The objective of this study was to investigate changes in physical activity (PA) between January (before the COVID-19 epidemic) and April (during the COVID-19 epidemic) 2020 in community-dwelling ...older adults in Japan.
Cross-sectional online survey.
From April 23 to 27, 2020, an online survey was completed by 1,600 community-dwelling older adults in Japan.
We assessed the frailty status using the Kihon checklist, and other demographics and asked questions regarding PA at two time points: January and April 2020. We defined the total PA time (minutes) per week based on activity frequency and time.
The study participants' mean age, proportion of women, and prevalence of frailty were 74.0±5.6 years, 50% (n=800), and 24.3% (n=388), respectively. We found a significant decrease in total PA time in April 2020 (median interquartile range (IQR), 180 0 to 420) when compared to January 2020 (median IQR, 245 90 to 480) (P<0.001). We also performed a subgroup analysis according to the frailty category; total PA time significantly decreased in April 2020 when compared to January 2020 for all frailty categories (P<0.001).
In conclusion, due to the COVID-19 epidemic, the total PA time in April 2020 significantly decreased compared to that in January 2020 in older adults. This finding may lead to a higher incidence of disability in the near future in older people.
Objectives
The objective of this study was to investigate changes in physical activity (PA) between January (before the COVID-19 epidemic) and April (during the COVID-19 epidemic) 2020 in ...community-dwelling older adults in Japan.
Design
Cross-sectional online survey.
Setting and Subjects
From April 23 to 27, 2020, an online survey was completed by 1,600 community-dwelling older adults in Japan.
Methods
We assessed the frailty status using the Kihon checklist, and other demographics and asked questions regarding PA at two time points: January and April 2020. We defined the total PA time (minutes) per week based on activity frequency and time.
Results
The study participants’ mean age, proportion of women, and prevalence of frailty were 74.0±5.6 years, 50% (n=800), and 24.3% (n=388), respectively. We found a significant decrease in total PA time in April 2020 (median interquartile range (IQR), 180 0 to 420) when compared to January 2020 (median IQR, 245 90 to 480) (P<0.001). We also performed a subgroup analysis according to the frailty category; total PA time significantly decreased in April 2020 when compared to January 2020 for all frailty categories (P<0.001).
Conclusion
In conclusion, due to the COVID-19 epidemic, the total PA time in April 2020 significantly decreased compared to that in January 2020 in older adults. This finding may lead to a higher incidence of disability in the near future in older people.
Objectives
The objective of this study was to investigate the influence of the COVID-19 pandemic on physical activity (PA) and the incidence of frailty among initially non-frail older adults in ...Japan.
Design
A follow-up online survey.
Setting and Subjects
Among the 1,600 baseline online survey participants, 388 adults were already frail, and 275 older adults did not respond to the follow-up survey. Thus, the final number of participants in this study was 937 (follow-up rate: 77.3%).
Methods
We assessed the total PA time at four time points according to the COVID-19 waves in Japan: January 2020 (before the pandemic), April 2020 (during the first wave), August 2020 (during the second wave), and January 2021 (during the third wave). We then investigated the incidence of frailty during a one-year follow-up period (during the pandemic).
Results
The total PA time during the first, second, and third waves of the pandemic decreased from the pre-pandemic PA time by 33.3%, 28.3%, and 40.0%, respectively. In particular, the total PA time of older adults who were living alone and socially inactive decreased significantly: 42.9% (first wave), 50.0% (second wave), and 61.9% (third wave) less than before the pandemic, respectively. Additionally, they were at a significantly higher risk of incident frailty than those who were not living alone and were socially active (adjusted odds ratio: 2.04 95% confidence interval: 1.01–4.10).
Conclusion
Our findings suggest that older adults who live alone and are socially inactive are more likely to experience incident frailty/disability due to decreased PA during the pandemic. Understanding this mechanism may be crucial for maintaining the health status of older adults.
Aim
Phase angle (PhA) can be determined through bioelectrical impedance analysis and is a unique variable for skeletal muscle. The objective of this study was to evaluate the relationship between PhA ...and muscle mass/quality in older adults. In addition, we attempted to determine the cutoff value of PhA for poor muscle function.
