[Need for livelihood support and relationship with community residents: A cross-sectional survey among older adults who do not use livelihood support in a rural area].

Objectives　In recent years, the Japanese government has promoted a livelihood support system based on residents-based mutual help in the community. This study aimed to examine the associations between the need for livelihood support and the relationship with community residents among older adults who do not use livelihood support in a rural area. We operationally defined livelihood support as helping older adults with daily problems so that they can continue to live in familiar neighborhoods.Methods　A self-administered questionnaire survey was conducted in Gejo Area of Tokamachi City, Niigata Prefecture in October 2018. The questionnaires were distributed to all 1,033 residents aged 65 years or over, excluding those certified with care levels 3-5 in the long-term care insurance system. The survey items included basic characteristics, health status, relationship with community residents, and need for 33 livelihood support items.Results　A total of 802 questionnaires were returned (response rate of 77.6%), and 653 community-dwelling individuals who had not used livelihood support were included in the analysis. Factor analysis grouped the 33 livelihood support items into four factors: temporary problems and troubles (53.4%), participation in events and gatherings (38.0%), daily household chores (31.7%), and small problems in daily life (27.7%). Logistic regression analysis showed that the need for assistance with temporary problems and troubles was related to "low trust in community residents," "willing to help community residents but have not yet done so," and "willing to help community residents and have already done so." The need for assistance with participation in events and gatherings was related to "willing to help community residents but have not yet done so," "willing to help community residents and have already done so," and "higher levels of sekentei." The need for assistance with daily household chores was related to "low trust in community residents" and "willing to help community residents and have already done so." Finally, the need for assistance with small problems in daily life was related to "willing to help community residents and have already done so."Conclusion　The need for livelihood support was related to relationships with community residents. To promote the livelihood support system in communities, the relationships between older adults and community residents should be considered.

[Current conditions and challenges of employing older assistant care workers based on geriatric health services facilities' scale].

Objectives　To support care workers, some care facilities employ older individuals as care assistants for peripheral, non-professional tasks. However, the size of the facilities influences their employment needs and support systems for older care workers. Therefore, this study examined the rationale for employing older assistant care workers; the challenges they face; educational systems; and the efforts to facilitate continued employment based on facility size.Methods　Initially, a fax survey was conducted with 3,591 facilities associated with the National Association of Geriatric Health Services Facilities to determine the proportion of older assistant care workers employed. Thereafter, a questionnaire survey was administered to gather more information. Out of 3,591 facilities, 2,170 responded to the survey, and 1,261 responded to the questionnaire. In this study, care assistants aged ≥60 years were classified as older care assistants. The facilities were categorized based on admission capacity into two groups: "small/medium facilities" (≤99 residents) and "large facilities" (≥100 residents). A chi-square test was conducted for data analysis.Results　Of the all geriatric health services facilities, 31.7% employed older assistant care workers. Moreover, the questionnaire survey responses showed they are employed by 687 facilities. Further analysis revealed that larger facilities employed a higher number of older care assistants than small/medium facilities. Small/medium facilities tended to have fewer training systems for older care assistants than larger facilities (30.0% for small/medium facilities vs. 21.6% for large facilities; P=0.014). Furthermore, the work of older care assistants in small/medium facilities was more susceptible to family circumstances than those in larger facilities (15.7% for small/medium facilities vs. 10.2% for large facilities; P=0.033). Compared to small/medium facilities, larger facilities were more likely to state that their employment objective was to reduce the risk of care accidents (19.8% for small/medium facilities vs. 26.3% for large facilities; P=0.046) and provide psychological support, such as periodic interviews, to older care workers to ensure continued employment (24.1% for small/medium facilities vs. for large facilities 37.3%; P<0.001).Conclusion　Larger facilities employeda higher number of older care assistants than small/medium facilities. Furthermore, small/medium facilities were less likely to provide psychological support and had a less structured training system, compared to larger facilities. Additionally, the work of older care assistants in small/medium facilities was more susceptible to family circumstances and other factors, which could affect their work performance. Thus, developing adequate support systems in small/medium facilities is crucial to promoting the employment of older care assistants.

