Daisuke Kato

Background: Loneliness is a long-standing and widely acknowledged public health problem among older adults, yet evidence remains mixed regarding how virtual communication is associated with loneliness. Less is known about whether this association varies across baseline profiles among older adults. Objective: This study aimed to examine the association between frequent virtual communication with family, friends, or acquaintances and loneliness among older adults in Japan and explore whether this association varied across baseline profiles. Methods: Using linked 2019 and 2022 data from the Japan Gerontological Evaluation Study, we conducted an observational analysis of community-dwelling Japanese adults aged 65 years or older (N=4807). Baseline covariates were measured in 2019. Frequent virtual communication was assessed in 2022 based on retrospective reports of internet or email use for communication with family, friends, or acquaintances in the preceding year; frequent use was defined as use at least 2 to 3 times per week. Participants not meeting this definition were categorized as nonusers or infrequent users. Loneliness was measured in 2022 using the 3-item UCLA Loneliness Scale (range 3-9). We used targeted maximum likelihood estimation with SuperLearner and 42 baseline covariates to estimate the sample average–adjusted association and a generalized random forest approach to explore heterogeneity in the estimated association across baseline profiles. Supplementary analyses examined baseline loneliness adjustment in an alternative linked sample, a dichotomized loneliness outcome, propensity score overlap, and model calibration. Results: The analytic sample included 4807 participants, of whom 1616 (33.6%) met the frequent virtual communication definition. After adjusting for observed baseline covariates, frequent virtual communication was associated with a difference of −0.136 in loneliness scores (95% CI −0.194 to −0.078). Generalized random forest analyses suggested exploratory heterogeneity in the estimated association across baseline profiles; most individual-level forest predictions for the estimated association were below 0 (4519/4807, 94.0%). In supplementary analyses, the association remained in the same direction after adjustment for baseline loneliness in an alternative linked sample (adjusted mean difference −0.117, 95% CI −0.173 to −0.061) and when loneliness was dichotomized (odds ratio for loneliness 0.734, 95% CI 0.597-0.904). Propensity score diagnostics showed overlap between exposure groups, although overlap was limited in the tails. Conclusions: In this observational analysis of older adults in Japan, frequent virtual communication was associated with modestly lower loneliness, and generalized random forest analyses suggested exploratory heterogeneity across baseline profiles. The findings should be interpreted cautiously because the exposure was retrospectively reported, loneliness was measured in the same survey wave, baseline loneliness was not available in the main analytic sample, and sample selection may have affected generalizability. The findings should not be interpreted as evidence of causal effects.

BACKGROUND Loneliness is a long-standing and widely acknowledged public health problem among older adults, yet evidence remains mixed regarding how virtual communication is associated with loneliness. Less is known about whether this association varies across baseline profiles among older adults. OBJECTIVE This study aimed to examine the association between frequent virtual communication with family, friends, or acquaintances and loneliness among older adults in Japan and explore whether this association varied across baseline profiles. METHODS Using linked 2019 and 2022 data from the Japan Gerontological Evaluation Study, we conducted an observational analysis of community-dwelling Japanese adults aged 65 years or older (N=4807). Baseline covariates were measured in 2019. Frequent virtual communication was assessed in 2022 based on retrospective reports of internet or email use for communication with family, friends, or acquaintances in the preceding year; frequent use was defined as use at least 2 to 3 times per week. Participants not meeting this definition were categorized as nonusers or infrequent users. Loneliness was measured in 2022 using the 3-item UCLA Loneliness Scale (range 3-9). We used targeted maximum likelihood estimation with SuperLearner and 42 baseline covariates to estimate the sample average–adjusted association and a generalized random forest approach to explore heterogeneity in the estimated association across baseline profiles. Supplementary analyses examined baseline loneliness adjustment in an alternative linked sample, a dichotomized loneliness outcome, propensity score overlap, and model calibration. RESULTS The analytic sample included 4807 participants, of whom 1616 (33.6%) met the frequent virtual communication definition. After adjusting for observed baseline covariates, frequent virtual communication was associated with a difference of −0.136 in loneliness scores (95% CI −0.194 to −0.078). Generalized random forest analyses suggested exploratory heterogeneity in the estimated association across baseline profiles; most individual-level forest predictions for the estimated association were below 0 (4519/4807, 94.0%). In supplementary analyses, the association remained in the same direction after adjustment for baseline loneliness in an alternative linked sample (adjusted mean difference −0.117, 95% CI −0.173 to −0.061) and when loneliness was dichotomized (odds ratio for loneliness 0.734, 95% CI 0.597-0.904). Propensity score diagnostics showed overlap between exposure groups, although overlap was limited in the tails. CONCLUSIONS In this observational analysis of older adults in Japan, frequent virtual communication was associated with modestly lower loneliness, and generalized random forest analyses suggested exploratory heterogeneity across baseline profiles. The findings should be interpreted cautiously because the exposure was retrospectively reported, loneliness was measured in the same survey wave, baseline loneliness was not available in the main analytic sample, and sample selection may have affected generalizability. The findings should not be interpreted as evidence of causal effects.

