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Todd A MacKenzie, PhD

Professor of Biomedical Data Science
Professor of Medicine
Professor of The Dartmouth Institute

Biomedical Data Science
The Dartmouth Institute

PhD (Statistics), McGill University, 1997
MSc (Statistics), McGill University, 1993
BSc, Dalhousie University, 1990

Norris Cotton Cancer Center
Quantitative Biomedical Sciences
The Dartmouth Institute for Health Policy and Clinical Practice


Contact Information

Section of Clinical Research, HB 7505
One Medical Center Drive
Dartmouth Hitchcock Medical Center
Lebanon NH 03756

Phone: 603-653-3542
Fax: 603-653-3554

Professional Interests

I use statistics to facilitate clinical and health services research across a spectrum of disciplines and specialties. This work has been reported in over 280 publications. The majority of these projects involve comparative effectiveness, clinical trials, association studies, and prediction modeling. I am especially interested in survival (aka, time-to-event) analysis, and causal inference. Recently I have been studying the association of government spending with reduced mortality in order to help explain the stagnation of American longevity.

Courses Taught

QBS 121: Biostatistics II; a course in statistical modelling (Winter) with Tor Tosteson

QBS Biostatistics Consulting

Past Teaching:
PH 271 (TDI) "Practice of Statistics in Medicine" with James O'Malley: This course was aimed at junior faculty, post-doctoral fellows and PhD students.

PH 147 (TDI) "Advanced Methods in Health Services Research" with Tracy Onega

PEMM 107 "Biostatistics" : A course in biostatistics I developed for bench and translational scientists in molecular medicine.

Selected Publications


Clip closure does not reduce risk of bleeding after resection of large serrated polyps: results from a randomized trial.
Crockett SD, Khashab M, Rex DK, Grimm IS, Moyer MT, Rastogi A, Mackenzie TA, Pohl H, Large Polyp Study Group Consortium.
Clin Gastroenterol Hepatol. 2021 Dec 28; pii: S1542-3565(21)01360-4. doi: 10.1016/j.cgh.2021.12.036. Epub 2021 Dec 28.
PMID: 34971811

Long-Term Medicare Costs Associated With Opioid Analgesic Therapy vs Spinal Manipulative Therapy for Chronic Low Back Pain in a Cohort of Older Adults.
Whedon JM, Kizhakkeveettil A, Toler A, MacKenzie TA, Lurie JD, Bezdjian S, Haldeman S, Hurwitz E, Coulter I
J Manipulative Physiol Ther. 2021 Dec 5; pii: S0161-4754(21)00106-8. doi: 10.1016/j.jmpt.2021.09.001. Epub 2021 Dec 5.
PMID: 34876298

Using Satellite Images and Deep Learning to Identify Associations Between County-Level Mortality and Residential Neighborhood Features Proximal to Schools: A Cross-Sectional Study.
Levy JJ, Lebeaux RM, Hoen AG, Christensen BC, Vaickus LJ, MacKenzie TA
Front Public Health. 2021;9:766707. doi: 10.3389/fpubh.2021.766707. Epub 2021 Nov 5.
PMID: 34805078

Evaluation of an Artificial Intelligence-Augmented Digital System for Histologic Classification of Colorectal Polyps.
Nasir-Moin M, Suriawinata AA, Ren B, Liu X, Robertson DJ, Bagchi S, Tomita N, Wei JW, MacKenzie TA, Rees JR, Hassanpour S
JAMA Netw Open. 2021 Nov 1;4(11):e2135271. doi: 10.1001/jamanetworkopen.2021.35271. Epub 2021 Nov 1.
PMID: 34792588

Improvement of sepsis identification through multi-year comparison of sepsis and early warning scores.
McGrath SP, Perreard I, MacKenzie T, Calderwood M
Am J Emerg Med. 2022 Jan;51:239-247. doi: 10.1016/j.ajem.2021.10.046. Epub 2021 Nov 5.
PMID: 34775198

Incident Impaired Cognitive Function in Sarcopenic Obesity: Data From the National Health and Aging Trends Survey.
Batsis JA, Haudenschild C, Roth RM, Gooding TL, Roderka MN, Masterson T, Brand J, Lohman MC, Mackenzie TA
J Am Med Dir Assoc. 2020 Oct 21; pii: S1525-8610(20)30790-8. doi: 10.1016/j.jamda.2020.09.008. Epub 2020 Oct 21.
PMID: 34756360

Mendelian randomization in the multivariate general linear model framework.
Allman PH, Aban I, Long DM, Patki A, MacKenzie T, Irvin MR, Lange LA, Lange E, Cutter G, Tiwari HK
Genet Epidemiol. 2021 Oct 21; doi: 10.1002/gepi.22435. Epub 2021 Oct 21.
PMID: 34672390

Initial Choice of Spinal Manipulation Reduces Escalation of Care for Chronic Low Back Pain Among Older Medicare Beneficiaries.
Whedon JM, Kizhakkeveettil A, Toler AW, Bezdjian S, Rossi D, Uptmor S, MacKenzie TA, Lurie JD, Hurwitz EL, Coulter I, Haldeman S
Spine (Phila Pa 1976). 2022 Feb 15;47(4):E142-E148. doi: 10.1097/BRS.0000000000004118.
PMID: 34474443

Improving the prediction of long-term readmission and mortality using a novel biomarker panel.
Brown JR, M Parker D, Stabler ME, Jacobs ML, Jacobs JP, Everett AD, Lobdell KW, Wyler von Ballmoos MC, Thiessen-Philbrook H, Parikh C, Mackenzie T, DiScipio A, Malenka D, Matheny ME, Turchin A, Likosky DS
J Card Surg. 2021 Nov;36(11):4213-4223. doi: 10.1111/jocs.15954. Epub 2021 Sep 2.
PMID: 34472654

A robust hazard ratio for general modeling of survival-times.
Martinez-Camblor P, MacKenzie TA, O'Malley AJ
Int J Biostat. 2021 Aug 23; doi: 10.1515/ijb-2021-0003. Epub 2021 Aug 23.
PMID: 34428365

View more publications on PubMed