유한요소법을 이용한 인공 고관절의 역학적 거동 해석 및 설계

정재연(Jae Young Jeong),황운봉(Woon Bong Hwang),하성규(Sung Kyu Ha) 한국복합재료학회 1999 Composites research Vol.12 No.5

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복부 전산화단층촬영에서 Bolus triggering기법을 이용한 체질량 지수 변화에 따른 최적의 지연시간 연구

정재연(Jeong Jae yeon),김홍석(Kim Hong suck),최진영(Choi Jin Young),임상묵(Lim Sang Muk),조영기(Kim Dae Hyun),김대현(Cho Young Ki) 대한CT영상기술학회 2013 대한CT영상기술학회지 Vol.15 No.1

목적 조영증강 CT 검사에서 병변의 진단과 조영제 사용 등에 많은 영향을 주고 있는 조영증강 시간을 환자의 성별, 연령별, 비만, 고혈압 유무 등의 체질량지수에 따라 복부 대동맥에서 Bolus triggering 기법을 이용하여 평균 도달 시간이 사람마다 각각 다르게 나타난다는 점을 착안하여 조영 시간에 영향을 주는 인자들에 대해 살펴보고 환자방어의 최적화를 위한 그들의 상관관계에 대해 유용성을 알아보고자 연구하였다. 대상 및 방법 2010년 8월부터 2011년 8월까지 12개월간 본원에서 복부 전산화단층촬영을 시행한 환자 중 장비에 내장된 응용 소프트웨어 Bolus triggering 기법을 이용하여 검사를 시행한 환자를 대상으로 하였다. 정상 환자군에서 남, 여 각 50명씩 100명, 비만 환자군에서 남, 여 각 50명씩 100명, 고혈압 환자군에서 남, 여 각 50명씩 100명, 비만과 고혈압이 동시에 있는 환자군에서는 남, 여 각 40명씩 80명이었다. 스캔 범위를 결정한 다음 20G로 정맥내 주사를 확보하여 조영제 양을 3.5 ml/s, 2 ml/kg의 주입속도로 주입하고 난 후 생리식염수 20 ml를 같은 주입속도 비율로 주입하여 균일한 조영증강이 정점에 도달하게 하였다. 복부 대동맥에서 Bolus triggering을 실시하여 100 HU되는 시점으로부터 15초 후 영상을 얻기 시작하였다. 선량측정은 전체 스캔 선량을 표시하는 DLP값을 이용하여 비교하였다. 결과 연령별 분석에서 연령이 증가할수록 모니터링 횟수가 증가되었고 평균 도달 시간이 늦어지는 것을 알 수 있었으며 통계적으로 유의한 차이를 보였다(p= .001). 성별 분석에서는 남자군이 여자군보다 모니터링 횟수가 증가되었고 평균 도달 시간이 늦어지는 것을 알 수 있었으며 통계적으로 유의한 차이를 보였다(p= .001). 환자의 특성 중 100 HU값의 조영증강 시간은 체질량지수 측정 결과 비만 환자군 또는 고혈압 환자군 보다는 비만과 고혈압을 동시에 가지고 있는 환자군에서 모니터링 횟수가 증가되었고 평균 도달 시간이 늦어지는 것으로 나타냈다(p= .001). 기존의 모니터링 스캔 지연시간 15초를 비만 환자나 질환의 유무 및 정도에 따라 조절하여 모니터링 횟수 분석을 통해 적용했을 때 평균 4.4회로 DLP값 0.214 mSv였고, 모니터링 시작 시간을 4초 후에 시작함으로써 DLP값 0.214 mSv의 방사선 노출을 감소시킬 수 있었다. 비만인 남자 환자군에서 평균 5.4회로 DLP값 0.283mSv, 여자 환자군에서 평균 4.38회로 DLP값 0.212 mSv로 나타냈다. 고혈압인 남자 환자군에서 평균 5.18회로 DLP값 0.268 mSv, 여자 환자군에서 평균 3.62회로 DLP값 0.182 mSv로 나타났다. 결론 환자의 특성 중 100 HU값의 조영증강 시간은 연령이 증가할수록, 성별이 여자군 보다는 남자군에서, 체질량지수 측정결과 비만과 고혈압을 동시에 지닌 환자군에서 조영증강 시간이 증가하는 것으로 나타났다. 본 실험에서와 같이 모니터링 자료를 관리하여 환자 개개인의 특성을 알고 접근한다면 1년에 최소 2~3번까지 추적검사를 하는 환자에게 피폭되는 선량값을 줄일 수 있을 것으로 사료된다. Ⅰ. Purpose The purpose of this study is to review the factors influencing the contrast time and to identify the usefulness of their correlations of the factors for the optimization of patient protection, considering that in contrast enhancement CT, contrast enhancement time influences much on the lesion diagnosis and the use of contrast agent and average arrival time varies among people by sex, age, obesity, BMI and hypertension. In this study, it was measured at abdominal aorta using Bolus triggering technique. Ⅱ. Meterial and Methods The subjects were the patients who had a test using Bolus triggering technique among the patients who had abdominal Computed Tomography in Chonbuk National University Hospital for 12 months