Japan launched a municipal financial incentive program in 2018 to promote higher-quality long-term care (LTC). We quantified the association between municipal incentive performance and subsequent incident LTC certification and all-cause mortality among community-dwelling older people. Baseline 2016 data from the Japan Gerontological Evaluation Study (N = 90 896 adults aged ≥65 years in 23 municipalities) were linked to 2018-2020 administrative records. Each municipality received a composite incentive score (0-612). Using multivariable logistic regression with fixed effects, we estimated odds ratios (ORs) per 1 SD score increase, adjusting for demographics, socioeconomic status, and health. Over three years, 10.7% newly required LTC certification and 5.1% died. A 1 SD higher incentive score was associated with lower odds of incident LTC (OR: 0.91) and all-cause mortality (OR: 0.66). These benefits were driven by the “Support Functional Independence/Prevent Progression” domain in less-urban areas, while plan-do-check-act–style activities predominated in cities. Overall, better municipal performance under Japan’s financial incentive policy correlated with short-term reductions in LTC utilization and mortality among older residents, supporting continued monitoring and policy refinement.

We sought to understand the impact of multimorbidity (MM) on the trajectories of functional decline in the last three years of life among older people in Japan. We used nationwide longitudinal cohort data with 6-year follow-up and analyzed 3731 functionally independent residents aged 65 years and older. The primary outcome was the five trajectory groups of functional disability in the last three years of life, defined by group-based trajectory modeling (GBTM). The explanatory variable was two alternative definitions of MM: basic MM (BMM; two or more comorbid diseases) versus complex MM (CMM; three or more body system disorders due to disease). A multinomial logistic regression analysis showed both MMs were associated with earlier trajectories of functional decline (maximum odds ratio: BMM 1.12 [0.99–1.27]; CMM 1.29 [1.16–1.44]). Preventing MMs, especially CMM, by providing appropriate care and support could contribute to healthy longevity by delaying the onset of functional disability.

Background: There is a shortage of general practitioners in Japan. With the revision of educational guidelines, general practice (GP) education has improved. However, the amount of education on GP in medical schools remains inconsistent. This study examined the relationship between medical students’ amount of GP-related education and their subsequent choice of GP majors.Methods: A retrospective cohort study was conducted in a teaching hospital in Japan. Participants were residents in the hospital. The exposure comprised compulsory lectures and training time for community-based medicine in medical schools. The outcome included participants choosing GP majors after their initial 2-year junior residency.Results: Fifty-one participants were included in the final analysis. Of these, 14 majored in GP and 37 in non-GP after their initial 2-year junior residency. Of the participants who took GP lectures for 18 hours or more, 11 chose GP majors, and 18 chose non-GP majors (risk ratio, 2.78; 95% confidence interval [CI], 0.88–8.79). Of the participants who underwent training for 12 days or more, 10 chose GP majors, and 16 chose non-GP majors (risk ratio, 2.40; 95% CI, 0.87–6.68).Conclusion: The results do not support the association between the amount of compulsory undergraduate education for community-based medicine and the subsequent increase in the number of residents choosing GP majors in Japan. Educators would do well to explore different approaches, such as improving the quality of education to increase the number of GP residents. Further research is needed to reach more definitive conclusions.