[Examination of the relationship between tasks in geriatric health service facilities and benefits of working for older assistant care workers].

Objective　In this study, we clarified the characteristics of tasks performed by older assistant care workers at geriatric health services facilities, by individual characteristics and work status. Additionally, we examined the relationship between the tasks and benefits of working for older assistant care workers.Methods　A self-administered questionnaire survey was provided to 2,571 elderly care facilities employing assistant care workers aged ≥60.　A total of 1,606 responses were obtained, and personal characteristics, working conditions, tasks, and benefits of working for older care assistants were surveyed. Thirteen work tasks were established and categorized into four broad categories; user transfer assistance, facility maintenance, meal-related assistance, and managing and talking to users. Seven benefits of working as care assistants were "contribution to society," "social connection," "purpose of life," "income," "learning from caregiving," "health maintenance and promotion," and "time utilization."Results　Most of the respondents were women and relatively young workers. Among tasks, men, younger workers, and those working >5 days weekly represented a high proportion of those performing user transfer assistance tasks. Tasks on managing and talking to users were not correlated with sex, age, and number of days worked, but those with more flexible work patterns were more likely to be engaged in such tasks. Logistic regression analysis showed that user transfer assistance was correlated with benefits of working, such as "contribution to society," "social connection," and "learning from caregiving." Moreover, facility maintenance was associated with "income," "health maintenance and promotion," and "time utilization" and meal-related assistance was associated with "learning from caregiving." Managing and talking to users was associated with "contribution of society," "social connection," "purpose of life," and "learning from caregiving."Conclusion　The tasks of the workers were associated with individual characteristics and work status. The perception of benefits between the working tasks that involved frequent contact with users and those that did not were considerably different.

[Association between the change in the job facilitating and inhibiting factors of care staff due to the employment of older assistant workers and the emotional exhaustion among care staff].

Objectives　The mental health condition of care staff in Japan is becoming problematic. Older assistant workers are currently being employed to assist care staff with their jobs and alleviate their job burden. This employment of older assistant workers is drawing attention; however, their influence on the job facilitating and inhibiting factors of care staff and the association with the care staff's emotional exhaustion remains unclear. In this study, we aim to examine how the employment of older care assistant workers relates to the job-facilitating and job-inhibiting factors of care staff and explore that association with the care staff's emotional exhaustion.Methods　Data from a mail survey of geriatric health services facilities with older assistant workers were analyzed. Among the answers obtained from the care staff, answers from 5,185 who reported working in facilities that employ older assistant workers (over the age of 60) were analyzed. The Emotional Exhaustion subscale of the Japanese Version of the Burnout Questionnaire was used as the dependent variable. The change in job-facilitating and job-inhibiting factors of care staff due to the employment of older assistant workers (improve, maintain/exacerbate) was explored for nine contents.Results　Care staff reported a decrease in the total volume of the task (63.6%), less stress during daily tasks (39.8%), and more concentration on the tasks that require expert care knowledge (38.0%). The results of multiple regression analysis showed that the emotional exhaustion score of care staff was low when the total volume of tasks decreased (ß=－0.383, 95%CI=－0.719, －0.047), when less stress was perceived during daily tasks (ß=－0.432, 95%CI=－0.796, －0.068), when concentration on tasks that required expert care knowledge increased (ß=－0.574, 95%CI=－0.937, －0.210), and when human relationships among staff improved (ß=－0.871, 95%CI=－1.263, －0.480). Conversely, an increase in tasks requiring work with regional personnel and organizations (ß=0.800, 95%CI=0.162, 1.437) was associated with a high emotional exhaustion score.Conclusion　The employment of older care workers was related to the job-facilitating or job-inhibiting factors of care staff, and the change in these factors was associated with lower emotional exhaustion. The employment of older personnel may lower the risk of burnout among care staff.

Designing a Novel Coamorphous Salt Formulation of Telmisartan with Amlodipine to Enhance Permeability and Oral Absorption.

