47).

Regardless of social circumstances, engaging in leisure and other activities has always been important for the health of older adults. Moreover, it is important for one's health to have a good living environment and to engage in leisure activities of one's choice. Thus, our findings indicate that following national emergencies, such as the COVID-19 pandemic, efforts to promote lifestyle restructuring and engagement in leisure activities are needed to maintain mental and physical health among community-dwelling older adults.

We understand that this study has several limitations. First, our data are from a cross-sectional analysis conducted at a single point in time. Thus, without longitudinal data, we are unable to examine causal relationships over time. Second, the subjects were participants in a resident-participating long-term care-prevention project and are considered to be a group with high health consciousness and good physical and mental functions compared to their peers. Third, we assumed they are all Japanese based on their name, but ethnicity data was not included in the survey which may limit our implications. Lastly, the majority of participants were female. As gender differences in social and leisure activities have been reported, additional research is needed to investigate the effects of gender on the observed relationships.