Outcome assessment for out-of-hospital cardiac arrest patients in Singapore and Japan with initial shockable rhythm
Yohei Okada,
Nur Shahidah,
Yih Yng Ng,
Michael Y. C. Chia,
Han Nee Gan,
Benjamin S. H. Leong,
Desmond R. Mao,
Wei Ming Ng,
Taro Irisawa,
Tomoki Yamada,
Tetsuro Nishimura,
Takeyuki Kiguchi,
Masafumi Kishimoto,
Tasuku Matsuyama,
Norihiro Nishioka,
Kosuke Kiyohara,
Tetsuhisa Kitamura,
Taku Iwami,
Marcus Eng Hock Ong
Affiliations
Yohei Okada
Health Services and Systems Research, Duke-NUS Medical School
Nur Shahidah
Department of Emergency Medicine, Singapore General Hospital
Yih Yng Ng
Lee Kong Chian School of Medicine, Nanyang Technological University
Michael Y. C. Chia
Emergency Department, Tan Tock Seng Hospital
Han Nee Gan
Accident & Emergency, Changi General Hospital
Benjamin S. H. Leong
Emergency Medicine Department, National University Hospital
Desmond R. Mao
Department of Acute and Emergency Care, Khoo Teck Puat Hospital
Wei Ming Ng
Emergency Medicine Department, Ng Teng Fong General Hospital
Taro Irisawa
Department of Traumatology and Acute Critical Medicine, Osaka University Graduate School of Medicine
Tomoki Yamada
Emergency and Critical Care Medical Center, Osaka Police Hospital
Tetsuro Nishimura
Department of Critical Care Medicine, Osaka Metropolitan University
Takeyuki Kiguchi
Critical Care and Trauma Center, Osaka General Medical Center
Masafumi Kishimoto
Osaka Prefectural Nakakawachi Medical Center of Acute Medicine
Tasuku Matsuyama
Department of Emergency Medicine, Kyoto Prefectural University of Medicine
Norihiro Nishioka
Department of Preventive Services, Graduate School of Medicine, Kyoto University
Kosuke Kiyohara
Department of Food Science Faculty of Home Economics, Otsuma Women’s University
Tetsuhisa Kitamura
Division of Environmental Medicine and Population Sciences, Department of Social and Environmental Medicine, Graduate School of Medicine, Osaka University
Taku Iwami
Department of Preventive Services, Graduate School of Medicine, Kyoto University
Marcus Eng Hock Ong
Health Services and Systems Research, Duke-NUS Medical School
Abstract Background Singapore and Osaka in Japan have comparable population sizes and prehospital management; however, the frequency of ECPR differs greatly for out-of-hospital cardiac arrest (OHCA) patients with initial shockable rhythm. Given this disparity, we hypothesized that the outcomes among the OHCA patients with initial shockable rhythm in Singapore were different from those in Osaka. The aim of this study was to evaluate the outcomes of OHCA patients with initial shockable rhythm in Singapore compared to the expected outcomes derived from Osaka data using machine learning-based prediction models. Methods This was a secondary analysis of two OHCA databases: the Singapore PAROS database (SG-PAROS) and the Osaka-CRITICAL database from Osaka, Japan. This study included adult (18–74 years) OHCA patients with initial shockable rhythm. A machine learning-based prediction model was derived and validated using data from the Osaka-CRITICAL database (derivation data 2012–2017, validation data 2018–2019), and applied to the SG-PAROS database (2010–2016 data), to predict the risk-adjusted probability of favorable neurological outcomes. The observed and expected outcomes were compared using the observed–expected ratio (OE ratio) with 95% confidence intervals (CI). Results From the SG-PAROS database, 1,789 patients were included in the analysis. For OHCA patients who achieved return of spontaneous circulation (ROSC) on hospital arrival, the observed favorable neurological outcome was at the same level as expected (OE ratio: 0.905 [95%CI: 0.784–1.036]). On the other hand, for those who had continued cardiac arrest on hospital arrival, the outcomes were lower than expected (shockable rhythm on hospital arrival, OE ratio: 0.369 [95%CI: 0.258–0.499], and nonshockable rhythm, OE ratio: 0.137 [95%CI: 0.065–0.235]). Conclusion This observational study found that the outcomes for patients with initial shockable rhythm but who did not obtain ROSC on hospital arrival in Singapore were lower than expected from Osaka. We hypothesize this is mainly due to differences in the use of ECPR.
