{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,25]],"date-time":"2026-09-25T08:02:17Z","timestamp":1790323337014,"version":"4.1.0"},"reference-count":31,"publisher":"Springer Science and Business Media LLC","issue":"9","license":[{"start":{"date-parts":[[2026,9,1]],"date-time":"2026-09-01T00:00:00Z","timestamp":1788220800000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/www.springernature.com\/gp\/researchers\/text-and-data-mining"},{"start":{"date-parts":[[2026,9,1]],"date-time":"2026-09-01T00:00:00Z","timestamp":1788220800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/www.springernature.com\/gp\/researchers\/text-and-data-mining"}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["Int J Biometeorol"],"published-print":{"date-parts":[[2026,9]]},"DOI":"10.1007\/s00484-026-03320-3","type":"journal-article","created":{"date-parts":[[2026,9,14]],"date-time":"2026-09-14T08:10:47Z","timestamp":1789373447000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Population age structure explains the ecological association between older-adult solo household rate and infusion therapy utilization in Japan: An ecological study"],"prefix":"10.1007","volume":"70","author":[{"ORCID":"https:\/\/orcid.org\/0009-0009-7890-6068","authenticated-orcid":false,"given":"Haruki","family":"Saito","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tetsuya","family":"Ohira","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2026,9,14]]},"reference":[{"key":"3320_CR1","doi-asserted-by":"publisher","first-page":"4","DOI":"10.1080\/23328940.2023.2242062","volume":"11","author":"AJE Bach","year":"2024","unstructured":"Bach AJE, Cunningham SJK, Morris NR, Xu Z, Rutherford S, Binnewies S et al (2024) Experimental research in environmentally induced hyperthermic older persons: a systematic quantitative literature review mapping the available evidence. Temp (Austin) 11:4\u201326. https:\/\/doi.org\/10.1080\/23328940.2023.2242062","journal-title":"Temp (Austin)"},{"key":"3320_CR2","doi-asserted-by":"publisher","first-page":"97","DOI":"10.7326\/0003-4819-155-2-201107190-00005","volume":"155","author":"ND Berkman","year":"2011","unstructured":"Berkman ND, Sheridan SL, Donahue KE, Halpern DJ, Crotty K (2011) Low health literacy and health outcomes: an updated systematic review. Ann Intern Med 155:97\u2013107. https:\/\/doi.org\/10.7326\/0003-4819-155-2-201107190-00005","journal-title":"Ann Intern Med"},{"key":"3320_CR3","doi-asserted-by":"publisher","first-page":"289","DOI":"10.1159\/000333148","volume":"58","author":"CM Blatteis","year":"2012","unstructured":"Blatteis CM (2012) Age-dependent changes in temperature regulation - a mini review. Gerontology 58:289\u2013295. https:\/\/doi.org\/10.1159\/000333148","journal-title":"Gerontology"},{"key":"3320_CR4","doi-asserted-by":"publisher","first-page":"515","DOI":"10.1007\/s00484-011-0453-2","volume":"56","author":"K Blazejczyk","year":"2012","unstructured":"Blazejczyk K, Epstein Y, Jendritzky G, Staiger H, Tinz B (2012) Comparison of UTCI to selected thermal indices. Int J Biometeorol 56:515\u2013535. https:\/\/doi.org\/10.1007\/s00484-011-0453-2","journal-title":"Int J Biometeorol"},{"key":"3320_CR5","doi-asserted-by":"publisher","first-page":"1978","DOI":"10.1056\/NEJMra011089","volume":"346","author":"A Bouchama","year":"2002","unstructured":"Bouchama A, Knochel JP (2002) Heat stroke. N Engl J Med 346:1978\u20131988. https:\/\/doi.org\/10.1056\/NEJMra011089","journal-title":"N Engl J Med"},{"key":"3320_CR6","doi-asserted-by":"publisher","first-page":"127","DOI":"10.1016\/S0398-7620(06)76706-2","volume":"54","author":"F Canou\u00ef-Poitrine","year":"2006","unstructured":"Canou\u00ef-Poitrine F, Cadot E, Spira A, Groupe R\u00e9gional C (2006) Excess deaths during the August 2003 heat wave in Paris, France. Rev Epidemiol Sante Publique 54:127\u2013135. https:\/\/doi.org\/10.1016\/S0398-7620(06)76706-2","journal-title":"Rev Epidemiol Sante Publique"},{"key":"3320_CR7","doi-asserted-by":"publisher","first-page":"390","DOI":"10.1016\/j.envres.2004.10.009","volume":"98","author":"S Conti","year":"2005","unstructured":"Conti S, Meli P, Minelli G et al (2005) Epidemiologic study of mortality during the Summer 2003 heat wave in Italy. Environ Res 