from August 2010 to August 2011. Subjects were selected as 100 people (50 males and females respectively) from normal group, 100 people (50 males and females respectively) from the group of hypertension patients, and 80 people (40 males and females respectively) from the group with obesity and hypertension together. After determining the scan scope, contrast agent was injected at 3.5 ml/s or 2 ml/kg by securing the intravenous injection with 20 gauge and 20 ml physiological saline was injected at the same injection speed to make the even contrast enhancement arrive at peak. Performing Bolus triggering at abdominal aorta, images were acquired from 15 seconds after 100HU. Dosimetry was compared using DLP value showing the total scan dose. Ⅲ. Result From the analysis by age, the times of monitoring increased with the increase of age, average arrival time became delayed, and the difference was statistically significant (p= .001). In the analysis by sex, male patients had more monitoring sessions than female patients, average arrival time was delayed, and the difference was also statistically significant (p= .001). From the characteristics of the patients, contrast enhancement time of 100HU was seen more frequently among the group with obesity and hypertension together than the group of obesity or hypertension and the arrival time was later in obese and hypertension group (p= .001). When applying by coordinating the conventional monitoring scan delay time (15 seconds) according to the obesity or the presence of a disease and analyzing the monitoring times, the average monitoring times was 4.4 or 0.214 mSv in DLP value. By adjusting the monitoring starting time to 4 seconds late, radioactive exposure such as DLP value of 0.214 mSv could be reduced. It was shown as 5.4 times and 0.283 mSv of DLP in obese male patients, and 4.38 times and 0.212 mSv of DLP in obese female patients. It was shown as 5.18 times and 0.268 mSv of DLP in hypertension male patients, and 3.62 times and 0.182 mSv of DLP in hypertension female patients. Ⅳ. Conclusions Contrast enhancement time of 100 HU increased in the patients who were older males and had obesity and hypertension together. If approaching the characteristics of each patient by managing the monitoring data just as in this experiment, we may be able to reduce the radioactive dose that the patients would have who should have at least 2-3 times follow up treatment a year.

관상동맥 중재술을 받은 급성 심근경색증 환자에서 체질량 지수의 영향

정선영 ( Seon Young Jeong ),이정애 ( Jung Ae Rhee ),정명호 ( Myung Ho Jeong ),황선호 ( Seon Ho Hwang ),윤남식 ( Nam Sik Yoon ),홍서나 ( Seo Na Hong ),이상록 ( Sang Rok Lee ),김계훈 ( Kye Hun Kim ),문재연 ( Jae Youn Moon ),홍영준 ( 대한내과학회 2007 대한내과학회지 Vol.73 No.6

