confounding variable

The Book of Why: The New Science of Cause and Effect

by Judea Pearl and Dana Mackenzie  · 1 Mar 2018

. If we do have measurements of the third variable, then it is very easy to deconfound the true and spurious effects. For instance, if the confounding variable Z is age, we compare the treatment and control groups in every age group separately. We can then take an average of the effects, weighting

…

have to control for A and B or for C; but C is an unobservable and therefore uncontrollable variable. In addition we have four new confounding variables: D = parental asthma, E = chronic bronchitis, F = sex, and G = socioeconomic status. The reader might enjoy figuring out that we must control for E, F

…

the participants. Unfortunately, we cannot collect data on the Smoking Gene because we do not know whether such a gene exists. Lacking data on the confounding variable, we cannot block the back-door path Smoking Smoking Gene Cancer. Thus we cannot use back-door adjustment to control for the effect of the

…

outcome variable Yx. It requires that Yx be independent of the treatment actually received, namely X, given the values of a certain set of (de)confounding variables Z. Before exploring its interpretation, we should acknowledge that any assumption expressed as conditional independence inherits a large body of familiar mathematical machinery developed by

…

, who included R. A. Fisher and Jacob Yerushalmy, argued that the apparent link between smoking and cancer might be a statistical artifact due to a confounding variable. Yerushalmy thought in terms of a smoking personality type, while Fisher suggested the possibility of a gene that would predispose people both toward smoking and

Doing Data Science: Straight Talk From the Frontline

by Cathy O'Neil and Rachel Schutt  · 8 Oct 2013  · 523pp  · 112,185 words

Practice? In spite of the raised objections, experts in this field essentially use stratification as a major method to working through studies. They deal with confounding variables, or rather variables they deem potentially confounding, by stratifying with respect to them or make other sorts of model-based adjustments, such as propensity score

Statistics in a Nutshell

by Sarah Boslaugh  · 10 Nov 2012

of them. More than one variable can be involved in confounding, but for the sake of simplicity, we demonstrate methods to deal with a single confounding variable. Researchers in epidemiology need to be alert to the potential for confounding in their data, particularly in observational studies when group membership is not under

…

match the cases already enrolled in the study. There are different systems for matching, but the basic concept is that categories are constructed for the confounding variables, and assignment to groups is controlled so that the distribution of the confounders is the same in each group. There are two ways to implement

…

confounding is the use of stratified analysis, in which the groups to be studied are divided into strata or subgroups based on values of the confounding variable. Stratification by age category is a common example. As discussed in the section earlier on standardized rates, the populations of different countries have different age

…

increases. This distinction would be missed if only crude mortality rates were considered but becomes clear when a stratified analysis removes the influence of the confounding variable (age) from the outcome (mortality). There is no absolute test for confounding, but there are ways to examine the effects of potential confounders on the

…

to follow in assessing confounding are as follows: Calculate the crude measure of association, ignoring the confounding variable. Stratify the study population by the confounding variable, that is, divide the population into smaller subgroups based on values of the confounding variable. Calculate an adjusted measure of association. Compare the crude and adjusted measures; a difference of

…

the same (or even if they were of the same general form). Third, there is no way the researchers can be sure that some other confounding variable was not responsible for the result because there was no experimental control in the overall process; for example, there could be some physiological response to

…

nominal data. Cohort A group of people having a time-related factor in common (for instance, being born in 1950 or entering college in 2000). Confounding variable In research design, a variable that correlates with both the independent and dependent variables and is not in the causal pathway between them. Construct validity

…

Repeated Measures t-Test confounding, Confounding, Stratified Analysis, and the Mantel-Haenszel Common Odds Ratio–Confounding, Stratified Analysis, and the Mantel-Haenszel Common Odds Ratio confounding variable, Glossary of Statistical Terms Conover, William, Practical Nonparametric Statistics, Nonparametric Statistics consistency measurements, Measures of Internal Consistency construct validity, Glossary of Statistical Terms Consumer Price

