Jeonghyun Chang

Dr. Jeonghyun Chang


Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

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

Representative Publications

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17 June 2025 in Annals of Laboratory Medicine
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Journal Article
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JCJeonghyun Chang
Jeonghyun Chang
SCSooin Choi
Sooin Choi
HCHanwool Cho
Hanwool Cho
SKSollip Kim
Sollip Kim
JCJae-Woo Chung
Jae-Woo Chung
OMon behalf of the Working Group on Venous Blood Collection Guideline of the Korean Society for Laboratory Medicine
on behalf of the Working Group on Venous Blood Collection Guideline of the Korean Society for Laboratory Medicine
Jeonghyun Chang, M.D., Ph.D., Sooin Choi, M.D., Hanwool Cho, M.D., Ph.D., Sollip Kim, M.D., Ph.D., Jae-Woo Chung, M.D., Ph.D., Soo Jin Yoo, M.D., Ph.D., Eun Young Song, M.D., Ph.D., and Sail Chun, M.D., Ph.D., on behalf of the Working Group on Venous Blood Collection Guideline of the Korean Society for Laboratory Medicine. Ann Lab Med -0001;0:. https://doi.org/10.3343/alm.2025.0022

1 July 2020 in Annals of Laboratory Medicine
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Journal Article
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KPKuenyoul Park
Kuenyoul Park
YJYun Sil Jeong
Yun Sil Jeong
JCJeonghyun Chang
Jeonghyun Chang
HSHeungsup Sung
Heungsup Sung
MKMi-Na Kim
Mi-Na Kim
Kuenyoul Park, M.D., Yun Sil Jeong, M.T., Jeonghyun Chang, M.D., Heungsup Sung, M.D., and Mi-Na Kim, M.D., Ph.D.. Ann Lab Med 2020;40:321-5. https://doi.org/10.3343/alm.2020.40.4.321

27 March 2020 in Healthcare
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Hyeongsu KimHyeongsu Kim
Hyeongsu Kim
SKSollip Kim
Sollip Kim
YYYeo-Min Yun
Yeo-Min Yun
TUTae Hyun Um
Tae Hyun Um
JCJeonghyun Chang
Jeonghyun Chang
THTaehwa Han
Taehwa Han
External quality assessment (EQA) is a commonly used tool to track the performance of laboratory tests. In Korea, EQA participation is not mandatory, and even basic data about EQA participation are not available. We used data of a 10-year period extracted from two databases (2009–2018): (1) the database of the National Health Insurance Service to calculate the number of medical institutions that claimed health insurance benefits, and (2) the database of the Korean Association of External Quality Assessment Service to calculate the number of medical institutions participating in EQA. The proportion of institutions that made claims for the performance of laboratory testing throughout the 10 years were 73.6%–76.0% for clinics, 91.9%–97.5% for long-term care hospitals, 97.9%–99.5% for small to medium hospitals, 99.6%–100% for general hospitals, and 100% for tertiary hospitals. The mean EQA participation rate of institutions that performed laboratory testing for the 10 years was 1.9% for clinics, 3.1% for long-term care hospitals, 27.7% for small to medium hospitals, 96.6% for general hospitals, and 100% for tertiary hospitals. The mean EQA participation of clinics, long-term care hospitals, and small to medium hospitals are increasing but is still not sufficient. Regulatory approaches are needed to increase participation rates. This result would be used for health policymaking on the quality improvement of laboratory tests.

11 May 2021 in Medicina
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Journal Article
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JCJeonghyun Chang
Jeonghyun Chang
SYSoo Jin Yoo
Soo Jin Yoo
SKSollip Kim
Sollip Kim
Background and Objectives: Risk management is considered an integral part of laboratory medicine to assure laboratory quality and patient safety. However, the concept of risk management is philosophical, so actually performing risk management in a clinical laboratory can be challenging. Therefore, we would like to develop a sustainable, practical system for continuous total laboratory risk management. Materials and Methods: This study was composed of two phases: the development phase in 2019 and the application phase in 2020. A concept flow diagram for the computerized risk registry and management tool (RRMT) was designed using the failure mode and effects analysis (FMEA) and the failure reporting, analysis, and corrective action system (FRACAS) methods. The failure stage was divided into six according to the testing sequence. We applied laboratory errors to this system over one year in 2020. The risk priority number (RPN) score was calculated by multiplying the severity of the failure mode, frequency (or probability) of occurrence, and detection difficulty. Results: 103 cases were reported to RRMT during one year. Among them, 32 cases (31.1%) were summarized using the FMEA method, and the remaining 71 cases (68.9%) were evaluated using the FRACAS method. There was no failure in the patient registration phase. Chemistry units accounted for the highest proportion of failure with 18 cases (17.5%), while urine test units accounted for the lowest portion of failure with two cases (1.9%). Conclusion: We developed and applied a practical computerized risk-management tool based on FMEA and FRACAS methods for the entire testing process. RRMT was useful to detect, evaluate, and report failures. This system might be a great example of a risk management system optimized for clinical laboratories.

