Onyebuchi A. Arah

Onyebuchi ("Onyi") Arah, MD, MSc, MPH, DSc, PhD, is a Professor and Interim Chair of Epidemiology at the Fielding School of Public Health and an Affiliated Professor in the Department of Statistics and Data Science. He has been an Associate Dean at UCLA's Division of Graduate Education. He has served as President-Elect, President, and Past-President of the Society for Epidemiologic Research (SER). He is the Co-Director of the Practical Causal Inference Lab at UCLA. An internationally renowned scholar, he is also Honorary Skou Professor at Aarhus University in Denmark. He has served as Director of the Center for Global and Immigrant Health and Associate Dean at the Fielding School of Public Health. He is the Chair of the Epidemiology Doctoral Qualifying Examination Committee. He has received several research, teaching, and service awards, including the Council of Science Editors Award (hosted by Fogarty International, NIH) for outstanding contributions to global health policy and practice, the European Society for Philosophy, Medicine and Health Care’s First Prize for Young Scholars under age 35 who have made innovative contributions to the philosophy of medicine and health care, the  Causality in Statistics Education Award from the American Statistical Association, an Honorary Skou Professorship in Epidemiology, Health Policy and Biostatistics from Aarhus University in Denmark, the Academic Council Chairs Award for Mid-Career Leadership from the University of California Systemwide Academic Senate, and the Faculty Award for Excellence in Graduate Student Mentoring. In addition to serving on the editorial boards of epidemiology, public health, and interdisciplinary science journals, he regularly reviews manuscripts for biostatistics, epidemiology, general medicine, and public health journals. His research areas include causal inference, quantitative bias analysis, computational epidemiology, population health data science, and reproductive, pediatric, perinatal, occupational, clinical, and social epidemiology.

Selected Courses

• EPIDEM M204 / STATS M243: Logic, Causation & Probability
• EPIDEM M211 / STATS M250: Statistical Methods for Epidemiology
• EPIDEM M210 / HLTHPOL M210: System Science in Population Health
• EPIDEM 211: Statistical Modeling in Epidemiology

