{'fraction_non_alphanumeric': 0.031563435851119453, 'fraction_numerical': 0.023434900413557065, 'mean_word_length': 5.151461988304094, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 1, 'https://': 1, 'lorem ipsum': 0, 'www.': 4, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Loneliness and its correlates among Bangladeshi older adults during the COVID-19 pandemic

The present study aims to investigate the prevalence of loneliness and its associated factors among older adults during the COVID-19 pandemic in Bangladesh. This cross-sectional study was conducted in October 2020 among 1032 older Bangladeshi adults aged 60 years and above through telephone interviews. A semi-structured questionnaire was used to collect information on participants’ characteristics and COVID-19-related information. Meanwhile, the level of loneliness was measured using a 3-item UCLA Loneliness scale. More than half (51.5%) of the older adults experienced loneliness. We found that participants formally schooled [adjusted odds ratio (aOR = 0.62, 95% CI 0.43–0.88)] and received COVID-19-related information from health workers (aOR = 0.33, 95% CI 0.22–0.49) had lower odds of being lonely during the pandemic. However, older adults living alone (aOR: 2.57, 95% CI 1.34–4.94), residing distant from a health facility (aOR = 1.46, 95% CI 1.02–2.08) and in rural areas (aOR = 1.53, 95% CI 1.02–2.23) had higher odds of loneliness than their counterparts. Likewise, odds of loneliness were higher among those overwhelmed by COVID-19 (aOR = 1.93, 95% CI 1.29–2.86), who faced difficulty in earning (aOR = 1.77, 95% CI 1.18–2.67) and receiving routine medical care during pandemic (aOR = 2.94, 95% CI 1.78–4.87), and those perceiving requiring additional care during the pandemic (aOR = 6.01, 95% CI 3.80–9.49). The findings suggest that policies and plans should be directed to reduce loneliness among older adults who require additional care.

www.nature.com/scientificreports/ from work, staying alone away from children and family, widowhood, lack of social engagement and entertainment activities, sedentary lifestyle 25 , and physical disabilities 26,27 . In Bangladesh, the first COVID-19 case was reported at the beginning of March 2020, and since then, the cases have constantly been increasing 28 . As of 13 July 2022, there were more than 1,992,058 confirmed COVID-19 cases with 29,217 deaths related to COVID-19 in Bangladesh 29 . The government of Bangladesh implemented restrictive measures such as lockdown and shutdowns 30 to control the spread of the infection. While important to curb the spread of the infection, such measures also resulted in increased discomfort in getting everyday necessities and health care, in addition to creating an environment not conducive to mental health 28 . Some recent studies also documented increased mental health conditions such as stress, anxiety, fear, and depression among the older population in Bangladesh during the COVID-19 pandemic [31][32][33][34] . However, no study has explored the level of loneliness among the older population in Bangladesh during the COVID-19 pandemic, who are one of the most vulnerable population groups to the ongoing pandemic. Therefore, the present study aimed to investigate the prevalence of loneliness and its associated factors among older Bangladeshi adults amid the COVID-19 pandemic.

Methods
Study design and participants. This cross-sectional study was conducted remotely, through telephone interviews, in October 2020. Assuming a 50% prevalence of the outcome with a 5% margin of error, at 95% confidence level, 90% power of the test, and 80% response rate, the study sample size was estimated to be 1096. Although 1096 participants were approached, 1032 eligible participants agreed to participate, resulting in a ~ 94% response rate. A pre-existing registry, developed by the principal investigator's institute, based on previously completed community-based studies, served as the sampling frame for the current study and included households from all eight administrative divisions of Bangladesh. To ensure representativeness from all eight divisions of Bangladesh, probability proportionate to the number of older adults in each division was used 35 . In each administrative division, households were selected using a simple random sampling technique, and subsequently, one eligible participant was interviewed from the selected households. Hence, the number of included households and respondents are equal. When a household had more than one eligible participant, the oldest member was selected for the interview. The only inclusion criterion was defined in terms of age (i.e., ≥ 60 years). The age limit was set to ≥ 60 years because the Government of Bangladesh identifies individuals aged 60 years and above as older adults 35 . Notably, the proportion of older adults in Bangladesh, currently 8% of the total population, is rapidly growing 35 and is projected to increase to 21.9% by 2050 36 . The exclusion criteria included severe mental conditions (clinically diagnosed schizophrenia, bipolar mood disorder), a hearing disability, or an inability to communicate 28 .

