Japan's health system is well known for achieving one of the world's highest life expectancy with universal health coverage. However, the country now faces challenges of a rapidly aging population and changes in patterns and burden of disease. Primary care is an important component of a well‐functioning health system. In Japan, primary care services are provided in both the community and hospital settings. The distinction between primary and secondary care may not always be clear. This review is based on the framework from the 2015 WHO publication on primary care systems in Europe. Our aim is to describe the journey of primary care in Japan, with its past, present, and future as a valuable addition to the academic English literature. We also hope that this article would inspire readers outside of Japan who might face similar issues in their respective countries.

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.

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.

Two huge earthquakes struck Kumamoto, Japan, in April 2016, forcing residents to evacuate. Few studies have reported early-phase disease and injury trends among evacuees following major inland earthquakes. We evaluated the trends among evacuees who visited a medical clinic in a shelter located at the epicenter of the 2016 Kumamoto earthquakes. The clinic opened on April 15, the day after the foreshock, and closed 3 weeks later. We reviewed medical charts related to 929 outpatient visits and conducted descriptive analyses. The evacuees experienced mild injuries and common diseases. The types of diseases changed weekly. Elderly people needed medical support for longer than other age groups. Future earthquakes may be inevitable, but establishing arrangements for medical needs or making precautions for infectious diseases in shelters could reduce the effects of earthquake-related health problems.

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.

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.