목적: 비만은 관상동맥 질환의 위험인자로 알려져 있으나, 급성 심근경색증 환자에서 비만이 미치는 영향이나 관상동맥 중재술 후 장기 예후에 대한 영향은 잘 알려져 있지 않다. 본 연구를 통해 급성 심근경색증 환자에서 비만이 미치는 영향과 관상동맥 중재술 후 장기 예후에 미치는 영향을 알아보고자 하였다. 방법: 2002년 2월 1일부터 2006년 6월 30일까지 전남대학교 심장센터에서 급성 심근경색증으로 진단되어 관상동맥 중재술을 시행한 309예(60.5±11.3세, 남:여=243:66)를 대상으로 하였다. 체질량 지수가 25 kg/m2미만인 194예의 환자를 I 군(61.7±11.1세, 남:여=151:43), 체질량 지수가 25 kg/m2 이상인 115예의 환자를 II 군(58.6±11.5세, 남:여=92:23)으로 하여 두 군 간의 임상적 특성이나 위험인자들을 비교하였고, 6개월간 추적 경과관찰 동안 발생한 주요 심장 사건을 분석하였다. 결과: I 군에서 II 군에 비하여 나이가 많았고(61.7±11.1세 vs. 58.6±11.5세, p=0.017), II 군에서 고혈압(59/115 vs. 75/194예, p=0.033)과 고지혈증(60/115 vs. 75/194예, p=0.024)의 빈도가 높았다. 고지혈증의 경우 II 군이 I 군에 비해 혈중 총 콜레스테롤(201.4±42.6 mg/dL vs. 184.3±39.9 mg/dL, p=0.001), 중성지방(147.1±96.2 mg/dL vs. 121.2±61.6 mg/dL, p=0.005), 저밀도 콜레스테롤(134.1±37.8 mg/dL vs. 120.3±35.1 mg/dL, p=0.002)이 높았으나, 고밀도 콜레스테롤(42.3±10.2 mg/dL vs. 44.5±12.1mg/dL, p=0.109)은 차이가 없었다. 관상동맥 조영술이나 중재술과 연관된 인자는 두 군에서 차이가 없었다. 178예(I 군 109예, II 군 69예)의 환자에서 6개월 추적 관상동맥 조영술이 시행되었다. 재협착은 I 군에서 14예(12.8%), II 군에서 18예(26.1%)가 발생하여 II 군이 I 군에 비해 재협착율이 유의하게 높았다(p=0.025). 결론: 비만을 동반한 급성 심근경색증 환자에서는 고지혈증과 고혈압이 동반되는 경우가 많았으며, 관상동맥 중재술 후 재협착이 유의하게 많이 발생함을 알 수 있었다. 따라서 비만에 대한 적극적인 치료가 심근경색증 환자에서 중재술 후 재협착 예방에 중요할 것으로 생각되었다. Background: Obesity is one of the major risk factors for coronary artery disease. However, the long-term clinical effects of obesity after percutaneus coronary intervention (PCI) in Korean patients with acute myocardial infarction (AMI) have not been sufficiently evaluated. Methods: A total of 309 patients (mean age 60.5±11.3 years, M:F=243:66) that underwent PCI with a diagnosis of AMI between February 2002 and June 2006. Thepatients were divided into two groups according to the body mass index (BMI): group I (n=194; BMI<25 kg/m2; mean age 61.7±11.1 years, M:F=151:43) and group II (n=115; BMI≥25 kg/m2, mean age 58.2±11.3 years, M:F=92:23). Clinical characteristics and risk factors, and major adverse cardiac events during a six-month follow-up were compared between patients in the two gropus. Results: The mean age of group I patients was older than that of group II patients (61.7±11.1 years vs. 58.6±11.5 years, p=0.017). The prevalence of hypertension was higher in group II patients (75/194, 38.7% vs.59/115, 51.3%, p=0.033) and hyperlipidemia was more prevalent in group II patients (75/194, 38.7% vs. 60/115, 52.2%, p=0.024). The levels of total cholesterol (184.3±39.9 mg/dL vs. 201.4±42.6 mg/dL, p=0.001), triglycerides (121.2±61.6 mg/dL vs. 147.1±96.2 mg/dL, p=0.005), low-density lipoprotein-cholesterol (120.3±35.1 mg/dL vs. 134.1±37.8 mg/dL, p=0.002) were lower in group I patients than in group II patients. The restenosis rate on a follow-up coronary angiogram was higher in group II patients (18/69, 26.1%) than in group I patients (14/109, 12.8%, p=0.025). Conclusions: Obesity is associated with hyperlipidemia and hypertension in patients with AMI. The restenosis rate after PCI was higher in obese AMI patients. (Korean J Med 73:603-610, 2007)

