Snowball in a Blizzard: A Physician's Notes on Uncertainty in Medicine

by Steven Hatch

Overview

There's a running joke among radiologists: finding a tumor in a mammogram is akin to finding a snowball in a blizzard. A bit of medical gallows humor, this simile illustrates the difficulties of finding signals (the snowball) against a background of noise (the blizzard). Doctors are faced with similar difficulties every day when sifting through piles of data from blood tests to X-rays to endless lists of patient symptoms.

Diagnoses are often just educated guesses, and prognoses less certain still. There is a significant amount of uncertainty in the daily practice of medicine, resulting in confusion and potentially deadly complications. Dr. Steven Hatch argues that instead of ignoring this uncertainty, we should embrace it. By digging deeply into a number of rancorous controversies, from breast cancer screening to blood pressure management, Hatch shows us how medicine can fail-sometimes spectacularly-when patients and doctors alike place too much faith in modern medical technology. The key to good health might lie in the ability to recognize the hype created by so many medical reports, sense when to push a physician for more testing, or resist a physician's enthusiasm when unnecessary tests or treatments are being offered.

Both humbling and empowering, Snowball in a Blizzard lays bare the inescapable murkiness that permeates the theory and practice of modern medicine. Essential reading for physicians and patients alike, this book shows how, by recognizing rather than denying that uncertainty, we can all make better health decisions.

Product Details

ISBN-13:	9780465098576
Publisher:	Basic Books
Publication date:	02/23/2016
Sold by:	Hachette Digital, Inc.
Format:	eBook
Pages:	312
File size:	3 MB

About the Author

Steven Hatch is an assistant professor of medicine at the University of Massachusetts Medical School, working in the Division of Infectious Disease and Immunology. He lives in Newton, Massachusetts.

Table of Contents

Author's Note ix

Foreword xiii

Introduction 1

1 Primum Non Nocere: The Motivations and Hazards of Overdiagnosis 23

2 Vignette: The Perils of Predictive Value 53

3 Snowball in a Blizzard 57

4 The Pressures of Managing Pressure 87

5 Lyme's False Prophets: Chronic Fatigue, Tick-Borne Illness, and the Overselling of Certainty 99

6 The Origins of Knowledge and the Seeds of Uncertainty 127

7 The Correlation/Causation Problem, or Why Dark Chocolate May Not Lower Your Risk of Heart Failure 153

8 "Health Watch": Hype, Hysteria, and the Media's Overconfident March of Progress 181

9 Conclusion: The Conversation 211

Acknowledgments 237

Appendix: A Very Nonmathematical Description of Statistical Significance 241

Bibliography 261

Index 275

Editorial Reviews

01/04/2016
In this carefully argued, unsettling, and important work, Hatch, assistant professor of medicine at the University of Massachusetts Medical School, analyzes how doctors deal with diagnostic ambiguity. Early detection should save lives, yet, unnervingly, as diagnostic tests detect more early disease, death rates haven’t declined. Hatch explains sophisticated technology (ultrasound, the PSA blood test, CT scans) that turn up subtle abnormalities, and why interpreting a mammogram, for instance, is difficult. He discusses the aftermath of a 2009 decision by the U.S. Preventative Services Task Force, which concluded that yearly mammograms are often not lifesaving and are sometimes harmful. They recommended that women between the ages of 50 and 74 have one biennially, though older and younger women could skip it. Their recommendation was unanimous, but so was the outrage from both doctors and women who have ignored it, despite subsequent studies that confirm its validity. Using simple math, illustrations, and vivid anecdotes, Hatch explains that “positive” tests may be vague, and that people yearn for treatments to succeed so much that they tend to ignore evidence that casts doubt. Hatch’s book may prove to be a tough sell because its conclusions contradict human impulses, but it is worthwhile reading for both doctors and patients. Agent: Andy Ross, Andy Ross Literary Agency. (Feb.)

Publishers Weekly

"Uncertainty lies at the heart of modern medicine in ways that most physicians—not to mention their patients—often fail to recognize. Fundamental imperfections in our understanding of health and disease limit doctors' ability to combat illness. Hatch, an assistant professor of medicine at the University of Massachusetts Medical School, argues that physicians who ignore this uncertainty often overtreat their patients, resulting in sometimes harmful, even fatal consequences. By the same token, far too many patients assume that more medical care is always better than less, thereby seeking or consenting to toxic treatments that trigger needless suffering. Hatch provides examples from such fields as breast cancer, cardiology and infectious disease. He also offers straightforward rules of thumb to help readers navigate medical advice."—Scientific American

