Sameer Parpia, PhD



I am an Associate Professor, applied biostatistician and clinical trialist in the Department of Oncology and the Department of Health Research Methods, Evidence, & Impact (formerly Clinical Epidemiology & Biostatistics) at McMaster University in Hamilton, Ontario, Canada.

I completed an MSc degree (Biostatistics) in the Department of Epidemiology and Biostatistics at the University of Western Ontario (Western University), and a PhD in Health Research Methods (Biostatistics) in the department of Clinical Epidemiology & Biostatistics at McMaster University.


My research interests and expertise are in applied clinical trial design, conduct, monitoring, statistical analysis and reporting.

I am a lead biostatistician with the Ontario Clinical Oncology Group (OCOG), an academic clinical trials organization that designs and conducts clinical trials in the areas of cancer and thrombosis. For a full list of OCOG studies, please visit OCOG-Trials.

I have collaborated and consulted on numerous projects, including randomized trials, diagnostic studies, pilot and feasibility studies, systematic reviews and meta-analysis, and clinical decision and prediction rules in a variety of clinical areas, such as cancer, venous thromboembolism, surgery, critical care and emergency medicine.


A few selected publications:

DUCHESS: an evaluation of the ductal carcinoma in situ score for decisions on radiotherapy in patients with low/intermediate-risk DCIS.
Rakovitch E, Parpia S, Koch A, Grimard L, Soliman H, Stevens C, Perera F, Kong I, Senthelal S, Anthes M, Wiebe E, Cao J, Goldberg M, Smith S, Spadafora L, Whelan TJ.
Breast Cancer Research & Treatment. 2021. Read More

A simplified decision rule to rule out deep vein thrombosis using clinical assessment and D-dimer.
Xu K, de Wit K, Geersing GJ, Takada T, Schutgens R, Elf J, Kearon C, Parpia S.
Journal of Thrombosis & Haemostasis. 2021. Read More

Clinical pre-test probability adjusted versus age-adjusted D-dimer interpretation strategy for DVT diagnosis: A diagnostic individual patient data meta-analysis
Parpia S, Takach Lapner S, Schutgens R, Elf J, Geersing GJ, Kearon C
Journal of Thrombosis & Haemostasis. 2020. Read More

Diagnosis of Pulmonary Embolism with d-Dimer Adjusted to Clinical Probability.
Kearon C, de Wit K, Parpia S, Schulman S, Afilalo M, Hirsch A, Spencer FA, Sharma S, D’Aragon F, Deshaies JF, Le Gal G, Lazo-Langner A, Wu C, Rudd-Scott L, Bates SM, Julian JA.
New England Journal of Medicine. 2019. Read More

D-dimer testing to select patients with a first unprovoked venous thromboembolism who can stop anticoagulant therapy: a cohort study.
Kearon C, Spencer FA, O’Keeffe D, Parpia S, Schulman S, Baglin T, Stevens SM, Kaatz S, Bauer KA, Douketis JD, Lentz SR, Kessler CM, Moll S, Connors JM, Ginsberg JS, Spadafora L, Julian JA.
Annals of Internal Medicine. 2015. Read More

Interim cosmetic and toxicity results from RAPID: a randomized trial of accelerated partial breast irradiation using three-dimensional conformal external beam radiation therapy.
Olivotto IA, Whelan TJ, Parpia S, Kim DH, Berrang T, Truong PT, Kong I, Cochrane B, Nichol A, Roy I, Germain I, Akra M, Reed M, Fyles A, Trotter T, Perera F, Beckham W, Levine MN, Julian JA.
Journal of Clinical Oncology. 2013. Read More

Long-term results of hypofractionated radiation therapy for breast cancer.
Whelan TJ, Pignol JP, Levine MN, Julian JA, MacKenzie R, Parpia S, Shelley W, Grimard L, Bowen J, Lukka H, Perera F, Fyles A, Schneider K, Gulavita S, Freeman C.
New England Journal of Medicine. 2010. Read More

A full list of my publications can be found on my Zotero page. Similar listings can be found on PubMed or Google Scholar.

Teaching and Student Supervision


I contribute to teaching biostatistics and health research methods in the graduate Health Research Methodology Program (HRM) in the Department of Health Research Methods, Evidence, & Impact at McMaster University. Currently, I contribute to the following courses:

HRM 730 – Introduction to Research Methods for Randomized Controlled Trials
HRM 733 – Statistical and Methodological Issues in Randomized Clinical Trials
HRM 739 – Biostatistical Collaboration
HRM 723 – Regression Analysis
HRM 777 – Methods for Diagnostic and Prognostic Research

Student Supervision

I supervise graduate students (MSc and PhD) in biostatistics and clinical epidemiology through the HRM program as well. For inquiries about student supervision, please contact me using the form below.

Biostatistical Consulting & Collaboration

For collaboration or consultation on research projects, please reach out using the contact form at the bottom of the page.


Statistical and Methodological Blogs – discussion forum for data methodologists, clinical trialists and clinical researchers
Statistical Thinking – Frank Harrell
Statistical Modeling, Causal Inference, and Social Science – Andrew Gelman
The Stats Geek – Jonathan Bartlett
Winton Centre for Risk and Evidence Communication – Winton Centre
Error Statistics Philosophy – Deborah Mayo


Feel free to get in touch with me regarding collaboration, graduate student supervision or statistical consulting.