Data collection tools and techniques.
A pre-tested semi-structured questionnaire was used to collect the information through a telephone interview. Data were collected electronically using SurveyCTO mobile app (https:// www. surve ycto. com/) and following the best practices for conducting phone surveys 37 . Our pre-existing registry, which had household contact information including mobile phone numbers, aided data collection. Participants were contacted on their mobile phones and interviewed by trained research assistants recruited based on previous experiences in administering health surveys on the electronic platform. The research assistants were trained extensively online in the Zoom platform before the data collection 28 . The interview sessions covered different methodological aspects of the study, tools and interviewing technique. The research assistants were trained on building rapport and instructed about the voluntary participation of the respondents and that they could skip any question they are not comfortable with. Participants who could not be reached on the first attempt were followed up multiple times and at different hours of the day. The English version of the questionnaire was first translated into Bengali language and then back-translated to English by two researchers to ensure the contents' consistency. The questionnaire was then piloted among a small sample (n = 10) of older adults to refine the language in the final version. The tool used in the pilot study did not receive any corrections/suggestions from the participants in relation to the contents developed in the Bengali language. The interview was coundcted with this questionnaire which took around half an hour for each respondents. Considering the sensitivity of the topic we explored, the research assistants were also instructed to stop surveys and refer the respondents to the nearby primary care services if they felt stressed.
Measures. Outcome measurement. The primary outcome of the study was loneliness, measured using a short 3-item UCLA Loneliness scale 38 . The three items included: how often do you feel (i) lack of companionship, (ii) left out, and (iii) isolated in the last two weeks. Each item in the scale was measured in terms of 3-item Likert responses: hardly ever (1 point), some of the time (2 points), and often (3 points). The participants were classified as lonely if they answered 'some of the time' or 'often' to any item 6 . Dichotomised loneliness variable was used for all data analyses. High internal consistency (Cronbach's alpha 0.89) suggests the scale to be reliable among the study participants. A previous study has established the validity of the Bangladeshi version of the tool 39 .

Method of analysis.
Descriptive analyses explored the distribution of variables in terms of frequencies and percentages. Chi-square tests compared the differences in loneliness by explanatory variables with a 5% significance level. Binary logistic regression models explored the factors associated with loneliness. The initial model was run with all potential covariates (listed in Table 1), and then, using the backward elimination criteria with the Akaike information criterion (AIC), the final model was selected 28 . The variables retained in the final model are presented in Table 2 and were adjusted for each other. Unadjusted and adjusted odds ratio (aOR) and associated 95% confidence interval (95% CI) are reported. All analyses were performed using the statistical software package Stata (Version 14.0).

Ethics approval. The institutional review board of the Institute of Health Economics, University of Dhaka,
Bangladesh, approved the study protocol (Ref: IHE/2020/1037), and the guidelines of the Declaration of Helsinki were followed in every stage of the study. Verbal informed consent was sought from the participants before administering the survey. Participation was voluntary, and participants did not receive any compensation 28 .

Results
Characteristics of the participants. Table 1 shows the summary statistics of the study participants.
Among the 1032 study participants, 20.4% were from the Dhaka division, 77.8% were aged 60-69 years, 65.5% were male, 81.4% were currently married, 73.9% were rural residents, and 58.3% lacked formal schooling. Over half of the participants (53.8%) had a family income of > 10,000 BDT, 40.6% were currently employed, 92.3% resided with family members, and 58.9% had at least one pre-existing NCD. Moreover, 71.0% of the participants were concerned about the pandemic, 62.6% had difficulty earning, 24.7% had difficulty procuring medicine, and 30.4% had difficulty receiving routine medical care during the pandemic ( Table 1).
Factors associated with loneliness. .87) had higher odds of loneliness than their counterparts. Moreover, the participants who perceived that they required additional care during the pandemic had more than five times higher odds of loneliness (aOR = 6.01, 95% CI 3.80-9.49) than those who did not feel so.