Coamorphous formulation is a useful approach for enhancing the solubility of poorly water-soluble drugs via intermolecular interactions. In this study, a hydrogen-bonding-based coamorphous system was developed to improve drug solubility, but it barely changed the apparent permeability (Papp) of the drug. This study aimed to design a novel coamorphous salt using ionic interactions to improve drug permeability and absorption. Telmisartan (TMS), with an acidic group, was used to form a coamorphous salt with basic amlodipine (AML). Evaluation of the physicochemical properties confirmed the formation of a coamorphous salt via ionic interactions between the amine group of AML and the carboxyl group of TMS at a molar ratio of 1:1. The coamorphous salt of TMS/AML enhanced the partitioning of both drugs into octanol, indicating increased lipophilicity owing to the interaction between TMS and AML. The coamorphous salt dramatically enhanced TMS solubility (99.8 times that of untreated TMS) and decreased AML solubility owing to the interaction between TMS and AML. Although the coamorphous salt showed a decreased Papp in the permeation study in the presence of a thicker unstirred water layer (UWL) without stirring, Papp increased in the presence of a thinner UWL with stirring. The oral absorption of TMS from the coamorphous salt increased by up to 4.1 times compared to that of untreated TMS, whereas that of AML remained unchanged. Although the coamorphous salt with increased lipophilicity has a disadvantage in terms of diffusion through the UWL, the UWL is thin in human/animal bodies owing to the peristaltic action of the digestive tract. Dissociation of the coamorphous salt on the membrane surface could contribute to the partitioning of the neutral form of drugs to the membrane cells compared with untreated drugs. As a result, coamorphous salt formation has the advantage of improving the membrane permeation and oral absorption of TMS, owing to the enhanced solubility and supply of membrane-permeable free TMS on the surface of the membrane.

Message framing effects on attitude and intention toward social participation in old age.

BACKGROUND: Message framing is frequently used to advocate health perceptions and behaviors. The effects of message framing on various health behaviors have been examined; however, its effects on social participation, a key determinant of healthy aging, are unclear. This study investigated the effects of message framing on older adults' attitudes and intentions toward social participation. METHODS: A questionnaire survey conducted in 2020 targeted community-dwelling people aged ≥ 65 years in two rural areas in Japan. Participants were randomly allocated to four groups according to the types of framed messages to promote social participation activities: "private gain-framed message," "private loss-framed message," "public gain-framed message," or "no message." Outcomes included attitudes and intentions toward social participation (impression, interest, and readiness for social participation activities). RESULTS: A total of 1,524 participants were analyzed (men: 46.3%; average age: 75.7 ± 7.9 years). Ordinal logistic regression analyses of individuals who engaged in any social participation activity showed no significant intergroup difference in the outcomes after adjusting for potential covariates. Among people who did not engage in any activity, the private loss-framed message was associated with a more favorable impression and higher interest and readiness than no message. The private gain-framed message was related to a higher interest in social participation. CONCLUSIONS: Private loss-framed messages are possibly most effective in reinforcing attitudes and intentions toward social participation, particularly among individuals without social participation experience. These findings highlight the possibility of using a message-framing approach to promote social participation in older adults.

Effect of Solubility Improvement via Formation of an Amorphous Composite of Indomethacin and Sulindac on Membrane Permeability.

The importance of permeability as well as solubility of the drug has been recognized in improving the solubility of poorly water-soluble drugs. This study investigated the impact of amorphous composites of indomethacin (IMC) and sulindac (SLD) on the membrane permeability of drugs. The IMC/SLD (1/1) formulation prepared by dry grinding was amorphous with a single glass transition temperature. The Fourier transform IR spectra and Raman spectra revealed formation of hydrogen bonds between the OH group of IMC and the carbonyl group of SLD. These results suggest that an amorphous composite was formed between IMC and SLD through hydrogen bonding. The amount of dissolved IMC and SLD from the amorphous composite of IMC/SLD (1/1) was higher than that of the untreated IMC or SLD in the dissolution test. The permeated amounts and permeation rates of both drugs were enhanced by increasing the solubility of the amorphous composite. Conversely, the apparent membrane permeability coefficients (Papp) were almost same for untreated drugs and amorphous composites. In the case of hydroxypropyl-ß-cyclodextrin and sodium dodecyl sulfate, Papp of the drugs decreased with the addition of these compounds, although the drug solubility was enhanced by the solubilization effect. This study revealed that an amorphous composite formed through hydrogen bonding is an attractive pharmaceutical way to enhance the permeated amount and permeation rate without changing the Papp of both the drugs.

