Background: In meta-analysis, the normal distribution assumption has been adopted in most systematic reviews of random-effects distribution models due to its computational and conceptual simplicity. However, this restrictive model assumption is possibly unsuitable and might have serious influences in practices.

Methods: We provide two examples of real-world evidence that clearly show that the normal distribution assumption is explicitly unsuitable. We propose new random-effects meta-analysis methods using five flexible random-effects distribution models that can flexibly regulate skewness, kurtosis and tailweight: skew normal distribution, skew t-distribution, asymmetric Subbotin distribution, Jones–Faddy distribution, and sinh–arcsinh distribution. We also developed a statistical package, flexmeta, that can easily perform these methods.

Results: Using the flexible random-effects distribution models, the results of the two meta-analyses were markedly altered, potentially influencing the overall conclusions of these systematic reviews.

Conclusion: The restrictive normal distribution assumption in the random-effects model can yield misleading conclusions. The proposed flexible methods can provide more precise conclusions in systematic reviews.

Background: Chronic kidney disease (CKD) is an important contributor to morbidity and mortality from noncommunicable diseases. We aimed to examine the longitudinal trajectories in risk factors, estimate their impact on CKD burden in China from 1991 to 2011, and project trends in the next 20 years.

Methods: We used data from a cohort of the China Health and Nutrition Survey and applied the comparative risk assessment method to estimate the number of CKD events attributable to all non-optimal levels of each risk factors.

Results: In 2011, current smoking was the leading individual attributable factor for CKD burden in China responsible for 7.9 (95% confidence interval [CI], 7.5–8.3) million CKD cases with a population-attributable fraction of 8.7% (95% CI, 6.0–11.6), while the rates of smoking have reduced and may have mitigated the increase in CKD. High triglyceride (TG) and high systolic blood pressure (SBP) were the leading metabolic risk factors responsible for 6.8 (95% CI, 6.4–7.1) million and 5.8 (95% CI, 5.5–6.1) million CKD-attributable cases, respectively. Additionally, the number of CKD cases associated with high body mass index (BMI), high diastolic blood pressure (DBP), high plasma glucose, and low high-density lipoprotein cholesterol (HDL-C) was 5.4 (95% CI, 5.1–5.6), 3.9 (95% CI, 3.7–4.1), 3.0 (95% CI, 2.8–3.1) and 2.6 (95% CI, 2.5–2.8) million, respectively.

Conclusion: Current smoking, high TG, and high SBP were the top three risk factors that contributed to CKD burden in China. Increased BMI, DBP, plasma glucose, and decreased HDL-C were also associated with the increase in CKD burden.

Background: Although social participation has been reported to be associated with significantly lower risks of mortality and disability, to our knowledge, no study has estimated its impact on disability-free life expectancy (DFLE). Therefore, this study aimed to investigate the association between social participation and DFLE in community-dwelling older people.

Methods: We analyzed 11-year follow-up data from a cohort study of 11,982 Japanese older adults (age ≥65 years) in 2006. We collected information on the number of social participations using a questionnaire. Using this information, we categorized the participants into four groups. DFLE was defined as the average number of years a person could expect to live without disability. The multistate life table method using a Markov model was employed for calculating DFLE.

Results: The results revealed that DFLE according to the number of social participations was 17.8 years (95% confidence interval [CI], 17.3–18.2) for no activities, 20.9 (95% CI, 20.4–21.5) for one activity, 21.5 (95% CI, 20.9–22.0) for two activities, and 22.7 (95% CI, 22.1–23.2) for three activities in men, and 21.8 (95% CI, 21.5–22.2), 25.1 (95% CI, 24.6–25.6), 25.3 (95% CI, 24.7–25.9), and 26.7 years (95% CI, 26.1–27.4), respectively, in women. This difference in DFLE did not change after the participants were stratified for smoking, body mass index, physical activity, and depression.

Conclusion: Social participation is associated with longer DFLE among Japanese older people; therefore, encouraging social participation at the population level could increase life-years lived in good health.

Background: Procrastination is associated with stress and unhealthy behaviors. The oral condition reflects the long-term history of an individual’s stress exposure and oral health behaviors; however, empirical studies on the association of procrastination in childhood with remaining teeth in older age are limited. We investigated the association of procrastination in childhood with the number of remaining teeth among community-dwelling older Japanese adults.

