{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,9]],"date-time":"2026-06-09T07:34:20Z","timestamp":1780990460804,"version":"3.54.1"},"reference-count":31,"publisher":"Public Library of Science (PLoS)","issue":"2","license":[{"start":{"date-parts":[[2025,2,5]],"date-time":"2025-02-05T00:00:00Z","timestamp":1738713600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS ONE"],"abstract":"<jats:p>Road traffic accidents are a global health concern. K-car vehicles, also known as \"mini vehicles,\" are defined as those having an engine displacement &lt;660 cc, vehicle length &lt;3.4 m, width &lt;1.48 m, and height &lt;2.0 m. K-cars have become increasing popular not only in Japan but also in other countries. Compared with standard vehicles, the occupant space of a K-car vehicle is considerably smaller; thus, passengers may be more vulnerable to the external forces generated in a collision, which in turn can lead to deformation of the occupant space and less protection against injuries. However, data are scarce regarding whether K-car vehicles are related to poorer survival outcomes and severe trauma. We conducted a retrospective cohort study involving patients who were injured in four-wheeled vehicle accidents between 2002 and 2023 and admitted to a community teaching hospital in Japan. The vehicle configuration was divided into standard and K-car vehicles. The primary endpoint was in-hospital mortality. Other outcomes included severe trauma, defined as Injury Severity Score (ISS) &gt;15, and anatomically specific severe injury of the head and neck, chest, abdomen, pelvis, and extremities, defined as Abbreviated Injury Scale score \u22653. Of 5331 eligible patients, 2384 (44.7%) were K-car vehicle occupants. In propensity score-matched analysis with 1947 pairs, we observed an increase for in-hospital mortality in the K-car vehicle group (2.6% vs. 4.0%, odds ratio 1.53, 95% confidence interval 1.07\u20132.19). Compared with standard vehicles, K-car vehicles were associated with a greater risk of severe trauma and serious injuries of the head and neck, chest, abdomen, pelvis, and extremities. These study data should be used to encourage vehicle occupants and automobile manufacturers to consider objective facts regarding the safety of vehicles in a traffic accident.<\/jats:p>","DOI":"10.1371\/journal.pone.0318748","type":"journal-article","created":{"date-parts":[[2025,2,5]],"date-time":"2025-02-05T18:34:10Z","timestamp":1738780450000},"page":"e0318748","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":2,"title":["Comparison of survival outcomes and anatomically specific severe injuries following traffic accidents among occupants of standard and K-car vehicles: A retrospective cohort study at a teaching hospital in Japan"],"prefix":"10.1371","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5953-3042","authenticated-orcid":true,"given":"Yuko","family":"Ono","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tasuku","family":"Uzawa","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jun","family":"Sugiyama","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nozomi","family":"Tomita","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Takeyasu","family":"Kakamu","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tokiya","family":"Ishida","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Joji","family":"Kotani","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kazuaki","family":"Shinohara","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2025,2,5]]},"reference":[{"key":"pone.0318748.ref001","author":"World 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describing patients with multiple injuries and evaluating emergency care","volume":"14","author":"SP Baker","year":"1974","journal-title":"J Trauma"},{"key":"pone.0318748.ref014","doi-asserted-by":"crossref","first-page":"623","DOI":"10.1097\/00005373-198905000-00017","article-title":"A revision of the Trauma Score","volume":"29","author":"HR Champion","year":"1989","journal-title":"J Trauma"},{"key":"pone.0318748.ref015","doi-asserted-by":"crossref","first-page":"975","DOI":"10.1097\/00005373-200111000-00024","article-title":"Factors influencing the patterns of injuries and outcomes in car versus car crashes compared with sport utility, van, or pick-up truck versus car crashes: Crash Injury Research Engineering Network Study","volume":"51","author":"JH Siegel","year":"2001","journal-title":"J Trauma"},{"key":"pone.0318748.ref016","first-page":"185","article-title":"Injury mechanisms and severity in narrow offset frontal impacts.","volume":"52","author":"FA Pintar","year":"2008","journal-title":"Ann Adv Automot Med"},{"key":"pone.0318748.ref017","doi-asserted-by":"crossref","first-page":"1413","DOI":"10.1186\/s12889-018-6280-1","article-title":"Seatbelt use and risk of major injuries sustained by vehicle occupants during motor-vehicle crashes: a systematic review and meta-analysis of cohort studies.","volume":"18","author":"N Fouda Mbarga","year":"2018","journal-title":"BMC Public Health."