[Relationship between the perceived benefits of working and emotional exhaustion among older assistant care workers: A cross-sectional study].

Objectives　This study is intended to clarify the perceived benefits of working among older assistant care workers employed in geriatric health service facilities and examine the relationship between perceived benefits and emotional exhaustion.Methods　We analyzed data from a mail survey of older assistant care workers employed in geriatric health service facilities that the Japan Association of Geriatric Health Services Facilities conducted in 2020. In this survey, those aged ≥60 were defined as older assistant care workers. Responses were obtained from 1,606 older assistant care workers at 599 facilities. The dependent variable was the emotional exhaustion subscale of the Japanese version of the Burnout Questionnaire. The independent variables were the seven benefits of working as an assistant care worker: 1) I can contribute to society; 2) I am connected to society; 3) I have a sense of purpose in life; 4) I am earning the income I expected since I started working as an assistant care worker; 5) I am learning about care; 6) It has maintained and improved my health; and 7) I can use my time effectively. Latent class analysis (LCA) was performed using these seven benefits as independent variables. Multiple regression analysis was performed using emotional exhaustion and the perceived benefits as dependent and independent variables, respectively. The missing values were supplemented by the multiple imputation method.Results　Overall, 1,601 responses were analyzed after excluding 5 respondents who did not answer all the questions. Four patterns were identified from the LCA results: the "benefit-full type," who perceived all benefits; the "benefit-less type," who perceived few benefits; the "benefit-extroverted type," who perceived social contribution and connection as benefits; and the "benefit-introverted type," who perceived health maintenance and improvement and time utilization as benefits. The multiple regression analysis showed that emotional exhaustion scores were higher for the "benefit-extroverted" and "benefit-less" types than for the "benefit-full" type (b=2.465, P<.001 and b=1.931, P<.001, respectively). No difference was found in the case of the "benefit-introverted" type (b=0.050, P=.851).Conclusion　The perceptions of diverse and introverted benefits were associated with lower emotional exhaustion scores among older assistant care workers. Future intervention studies are needed to examine whether obtaining diverse or introverted benefits can decrease the emotional exhaustion score.

[Longitudinal association between work and self-rated health in older adults: a systematic review].

Objective　Japan's shortage in labor force due to a declining birth rate and aging population has led to the rapid development of various systems and work environments to promote the employment of older adults. With increasing expectations for the active participation of older adults in the labor market, it is necessary to clarify the relationship between work and physical and mental health in this population, as well as the challenges they face. In particular, self-rated health is an important health indicator that captures the overall health status of older adults, which is strongly related to the decline in life functions and the increase in healthy life expectancy. In this study, we examined the longitudinal association between work and self-rated health perception among older adults.Methods　A literature search was conducted using PubMed, PsycINFO, CINAHL, and the Japana Centra Revuo Medicina (Igaku Chuo Zasshi in Japanese). The keywords selected for the search were "older adult," "employment," and "self-rated health." The inclusion criteria were i) the baseline age of study subjects was 60 years or older, ii) employment was used as an independent variable and self-rated health was used as a dependent variable, and iii) studies were longitudinal. The quality of the selected literature was assessed using the Newcastle-Ottawa Scale (NOS).Results　As a result of the review, a total of five studies were accepted. Four studies were from Japan and one was from the United States. The NOS scores showed that all selected studies were of high quality, scoring 6 or 7 on a 9-point scale. Three of the five studies reported that older adults who were working had higher self-rated health than those who were not working. Two of the five studies reported no significant association between employment and self-rated health among older adults.Conclusion　This systematic review suggested a significant relationship between work and self-rated health among older adults. However, the number of studies that focused on the longitudinal effect of employment was limited. Employment in later life is becoming increasingly common, therefore further evidence on its effect on health should be gathered.