Discussion
This study investigated the prevalence of loneliness and its correlates among Bangladeshi older adults during the COVID-19 pandemic. More than half of the participants experienced loneliness during the COVID-19 pandemic. We did not find any single study on older adults' loneliness during the pandemic in Bangladesh and other lowand middle-income countries to compare the current study's findings. However, an online self-reporting survey on the general Bangladeshi population (aged ≥ 15) found a higher prevalence of loneliness (71%) than the current study 40 . While, another study conducted among graduate students in Bangladesh reported a slightly lower prevalence of loneliness (43.3%) during the pandemic 41 . The plausible reasons for such a difference in loneliness prevalence include differences in study tools to measure loneliness, differences in the age range of participants, The high prevalence of loneliness among older Bangladeshi adults was expected, given their high agerelated changes and losses such as loss of jobs (due to retirement), partners, friends, and social networks (due to death) 45,46 . Declining physical and cognitive health also makes older adults more vulnerable to loneliness 47 . Further, social interaction and participation, two important protective factors of loneliness 48 , were minimized amid the pandemic. Due to COVID-19-related lockdown and isolation measures, older adults' infrequent interactions with relatives, neighbours, and friends 49 , inadequate social participation in voluntary and religious activities 50 , and limited regular activities 51,52 may result an increase in loneliness. Our study's findings highlight the necessity for undertaking interventions to engage older adults in activities and improve social interactions and community participation (while practising safety measures to curb the COVID-19 spread) to decrease the likelihood of experiencing loneliness.
Our study revealed that, older individuals with formal education had lower odds of being lonely during the COVID-19 pandemic. This finding is similar to previous literature, which identified higher education as an essential correlate of loneliness 53,54 . This could be because educated people may be aware of the adverse physical and mental health consequences of loneliness and its coping strategies 55 . Neuroticism and stress are directly related to loneliness, and educational attainment reduces loneliness by decreasing the vulnerability to neuroticism and stress 56 . Furthermore, education has been considered a proxy for socioeconomic status and correlates with income and accessibility to resources 57 . Education can reduce loneliness by enriching social networks and connectedness with friends and external individuals via social media 58 . In contrast, illiteracy restricts access to information on community events and resources, limiting social activity and participation 59 , thus increasing the likelihood of loneliness. This suggests that education enhances the social activity and community participation and decreases loneliness in older adults.
The current study suggested that female participants and those living in rural areas were more likely to feel lonely than males and their urban counterparts, similar to existing literature 46,60 . Our finding that older adults who lived alone (without family) were more like to feel lonely is supported by 15 studies included in a review 26 and several other studies 43,61,62 . As indicated above, older individuals may live alone due to their loss of spouses and limited relationships with their family members 45,46 . Specifically, older females are more likely to be alone due to higher life expectancy and increased likelihood of widowhood, making them vulnerable to chronic diseases, and poor functional status in later life 60 . Household members are the first line of social networks and provide inherent opportunities for socialization which otherwise may be unavailable to those living alone, leading to more loneliness 26 . Older rural residents, especially females, may experience many challenges 11 , including limited transportation facilities, inadequate financial means, and reduced access to internet services 11,63 . Such limited Table 1. Participants' characteristics and bivariate analyses (N = 1032). a P value obtained from Chi-square test evaluating the differences between those who experienced and did not experience loneliness. b Without partner group includes divorced, separated and never married. c BDT stands for Bangladesh taka and 1 BDT ~ 84.7 US dollars.