98:390\u2013399. https:\/\/doi.org\/10.1016\/j.envres.2004.10.009","journal-title":"Environ Res"},{"key":"3320_CR8","doi-asserted-by":"publisher","first-page":"13","DOI":"10.1071\/HE11413","volume":"22","author":"C Farbotko","year":"2011","unstructured":"Farbotko C, Waitt G (2011) Residential air-conditioning and climate change: voices of the vulnerable. Health Promot J Austr 22:13\u201315. https:\/\/doi.org\/10.1071\/HE11413","journal-title":"Health Promot J Austr"},{"key":"3320_CR9","volume-title":"Daily number of patients with heatstroke transported by ambulance in Japan","author":"Fire and Disaster Management Agency","year":"2023","unstructured":"Fire and Disaster Management Agency (2023) Daily number of patients with heatstroke transported by ambulance in Japan. FDMA, Tokyo. https:\/\/www.fdma.go.jp\/disaster\/heatstroke\/post4.html"},{"key":"3320_CR10","doi-asserted-by":"publisher","first-page":"110129","DOI":"10.1016\/j.envint.2026.110129","volume":"208","author":"S G\u00fcnsche","year":"2026","unstructured":"G\u00fcnsche S, Borg MA, Anikeeva O, Varghese BM, Li Y, Bhandari D et al (2026) Mortality, morbidity and healthcare costs of short-term high temperatures and heatwaves exposure in older populations: a global systematic review and meta-analysis. Environ Int 208:110129. https:\/\/doi.org\/10.1016\/j.envint.2026.110129","journal-title":"Environ Int"},{"key":"3320_CR11","doi-asserted-by":"publisher","first-page":"197","DOI":"10.1289\/ehp.1104625","volume":"121","author":"SL Harlan","year":"2013","unstructured":"Harlan SL, Declet-Barreto JH, Stefanov WL, Petitti DB (2013) Neighborhood effects on heat deaths: social and environmental predictors of vulnerability in Maricopa County, Arizona. Environ Health Perspect 121:197\u2013204. https:\/\/doi.org\/10.1289\/ehp.1104625","journal-title":"Environ Health Perspect"},{"issue":"Suppl 1","key":"3320_CR12","doi-asserted-by":"publisher","first-page":"59","DOI":"10.1007\/s00484-017-1412-3","volume":"61","author":"DM Hondula","year":"2017","unstructured":"Hondula DM, Balling RC, Andrade R, Krayenhoff ES, Middel A, Urban A, Georgescu M, Sailor DJ (2017) Biometeorology for cities. Int J Biometeorol 61(Suppl 1):59\u201369. https:\/\/doi.org\/10.1007\/s00484-017-1412-3","journal-title":"Int J Biometeorol"},{"key":"3320_CR13","volume-title":"Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report","author":"Intergovernmental Panel on Climate Change (IPCC)","year":"2021","unstructured":"Intergovernmental Panel on Climate Change (IPCC) (2021) Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report. Cambridge University Press, Cambridge. https:\/\/www.ipcc.ch\/report\/ar6\/wg1\/"},{"key":"3320_CR14","volume-title":"Climate characteristics of summer 2023 (June\u2013August): the warmest summer since observations began in 1898 (mean temperature anomaly + 1.76\u00b0C, exceeding the previous record of + 1.08\u00b0C set in 2010)","author":"Japan Meteorological Agency","year":"2023","unstructured":"Japan Meteorological Agency (2023) Climate characteristics of summer 2023 (June\u2013August): the warmest summer since observations began in 1898 (mean temperature anomaly + 1.76\u00b0C, exceeding the previous record of + 1.08\u00b0C set in 2010). JMA, Tokyo. https:\/\/www.jma.go.jp\/jma\/press\/2309\/01b\/tenko230608.html"},{"key":"3320_CR15","doi-asserted-by":"publisher","first-page":"2598","DOI":"10.1152\/japplphysiol.00202.2003","volume":"95","author":"WL Kenney","year":"2003","unstructured":"Kenney WL, Munce TA (2003) Invited review: aging and human temperature regulation. J Appl Physiol 95:2598\u20132603. https:\/\/doi.org\/10.1152\/japplphysiol.00202.2003","journal-title":"J Appl Physiol"},{"key":"3320_CR16","doi-asserted-by":"publisher","first-page":"645","DOI":"10.1080\/15459620802310770","volume":"5","author":"JC Liljegren","year":"2008","unstructured":"Liljegren JC, Carhart RA, Lawday P, Tschopp S, Sharp R (2008) Modeling the wet bulb globe temperature using standard meteorological measurements. J Occup Environ Hyg 5:645\u2013655. https:\/\/doi.org\/10.1080\/15459620802310770","journal-title":"J Occup Environ Hyg"},{"key":"3320_CR17","volume-title":"Vital Statistics: Annual status of deaths due to heatstroke in Japan","author":"Ministry of Health, Labour and Welfare (MHLW)","year":"2024","unstructured":"Ministry