"Informative...Snowball in a Blizzard adds an important perspective...[The book] rightly sounds the alarm: Better communication between doctors and patients is essential to improve medical decision making."—Wall Street Journal

"A penetrating examination of uncertainty in diagnoses and treatment."—Nature

"Snowball in a Blizzard is Hatch's first book, but the clarity and wit of his discussions rank with that of the best science writers."—Shelf Awareness

"This intriguing perspective on the obscurity of medicine...is highly recommended for health-care professionals, health-conscious patients, and well-informed consumer health readers."—Library Journal, starred review

"A carefully argued, unsettling, and important work."—Publishers Weekly

"In writing, Hatch strives to find 'that sweet spot where readability and scholarliness overlap'... he succeeds, telling stories that clarify the points he's making, and he even includes a highly personal anecdote that shows him struggling to deal with doctors who were sure they knew the right treatment for his elderly, hospitalized father... Hatch ably reveals the shortcomings of medicine."—Kirkus Reviews

"I can say with certainty that Steven Hatch's Snowball astutely deconstructs the uncertainty in the practice of medicine—from diagnosis to treatment to media coverage—as well as this important topic has ever been tackled."—Eric Topol, author of The Patient Will See You Now

"What could be more intuitive: that physicians should be humble, admitting the uncertainty of their medical sciences and treating their patients like equals. Would that it were. Although who knows—if enough doctors and patients read Steve Hatch's masterfully-argued Snowball—maybe someday it will be."—Larry Tye, Director of the Boston-based Health Coverage Fellowship and author of New York Times bestseller Satchel

"Hatch's Snowball in a Blizzard is like Carl Sagan's famous 'baloney detection kit' for medical scientific research. How can we figure out which 'discoveries' to trust or to take with a grain of salt? First step: Read this book."—Katrina Firlik, MD, Author of Another Day in the Frontal Lobe: A Brain Surgeon Exposes Life on the Inside

From the Publisher

★ 02/01/2016
Hatch, a medical doctor and assistant professor (medicine, Univ. of Massachusetts Medical Sch.), takes a thought-provoking stand in this work that argues that the medical field isn't defined by simple yes-or-no decisions. The foundation of the text is the spectrum of certainty, a scale correlating benefit and harm based on levels of evidence: the stronger the documentation, the more confidence is applied to the physician's decisions. However, since much of medicine functions somewhere in the middle of the scale, Hatch asserts that many interventions and care measures have little to no evidence, or even contradictory proof. Thus, he argues, the majority of judgements are made within at least some level of uncertainty. Chapters focus on overdiagnosis, overscreening, correlation/causation cautions, issues with health statistics, and the media's role in presenting health news. The well-researched findings are supplemented by personal anecdotes from Hatch's practice. The overall message is that medicine isn't as definitive as society may suppose it to be. VERDICT This intriguing perspective on the obscurity of medicine, similar to Atul Gawande's Being Mortal or Jerome Groopman's How Doctors Think, is highly recommended for health-care professionals, health-conscious patients, and well-informed consumer health readers.—Carolann Curry, Mercer Univ. Lib., Macon, GA

Library Journal

2015-11-18
An exploration of the uncertainty that lies at the heart of Western medicine. Hatch (Medicine/Univ. of Massachusetts Medical School), an infectious disease specialist, seeks to help patients understand the consequences of this uncertainty. He presents a spectrum of uncertainty, ranging from strong evidence supporting a high confidence of benefit through pure speculation all the way to strong evidence supporting a high confidence of harm. His focus is the middle of the spectrum, the known unknowns, where much of medicine functions. The opening chapters deal with uncertainty in diagnosis, which takes the author into a discussion of the debate over screening for prostate cancers and breast cancers—reading a mammogram can be as tricky as looking for a snowball in a blizzard. In the next section, Hatch considers uncertainty in treatment, including controversies over how to treat hypertension and Lyme disease. The author also examines uncertainty in drug trials, how the media deal with uncertainty in their reporting, and how patients can best use their knowledge of these uncertainties. In writing, Hatch strives to find "that sweet spot where readability and scholarliness overlap." Generally, he succeeds, telling stories that clarify the points he's making, and he even includes a highly personal anecdote that shows him struggling to deal with doctors who were sure they knew the right treatment for his elderly, hospitalized father. The illustrations, however, often seem to have been lifted straight from academic papers and add little to the text. A challenging appendix on the concept of statistical significance provides more information on the subject for curious readers. For doctors, Hatch's message is that it is acceptable to say, "I don't know." For patients, he suggests asking lots of questions and remembering that your doctor should be your guide, not your director. Hatch ably reveals the shortcomings of medicine but is less successful in providing guidance for those trying to find their ways through the confusion.

Kirkus Reviews