Methods: In total, 1,616 community-dwelling senior residents of Wakuya City (Miyagi Prefecture, Japan) who were enrolled in the National Health Plan & the Medical Care System for the Elderly completed a self-administered questionnaire on the number of teeth. Procrastination was measured using a single binary question about timing of holiday homework completion in childhood. The number of remaining teeth was assessed via a questionnaire with response options of ≥20, 10–19, 1–9, and 0 teeth. Ordered logistic regression models with potential confounders (sex, age, maternal education, childhood socioeconomic status [SES], childhood maltreatment, conscientiousness trait) and mediators (adulthood SES, smoking history, alcohol use history) were estimated.

Results: Forty-six percent of participants reported a higher tendency to procrastinate in childhood. The proportions of participants with ≥20, 10–19, 1–9, and 0 teeth were 39.6%, 22.7%, 24.0%, and 13.7%, respectively. After adjusting for all covariates, a higher tendency to procrastinate in childhood was significantly associated with having fewer remaining teeth (odds ratio 1.28; 95% confidence interval, 1.05–1.57).

Conclusion: A higher tendency to procrastinate in childhood was associated with having fewer remaining teeth in later life.

Background: Ginseng, an herbal remedy, has been commonly used in Asian countries to promote longevity and health for over 2,000 years. However, the association of ginseng consumption with all-cause and cause-specific mortality is still unclear. We analyzed the association of total and major cause-specific mortality (cardiovascular disease [CVD], cancer, and other death) with consumption of ginseng (primarily American and white ginseng).

Methods: This study included 56,183 female participants with an average follow-up of 14.7 years in the Shanghai Women’s Health Study, an ongoing prospective cohort study. Data were assessed via an in-person interview conducted at baseline recruitment. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for ginseng-mortality associations after adjusting for confounders.

Results: Compared with those who never used ginseng, regular ginseng use was associated with significantly reduced all-cause mortality (HR 0.92; 95% CI, 0.87–0.98). This inverse association was seen primarily among those who consumed ginseng for perceived general health benefit (HR 0.90; 95% CI, 0.85–0.96). A significant dose-response association was observed between duration of ginseng use and total mortality (HR 0.85, for using ≥6 years vs never use; P for trend <0.001), CVD mortality (HR 0.83; P for trend = 0.019), and other-cause mortality (HR 0.76; P for trend = 0.001). However, no dose-response association was observed between amount of ginseng consumption and mortality outcomes.

Conclusion: Regular ginseng consumption, particularly over a long duration, was associated with decreased risk of all causes of death, death due to CVD, and death due to certain other diseases.

Background: Regular visits with healthcare professionals are important for preventing serious complications in patients with diabetes. The purpose of this retrospective cohort study was to clarify whether there was any suppression of physician visits among patients with diabetes during the spread of the novel coronavirus 2019 (COVID-19) in Japan and to assess whether telemedicine contributed to continued visits.

Methods: We used the JMDC Claims database, which contains the monthly claims reported from July 2018 to May 2020 and included 4,595 (type 1) and 123,686 (type 2) patients with diabetes. Using a difference-in-differences analysis, we estimated the changes in the monthly numbers of physician visits or telemedicine per 100 patients in April and May 2020 compared with the same months in 2019.

Results: For patients with type 1 diabetes, the estimates for total overall physician visits were −2.53 (95% confidence interval [CI], −4.63 to 0.44) in April and −8.80 (95% CI, −10.85 to −6.74) in May; those for telemedicine visits were 0.71 (95% CI, 0.47–0.96) in April and 0.54 (95% CI, 0.32–0.76) in May. For patients with type 2 diabetes, the estimates for overall physician visits were −2.50 (95% CI, −2.95 to −2.04) in April and −3.74 (95% CI, −4.16 to −3.32) in May; those for telemedicine visits were 1.13 (95% CI, 1.07–1.20) in April and 0.73 (95% CI, 0.68–0.78) in May.

Conclusion: The COVID-19 pandemic was associated with suppression of physician visits and a slight increase in the utilization of telemedicine among patients with diabetes during April and May 2020.