Food Allergy: Adverse Reactions to Foods and Food Additives

by Dean D. Metcalfe  · 15 Dec 2008  · 623pp  · 448,848 words

, there were notable problems in this study, including 16 of the 36 subjects who did not complete the study (44% dropout) and poor control of confounding variables such as environmental factors and other triggers of AD. Neild et al. [39] studied 53 subjects with AD in another trial using a similar design

…

data based on a variety of methods that may not be directly comparable (e.g. mean wheal diameter versus largest diameter). Despite the numerous potential confounding variables involved in the PST procedure, the clinical utility is excellent. Technical issues that can impact PST sensitivity are summarized in Table 20.2. Diagnostic value

…

(asthma, atopy, rhinitis, and eczema) at least for the first 8 years of life in the prophylactic group. Repeated measurement analysis, adjusted for all relevant confounding variables, confirmed a preventive effect on asthma, AD, rhinitis, and atopy. The protective effects were primarily observed in the subgroup of children with persistent disease (symptoms

The Art of Statistics: Learning From Data

by David Spiegelhalter  · 14 Oct 2019  · 442pp  · 94,734 words

entered into the regression included age at diagnosis, calendar year, region of Sweden, marital status and income, all of which were considered to be potential confounding variables. This adjustment for confounders is an attempt to tease out a purer relationship between education and brain tumours, but it can never be wholly adequate

…

two, and not be misled into thinking that noise is actually a signal. Simpson’s paradox: when an apparent relationship reverses its sign when a confounding variable is taken into account. size of a test: the Type I error rate of a statistical test, generally denoted by α. skewed distribution: when a

The Art of Statistics: How to Learn From Data

by David Spiegelhalter  · 2 Sep 2019  · 404pp  · 92,713 words

entered into the regression included age at diagnosis, calendar year, region of Sweden, marital status and income, all of which were considered to be potential confounding variables. This adjustment for confounders is an attempt to tease out a purer relationship between education and brain tumours, but it can never be wholly adequate

…

two, and not be misled into thinking that noise is actually a signal. Simpson’s paradox: when an apparent relationship reverses its sign when a confounding variable is taken into account. size of a test: the Type I error rate of a statistical test, generally denoted by α. skewed distribution: when a

How Medicine Works and When It Doesn't: Learning Who to Trust to Get and Stay Healthy

by F. Perry Wilson  · 24 Jan 2023  · 286pp  · 92,521 words

more people are outside, leading to more confrontations). We say that outdoor temperature confounds the observed association between ice cream sales and murder rates. A confounding variable is one that is linked to the exposure of interest and the outcome of interest, and thus induces the illusion of causation between the exposure

…

promote poor vision. In fact, there was no causal relationship between leaving the light on and poor vision. Future studies found that there was a confounding variable—parental nearsightedness—that wasn’t accounted for. It turns out that parents who are nearsighted are more likely to have kids who are nearsighted. Parents

…

correlations so strong in the first place? In the case of vitamin D levels, we are (once again, and as usual) in the realm of confounding variables. I have often referred to vitamin D levels as the “lifestyle” biomarker. Let’s think of some behaviors that raise your vitamin D level: getting

Small Wars, Big Data: The Information Revolution in Modern Conflict

by Eli Berman, Joseph H. Felter, Jacob N. Shapiro and Vestal Mcintyre  · 12 May 2018  · 517pp  · 147,591 words

food aid related to violence only through its effect on conflict, as opposed to food aid that occurred because of violence or because of some confounding variable, such as poor governance, that resulted in both violence and food aid. (In the Philippine CCT example, randomization ensured that exogeneity.) Nunn and Qian found

…

to strategic losses” (3). Those reports do not pass the causal identification test: the findings of opinion polls, for example, did not control for possible confounding variables, such as response bias. However, it is important and reassuring that military thinkers and practitioners drawing on qualitative evidence come to the same conclusion. 35

How to Read Numbers: A Guide to Statistics in the News (And Knowing When to Trust Them)

by Tom Chivers and David Chivers  · 18 Mar 2021  · 172pp  · 51,837 words

things – in this case, vaping and marijuana use – are strongly correlated: is there something else that correlates with both? This something else is called a ‘confounding variable’. In case you’re not quite following, here’s an example. The proportion of deaths linked to obesity worldwide by year correlates with the amount