Selected Publications

• Komura T, Bargagli-Stoffi FJ, Arah OA, Inoue K. Estimating and discovering heterogeneous treatment effects using machine learning in epidemiological studies: a practical guide. Int J Epidemiol. 2026 Apr 17;55(3):dyag092. doi: 10.1093/ije/dyag092. PMID: 42287695; PMCID: PMC13264450.
• Lee PC, Chuang YH, Hu YH, Lin CN, Li CY, Chen YY, Heck JE, Bellia G, Zhuo H, Arah OA, Liew Z. Maternal acetaminophen use and child neurodevelopment. JAMA Pediatr. 2026 May 1;180(5):527-534. doi: 10.1001/jamapediatrics.2026.0071. Erratum in: JAMA Pediatr. 2026 May 1;180(5):588. doi: 10.1001/jamapediatrics.2026.1209. PMID: 41801232; PMCID: PMC12973218.
• Coates MM, Wolock CJ, Arah OA. Re: Prediagnostic exposures and cancer survival: can a meaningful causal estimand be specified? Epidemiology. 2026 Jan 1;37(1):e1-e2. doi: 10.1097/EDE.0000000000001909. Epub 2025 Aug 19. PMID: 40827761; PMCID: PMC12880854.
• Guo P, Luo J, Zhang J, Bonde JP, Struciński P, Ohniev V, Arah OA, Deziel NC, Warren JL, Toft G, Liew Z. Paternal and maternal exposures to per- and polyfluoroalkyl substances (PFAS) and birth outcomes: a multi-country cohort study. Environ Health. 2025 Jul 12;24(1):48. doi: 10.1186/s12940-025-01199-y. PMID: 40652244; PMCID: PMC12255010.
• Uleman JF, Stronks K, Rutter H, Arah OA, Rod NH. Mapping complex public health problems with causal loop diagrams. Int J Epidemiol. 2024 Jun 12;53(4):dyae091. doi: 10.1093/ije/dyae091. PMID: 38990180.
• Rowe SL, Sullivan SG, Koerber JJ, Muñoz FM, Coates MM, Arah OA, Regan AK. Adverse events associated with COVID-19 vaccination or diagnosis among pregnant and non-pregnant women in the United States, 2021-2022. Int J Infect Dis. 2025 Nov;160:108050. doi: 10.1016/j.ijid.2025.108050. Epub 2025 Sep 5. PMID: 40915347; PMCID: PMC12994916.
• Gaml-Sørensen A, Brix N, Ernst A, Lunddorf LLH, Arah OA, Strandberg-Larsen K, Ramlau-Hansen CH. Pubertal timing and tempo and body mass index trajectories: investigating the confounding role of childhood body mass index. Am J Epidemiol. 2025 Aug 5;194(8):2270-2280. doi: 10.1093/aje/kwaf063. PMID: 40119643; PMCID: PMC12342948.
• Regan AK, Rowe SL, Sullivan SG, Coates MM, Muñoz FM, Arah OA. COVID-19 antiviral medication use among pregnant and recently pregnant US outpatients. Clin Infect Dis. 2025 Mar 17;80(3):512-519. doi: 10.1093/cid/ciae580. PMID: 39907453; PMCID: PMC11912976.
• Rowe SL, Sullivan SG, Muñoz FM, Coates MM, Agnew B, Arah OA, Regan AK. COVID-19 Vaccination during pregnancy and major structural birth defects. Pediatrics. 2025 Apr 1;155(4):e2024069778. doi: 10.1542/peds.2024-069778. PMID: 40081452; PMCID: PMC12139448.
• Regan AK, Sullivan SG, Arah OA. Maternal influenza vaccination and associated risk of fetal loss: a claims-based prospective cohort study. Vaccine. 2024 Dec 2;42(26):126256. doi: 10.1016/j.vaccine.2024.126256. Epub 2024 Sep 10. PMID: 39260053; PMCID: PMC11911014.
• Rieckmann A, Nielsen S, Dworzynski P, Amini H, Mogensen SW, Silva IB, Chang AY, Arah OA, Samek W, Rod NH, Ekstrøm CT, Benn CS, Aaby P, Fisker AB. Discovering subgroups of children with high mortality in urban Guinea-Bissau: exploratory and validation cohort study. JMIR Public Health Surveill. 2024 Apr 9;10:e48060. doi: 10.2196/48060. PMID: 38592761; PMCID: PMC11040440.
• Rod NH, Broadbent A, Rod MH, Russo F, Arah OA, Stronks K. Complexity in epidemiology and public health. Addressing complex health problems through a mix of epidemiologic methods and data. Epidemiology. 2023 Jul 1;34(4):505-514. doi: 10.1097/EDE.0000000000001612. Epub 2023 May 30. PMID: 37042967; PMCID: PMC10712344.
• Xu S, Nianogo RA, Jaga S, Arah OA. Development and validation of a prediction equation for body fat percentage from measured BMI: a supervised machine learning approach. Sci Rep. 2023 May 17;13(1):8010. doi: 10.1038/s41598-023-33914-5. PMID: 37198237; PMCID: PMC10192430.