해외금융계좌신고제도(FATCA) 도입과 정부간 협정(한미 IGA) 체결에 따른 보험업계의 주요이슈 검토 및 개선방안

정재연(Jae-Yeon Jeong),유혜영(Hae-Young Ryu) 대한경영학회 2015 大韓經營學會誌 Vol.28 No.5

체형 교정 시술 후 발생한 비정형 마이코박테리아 감염, 증례 보고

정재연,임소영,변재경,문구현,방사익,오갑성,Jeong, Jae-Yeon,Lim, So-Young,Pyon, Jai-Kyong,Mun, Goo-Hyun,Bang, Sa-Ik,Oh, Kap-Sung 대한성형외과학회 2010 Archives of Plastic Surgery Vol.37 No.3

Purpose: NTM (non tuberculous mycobacteria) is rare cause of surgical site infection after plastic surgery in immunocompetent patients. There are some reports about NTM infection after body contouring procedure from Latin America. But, there is no report in Korea. The purpose of this article is to report 2 patients with soft tissue infection caused by NTM after body contouring procedure. Methods: Two young female patients exhibited signs of inflammation and abscess after body contouring procedure. One patient underwent liposuction. The other underwent HPL (hypotonic pharmacologic lipo-dissolution) injection. Results: The result of tissue cultures were positive for NTM. All patients responded to the combined therapeutic approach. Conclusion: The goal of this article is to raise awareness among plastic surgeons who may encounter such patients in their practice. NTM should be included in the differential diagnosis of surgical site infection after body contouring surgery.

Extended Application of Endoscopic Repair for Frontal Sinus Fractures

정재연,임소영,변재경,방사익,오갑성,문구현,Jeong, Jae-Yeon,Lim, So-Young,Pyon, Jai-Kyong,Bang, Sa-Ik,Oh, Kap-Sung,Mun, Goo-Hyun Korean Society of Plastic and Reconstructive Surge 2010 Archives of Plastic Surgery Vol.37 No.5

Purpose: The coronal approach for repair of frontal sinus fractures is associated with significant adverse sequelae including a long scar, alopecia, paresthesias, and, uncommonly, facial nerve injury. To minimize these complications, an endoscopic approach for repair of frontal sinus fractures was developed. The authors now present the results of an endoscopy-assisted approach for the treatment of frontal sinus fractures. Methods: From 2002 to 2009, five patients with frontal sinus fracture underwent endoscopic repair. Two slit incisions were placed in the scalp, and one or two stab incisions directly over the fractures were placed in the forehead. After subperiosteal dissection, fracture segments were reduced under direct vision and fixed with microplates or fibrin glue. Results: All patients had good cosmetic results and remained free of sinus complaints. There were no perioperative complications reported. Conclusion: Endoscopic repair of frontal sinus fractures is an efficacious technique that significantly reduces patient morbidity. A relatively wide range of anterior table fractures can be reduced using an endoscope. In cases of complicated comminuted fractures, fibrin glue helps to achieve satisfactory endoscopic reduction. Endoscopic repair is an alternative treatment for various anterior table fractures of the frontal sinus.