…

, it’s easy to imagine how that might be the case – and if it is, then it will interfere with your measurement just like a confounding variable. So how can you tell the direction that the causal arrow is pointing? A → B, or B → A, or a loop? One way is to

…

creating imaginary relationships out of nothing: it can even make things look like the opposite of reality. We spoke in Chapter 7 about controlling for confounding variables. Let’s imagine that you’re conducting a study looking at how fast people can run. You notice something: on average, the more grey hairs

…

below. But even though they’re correlated, both are in fact influenced by a third factor, age, as shown by the white arrows. Controlling for confounding variables is necessary, and good statistical practice. But that doesn’t mean you should just control for as many variables as you can, assuming they’re

…

isn’t caused by only looking at a specific group (Hollywood actors). Instead, it’s caused by the researcher thinking they are controlling for a confounding variable, to reduce bias – but in fact they’ve added in a collider variable and accidentally created bias. A collider like this is the opposite of

The Elements of Data Analytic Style

by Jeff Leek  · 1 Mar 2015  · 50pp  · 13,399 words

literacy and shoe size and is a confounder for that relationship. When you observe a correlation or relationship in a data set, consider the potential confounders - variables associated with both variables you are trying to relate. 6.5 Check the distribution of missing data Determine whether missing values are associated with any

The World of Caffeine: The Science and Culture of the World's Most Popular Drug

by Bennett Alan Weinberg and Bonnie K. Bealer  · 5 Dec 2000  · 559pp  · 174,054 words

Thinking with Data

by Max Shron  · 15 Aug 2014

The Better Angels of Our Nature: Why Violence Has Declined

by Steven Pinker  · 24 Sep 2012  · 1,351pp  · 385,579 words

The Pot Book: A Complete Guide to Cannabis

by Julie Holland  · 22 Sep 2010  · 694pp  · 197,804 words

The Big Fat Surprise: Why Butter, Meat and Cheese Belong in a Healthy Diet

by Nina Teicholz  · 12 May 2014  · 743pp  · 189,512 words

Theory and Practice of Group Psychotherapy

by Irvin D. Yalom and Molyn Leszcz  · 1 Jan 1967

Mindware: Tools for Smart Thinking

by Richard E. Nisbett  · 17 Aug 2015  · 397pp  · 109,631 words

I Think You'll Find It's a Bit More Complicated Than That

by Ben Goldacre  · 22 Oct 2014  · 467pp  · 116,094 words

Ashes to Ashes: America's Hundred-Year Cigarette War, the Public Health, and the Unabashed Triumph of Philip Morris

by Richard Kluger  · 1 Jan 1996  · 1,157pp  · 379,558 words

Enlightenment Now: The Case for Reason, Science, Humanism, and Progress

by Steven Pinker  · 13 Feb 2018  · 1,034pp  · 241,773 words

Bad Science

by Ben Goldacre  · 1 Jan 2008  · 322pp  · 107,576 words

Data Science from Scratch: First Principles with Python

by Joel Grus  · 13 Apr 2015  · 579pp  · 76,657 words

The End of Illness

by David B. Agus  · 15 Oct 2012  · 433pp  · 106,048 words

How to Read a Paper: The Basics of Evidence-Based Medicine

by Trisha Greenhalgh  · 18 Nov 2010  · 321pp  · 97,661 words

Covid by Numbers

by David Spiegelhalter and Anthony Masters  · 28 Oct 2021

Alchemy: The Dark Art and Curious Science of Creating Magic in Brands, Business, and Life

by Rory Sutherland  · 6 May 2019  · 401pp  · 93,256 words

The 4-Hour Body: An Uncommon Guide to Rapid Fat-Loss, Incredible Sex, and Becoming Superhuman

by Timothy Ferriss  · 1 Dec 2010  · 836pp  · 158,284 words

Are We Getting Smarter?: Rising IQ in the Twenty-First Century

by James R. Flynn  · 5 Sep 2012

Free Money for All: A Basic Income Guarantee Solution for the Twenty-First Century

