Hyun-Ha Chang

Prof. Hyun-Ha Chang

orcid

Research Focus & Metrics

Academic Career Length

23Years (2004-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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11 July 2023 in Scientific Reports
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YKYoonjung Kim
Yoonjung Kim
SBSohyun Bae
Sohyun Bae
HCHyun-Ha Chang
Hyun-Ha Chang
SKShin-Woo Kim
Shin-Woo Kim
There has been an increasing interest in the long-term impact of long COVID. However, only a few studies have investigated the clinical manifestations of long COVID 24 months after acute COVID infection. In this study, prospective online surveys were conducted in adults previously diagnosed with coronavirus disease 2019 (COVID-19) in South Korea between February 13 and March 13, 2020, at 6, 12, and 24 months after COVID-19. We investigated self-reported symptoms and the EuroQol-5-dimension index. Among 900 individuals enrolled initially, 150 completed all 3 surveys. After excluding the cases of COVID-19 reinfection, 132 individuals were included in the final analysis. Among the 132 participants, 94 (71.2%) experienced symptoms of long COVID. The most frequently reported symptoms were fatigue (34.8%), amnesia (30.3%), concentration difficulties (24.2%), insomnia (20.5%), and depression (19.7%). Notably, no significant differences were noted in the incidence of long COVID at 24 months in terms of the number of vaccinations received. Although the neuropsychiatric quality of life improved over time, it continued to affect 32.7% of participants. Symptoms of long COVID, particularly neuropsychiatric symptoms, tend to persist over time, and COVID-19 vaccination or the number of vaccinations received may not significantly affect the incidence of long COVID.

27 January 2022 in BMC Infectious Diseases
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Journal Article
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YKYoonjung Kim
Yoonjung Kim
BHBitna- Ha
Bitna- Ha
SKShin-Woo Kim
Shin-Woo Kim
HCHyun-Ha Chang
Hyun-Ha Chang
KKKi Tae Kwon
Ki Tae Kwon
SHSoyoon Hwang
Soyoon Hwang
Background: As the coronavirus disease 2019 (COVID-19) pandemic continues to progress, awareness about its long-term impacts has been growing. To date, studies on the long-term course of symptoms, factors associated with persistent symptoms, and quality of life after 12 months since recovery from acute COVID-19 have been limited. Methods: A prospective online survey (First: September 8, 2020–September 10, 2020; Second: May 26, 2021–June 1, 2021) was conducted on recovered patients who were previously diagnosed with COVID-19 between February 13, 2020 and March 13, 2020 at Kyungpook National University Hospital. Responders aged between 17 and 70 years were included in the study. Overall, 900 and 241 responders were followed up at 6 and 12 months after recovery from COVID-19 in the first and second surveys, respectively. Clinical characteristics, self-reported persistent symptoms, and EuroQol-5-dimension (EQ5D) index score were investigated for evaluating quality of life. Results: The median period from the date of the first symptom onset or COVID-19 diagnosis to the time of the survey was 454 (interquartile range [IQR] 451–458) days. The median age of the responders was 37 (IQR 26.0–51.0) years, and 164 (68.0%) responders were women. Altogether, 11 (4.6%) responders were asymptomatic, and 194 (80.5%), 30 (12.4%), and 6 (2.5%) responders had mild, moderate, and severe illness, respectively. Overall, 127 (52.7%) responders still experienced COVID-19-related persistent symptoms and 12 (5.0%) were receiving outpatient treatment for such symptoms. The main symptoms were difficulty in concentration, cognitive dysfunction, amnesia, depression, fatigue, and anxiety. Considering the EQ5D index scores, only 59.3% of the responders did not have anxiety or depression. Older age, female sex, and disease severity were identified as risk factors for persistent neuropsychiatric symptoms. Conclusion: COVID-19-related persistent symptoms improved over time; however, neurological symptoms can last longer than other symptoms. Continuous careful observation of symptom improvement and multidisciplinary integrated research on recovered COVID-19 patients are required.