• Brendel P, Torres A, Arah OA. Simultaneous adjustment of uncontrolled confounding, selection bias and misclassification in multiple-bias modelling. Int J Epidemiol. 2023 Aug 2;52(4):1220-1230. doi: 10.1093/ije/dyad001. PMID: 36718093; PMCID: PMC10893963.
• Cook RR, Foot C, Arah OA, Humphreys K, Rudolph KE, Luo SX, Tsui JI, Levander XA, Korthuis PT. Estimating the impact of stimulant use on initiation of buprenorphine and extended-release naltrexone in two clinical trials and real-world populations. Addict Sci Clin Pract. 2023 Feb 14;18(1):11. doi: 10.1186/s13722-023-00364-3. PMID: 36788634; PMCID: PMC9930351.
• Soohoo M, Arah OA. Investigation of the structure and magnitude of time-varying uncontrolled confounding in simulated cohort data analyzed using g-computation. Int J Epidemiol. 2023 Dec 25;52(6):1907-1913. doi: 10.1093/ije/dyad150. PMID: 37898996; PMCID: PMC10749778.
• Inoue K, Ritz B, Arah OA. Causal effect of chronic pain on mortality through opioid prescriptions: application of the front-door formula. Epidemiology. 2022 Jul 1;33(4):572-580. doi: 10.1097/EDE.0000000000001490. Epub 2022 Apr 5. PMID: 35384895; PMCID: PMC9148671.
• Arah OA. Analyzing selection bias for credible causal inference: when in doubt, DAG it out. Epidemiology. 2019 Jul;30(4):517-520. doi: 10.1097/EDE.0000000000001033. PMID: 31033691; PMCID: PMC6597247.
• Arah OA. Bias analysis for uncontrolled confounding in the health sciences. Annu Rev Public Health. 2017 Mar 20;38:23-38. doi: 10.1146/annurev-publhealth-032315-021644. Epub 2017 Jan 6. PMID: 28125388.
• Wang A, Arah OA. G-computation demonstration in causal mediation analysis. Eur J Epidemiol. 2015 Oct;30(10):1119-27. doi: 10.1007/s10654-015-0100-z. Epub 2015 Nov 4. PMID: 26537707; PMCID: PMC4674449.
• Liew Z, Olsen J, Cui X, Ritz B, Arah OA. Bias from conditioning on live birth in pregnancy cohorts: an illustration based on neurodevelopment in children after prenatal exposure to organic pollutants. Int J Epidemiol. 2015 Feb;44(1):345-54. doi: 10.1093/ije/dyu249. Epub 2015 Jan 19. PMID: 25604449; PMCID: PMC4339763.
• Thompson CA, Arah OA. Selection bias modeling using observed data augmented with imputed record-level probabilities. Ann Epidemiol. 2014 Oct;24(10):747-53. doi: 10.1016/j.annepidem.2014.07.014. Epub 2014 Aug 12. PMID: 25175700; PMCID: PMC4259547.
• Goto A, Arah OA, Goto M, Terauchi Y, Noda M. Severe hypoglycaemia and cardiovascular disease: systematic review and meta-analysis with bias analysis. BMJ. 2013 Jul 29;347:f4533. doi: 10.1136/bmj.f4533. PMID: 23900314.
• Thompson CA, Zhang ZF, Arah OA. Competing risk bias to explain the inverse relationship between smoking and malignant melanoma. Eur J Epidemiol. 2013 Jul;28(7):557-67. doi: 10.1007/s10654-013-9812-0. Epub 2013 May 23. PMID: 23700026; PMCID: PMC3864891.
• Vanderweele TJ, Arah OA. Bias formulas for sensitivity analysis of unmeasured confounding for general outcomes, treatments, and confounders. Epidemiology. 2011 Jan;22(1):42-52. doi: 10.1097/EDE.0b013e3181f74493. PMID: 21052008; PMCID: PMC3073860.
• Arah OA, Sudan M, Olsen J, Kheifets L. Marginal structural models, doubly robust estimation, and bias analysis in perinatal and paediatric epidemiology. Paediatr Perinat Epidemiol. 2013 May;27(3):263-5. doi: 10.1111/ppe.12049. PMID: 23574414; PMCID: PMC4564255.
• Arah OA. On the relationship between individual and population health. Med Health Care Philos. 2009 Aug;12(3):235-44. doi: 10.1007/s11019-008-9173-8. Epub 2008 Dec 24. PMID: 19107577; PMCID: PMC2698967.
• Arah OA, Chiba Y, Greenland S. Bias formulas for external adjustment and sensitivity analysis of unmeasured confounders. Ann Epidemiol. 2008 Aug;18(8):637-46. doi: 10.1016/j.annepidem.2008.04.003. PMID: 18652982.