Total
Experienced loneliness Did not experience loneliness P a n (%) n (%) n (%) www.nature.com/scientificreports/ facilities tend to isolate them from family and community members, thus increasing their risk of loneliness 63 . Loneliness in elderly women may be compounded by lack of financial resources, supports and access to health care especially in rural areas 64 . Despite this, there are no loneliness prevention interventions for older adults in Bangladesh 65 . Our findings suggest undertaking loneliness prevention interventions for older people, specifically for females and rural residents.
Our study also indicated that older individuals who received COVID-19-related information from healthcare workers had lower odds of being lonely during the pandemic. To the best of our knowledge, this is the first study investigating the association between loneliness in older adults and the source of COVID-19-related information, such as healthcare workers. For those individuals, in addition to COVID-19-related information, healthcare workers may have provided additional information on health and well-being, such as the negative consequences of loneliness on their mental health and strategies to cope with it 66 . Such awareness of the negative aspects of loneliness may prompt individuals to take action to decrease loneliness 67 . Our study's findings highlight that it is vital to disseminate information about reducing loneliness during the pandemic alongside COVID-19-related information. www.nature.com/scientificreports/ Several COVID-19 pandemic-related measures, such as feeling overwhelmed by the pandemic, difficulty earning during the lockdown and receiving routine medical care, and perception that older people required additional care during the pandemic, were associated with an increased likelihood of experiencing loneliness. To our knowledge, this is the first study exploring the associations of these correlates with loneliness among older adults during the pandemic. The government of Bangladesh has taken some strong measures to control the spread of COVID-19 68,69 . However, it has not prioritized the mental, financial, and social wellbeing of its people, specifically older adults 33 . Thus, the findings could be explained on the grounds of psychological distress due to the ongoing pandemic 70 . On the one hand, as previously mentioned, the advent of COVID-19 has reduced visits of family members/friends and emotional closeness 1 , disrupted and overwhelmed older adults' lives 31,71 . These COVID-19-related changes in the daily lives increased tension, anxiety, fear, and the risk of developing loneliness among older adults 1 . On the other hand, frustration was induced in terms of the inability to meet daily needs, make earnings, and access health care during the lockdowns 33 . Poor income is the strongest predictor of loneliness 26 . Furthermore, inaccessibility to materialistic and financial resources increases loneliness through low self-esteem and self-efficacy 47 . As part of the nationwide lockdown in Bangladesh, public transportation was restricted to limit mass movement 69 . Given that most Bangladeshi population rely on public transit, such a halt of transportation services meant no vehicular means to go to jobs or health facilities. Closure to business meant job loss, either for older adults themselves or their family members they were directly dependent on 72 . In the absence of financial aid from the government, such economic loss may have brought financial distress to the family 73 . Participants in the current study who perceived that they required additional care during the pandemic were more than five folds more likely to experience loneliness. The absence of targeted policies to address their needs during these crucial times may have caused additional distress as they may have felt ignored, left out, and lonely. Therefore, the current study findings highlight the importance of providing additional support and care, including economic and mental health support, during public health emergencies.

Strengths and limitations of the study
Our study has several strengths. First, this study is among the first in the literature from Bangladesh to examine the prevalence of loneliness and its correlates among Bangladeshi older adults during the COVID-19 pandemic. Second, to the best of our knowledge, some of the correlates of loneliness in older adults (e.g., receiving COVID-19-related information from healthcare workers, feeling overwhelmed by the COVID-19 pandemic, perceiving that they required additional care during the pandemic, difficulty receiving routine medical care during the pandemic, and distance to the nearest healthcare centre) in the current study have been reported for the first time in Bangladesh and globally. Despite these strengths, our study's findings should be considered in the context of its limitations. First, our research was cross-sectional in nature. Therefore, causality cannot be established. Second, amidst the pandemic, we had to conduct telephone interviews, and it is likely that the sample may not be representative of the entire older population of Bangladesh, specifically excluding those who don't have telephone access. Third, our study is limited to quantitative analysis, as we did not explore the qualitative aspects of older adults' feelings of loneliness during the pandemic. These limitations highlight the need for further studies with a mixed-method approach, including a qualitative study exploring older adults' experience of loneliness and its associated factors during the COVID-19 pandemic. This will provide a better understanding of older adults' feelings of loneliness and the related factors during the COVID-19 pandemic in Bangladesh.

Conclusion
The present study revealed that a high proportion of older adults experienced loneliness during this COVID-19 pandemic in Bangladesh and suggests the need for supportive mental health intervention focusing on this vulnerable population. It is also very important to address various factors associated with loneliness identified in this study by providing information and improving access to health care. Policymakers and health care practitioners should also consider strengthening the social support structure for the older population as part of the emergency management plan, and involving health workers can be of value in this regard.

Data availability
Data is available upon reasonable request to the corresponding author.