Characteristics and outcomes of patients admitted to adult intensive care units in Hong Kong: a population retrospective cohort study from 2008 to 2018

• Main Authors: Lowell Ling, Chun Ming Ho, Pauline Yeung Ng, King Chung Kenny Chan, Hoi Ping Shum, Cheuk Yan Chan, Alwin Wai Tak Yeung, Wai Tat Wong, Shek Yin Au, Kit Hung Anne Leung, Jacky Ka Hing Chan, Chi Keung Ching, Oi Yan Tam, Hin Hung Tsang, Ting Liong, Kin Ip Law, Manimala Dharmangadan, Dominic So, Fu Loi Chow, Wai Ming Chan, Koon Ngai Lam, Kai Man Chan, Oi Fung Mok, Man Yee To, Sze Yuen Yau, Carmen Chan, Ella Lei, Gavin Matthew Joynt
• Format: Article
• Language: English
• Published: BMC 2021-01-01
• Series: Journal of Intensive Care
• Subjects: Intensive care; APACHE IV; Benchmarking; Hong Kong; Standard mortality ratio
• Online Access: https://doi.org/10.1186/s40560-020-00513-9

Abstract Background Globally, mortality rates of patients admitted to the intensive care unit (ICU) have decreased over the last two decades. However, evaluations of the temporal trends in the characteristics and outcomes of ICU patients in Asia are limited. The objective of this study was to describe the characteristics and risk adjusted outcomes of all patients admitted to publicly funded ICUs in Hong Kong over a 11-year period. The secondary objective was to validate the predictive performance of Acute Physiology And Chronic Health Evaluation (APACHE) IV for ICU patients in Hong Kong. Methods This was an 11-year population-based retrospective study of all patients admitted to adult general (mixed medical-surgical) intensive care units in Hong Kong public hospitals. ICU patients were identified from a population electronic health record database. Prospectively collected APACHE IV data and clinical outcomes were analysed. Results From 1 April 2008 to 31 March 2019, there were a total of 133,858 adult ICU admissions in Hong Kong public hospitals. During this time, annual ICU admissions increased from 11,267 to 14,068, whilst hospital mortality decreased from 19.7 to 14.3%. The APACHE IV standard mortality ratio (SMR) decreased from 0.81 to 0.65 during the same period. Linear regression demonstrated that APACHE IV SMR changed by − 0.15 (95% CI − 0.18 to − 0.11) per year (Pearson’s R = − 0.951, p < 0.001). Observed median ICU length of stay was shorter than that predicted by APACHE IV (1.98 vs. 4.77, p < 0.001). C-statistic for APACHE IV to predict hospital mortality was 0.889 (95% CI 0.887 to 0.891) whilst calibration was limited (Hosmer–Lemeshow test p < 0.001). Conclusions Despite relatively modest per capita health expenditure, and a small number of ICU beds per population, Hong Kong consistently provides a high-quality and efficient ICU service. Number of adult ICU admissions has increased, whilst adjusted mortality has decreased over the last decade. Although APACHE IV had good discrimination for hospital mortality, it overestimated hospital mortality of critically ill patients in Hong Kong.