},{"key":"pone.0318748.ref018","doi-asserted-by":"crossref","first-page":"276","DOI":"10.1016\/j.jsr.2021.06.013","article-title":"Injury severity analysis of rollover crashes for passenger cars and light trucks considering temporal stability: A random parameters logit approach with heterogeneity in mean and variance.","volume":"78","author":"S Liu","year":"2021","journal-title":"J Safety Res"},{"key":"pone.0318748.ref019","volume-title":"The text book of Japan Advanced Trauma Evaluation and Care, the 6th edition","year":"2021"},{"key":"pone.0318748.ref020","doi-asserted-by":"crossref","first-page":"125","DOI":"10.1136\/ip.2005.011056","article-title":"Road traffic casualties: understanding the night-time death toll","volume":"12","author":"S Plainis","year":"2006","journal-title":"Inj Prev"},{"key":"pone.0318748.ref021","doi-asserted-by":"crossref","first-page":"4486","DOI":"10.3390\/su15054486","article-title":"Temporal Instability and Transferability Analysis of Daytime and Nighttime Motorcyclist-Injury Severities Considering Unobserved Heterogeneity of Data.","volume":"15","author":"C Se","year":"2023","journal-title":"Sustainability"},{"key":"pone.0318748.ref022","doi-asserted-by":"crossref","first-page":"16","DOI":"10.21037\/atm.2018.12.10","article-title":"Balance diagnostics after propensity score matching.","volume":"7","author":"written on behalf of AME Big-Data Clinical Trial Collaborative Group","year":"2019","journal-title":"Ann Transl Med"},{"key":"pone.0318748.ref023","first-page":"535","article-title":"Pounds That Kill: The External Costs of Vehicle Weight.","volume":"81","author":"ML Anderson","year":"2014","journal-title":"REStud"},{"key":"pone.0318748.ref024","doi-asserted-by":"crossref","first-page":"e431","DOI":"10.1093\/pubmed\/fdy033","article-title":"The relationship between socioeconomic status and trauma outcomes.","volume":"40","author":"M Abedzadeh-Kalahroudi","year":"2018","journal-title":"J Public Health (Oxf)."},{"key":"pone.0318748.ref025","doi-asserted-by":"crossref","first-page":"123","DOI":"10.1533\/cras.1998.0066","article-title":"Compatibility analysis of Mini cars in frontal collisions using MADYMO","volume":"3","author":"K Mizuno","year":"1998","journal-title":"International Journal of Crashworthiness"},{"key":"pone.0318748.ref026","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.jsr.2015.07.006","article-title":"Vehicle choices for teenage drivers: A national survey of U.S. parents.","volume":"55","author":"AH Eichelberger","year":"2015","journal-title":"J Safety Res"},{"key":"pone.0318748.ref027","doi-asserted-by":"crossref","first-page":"707","DOI":"10.1016\/j.jsr.2007.10.003","article-title":"Choice of teenagers\u2019 vehicles and views on vehicle safety: survey of parents of novice teenage drivers.","volume":"38","author":"LA Hellinga","year":"2007","journal-title":"J Safety Res"},{"key":"pone.0318748.ref028","doi-asserted-by":"crossref","first-page":"e1145","DOI":"10.1097\/CCM.0000000000003428","article-title":"Use of Vasopressor Increases the Risk of Mortality in Traumatic Hemorrhagic Shock: A Nationwide Cohort Study in Japan.","volume":"46","author":"M Aoki","year":"2018","journal-title":"Crit Care Med"},{"key":"pone.0318748.ref029","doi-asserted-by":"crossref","first-page":"17891","DOI":"10.1038\/s41598-020-74753-y","article-title":"Alcohol use in severely injured trauma patients","volume":"10","author":"A Riuttanen","year":"2020","journal-title":"Sci Rep"},{"key":"pone.0318748.ref030","doi-asserted-by":"crossref","first-page":"1677","DOI":"10.1016\/j.aap.2011.03.026","article-title":"Injury severities of truck drivers in single- and multi-vehicle accidents on rural highways.","volume":"43","author":"F Chen","year":"2011","journal-title":"Accid Anal Prev"},{"key":"pone.0318748.ref031","doi-asserted-by":"crossref","first-page":"153","DOI":"10.1016\/j.jsr.2018.02.010","article-title":"Analysis of hourly crash likelihood using unbalanced panel data mixed logit model and real-time driving environmental big data.","volume":"65","author":"F Chen","year":"2018","journal-title":"J Safety Res."}],"container-title":["PLOS 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