Electrochemical control of strong coupling states between localized surface plasmons and molecule excitons for Raman enhancement.

The intensity of Raman scattering from dye molecules strongly coupled with localized surface plasmons of metal nanostructures was controlled by the electrochemical potential. Through in situ electrochemical extinction and surface-enhanced Raman scattering measurements, it is found that the redox state of the molecules affects the coupling strength, leading to the change in the intensity of the Raman scattering. Analysis of the Raman spectrum provides information on the molecules in strong coupling states showing effective enhancement of Raman scattering.

Development of mediator-type biosensor to wirelessly monitor whole cholesterol concentration in fish.

We developed a wireless monitoring system to monitor fish condition by tracking the change in whole cholesterol concentration. The whole cholesterol concentration of fish is a source of steroid hormones or indicator of immunity level, which makes its detection important for tracking physiological condition of fish. Wireless monitoring system comprises of mediator-type biosensor and wireless transmission device. Biosensor is implantable to fish body, and transmission device is so light, in that fish is allowed to swim freely during monitoring. Cholesterol esterase and oxidase were fixated on to the detection site of biosensor and used to detect the whole cholesterol concentration. However, cholesterol oxidase incorporates oxidation-reduction reaction of oxygen for detection, which concentration fluctuates easily due to change in environmental condition. Meanwhile, mediator-type biosensor enables monitoring of whole cholesterol concentration by using mediator to substitute that oxidation-reduction reaction of oxygen. Characteristic of fabricated mediator-type biosensor was tested. The sensor output current of mediator-type biosensor remained stable compared to output current of non-mediator-type biosensor under fluctuating oxygen concentration of 0-8 ppm, which implied that this sensor is less affected by change in dissolved oxygen concentration. That biosensor was then implanted into fish for wireless monitoring. As a result, approximately 48 h of real-time monitoring was successful.

Plasmonically nanoconfined light probing invisible phonon modes in defect-free graphene.

We present a simple plasmonic method that enables tuning of accessibility to the dipole-forbidden transition states of matter. This technique is realized by well-controlled plasmonic dimers, which can confine optical fields on the order of molecular dimensions. As an example, the approach is applied to activate invisible noncenter phonon modes of defect-free graphene in resonance Raman spectra. The relative intensity of the normally forbidden modes with respect to the dipole allowed modes progressively increases as the degree of field confinement increases. This opens up a novel avenue for both photochemical excitation of molecular systems and nanoscale characterization of materials.

Single molecule dynamics at a mechanically controllable break junction in solution at room temperature.

The in situ observation of geometrical and electronic structural dynamics of a single molecule junction is critically important in order to further progress in molecular electronics. Observations of single molecular junctions are difficult, however, because of sensitivity limits. Here, we report surface-enhanced Raman scattering (SERS) of a single 4,4'-bipyridine molecule under conditions of in situ current flow in a nanogap, by using nano-fabricated, mechanically controllable break junction (MCBJ) electrodes. When adsorbed at room temperature on metal nanoelectrodes in solution to form a single molecule junction, statistical analysis showed that nontotally symmetric b(1) and b(2) modes of 4,4'-bipyridine were strongly enhanced relative to observations of the same modes in solid or aqueous solutions. Significant changes in SERS intensity, energy (wavenumber), and selectivity of Raman vibrational bands that are coincident with current fluctuations provide information on distinct states of electronic and geometrical structure of the single molecule junction, even under large thermal fluctuations occurring at room temperature. We observed the dynamics of 4,4'-bipyridine motion between vertical and tilting configurations in the Au nanogap via b(1) and b(2) mode switching. A slight increase in the tilting angle of the molecule was also observed by noting the increase in the energies of Raman modes and the decrease in conductance of the molecular junction.