of Health, Labour and Welfare (MHLW) (2024) Vital Statistics: Annual status of deaths due to heatstroke in Japan. MHLW, Tokyo. https:\/\/www.mhlw.go.jp\/toukei\/saikin\/hw\/jinkou\/tokusyu\/necchusho24\/index.html"},{"key":"3320_CR18","volume-title":"National Survey of Family Income and Expenditure 2014","author":"Ministry of Internal Affairs and Communications (MIC)","year":"2015","unstructured":"Ministry of Internal Affairs and Communications (MIC) (2015) National Survey of Family Income and Expenditure 2014. MIC, Tokyo"},{"key":"3320_CR19","unstructured":"Ministry of the Environment, Government of Japan (n.d.) Heat Illness Prevention Information: Heat Stress Index (WBGT) and Heat Stroke Alerts. https:\/\/www.wbgt.env.go.jp\/en\/"},{"key":"3320_CR20","doi-asserted-by":"publisher","first-page":"77","DOI":"10.1007\/s12199-011-0221-2","volume":"17","author":"N Miyatake","year":"2012","unstructured":"Miyatake N, Sakano N, Murakami S (2012) The relation between ambulance transports stratified by heat stroke and air temperature in all 47 prefectures of Japan in August, 2009: Ecological study. Environ Health Prev Med 17:77\u201380. https:\/\/doi.org\/10.1007\/s12199-011-0221-2","journal-title":"Environ Health Prev Med"},{"key":"3320_CR21","doi-asserted-by":"publisher","first-page":"221","DOI":"10.1016\/S0749-3797(02)00421-X","volume":"22","author":"MP Naughton","year":"2002","unstructured":"Naughton MP, Henderson A, Mirabelli MC et al (2002) Heat-related mortality during a 1999 heat wave in Chicago. Am J Prev Med 22:221\u2013227. https:\/\/doi.org\/10.1016\/S0749-3797(02)00421-X","journal-title":"Am J Prev Med"},{"key":"3320_CR22","doi-asserted-by":"publisher","first-page":"15","DOI":"10.2188\/jea.JE20130051","volume":"24","author":"CF Ng","year":"2014","unstructured":"Ng CF, Ueda K, Takeuchi A et al (2014) Sociogeographic variation in the effects of heat and cold on daily mortality in Japan. J Epidemiol 24:15\u201324. https:\/\/doi.org\/10.2188\/jea.JE20130051","journal-title":"J Epidemiol"},{"key":"3320_CR23","doi-asserted-by":"publisher","first-page":"114","DOI":"10.1038\/s41746-025-01505-5","volume":"8","author":"M Oberai","year":"2025","unstructured":"Oberai M, Xu Z, Bach A, Forbes C, Jackman E, O\u2019Connor F et al (2025) A digital heat early warning system for older adults. NPJ Digit Med 8:114. https:\/\/doi.org\/10.1038\/s41746-025-01505-5","journal-title":"NPJ Digit Med"},{"key":"3320_CR24","doi-asserted-by":"publisher","first-page":"114666","DOI":"10.1016\/j.envres.2022.114666","volume":"216","author":"K Oka","year":"2023","unstructured":"Oka K, Honda Y, Hui Phung VL, Hijioka Y (2023) Potential effect of heat adaptation on association between number of heatstroke patients transported by ambulance and wet bulb globe temperature in Japan. Environ Res 216:114666. https:\/\/doi.org\/10.1016\/j.envres.2022.114666","journal-title":"Environ Res"},{"key":"3320_CR25","doi-asserted-by":"publisher","first-page":"368","DOI":"10.2486\/indhealth.44.368","volume":"44","author":"K Parsons","year":"2006","unstructured":"Parsons K (2006) Heat stress standard ISO 7243 and its global application. Ind Health 44:368\u2013379. https:\/\/doi.org\/10.2486\/indhealth.44.368","journal-title":"Ind Health"},{"key":"3320_CR26","doi-asserted-by":"publisher","first-page":"926","DOI":"10.7205\/MILMED-D-13-00117","volume":"178","author":"T Patel","year":"2013","unstructured":"Patel T, Mullen SP, Santee WR (2013) Comparison of methods for estimating wet-bulb globe temperature index from standard meteorological measurements. Mil Med 178:926\u2013933. https:\/\/doi.org\/10.7205\/MILMED-D-13-00117","journal-title":"Mil Med"},{"key":"3320_CR27","doi-asserted-by":"publisher","first-page":"109659","DOI":"10.1016\/j.envint.2025.109659","volume":"202","author":"Y Romitti","year":"2025","unstructured":"Romitti Y, Sue Wing I, Spangler KR, Wellenius GA (2025) The effects of residential air conditioning and social vulnerability on heat-related hospitalizations in California. Environ Int 202:109659. https:\/\/doi.org\/10.1016\/j.envint.2025.109659","journal-title":"Environ Int"},{"key":"3320_CR28","doi-asserted-by":"publisher","first-page":"84","DOI":"10.1056\/NEJM199607113350203","volume":"335","author":"JC Semenza","year":"1996","unstructured":"Semenza