Reply to comment on “Regional disparities in home health care utilization for older adults and their associated factors at the secondary medical area level: A nationwide study in Japan”

We sincerely appreciate Luthfiyah et al.'s interest in and comments¹ on our recently published work in Geriatrics and Gerontology International.² They expressed concerns regarding (1) data aggregation at the secondary medical area level, (2) the exclusion of patient-specific variables, and (3) the lack of dynamics between facility-based and home-visit care. We have provided responses to address these points and to clarify and contextualize our findings.

First, as mentioned in the limitations of our study, we used “secondary medical areas” as the unit of analysis because they were the smallest geographic units available in the National Database (NDB) Open Data. As Luthfiyah et al. suggested, future studies could benefit from analyzing smaller units, such as municipalities, to enhance the precision of findings and guide more localized interventions. However, it is important to note that “secondary medical areas” in Japan are integral to planning the medical provision system.³ Moreover, using municipalities as the unit of analysis would reveal that approximately half of them lack enhanced home care support clinics,⁴ which could lead to instability in multivariate analysis models. Therefore, we believe that it is appropriate to capture overall trends in regional disparities at the secondary medical area level.

Second, because our study used aggregated data, we could not access individual-level patient data or adjust for patient-specific factors. This limitation suggests that patients who receive home visits may have different characteristics depending on their region. Moreover, there is the possibility that home visits may be disproportionately provided to patients with lower actual needs (such as to patients capable of visiting medical institutions) in regions with high home-visit utilization rates. To address this issue, our ongoing study has leveraged individual-level data from the NDB, enabling adjustments for patient-specific variables and providing deeper insights into regional differences in home healthcare utilization.

Third, as Luthfiyah et al. pointed out, home-visit care and long-term care (LTC) facilities often exhibit a complementary relationship. In line with this, our study found a negative association between home-visit rates and the number of beds in the LTC welfare and health facilities within a region. As described in the Discussion section, this suggests that in depopulated areas with fewer home-visit care services available, a higher proportion of older adults tend to reside in LTC facilities. In Japan, visiting medical care is also provided in non-LTC facilities, such as assisted-living facilities with services and group homes for patients with dementia. In an additional analysis, we included the visiting medical care provided to these non-LTC facilities to examine regional disparities in all home-visiting care. As we mentioned in the Limitations section, the absence of accurate data on the number of beds in non-LTC facilities at the secondary medical area level restricted the comprehensive analysis of the living arrangements and care services provided to older adults. Nevertheless, given that older adults with higher care needs are more likely to use LTC facilities, our findings reinforce the complementary relationship between facility-based care and home-visit care for these patients.

Finally, although we highlighted regional disparities and proposed several approaches to address these differences in the Discussion section, we do not advocate the complete elimination or standardization of regional disparities. Instead, developing medical and LTC care delivery systems tailored to the unique characteristics of each region is crucial. By 2040, the older adult population in Japan is expected to have increased, but demographic trends will vary significantly across regions.⁵ In some depopulated areas, both the older adult population and healthcare demands are already declining, whereas in urban areas, healthcare demands are expected to increase.⁵ As these regional disparities widen, the challenges and healthcare systems required will differ across regions.

Moreover, the uneven distribution of physicians will worsen, exacerbating the shortage of healthcare professionals in depopulated areas.⁶ To address these issues, a multifaceted approach, including ensuring adequate facilities (both LTC and non-LTC) for older adults and their staff and implementing efficient home healthcare strategies, such as telemedicine and task-shifting among medical staff, is needed, especially in depopulated areas.⁵

In conclusion, this study provides valuable insights by presenting a comprehensive overview of the current state of home healthcare across Japan, which can serve as a foundation for region-specific healthcare and LTC systems.

This work was supported by the Institute for Health Economics and Policy. The funder played no role in the conception, design, implementation, or reporting of this study.

The authors declare no competing interest.

No ethical approval was obtained, as we used only publicly available data.