Mass screening is associated with low rates of acute kidney injury among COVID-19 patients in Hong Kong

Kam Wa Chan, Ivan Fan Ngai Hung, Owen Tak Yin Tsang, Tak Chiu Wu, Eugene Yuk Keung Tso, Kwok Cheung Lung, Chung Man Lam, Gary Chi Wang Chan, Sunny Sze Ho Wong, Kam Yan Yu, Johnny Wai Man Chan, Sydney Chi Wai Tang*

*Corresponding author for this work

Research output: Contribution to journalJournal articlepeer-review

10 Citations (Scopus)


Introduction: Renal involvement in COVID-19 is less well characterized in settings with vigilant public health surveillance, including mass screening and early hospitalization. We assessed kidney complications among COVID-19 patients in Hong Kong, including the association with risk factors, length of hospitalization, critical presentation, and mortality. 

Methods: Linked electronic records of all patients with confirmed COVID-19 from 5 major designated hospitals were extracted. Duplicated records due to interhospital transferal were removed. Primary outcome was the incidence of in-hospital acute kidney injury (AKI). Secondary outcomes were AKI-associated mortality, incident renal replacement therapy (RRT), intensive care admission, prolonged hospitalization and disease course (defined as >90th percentile of hospitalization duration [35 days] and duration from symptom onset to discharge [43 days], respectively), and change of estimated glomerular filtration rate (GFR). Patients were further stratified into being symptomatic or asymptomatic. 

Results: Patients were characterized by young age (median: 38.4, IQR: 28.4-55.8 years) and short time (median: 5, IQR: 2-9 days) from symptom onset to admission. Among the 591 patients, 22 (3.72%) developed AKI and 4 (0.68%) required RRT. The median time from symptom onset to in-hospital AKI was 15 days. AKI increased the odds of prolonged hospitalization and disease course by 2.0- and 3.5-folds, respectively. Estimated GFR 24 weeks post-discharge reduced by 7.51 and 1.06 mL/min/1.73 m;2 versus baseline (upon admission) in the AKI and non-AKI groups, respectively. The incidence of AKI was comparable between asymptomatic (4.8%, n = 3/62) and symptomatic (3.7%, n = 19/519) patients. 

Conclusion: The overall rate of AKI among COVID-19 patients in Hong Kong is low, which could be attributable to a vigilant screening program and early hospitalization. Among patients who developed in-hospital AKI, the duration of hospitalization is prolonged and kidney function impairment can persist for up to 6 months post-discharge. Mass surveillance for COVID-19 is warranted in identifying asymptomatic subjects for earlier AKI management.

Original languageEnglish
Pages (from-to)161-172
Number of pages12
JournalAmerican Journal of Nephrology
Issue number2
Publication statusPublished - Apr 2021

Scopus Subject Areas

  • Medicine(all)
  • Nephrology
  • Infectious Diseases
  • Epidemiology

User-Defined Keywords

  • Acute kidney injury
  • Cohort
  • COVID-19
  • Renal medicine
  • Risk factors


Dive into the research topics of 'Mass screening is associated with low rates of acute kidney injury among COVID-19 patients in Hong Kong'. Together they form a unique fingerprint.

Cite this