28 September 2020 in Medicina
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Journal Article
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SKSollip Kim
Sollip Kim
SYSoo Jin Yoo
Soo Jin Yoo
JCJeonghyun Chang
Jeonghyun Chang
Background and objectives: For proper antimicrobial therapy, cumulative antibiograms should be representative of geographic region and be accurate. Clinical and Laboratory Standards Institute (CLSI) guidelines recommend that only the first isolates (FI) of a species per patient are used when reporting cumulative antibiograms. However, >50% of hospitals in the United States report antibiograms of all isolates. We compared antibiograms from the FI with those from total isolates (TI). Materials and Methods: Antimicrobial data of all isolates identified in the Microbiology unit of Ilsan Paik Hospital in 2019 were retrospectively acquired from the hospital information system. The susceptibility rates to antimicrobials of Escherichia coli, Acinetobacter baumannii, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, Enterococcus faecium, and Enterococcus faecalis were analyzed by FI and TI, respectively. Isolate counts and susceptibility rates of each species for the reported antimicrobials were compared. Results: The numbers of isolates by FI/TI were as follows: 1824/2692 E. coli, 480/1611 A. baumannii, and 662/1306 K. pneumoniae, and 407/953 P. aeruginosa for gram-negative bacteria and 649/1364 S. aureus, 211/313 E. faecium, and 323/394 E. faecalis for gram-positive bacteria. All antimicrobial agents showed higher susceptibility rates when calculated as FI than as TI in gram-negative bacteria except colistin: 3.7% for E. coli, 14.5% for A. baumannii, 8.3% for K. pneumoniae, and 7.9% for P. aeruginosa. In S. aureus, 8/11 antimicrobial agents revealed higher susceptibility rates for FI than for TI. E. faecalis and E. faecium showed lower susceptibility rates for 7/10 antimicrobial agents for FI than for TI. The oxacillin susceptibility rates of S. aureus were 36.6%/30.2% with FI/TI and vancomycin susceptibility rates for E. faecium were 54.1% and 49.5%, respectively. Conclusions: When comparing cumulative antibiograms by FI with TI using real-world data, there is a large gap for critical species requiring hospital infection control. Although FI calculation is difficult, antibiograms must be calculated as FI for proper preemptive antimicrobial therapy because FI provides proper antimicrobial susceptibility data.

25 November 2021 in BMC Infectious Diseases
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JCJeong Min Cho
Jeong Min Cho
JCJeonghyun Chang
Jeonghyun Chang
DKDong-Min Kim
Dong-Min Kim
YKYee Gyung Kwak
Yee Gyung Kwak
CCChong Rae Cho
Chong Rae Cho
JSJe Eun Song
Je Eun Song
Background: Human granulocytic anaplasmosis (HGA) is a systemic inflammatory response caused by the rickettsial bacteriumAnaplasma phagocytophilum. Rhabdomyolysis and acute kidney injury (AKI) are rare complications of HGA. Here, we report a case of HGA concurrent with rhabdomyolysis and AKI in an elderly patient.Case presentation: An 84-year old woman with a medical history of hypertension was hospitalised after two days of fever, dizziness, whole body pain, and general weakness. Laboratory investigations showed severe thrombocytopenia, leukopenia, impaired renal function, and elevated cardiac enzyme and myoglobin levels. On the day after admission, peripheral blood smear revealed morula inclusions in neutrophils, a suggestive finding of HGA. Real-time polymerase chain reaction (PCR) results indicated the presence ofA. phagocytophilum. Antibiotics were de-escalated to doxycycline monotherapy. After 10 days of antibiotic treatment, laboratory tests showed complete recovery from HGA complicated with rhabdomyolysis and AKI.Conclusions: HGA can lead to serious complications in patients with associated risk factors. Therefore, in patients with HGA accompanied by rhabdomyolysis, management with antibiotics and hydration should be initiated immediately, and not delayed until diagnostic confirmation.