도·농간 재난적의료비 발생에 영향을 미치는 요인 비교

정지윤 ( Jeong Ji Yun ),정재연 ( Jeong Jae Yeon ),최화영 ( Choi Hwa Young ),이해종 ( Lee Hae Jong ) 한국보건사회연구원 2021 保健社會硏究 Vol.41 No.1

이 연구의 목적은 도시와 농촌에 의한 재난적의료비 발생의 규모를 파악하고, 이에 영향을 줄 수 있는 요인을 비교·확인하는 것이다. 연구에서는 한국보건사회연구원이 제공한 제14차(2019년) 한국복지패널 자료를 활용하였다. 종속변수는 재난적의료비 발생 유무이고, 10, 20, 30 및 40% 역치수준별로 나누어 살펴보았다. 독립변수는 가구주의 특성과 가구특성으로 구분하였다. 가구주·가구 특성이 도시·농촌 간 차이가 있는지와 역치기준별로 도농간 재난적의료비 지출빈도 차이가 있는지 살펴보기 위해 X²-text를 실시하였다. 또한, 재난적의료비 발생에 영향을 미치는 요인을 분석하기 위해 로지스틱 회귀분석을 실시하였다. 분석결과 가구주의 특성과 도시·농촌 가구의 특성은 다르게 나타났고, 모든 역치수준에서 도시보다 시골가구에서 재난적의료비 지출이 더 많았다. 도시 가구에 비해 농촌 가계의 재난적의료비의 발생 확률이 높았고, 40%역치수준에서 상당한 차이가 있었다. 재난적의료비 발생에 영향을 미치는 요인은 ‘배우자 유무, 경제활동 유무, 주관적 건강상태, 의료보장형태, 가구원수, 가구원 장애유무’변수들 이었다. 따라서 재난적의료비의 발생을 막기 위해서는 정의 설정과 정책 마련에 대한 논의가 필요하다. The purpose of this study is to identify the scale of catastrophic health expenditure by urban and rural areas, and to compare and identify factors that may affect them. In this study, the 14th (2019) Korea Welfare Panel data, provided by the Korea Institute for Health and Social Affairs, was used. The dependent variable was occurrence of catastrophic health expenditure, divided into 10, 20, 30, and 40% threshold levels. The independent variables were divided into household head's characteristics and household characteristics. Logistic regression analysis was performed to analyze the factors affecting the occurrence of catastrophic health expenditure at each threshold level. The characteristics of household heads and the characteristics of households were of urban and rural households were different. At all threshold levels, there were more rural households with catastrophic health expenditure than urban. Compared to urban households, there was a higher probability of catastrophic health expenditure in rural households and had a significant effect at the 40% threshold level. Factors influencing the occurrence of catastrophic health expenditure were different in urban and rural areas, especially at the 40% threshold level. In order to prevent the occurrence of catastrophic health expenditure, discussions on the definition settings and policy preparation are needed.

위절제술을 시행한 조기위암환자에서 위치확인을 위한 위장조영검사와 위내시경검사의 비교분석에 따른 진단률 향상에 관한 연구 : 4cm미만의 조기위암 중심으로

고주영(Ju Young Ko),이보영(Bo Young Lee),김상균(Sang Gyun Kim),정재연(Jae Yeon Jeong),김금남(Geum Nam Kim),조영기(Young Gi Cho) 대한영상의학기술학회 2009 대한영상의학기술학회 논문지 Vol.2009 No.-