Local thermal elevation probing of metal nanostructures during laser illumination utilizing surface-enhanced Raman scattering from a single-walled carbon nanotube.

Localized laser-induced heating of an individual Au nano-dimer was quantitatively evaluated by measuring the surface-enhanced Raman scattering (SERS) from an isolated single-walled carbon nanotube (SWNT) supported above the nano-gap between the two metal centres of the dimer. The SERS measurement showed an apparent wavenumber shift in the G-band of the Raman spectra with an increase in the power of the illuminated laser light, indicating the laser-induced local thermal elevation of the Au nano-dimer. In addition, it was found that the effect of the laser illumination on the thermal elevation in air was larger than that in aqueous solution, indicating that the localized laser-heating effect is strongly influenced by the surrounding environment. The present technique provides a measure of the highly localized heating effect of plasmonic metal nanostructures under photo-illumination.

Carbon nanotube enhanced mediator-type biosensor for real-time monitoring of glucose concentrations in fish.

We have developed a mediator-type biosensor to rapidly monitor blood glucose concentrations in fish, which are an indicator of stress. Glucose oxidase was used to detect glucose concentrations and ferrocene was used to limit the effect of oxygen. We also improved the sensitivity and durability of the sensor for better performance. Single-walled carbon nanotubes were used to enhance sensor sensitivity. Affixing the carbon nanotubes (30 mg ml(-1)) to the working electrode increased the sensor sensitivity to 61.9 mM nA(-1) mm(-2), twice the value for the sensor without single-walled carbon nanotubes. A fabricated mediator-type biosensor sensor was used to perform real-time in vivo measurements. The sensor was implanted into the interstitial fluid of a fish eyeball, and detection was transmitted to a personal computer by a wireless potentiostat. Continuous measurement of the glucose concentration was possible for 78 hours. Stress was artificially applied to the fish during the measurement, and the change of blood glucose concentrations were observed. Our proposed sensor is applicable for effectively monitoring stress in free-swimming fish.

Wireless biosensor system for real-time L-lactic acid monitoring in fish.

We have developed a wireless biosensor system to continuously monitor L-lactic acid concentrations in fish. The blood L-lactic acid level of fish is a barometer of stress. The biosensor comprised Pt-Ir wire (φ0.178 mm) as the working electrode and Ag/AgCl paste as the reference electrode. Lactate oxidase was immobilized on the working electrode using glutaraldehyde. The sensor calibration was linear and good correlated with L-lactic acid levels (R = 0.9959) in the range of 0.04 to 6.0 mg · dL(-1). We used the eyeball interstitial sclera fluid (EISF) as the site of sensor implantation. The blood L-lactic acid levels correlated closely with the EISF L-lactic acid levels in the range of 3 to 13 mg · dL(-1) (R = 0.8173, n = 26). Wireless monitoring of L-lactic acid was performed using the sensor system in free-swimming fish in an aquarium. The sensor response was stable for over 60 h. Thus, our biosensor provided a rapid and convenient method for real-time monitoring of L-lactic acid levels in fish.

Experience of voluntary support provision in youth is associated with later-life supportive actions: A community-based study in Japan.

Enhancing the voluntary supportive actions of older adults towards other community-dwelling citizens is an important measure for a healthy community. Volunteering action in adulthood is related to the volunteering actions of older adults' parents, which they remember from their youth. In this study, the association between parents' former voluntary supportive actions and the current voluntary supportive actions of older adults is explored. Questionnaires were distributed to community-dwelling citizens aged 65 years and above, in Tokamachi city, Niigata Prefecture, Japan (response rate: 81.7%). Participants self-reported their current voluntary supportive actions and reported on their parents' former voluntary actions during their youth. The results indicated that the current voluntary supportive actions of the study participants were related to the former voluntary actions of their parents (OR: 2.28, 95% CI: 1.62-3.20). Moreover, the participants were more likely to extend support in contexts which are more closely related to one's private life, only when their parents provided support in those private contexts. The study provides implications for the importance of considering life experiences when facilitating voluntary supportive actions and renders information on how unique strategies should to be implemented to involve individuals who are unfamiliar with volunteering actions.