Methods
Community-dwelling Japanese older men (n=285, 81.1±7.1 years) and women (n=724, 80.4±6.8 years) participated in this study and were classified into four groups based on the Asian Working Group for Sarcopenia (normal, presarcopenia, dynapenia, and sarcopenia). We measured PhA using bioelectrical impedance analysis, muscle quantity and quality indicators using ultrasonography, muscle strength, and physical performance and compared them in four groups. We also tried to determine the cutoff value of PhA for poor muscle function.
Results
We found a significant difference in PhA among the four groups in men (P<0.05), and the dynapenia (3.61±0.75°) and sarcopenia groups (3.40±0.74°) showed significantly lower values than the normal group (4.50±0.86°) (P<0.05), but not the presarcopenia group (4.12±0.85°). In women, a significant difference was also observed among the four groups (P<0.05), and the dynapenia (3.41±0.65°) and sarcopenia groups (3.31±0.66°) showed significantly lower measures than the normal group (4.14±0.71°) (P<0.05), but not the presarcopenia group (4.07±0.51°). The receiver-operating characteristic curve analysis indicated the best cutoff value of PhA (men: 4.05°, women: 3.55°) to discriminate sarcopenia and dynapenia from normal and presarcopenia.
Conclusion
These findings suggest that PhA is a useful indicator for muscle function.
This study’s objective was to explore the association between various factors and the increased caregiver burden of informal caregivers during the COVID-19 pandemic. On February, 2021, 700 informal ...caregivers completed an online survey. We assessed the change in caregiver burden during the COVID-19 pandemic. Among all caregiver participants, 287 (41.0%) complained of an increased caregiver burden due to the COVID-19 pandemic. The factors associated with increased caregiver burden were depressive symptoms in caregivers odds ratio (OR), 2.20; 95% confidence interval (CI), 1.50–3.23, dementia (OR, 2.48; 95%CI, 1.07–5.73) and low Barthel Index scores (OR, 2.01; 95%CI, 1.39–2.90) in care receivers, care days (OR, 1.09; 95%CI, 1.01–1.17) and times (OR, 1.06; 95%CI, 1.01–1.10), and use of home care service (OR, 1.46; 95%CI, 1.01–2.10) and visiting care service (OR, 1.71; 95%CI, 1.20–2.45). These findings suggest we need to pay attention to the physical and mental health of both the care receivers and caregivers.
We consider power means of independent and identically distributed (i.i.d.) non-integrable random variables. The power mean is an example of a homogeneous quasi-arithmetic mean. Under certain ...conditions, several limit theorems hold for the power mean, similar to the case of the arithmetic mean of i.i.d. integrable random variables. Our feature is that the generators of the power means are allowed to be complex-valued, which enables us to consider the power mean of random variables supported on the whole set of real numbers. We establish integrabilities of the power mean of i.i.d. non-integrable random variables and a limit theorem for the variances of the power mean. We also consider the behavior of the power mean as the parameter of the power varies. The complex-valued power means are unbiased, strongly-consistent, robust estimators for the joint of the location and scale parameters of the Cauchy distribution.
This paper gives a new approach for the maximum likelihood estimation of the joint of the location and scale of the Cauchy distribution. We regard the joint as a single complex parameter and derive a ...new form of the likelihood equation of a complex variable. Based on the equation, we provide a new iterative scheme approximating the maximum likelihood estimate. We also handle the equation in an algebraic manner and derive a polynomial containing the maximum likelihood estimate as a root. This algebraic approach provides another scheme approximating the maximum likelihood estimate by root-finding algorithms for polynomials, and furthermore, gives the non-existence of closed-form formulae for the case that the sample size is five. We finally provide some numerical examples to show our method is effective.
We construct a confidence region of parameters for a sample of size
N
from the Cauchy distributed random variables. Although the Cauchy distribution has two parameters, namely, a location parameter
μ
...∈ ℝ and a scale parameter
σ >
0
,
we consider them simultaneously by regarding them as a single complex parameter
γ
:=
μ
+
iσ.
The region should be a domain in the complex plane. We give a simple and specific formula to represent the region as a disc and as a square.
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