Background: With the aging of populations worldwide, the extension of people’s working lives has become a crucial policy issue. The aim of this study is to assess the impact of complex multimorbidity (CMM) as a predictor of working status among retirement-aged adults in Japan. Methods: Using a nationwide longitudinal cohort study of people aged over 65 who were free of documented disability at baseline, we matched individuals with respect to their propensity to develop CMM. The primary outcome of the study was working status after the six-year follow-up. Results: Among 5613 older adults (mean age: 74.2 years) included in the study, 726 had CMM and 2211 were still working at the end of the follow-up. In propensity-matched analyses, the employment rate was 6.4% higher in the CMM-free group at the end of the six-year follow-up compared to the CMM group (725 pairs; 29.5% vs. 35.9%; p = 0.012). Logistic regression analysis showed that CMM prevented older people from continuing to work beyond retirement age and was a more important factor than socioeconomic factors (income or educational attainment) or psychological factors (depressive symptoms or purpose in life). Conclusions: Our study found that CMM has an adverse impact on the employment rate of older adults in Japan. This finding suggests that providing appropriate support to CMM patients may extend their working lives.

Complex multimorbidity (CMM) has been proposed as a more nuanced concept of multimorbidity (MM). We sought to quantify the association of CMM and MM on the incidence of long-term care (LTC) needs in a cohort of older Japanese people. Our follow-up was based on a nationwide longitudinal cohort study of people aged over 65 years who were functionally dependent at baseline. Our outcome was incident LTC needs, based on certification under the Japanese LTC insurance scheme. We used both propensity score matching and inverse probability of treatment weights (IPTW) to compare individuals with and without MM versus CMM. A total of 38,889 older adults were included: 20,233 (52.0%) and 7565 (19.5%) adults with MM and CMM, respectively. In propensity-matched analyses, both MM (n = 15,666 pairs) and CMM (n = 7524 pairs) were statistically significantly associated with the six-year LTC insurance certification rate (MM, hazard ratio (HR) 1.07, 95% confidence interval (95%CI) 1.02–1.12; CMM, HR 1.10, 95%CI 1.04–1.16). Both MM and CMM were associated with a modest but statistically significantly higher rate of LTC insurance certification. These findings support the inclusion of multimorbidity in the assessment of LTC insurance needs, although the Japanese government currently has not adopted this.

Objectives There are limitations to defining multimorbidity (MM) based on a simple count of diseases. To address these limitations, the concept of complex MM (CMM) focuses on how many body systems are affected in a single patient, rather than counting comorbid conditions. This study compared the prediction of mortality among older Japanese adults between CMM and conventional MM. Design A population-based prospective cohort study. Setting The Japan Gerontological Evaluation Study, a nationwide longitudinal cohort study, which ran from 2010 to 2016. Participants Functionally independent individuals who were older than 65 and had complete illness data at the time of baseline survey were eligible. Outcomes measure CMM was defined as the coexistence of 3 or more body system disorders at baseline. We calculated the propensity for each individual to develop CMM based on a wide array of characteristics, including socioeconomic status and health behaviours. Individuals with and without CMM were then matched on their propensity scores before we estimated overall survival using a log-rank test. Results Our 6-year follow-up included 38 889 older adults: 20 233 (52.0%) and 7565 (19.5%) adults with MM and CMM, respectively. In the MM-matched cohort (n=15 666 pairs), the presence of MM was significantly associated with increased mortality (HR 1.07; 95% CI 1.01 to 1.14; p=0.02 by the log-rank test). A similar mortality association was found in the CMM-matched cohort (n=7524 pairs, HR, 1.07; 95% CI 0.99 to 1.16; p=0.08 by the log-rank test). Conclusion This is the first study to report the association between CMM and mortality among older adults in Japan. MM and CMM predict mortality in older adults to a similar degree. This finding needs to be replicated with more precision in larger samples.

The objective of this study was to assess the impact of a 2010 community-based participatory research (CBPR) reporting guideline on the quality of reporting a CBPR on smoking cessation. We searched the MEDLINE, Embase, the Cochrane Central Register for Controlled Trials (CENTRAL), PsycINFO, and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases and included articles published up to December 2019 (PROSPERO: CRD42019111668). We assessed reporting quality using the 13-item checklist. Of the 80 articles identified, 42 (53%) were published after 2010. The overall reporting quality before and after 2010 was poor and did not differ significantly (mean difference: 0.66, 95% confidence interval [CI]: −0.21 to 1.53). The total reporting scores of the studies did not differ significantly according to the effect size of the intervention (beta coefficient: −2.86, 95% CI: −5.77 to 0.04). This study demonstrates the need to improve the quality of reporting CBPRs. We recommend that journal editors endorse the CBPR reporting guideline to encourage its use by more researchers.