Functional capacity in community-dwelling older adults maintained by a higher friend network than family network: implications from a two-year longitudinal study.

OBJECTIVE: Maintaining a level of functional capacity is essential for healthy aging. In this research, the association between the change in the level of functional capacity and social network typology was explored over a two-year period. Participants were recruited from a community-based cohort study within Kashiwa City, Japan, and data from the years 2016 and 2018 were used. Cognitive functions, functional capacity, and social network typology were assessed using the Mini-Mental State Examination, the Japan Science and Technology Agency Index of Competence, and the Lubben Social Network Scale, respectively. Binomial logistic regression analysis was then conducted to evaluate the association of individuals' personal network and their functional capacity. RESULTS: Results showed that, when compared to the group with both a high family and friend network, the group of community-dwelling older adults with both a low family and friend network (OR: 0.58, 95% CI: 0.34-1.00), and the group with a high family but low friend network demonstrated a lower functional capacity (OR:0.47, 95% CI: 0.26-0.85). Active social participation, facilitated by a friend network, could be a contributing factor to the maintenance of functional capacity.

Employment in old age and all-cause mortality: A systematic review.

Social participation promotes and maintains the health of older adults. Working is a type of social participation; however, the effect of employment in old age on health outcomes has not been established. This study aimed to review the relationship between employment in old age (≥60 years) and all-cause mortality. For this systematic review, a computerized search was performed using PubMed, CINAHL and PsycINFO for prospective studies published through June 2020. The observational studies were extracted according to the study participants, indicators, follow-up period, statistical approach and main results. The quality of the studies was assessed using the Newcastle-Ottawa Scale. Of the 37 832 records identified, 14 studies were included in the systematic review based on the inclusion and exclusion criteria. Eight studies were derived from Asian countries (four from Japan, two from Taiwan and one from Thailand and South Korea), three were from the United States, two were from Israel and one was from Brazil. The baseline data of 13 studies were collected before 2000. Thirteen of the 14 studies reported any association between employment in later life and a lower risk of mortality. Four studies examined the sex-related differences in the effect of later-life employment on all-cause mortality, but the association was controversial. Overall, we revealed that working in old age would lower mortality risk. Although more findings based on recent data are required, this study indicates that working later in life is beneficial for promoting and maintaining health. Geriatr Gerontol Int 2022; 22: 705-714.

Association between increased caregiver burden and severe psychological distress for informal caregivers during the COVID-19 pandemic in Japan: A cross-sectional study.

OBJECTIVE: During the coronavirus disease 2019 (COVID-19) pandemic, informal caregivers' mental health deteriorated more than that of non-caregivers. We examined the association between increased caregiver burden during the pandemic and severe psychological distress (SPD). METHODS: We used cross-sectional data from a nationwide internet survey conducted between August and September 2020 in Japan. Of 25,482 participants aged 15-79 years, 1,920 informal caregivers were included. SPD was defined as Kessler 6 Scale (K6) score ≥ 13. Self-rated change in caregiver burden was measured retrospectively with a single question item. Binary logistic regression analysis was used to examine the association between SPD and increased caregiver burden during the pandemic, adjusted for demographic, socioeconomic, health, and caregiving variables. To examine the differential association between increased caregiver burden and SPD, interaction terms were added and binary logistic regression was separately conducted for all variables. RESULTS: Participants' mean age was 52.3 years (standard deviation 15.9), 48.8% of participants were male, 56.7% reported increased caregiver burden, and 19.3% exhibited SPD. Increased caregiver burden was significantly associated with SPD (adjusted odds ratio: 1.90; 95% confidence interval: 1.37-2.66). The association between increased caregiver burden and SPD was stronger among caregivers who were married, those undergoing disease treatment, and those with a care-receiver with a care need level of 1-2. CONCLUSIONS: The results revealed that more than half of caregivers reported increased caregiver burden, and increased caregiver burden was associated with SPD during the pandemic. Measures supporting mental health for caregivers with increased caregiver burden should be implemented immediately.