A total of 481,414 Korean participants aged 40-79 years at enrollment were examined. The hazard ratios for all-cause, all-cancer, and head and neck cancer mortality were analyzed using Cox proportional hazards models, which were adjusted for potential confounding factors. In the overall study population, the highest AST/ALT ratio level was significantly associated with risk of all-cause, all-cancer, and head and neck cancer mortality (p < 0.01). After excluding participants who died of all-cause, all-cancer, and head and neck cancer within five years of enrollment, the main results remained similar to those of the analysis of all deaths in the study population. These findings indicate that serum AST/ALT ratio is positively associated with an increased mortality risk in all-cause, all-cancer, and head and neck cancer.

Ⅰ. INTRODUCTION
Ⅱ. MATERIALS and METHODS
    1. 연구 자료
    2. 연구 대상
    3. 변수의 정의
    4. 통계분석
Ⅲ. RESULTS
    1. 혈청 AST/ALT 비 오분위수에 따른 기저조사 특성
    2. 혈청 AST/ALT 비 오분위수와 전체원인, 전체암,두경부암 사망위험과의 연관성
    3. 추적 관찰 개시 5년 이내 사망자를 제외한연구대상에서의 혈청 AST/ALT 비와 전체원인,전체암, 두경부암 사망 위험과의 연관성
    4. 혈청 AST/ALT 비의 종단 분석
Ⅳ. DISCUSSION
Ⅴ. CONCLUSION
REFERENCES

• 김은진(연세대학교 의과대학 예방의학교실) | Eun-Jin Kim (Department of Preventive Medicine, Yonsei University College of Medicine, Seoul, South Korea)
• 조혜민(전북대학교 자연과학대학 통계학과) | Hye Min Cho (epartment of Statistics, Research Institute of Applied Statistics, Jeonbuk National University)
• 최혜미(전북대학교 자연과학대학 통계학과) | Hye Mi Choi (epartment of Statistics, Research Institute of Applied Statistics, Jeonbuk National University)
• 조남표(전북대학교 치과대학 구강병리학교실) | Nam-Pyo Cho (Department of Oral Pathology, School of Dentistry, Institute of Oral Bioscience, Jeonbuk National University) Corresponding author