1 January 2020 in Journal of Korean Medical Science
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JLJi Yeon Lee
Ji Yeon Lee
HKHyun ah Kim
Hyun ah Kim
KHKyungmin Huh
Kyungmin Huh
MHMiri Hyun
Miri Hyun
JRJi-Young Rhee
Ji-Young Rhee
HCHyun-Ha Chang
Hyun-Ha Chang
Lee JY, et al. J Korean Med Sci. 2020 Apr;35(23):e223. https://doi.org/10.3346/jkms.2020.35.e223

1 June 2004 in Clinical Infectious Diseases
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JSJae-Hoon Song
Jae-Hoon Song
SJSook-In Jung
Sook-In Jung
HKHyun Kyun Ki
Hyun Kyun Ki
MSMyung-Hee Shin
Myung-Hee Shin
Kwan Soo KoKwan Soo Ko
Kwan Soo Ko
AGAsian Network for Surveillance of Resistant Pathogens Study Group
Asian Network for Surveillance of Resistant Pathogens Study Group
To evaluate the clinical outcomes of pneumococcal pneumonia caused by antibiotic-resistant strains in Asian countries, we performed a prospective observational study of 233 cases of adult pneumococcal pneumonia in 9 Asian countries from January 2000 to June 2001. Among 233 isolates, 128 (55%) were not susceptible to penicillin (25.3% were intermediately susceptible, and 29.6% were resistant). Clinical severity of pneumococcal pneumonia was not significantly different between antibiotic-resistant and antibiotic-susceptible groups. Mortality rates among patients with pneumococcal pneumonia caused by penicillin-, cephalosporin-, or macrolide-resistant strains were not higher than those with antibiotic-susceptible pneumococcal pneumonia. Bacteremia and mechanical ventilation were significant risk factors for death, but any kind of antibiotic resistance was not associated with increased mortality due to pneumococcal pneumonia. Outcome of pneumococcal pneumonia was not significantly affected by drug resistance, and current antimicrobial regimens are mostly effective in the treatment of pneumococcal pneumonia, despite the widespread emergence of in vitro resistance.

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JLJeong-Hoon Lim
Jeong-Hoon Lim
SPSun-Hee Park
Sun-Hee Park
YJYena Jeon
Yena Jeon
Jang-Hee ChoJang-Hee Cho
Jang-Hee Cho
HJHee-Yeon Jung
Hee-Yeon Jung
Yong-Lim KimYong-Lim Kim
Yong-Lim Kim
The outcome of coronavirus disease 2019 (COVID-19) is associated with organ damage; however, the information about the relationship between acute kidney injury (AKI) and COVID-19 is still rare. We evaluated the clinical features and prognosis of COVID-19 patients with AKI according to the AKI severity. Medical data of hospitalized COVID-19 patients in two university-based hospitals during an outbreak in Daegu, South Korea, were retrospectively analyzed. AKI and its severity were defined according to the Acute Kidney Injury Network. Of the 164 hospitalized patients with COVID-19, 30 patients (18.3%) had AKI; 14, 4, and 12 patients had stage 1, 2, and 3, respectively. The median age was significantly higher in AKI patients than in non-AKI patients (75.5 vs. 67.0 years, p = 0.005). There were 17 deaths (56.7%) among AKI patients; 4 (28.6%), 1 (25.0%), and 12 (100.0%), respectively. In-hospital mortality was higher in AKI patients than in non-AKI patients (56.7% vs. 20.8%, p < 0.001). After adjusting for potential confounding factors, stage 3 AKI was associated with higher mortality than either non-AKI or stage 1 AKI (hazard ratio (HR) = 3.62 (95% confidence interval (CI) = 1.75–7.48), p = 0.001; HR = 15.65 (95% CI = 2.43–100.64), p = 0.004). Among the AKI patients, acute respiratory distress syndrome and low serum albumin on admission were considered independent risk factors for stage 3 AKI (both p < 0.05). Five patients with stage 3 AKI underwent dialysis and eventually died. In conclusion, COVID-19 patients with severe AKI had fatal outcomes.

1 January 2020 in Journal of Korean Medical Science
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Journal Article
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HSHo Kyung Sung
Ho Kyung Sung
JKJin Yong Kim
Jin Yong Kim
JHJeonghun Heo
Jeonghun Heo
HSHaesook Seo
Haesook Seo
YJYoung Soo Jang
Young Soo Jang
TCThe Korea National Committee for Clinical Management of COVID-19
The Korea National Committee for Clinical Management of COVID-19
Sung HK, et al. J Korean Med Sci. 2020 Jul;35(30):e280. https://doi.org/10.3346/jkms.2020.35.e280