Purpose : It was prepared to help patients with early gastric cancer who underwent a gastrectomy to detect early gastric cancer by comparing observations from pre-operation UGI series and Endoscopy as well as post-operation pathological observations of type, size, and location. Materials and Methods : It targeted 27 cases who underwent a gastrectomy for early gastric cancer by visiting the department of surgery from February 2007 to September 2008 while the pathological observations of type, size, and location were compared and analyzed through observations from pre-operation gastroscopy and UGI series and medical record after the gastrectomy. Results : Considering the generation frequency after gastrectomy, pyloric antrum was the most with 15 cases (55.6%); specifically, lesser curvature of stomach was the most with 14 cases (51.9%). When 2 accompanied observations were combined, atrophic gastritis and intestinal metaplasia showed high frequencies with 23 cases (85.2%) and 22 cases(81.5%) respectively. Through radiologic severity, 14cases (51.8%) were judged as “concordance” while 13 cases (48.2%) were judged as “discordance”. In the origin site of the 13 cases judged as “discordance” in radiologic severity, pyloric antrum was the most with 9 cases (69.2%); specifically, lesser curvature of stomach was the most with 6 cases (41.6%). Lesser curvature and the anterior wall part of stomach are difficult to be technically depicted minutely during the UGI series, and they are parts where false positive rates are frequently generated. Conclusion : Observation of accompanied intestinal metaplasia(81.5%) is evaluated as the important standard in the discovery of early gastric cancer. Intensive tests are executed for intestinal metaplasia because it is considered as a high risk group and require follow up when suspected. In the result of radiologic severity, there were many observations which looked normal yet it was early gastric cancer in lesser curvature and the anterior wall of stomach including the gastric angle. Only habitual scans of that part with compression and flow technique, while at the same time, confirming the change of mucosa are thought to contribute to discovering early gastric cancer exactly and swiftly in gastric cancer screening tests.

미세먼지 고농도 시즌 방진용 마스크에 관한 인식과 착용 행동에서 전국 지역별 차이 및 성차

이주영 ( Joo-young Lee ),박준희 ( Joonhee Park ),백윤정 ( Yoon Jeong Baek ),정다희 ( Dahee Jung ),고예린 ( Yelin Ko ),정재연 ( Jae Yeon Jung ),강주호 ( Juho Kang ),이태경 ( Taekyung Lee ),이예진 ( Yejin Lee ),송은영 ( Eunyoung Son 한국의류학회 2020 한국의류학회지 Vol.44 No.3

The present study investigated regional and sex differences in knowledge, perception, cognition and behavior of fine-dust protective masks for periods of high concentration of fine dust in Korea. A total of 2,012 adults from seven provinces responded to the questionnaire. The results (all p<.05) showed that 78% of respondents considered pollution from China to be the greatest contributor of fine dust. Seoul and Gyeonggi residents more frequently checked fine dust forecasts than other provinces and consulted their smartphone applications to do so more than other residents. Jeju, Gwangwon, and Jeonla residents had less knowledge of KF 80, 94, and 99 masks than residents of other provinces. Gwangwon and Jeju residents had less trust in the effectiveness of protective masks than other residents. Females perceived themselves as unhealthier respiratory, more frequently checked the concentration of fine dust, trusted more the effectiveness of masks, and more frequently wore masks, compared to male respondents. Those who self-identified their respiratory function as poor, more frequently checked fine dust forecasting, and had greater knowledge of masks, which resulted in greater trust in the protective function of masks, and finally had higher wear frequency of masks for days with high concentrations of fine dust.

감사시간과 감사보수가 이익조정에 미치는 영향

권수영 ( Soo Young Kwon ),신현걸 ( Hyun Geol Shin ),정재연 ( Jae Yeon Jeong ) 한국회계학회 2006 회계학연구 Vol.31 No.4

