Frontispiece
Table: A Guide to Unifactorial Statistical Methods
Design or Aim of Study | Type of Data/Assumptions | Statistical Method |
This guide may be used to indicate appropriate statistical methods. It is advisable to read the details of all these tests after consulting this table. |
COMPARE TWO INDEPENDENT SAMPLES |
Compare 2 means | Continuous, Normal distribution, same variance | t test for 2 independent samples |
Compare 2 proportions | Categorical, 2 categories, all expected values greater than 5 | Chi-squared test |
Compare 2 proportions | Categorical, 2 categories, some expected values less than 5 | Fishers exact test |
Compare distributions | Ordinal | Wilcoxon 2-sample signed rank test equivalent to Mann Whitney U test |
Compare time to an event (eg survival) in 2 groups | Continuous | Logrank test |
COMPARE SEVERAL INDEPENDENT SAMPLES |
Compare several means | Continuous, Normal distribution, same variance | One-way analysis of variance |
Compare time to an event (eg survival) in several groups | Continuous | Logrank test |
COMPARE DIFFERENCES IN A PAIRED SAMPLE |
Test mean difference | Continuous, Normal distribution for differences | t test for 2 paired (matched) samples |
Compare 2 paired proportions | Categorical, 2 categories (binary) | McNemars test |
Distribution of differences | Ordinal, symmetric distribution | Wilcoxon matched pairs test |
Distribution of differences | Ordinal | Sign test |
RELATIONSHIPS BETWEEN TWO VARIABLES |
Test strength of linear relationship between 2 variables | Continuous, at least one has Normal distribution | Pearsons correlation |
Test strength of relationship between 2 variables | Ordinal | Spearmans rank correlation, Kendalls tau (if many ties) |
Examine nature of linear relationship between 2 variables | Continuous, residuals from Normal distribution, constant variance | Simple linear regression |
Test association between 2 categorical variables | Categorical, more than 2 categories for either or both variables, at least 80% of expected frequencies greater than 5 | Chi-squared test |
Test for trend in proportions | Categorical, one variable has 2 categories and the other has several categories which are ordered, sample greater than 30 | Chi-squared test for trend |
Oxford Handbook of
Medical Statistics
Published and forthcoming Oxford Handbooks
Oxford Handbook for the Foundation Programme 4e
Oxford Handbook of Acute Medicine 3e
Oxford Handbook of Anaesthesia 4e
Oxford Handbook of Cardiology 2e
Oxford Handbook of Clinical and Healthcare Research
Oxford Handbook of Clinical and Laboratory Investigation 4e
Oxford Handbook of Clinical Dentistry 6e
Oxford Handbook of Clinical Diagnosis 3e
Oxford Handbook of Clinical Examination and Practical Skills 2e
Oxford Handbook of Clinical Haematology 4e
Oxford Handbook of Clinical Immunology and Allergy 3e
Oxford Handbook of Clinical Medicine Mini Edition 9e
Oxford Handbook of Clinical Medicine 10e
Oxford Handbook of Clinical Pathology
Oxford Handbook of Clinical Pharmacy 3e
Oxford Handbook of Clinical Specialties 10e
Oxford Handbook of Clinical Surgery 4e
Oxford Handbook of Complementary Medicine
Oxford Handbook of Critical Care 3e
Oxford Handbook of Dental Patient Care
Oxford Handbook of Dialysis 4e
Oxford Handbook of Emergency Medicine 4e
Oxford Handbook of Endocrinology and Diabetes 3e
Oxford Handbook of ENT and Head and Neck Surgery 2e
Oxford Handbook of Epidemiology for Clinicians
Oxford Handbook of Expedition and Wilderness Medicine 2e
Oxford Handbook of Forensic Medicine
Oxford Handbook of Gastroenterology & Hepatology 2e
Oxford Handbook of General Practice 4e
Oxford Handbook of Genetics
Oxford Handbook of Genitourinary Medicine, HIV, and Sexual Health 2e
Oxford Handbook of Geriatric Medicine 3e
Oxford Handbook of Infectious Diseases and Microbiology 2e
Oxford Handbook of Integrated Dental Biosciences 2e
Oxford Handbook of Humanitarian Medicine
Oxford Handbook of Key Clinical Evidence 2e
Oxford Handbook of Medical Dermatology 2e
Oxford Handbook of Medical Imaging
Oxford Handbook of Medical Sciences 2e
Oxford Handbook for Medical School
Oxford Handbook of Medical Statistics
Oxford Handbook of Neonatology 2e
Oxford Handbook of Nephrology and Hypertension 2e
Oxford Handbook of Neurology 2e
Oxford Handbook of Nutrition and Dietetics 2e
Oxford Handbook of Obstetrics and Gynaecology 3e
Oxford Handbook of Occupational Health 2e
Oxford Handbook of Oncology 3e
Oxford Handbook of Operative Surgery 3e
Oxford Handbook of Ophthalmology 4e
Oxford Handbook of Oral and Maxillofacial Surgery 2e
Oxford Handbook of Orthopaedics and Trauma
Oxford Handbook of Paediatrics 2e
Oxford Handbook of Pain Management
Oxford Handbook of Palliative Care 3e
Oxford Handbook of Practical Drug Therapy 2e
Oxford Handbook of Pre-Hospital Care
Oxford Handbook of Psychiatry 3e
Oxford Handbook of Public Health Practice 3e
Oxford Handbook of Rehabilitation Medicine 3e
Oxford Handbook of Reproductive Medicine & Family Planning 2e
Oxford Handbook of Respiratory Medicine 3e
Oxford Handbook of Rheumatology 4e
Oxford Handbook of Sport and Exercise Medicine 2e
Handbook of Surgical Consent
Oxford Handbook of Tropical Medicine 4e
Oxford Handbook of Urology 4e
Great Clarendon Street, Oxford, OX2 6DP,
United Kingdom
Oxford University Press is a department of the University of Oxford.
It furthers the Universitys objective of excellence in research, scholarship, and education by publishing worldwide. Oxford is a registered trade mark of Oxford University Press in the UK and in certain other countries
Oxford University Press 2020
The moral rights of the authors have been asserted
First Edition published in 2011
Second Edition published in 2020
Impression: 1
All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, without the prior permission in writing of Oxford University Press, or as expressly permitted by law, by licence or under terms agreed with the appropriate reprographics rights organization. Enquiries concerning reproduction outside the scope of the above should be sent to the Rights Department, Oxford University Press, at the address above
You must not circulate this work in any other form and you must impose this same condition on any acquirer
Published in the United States of America by Oxford University Press
198 Madison Avenue, New York, NY 10016, United States of America
British Library Cataloguing in Publication Data
Data available
Library of Congress Control Number: 2019953209