JC, Rubin CH, Falter KH et al (1996) Heat-related deaths during the July 1995 heat wave in Chicago. N Engl J Med 335:84\u201390. https:\/\/doi.org\/10.1056\/NEJM199607113350203","journal-title":"N Engl J Med"},{"key":"3320_CR29","doi-asserted-by":"publisher","first-page":"583","DOI":"10.1093\/eurpub\/ckl063","volume":"16","author":"S Vandentorren","year":"2006","unstructured":"Vandentorren S, Bretin P, Zeghnoun A et al (2006) August 2003 heat wave in France: risk factors for death of elderly people living at home. Eur J Public Health 16:583\u2013591. https:\/\/doi.org\/10.1093\/eurpub\/ckl063","journal-title":"Eur J Public Health"},{"key":"3320_CR30","doi-asserted-by":"publisher","first-page":"830","DOI":"10.2105\/AJPH.92.5.830","volume":"92","author":"MG Weisskopf","year":"2002","unstructured":"Weisskopf MG, Anderson HA, Foldy S et al (2002) Heat wave morbidity and mortality, Milwaukee, Wis, 1999 vs 1995: an improved response? Am J Public Health 92:830\u2013833. https:\/\/doi.org\/10.2105\/AJPH.92.5.830","journal-title":"Am J Public Health"},{"key":"3320_CR31","doi-asserted-by":"publisher","first-page":"e66058","DOI":"10.2196\/66058","volume":"27","author":"C Zhang","year":"2025","unstructured":"Zhang C, Mohamad E, Azlan AA, Wu A, Ma Y, Qi Y (2025) Social media and eHealth literacy among older adults: systematic literature review. J Med Internet Res 27:e66058. https:\/\/doi.org\/10.2196\/66058","journal-title":"J Med Internet Res"}],"container-title":["International Journal of Biometeorology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1007\/s00484-026-03320-3.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/article\/10.1007\/s00484-026-03320-3","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1007\/s00484-026-03320-3.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,25]],"date-time":"2026-09-25T07:25:45Z","timestamp":1790321145000},"score":1,"resource":{"primary":{"URL":"https:\/\/link.springer.com\/10.1007\/s00484-026-03320-3"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9]]},"references-count":31,"journal-issue":{"issue":"9","published-print":{"date-parts":[[2026,9]]}},"alternative-id":["3320"],"URL":"https:\/\/doi.org\/10.1007\/s00484-026-03320-3","relation":{},"ISSN":["0020-7128","1432-1254"],"issn-type":[{"value":"0020-7128","type":"print"},{"value":"1432-1254","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9]]},"assertion":[{"value":"23 June 2026","order":1,"name":"received","label":"Received","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"6 August 2026","order":2,"name":"revised","label":"Revised","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"8 September 2026","order":3,"name":"accepted","label":"Accepted","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"14 September 2026","order":4,"name":"first_online","label":"First Online","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"During the preparation of the original submission, the authors used AI-assisted tools to support manuscript drafting and statistical analysis scripting. Cursor 3.0 (Anysphere) and Google Antigravity (Google) were used for AI-assisted writing and Python code development. Large language models used through these platforms included Claude Sonnet 4.6 and Claude Opus 4.8 (Anthropic), GPT-5.5 (OpenAI), and Gemini 3 Pro (Google). During preparation of the revision, the authors used AI-assisted tools (Claude Sonnet 5, Anthropic, accessed via Claude Code) to support text drafting and the\u00a0development of data-processing and statistical-analysis code. The authors executed the code, verified all source data, numerical results, tables, and figures, and independently determined the statistical methods and interpretation. No generative image tools were used. The authors reviewed and edited all outputs and take full responsibility for the final manuscript. AI was not listed as an author.","order":1,"name":"Ethics","label":"Declaration of generative AI and AI-assisted\u00a0technologies in the manuscript preparation process","group":{"name":"EthicsHeading","label":"Declarations"}},{"value":"The authors declare no competing interests.","order":2,"name":"Ethics","label":"Competing interests","group":{"name":"EthicsHeading","label":"Declarations"}}],"article-number":"253"}}