본 연구는 감사인이 Big4와 제휴관계에 있는지의 여부가 이익조정에 직접적으로 영향을 미칠 뿐만 아니라 감사시간과 감사보수를 통해 간접적으로도 이익조정에 영향을 미칠 수 있음을 고려하였다. 이러한 설정에서 이익조정의 대용치인 재량적발생액 이외에도 감사시간과 감사보수도 내생적 변수이기 때문에 구조방정식 모형 (structural equation model)을 이용하여 분석하였다. 실증분석 결과 감사인의 규모와 감사시간 간에는 유의한 상관관계가 존재하지만, 감사인의 규모와 초과감사시간 간에는 유의한 상관관계가 존재하지 않았다. 이러한 결과는 Big 감사인이라고 해서 적정감사시간을 초과하는 감사시간을 투입하지는 않음을 보여주는 것이다. 또한 감사인의 규모, 감사시간 및 감사보수와의 분석을 통해서 Big 감사인이라고 해서 더 많은 감사보수를 청구한다기 보다는 적정시간을 초과하는 감사시간에 대한 보상으로 더 많은 감사보수를 청구하고 있다는 증거를 발견하였다. 마지막으로 감사시간은 이익조정과 유의한 상관관계가 존재하지 않았으나, 초과감사시간은 이익조정과 유의한 상관관계가 존재하는 것으로 나타나 적정감사시간 이상의 노력을 기울일 때 이익조정이 억제된다는 것을 발견하였다. 본 연구는 감사과정에서 감사위험이 높을 때 적정 감사시간을 초과하는 감사시간을 투입함으로써 이익조정을 감소시킬 수 있음을 제시하였다는 점에서 선행연구와 차별된다고 할 수 있다. 또한 Big 감사인이라고 해서 무조건 감사보수를 과다하게 청구하는 것이 아니라 초과감사시간을 보상받기 위해서 감사보수를 더 많이 청구하고 있음을 제시하였다는 점에서 의의를 찾을 수 있다. This study considers not only whether having an auditor that is Big 4-affiliated affects earnings management, but also whether audit hours and audit fees can affect earnings management. In this setting, discretionary accruals as a proxy for earnings management, audit hours as a proxy for audit efforts and audit fees as a measure of auditors` economic incentives are endogenously determined. Thus, we employ a structural equation model to take into account the endogeneity of variables under study. Prior studies in the literature of audit quality show that Big audit firms have higher audit fees and audit hours than non-Big audit firms and argue that this is consistent with the explanation that Big audit firms have higher audit quality. However, this may not be true if Big audit firms spend more audit hours, which result in higher audit fees, because their clients are large in size or if they are susceptible to greater litigation risk than non-Big audit firms. Furthermore, it is not clear whether more audit hours and fees fetch higher audit quality. Prior studies also separately consider that Big audit firms have higher audit quality than non-Big audit firms based on the result that Big audit firms have smaller discretionary accruals than non-Big audit firms. However, these studies do not control audit hours so that it is difficult to tell whether the result is due to Big auditors` ability to provide high audit quality or their increased efforts to reduce high litigation risk. This study examines the effect of Big audit firms on earnings management after controlling audit hours and audit fees. If Big audit firms continue to deter earnings management even after including control variables, then Big audit firms may be viewed as providing an audit ability superior to non-Big audit firms. In addition, this study investigates whether audit hours and audit fees play a role in reducing earnings management. Empirical results show that auditor size and audit hours are highly correlated, but auditor size and abnormal audit hours are not related to each other. This shows that even Big audit firms do not necessarily spend more than the standard number of audit hours. In addition, Big audit firms charge higher audit fees in compensation for additional audit hours in excess of the standard hours, rather than just charging audit fees merely because they are Big audit firms per se. Finally, we find that there is no statistically significant relation between audit hours and discretionary accruals. However, we do find a negative relation between abnormal audit hours and discretionary accruals. This is consistent with the explanation that earnings management is deterred when an auditor makes efforts over and above the standard audit hours required. This study makes three contributions to the literature of audit quality. First, this is the first to explicitly consider audit hours and audit fees in examining their effect on earnings management. Second, this study employs the structural equation to examine the relation between audit hours, audit fees and auditor reputation. This approach allows us to estimate both direct and indirect effects of study variables. Third, this paper differs from prior studies in that this study provides empirical evidence that audit hours in excess of the standard hours in the presence of high audit risk can reduce the extent of earnings management. Furthermore, high compensation for audit is related to audit firms` additional efforts, rather than auditors` mere premium for their brand reputation.