by Mark Walker  · 29 Nov 2015

Virtual Competition

by Ariel Ezrachi and Maurice E. Stucke  · 30 Nov 2016

Democracy and Prosperity: Reinventing Capitalism Through a Turbulent Century

by Torben Iversen and David Soskice  · 5 Feb 2019  · 550pp  · 124,073 words

Sleepyhead: Narcolepsy, Neuroscience and the Search for a Good Night

by Henry Nicholls  · 1 Mar 2018  · 367pp  · 102,188 words

The Diet Myth: Why America's Obsessions With Weight Is Hazardous to Your Health

by Paul Campos  · 4 May 2005

The death and life of the great American school system: how testing and choice are undermining education

by Diane Ravitch  · 2 Mar 2010  · 403pp  · 105,431 words

Our Kids: The American Dream in Crisis

by Robert D. Putnam  · 10 Mar 2015  · 459pp  · 123,220 words

The Great Leveler: Violence and the History of Inequality From the Stone Age to the Twenty-First Century

by Walter Scheidel  · 17 Jan 2017  · 775pp  · 208,604 words

Longevity: To the Limits and Beyond (Research and Perspectives in Longevity)

by Jean-Marie Robine, James W. Vaupel, Bernard Jeune and Michel Allard  · 2 Jan 1997

The Numbers Game: The Commonsense Guide to Understanding Numbers in the News,in Politics, and inLife

by Michael Blastland and Andrew Dilnot  · 26 Dec 2008  · 219pp  · 65,532 words

Adaptive Markets: Financial Evolution at the Speed of Thought

by Andrew W. Lo  · 3 Apr 2017  · 733pp  · 179,391 words

Back to School: Why Everyone Deserves a Second Chance at Education

by Mike Rose  · 17 Sep 2012  · 225pp  · 55,458 words

Testosterone Rex: Myths of Sex, Science, and Society

by Cordelia Fine  · 13 Jan 2017  · 312pp  · 83,998 words

The Great Stagnation

by Tyler Cowen  · 24 Jan 2011  · 76pp  · 20,238 words

Why We Drive: Toward a Philosophy of the Open Road

by Matthew B. Crawford  · 8 Jun 2020  · 386pp  · 113,709 words

The 4-Hour Chef: The Simple Path to Cooking Like a Pro, Learning Anything, and Living the Good Life

by Timothy Ferriss  · 1 Jan 2012  · 1,007pp  · 181,911 words

Safe Food: The Politics of Food Safety

by Marion Nestle  · 1 Jan 2010  · 736pp  · 147,021 words

A Mathematician Plays the Stock Market

by John Allen Paulos  · 1 Jan 2003  · 295pp  · 66,824 words

The Biggest Bluff: How I Learned to Pay Attention, Master Myself, and Win

by Maria Konnikova  · 22 Jun 2020  · 377pp  · 117,339 words

Know Thyself

by Stephen M Fleming  · 27 Apr 2021

California Burning: The Fall of Pacific Gas and Electric--And What It Means for America's Power Grid

by Katherine Blunt  · 29 Aug 2022  · 470pp  · 107,074 words

May Contain Lies: How Stories, Statistics, and Studies Exploit Our Biases—And What We Can Do About It

by Alex Edmans  · 13 May 2024  · 315pp  · 87,035 words

Reset

by Ronald J. Deibert  · 14 Aug 2020

Wool Omnibus Edition

by Hugh Howey  · 5 Jun 2012

The No Need to Diet Book: Become a Diet Rebel and Make Friends With Food

by Plantbased Pixie  · 7 Mar 2019  · 299pp  · 81,377 words

Potatoes not Prozac

by Kathleen DesMaisons, Ph. D.  · 265pp  · 75,669 words

Arbitrary Lines: How Zoning Broke the American City and How to Fix It

by M. Nolan Gray  · 20 Jun 2022  · 252pp  · 66,183 words

Rich White Men: What It Takes to Uproot the Old Boys' Club and Transform America

by Garrett Neiman  · 19 Jun 2023  · 386pp  · 112,064 words

What’s Your Type?

by Merve Emre  · 16 Aug 2018  · 384pp  · 112,971 words