Background
COVID-19 was declared a pandemic by the World Health Organization (WHO) on March 11, 2020 [
1]. The WHO Health Organization has identified COVID-19 as a public health emergency. This is because COVID-19 is characterized by rapid contamination and mortality and has a wide range of clinical manifestations in patients with COVID-19. COVID-19 can affect the lower respiratory tract in humans and can cause diseases ranging from simple colds to severe infections with up to 50% lethality [
2].
According to multinational data from clinical studies, retrospective mining of electronic health records, case reports, and various surveys, COVID-19 has the capacity to damage the brain [
3]. In several studies, patients showed neurological manifestations, with central involvement being more common, including dizziness, headache, altered level of consciousness, stroke, ataxia, and epilepsy [
4]. Regarding more specific cognitive impairment, patients with COVID-19 demonstrate attention and executive function impairment in the acute stage [
5] and other neuropsychological impairments, such as memory and verbal fluency [
6]. In systematic reviews, subjective cognitive dysfunction was found to be 23.8% [
7].
Prospective memory refers to the ability to plan future events and execute them successfully [
8]. For example, remembering and meeting family appointments and remembering the shopping list and making purchases are prospective memories. On the other hand, retrospective memory means remembering past events. For example, memories of riding a bicycle with father as a child or talking about stories at mealtime are retrospective memories [
9]. Previous research has demonstrated that RM is a prerequisite for PM, but not vice versa. When RM is damaged, PM tends to be low, but RM is preserved when PM is damaged [
9]. Prospective memory affects a wide range of daily activities in older adults. Therefore, prospective memory is an important factor in maintaining independence and autonomy [
10]. We need to find out whether COVID-19 affects prospective memory.
Social isolation with COVID-19 has had a negative impact on the lifestyle, mental health, and quality of life of many older adults [
11‐
13]. Tosato et al., (2022) reported that 56.3% older adult has changed in lifestyle after the COVID-19 pandemic, and their quality of life worsened compared to before COVID-19. Visits to relative and physical activity among lifestyle showed the most changes [
12]. Additionally, studies in Italy, Spain, France, and the United States showed that people felt more depressed and lonelier after the pandemic [
14,
15]. In a Canadian study, the odds of depressive symptoms doubled during the pandemic compared to the pre-pandemic period [
16]. Most studies have been conducted on changes in lifestyle, mental health, and quality of life of older adults in covid-19 pandemic. There is a lack of research on changes in lifestyle, mental health, and quality of life due to confirmed COVID-19.
Although there is much evidence regarding the correlation between COVID-19 and cognitive decline, evaluations and interventions related to cognitive impairment in patients with COVID-19 are currently lacking. Moreover, older adults aged > 55 years tend to be linked to more severe forms of COVID-19 and, therefore, potentially more severe cognitive impairment [
17]. Previous studies have reported that COVID-19 negatively affects cognition, lifestyle, mental health, and quality of life [
4,
18,
19]. However, these studies only partially interpreted the relationship between COVID-19 and these variables.
Therefore, the purpose of the present study was to investigate the effects of COVID-19 confirmation on cognition, lifestyle, mental health, and quality of life in adults aged 55 years or older by comparing older adults with and without COVID-19 infection.
We hypothesized that:
There will be differences in the lifestyles of hospitalized older adults with COVID-19 and non-COVID-19.
The memory, mental health, and quality of life of hospitalized older adults with COVID-19 will be worse than that of non-COVID-19.
Discussion
The COVID-19 pandemic has severely impacted the lifestyle, cognitive function, mental health, and quality of life of older adults. There were significant effects on COVID-19 of physical activity and diet on lifestyle, depression, and insomnia in terms of mental health and quality of life. In addition, only subjective discomfort with prospective memory was reported to differ significantly between the groups.
There were significant differences in physical activity and diet between the two groups, but no significant differences were observed in activity participation between the two groups. In many countries, social distancing has been ongoing for a long time during the COVID pandemic [
34]. Due to social distancing, schools were closed, teleworking was implemented, and mobility was limited in public spaces [
35]. Therefore, there were many restrictions on the activities of those who were not infected with COVID-19. The COVID group scored 1.89 and the non-COVID group scored 1.69 in the score of activity participation, indicating that both groups had very low scores. Therefore, there was no significant difference between the two groups.
Physical activity and diet have fewer spatial restrictions than active participation. Therefore, the physical activity and diet scores were relatively high in the non-COVID group. On the other hand, in the case of the COVID group, since they were hospitalized, there were significant spatial restrictions on physical activity, and it was difficult for them to choose a diet by themselves because meals were provided at the hospital. Therefore, physical activity and diet differed significantly between the two groups. Because reduced activity and mobility in older adults during the lockdown can have a negative impact on frailty and wellbeing [
34], relevant interventions are needed.
The total scores of the PRMQ and PM and the sub-score of the PRMQ were significantly lower in the COVID group, but the RM of the PRMQ and the total score of the SMCQ were not significantly different between the two groups. Prospective memory includes retrospective memory and several cognitive processes [
36]. In addition, cognitive function declines earlier in prospective memory than in retrospective memory, and older adults complain more about prospective memory than about retrospective memory [
37,
38]. Systematic reviews also did not confirm any changes in long-term memory by COVID-19, but COVID-19 patients showed lower performance in verbal short-term memory tasks [
39]. Self-reported cognitive impairment is associated with decline in mental health, such as anxiety, depression, and PTSD [
40]. Stress can contribute to cognitive impairment [
41] and depression is associated with working memory deficits [
42]. According to previous studies, there is a correlation between depression, anxiety, and overall cognitive function [
43] and there was an interaction between depression and cognitive function on quality of life [
44]. In this study, COVID-19 confirmation had a negative effect on depression, insomnia, and quality of life, like in previous studies [45]. It can be interpreted that COVID-19 has a negative impact on prospective memory, depression, insomnia, and quality of life. However, there was no significant effect on anxiety or COVID-19 fear. The COVID pandemic reported anxiety and fear not only in confirmed cases but also in the public [
46,
47]. The results of this study also suggest that there was no significant difference in anxiety and fear between the COVID group, which is a confirmed case, and the non-COVID group, which is the public.
This study had some limitations. We used self-reported measures from an online survey. Self-reported surveys can cause socially desirable responses, recall bias, and misunderstandings of questions. In addition, it has been implemented online, and it may not be accessible to some older populations. However, we collected data in the same manner and minimized bias by using a large sample. In this study, the subjective memory complaints (SMCs) of the participants were measured, not objective outcome measures. Unlike objective assessments, subjective complaints tend to be overestimated with age [
48]. Therefore, it is necessary to evaluate the cognitive function of participants using standardized assessment tools. Nevertheless, SCMs are associated with objectively measured cognitive performance [
49]. Finally, this study was conducted only in Korea; therefore, a cautious interpretation of the results is needed.
This study is meaningful in that lifestyle, cognition, mental health, and quality of life in COVID-confirmed and non-confirmed older adults were identified. Furthermore, this study revealed that when faced with a pandemic, prevention and intervention strategies are needed for memory, lifestyle, depression, insomnia, and quality of life in older adults.
Conclusions
Confirmation of COVID affected prospective memory, physical activity, diet, and quality of life, as well as increased depression and insomnia in older adults. In addition, the COVID pandemic has caused declines in physical activity and participation among older adults. Therefore, interventions are required to improve the memory, lifestyle, and mental health of older adults with COVID-19.
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