Table Of ContentScreening
Screening
Evidence and Practice
Angela E. Raffle
Consultant in Public Health, the NHS Screening Programmes
Honorary Senior Lecturer, University of Bristol Medical School:
Population Health Sciences, UK
Anne Mackie
Director of Programmes, UK National Screening Committee
Director of Screening Programmes,
Public Health England, UK
J. A. Muir Gray
Programmes Director, UK National Screening Committee
1996– 2007
Founding Director, the Oxford Centre for Triple Value
Healthcare
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Foreword
I feel privileged to have been asked to write this foreword to the second edition of
Screening: Evidence and Practice, a book that has had a profound effect on the thinking
of all those who are interested in health screening in any discipline and at any level.
I am also very pleased to see Anne Mackie as an author in addition to the original
distinguished duo of Angela Raffle and Muir Gray— her experience and knowledge
of current screening practice is unparalleled, and, in my role as Independent Chair of
the UK National Screening Committee, I have had the great good fortune to watch her
work over the past three years.
Surprisingly, the precise meaning of the term ‘screening’ in health terms has proved
difficult to pin down with precision, but we continue to come back to the criteria
laid down by Wilson and Jungner, and it is very appropriate that this second edition
has been written in the 50th anniversary year of their seminal WHO publication.
As in the first edition, we see how their original concept has stood the test of time,
and throughout the book we are reminded that systematic screening programmes
must be built on the notion that the inevitable harm caused by screening must be
outweighed by benefit. This requires not only robust evidence from well- conducted
research, but also rigorous quality assurance and monitoring of ongoing programmes
to ensure that the outcomes achieved in a research context are reproduced in the
real world.
As a young consultant surgeon working in Nottingham in the 1990s, I saw the effect
of the trial of faecal occult blood screening, then being conducted by Jack Hardcastle,
and it was very motivating to treat patients with screen-d etected disease who were
curable by surgery alone. Seeing the end result of this public health intervention first-
hand awakened my interest in screening, and, to start with, I was a very uncritical en-
thusiast. However, as my understanding of screening deepened, helped enormously by
the first edition of this book, I began to realize just what a complex, challenging, and
endlessly fascinating subject health screening has become.
Perhaps the biggest challenge faced by the screening community has been coming
to terms with the ethical dimensions of what we are doing, and this book does not shy
away from these, often difficult, issues. Working in both public health and in a front-
line clinical discipline it is easy to see screening from two viewpoints, and although it
is vital for systematic screening programmes to benefit the population, we must not
lose sight of the fact that the end- users are individuals, and their rights to making
informed decisions are just as relevant to screening as they are to the treatment of es-
tablished disease.
In my view, and in the view of many others, Screening: Evidence and Practice is es-
sential reading for anyone touched by screening, and that goes way beyond those who
are directly involved in the delivery of screening programmes; it includes any health
vi FOREwORD
professional who may be asked for advice, and, indeed, anyone who is considering
engaging in screening themselves. The new edition is not just a superficial update, it
has been radically revised, and I commend it to all, whether or not they are familiar
with the original.
Professor Bob Steele CBE
Independent Chair, UK National Screening Committee
Preface
All screening programmes do harm. Some do good as well and, of these, some do more
good than harm at reasonable cost. It is the responsibility of policy-m akers, public
health practitioners, managers, and the clinicians involved in screening to ensure that
only programmes that do more good than harm at reasonable cost are implemented
and, when they are implemented, that they are managed in such a way as to achieve a
level of quality which will ensure that the balance of good and harm demonstrated in
research is reproduced in the ordinary service setting. Unfortunately, many screening
services either have been introduced on the basis of inadequate evidence that they
do more good than harm at reasonable cost or, even if introduced on good evidence,
are managed so badly that the efficacy demonstrated in research is not translated into
effectiveness in practice. This results in a waste of resources and in harm to those indi-
viduals who accept the offer of screening.
For 30 years we have been involved in policy- making, and in subsequent imple-
mentation, and management of screening programmes offered to the populations for
which we have been responsible. We have also inherited screening programmes from
the past that were introduced either without an adequate evidence base or without an
adequate management system. This has given us good experience of working our way
out of the mess we inherited, in order to achieve a screening programme that does
more good than harm at reasonable cost.
During this time, we have had the pleasure of working with many public health
practitioners in training, mostly from the UK, but also from a number of other coun-
tries, and the teaching material that we have developed is brought together here into
this book.
This is a ‘how to’ book, focusing on the steps that professionals need to take, both
directly and in consultation with the population they serve, either to improve the pro-
grammes inherited or to ensure that new programmes are based on sound evidence
and then implemented in a way that will ensure that benefits demonstrated in research
are reproduced in practice. The public health practitioner responsible for screening at
a national level usually has to ensure that at least a hundred times as many workers are
identified, trained, motivated and informed as were required for the original study on
which the policy decision was based.
We have also tried to cover the ethical issues involved in screening because we have
found these to be of central importance in our discussions with colleagues, the public
and the media. Screening has one important distinction from clinical practice, namely
that some of the people who suffer the side-e ffects and harms, inherent in all med-
ical technology, do not have and will not get the condition for which screening was
initiated and are therefore harmed without any possibility of benefit. When you treat
viii PREFACE
someone who comes to you with an illness, the patient being treated has at least a pos-
sibility of benefit as well as a risk of harm.
New material for the second edition includes a brand new case study on abdom-
inal aortic aneurysm screening, new information about the improved UK National
Screening Committee Criteria, a carefully researched case study on what was prob-
ably the most difficult screening scandal to date— the events at the National Women’s
Hospital in Auckland, New Zealand, a new section on CONSORT, Cochrane, and
what we mean by ‘sound science’, and additional material on the concept of ‘best
value’ and on the groundbreaking work of W. Edwards Deming. The case studies on
overdiagnosis in breast screening and prostate screening have been updated to take
account of new evidence, and the language, diagrams, and conceptual frameworks
have been strengthened to reflect the continued learning about screening that has oc-
curred since the first edition was published.
This book is dedicated to all those we have worked with to improve screening in
the UK.
J. A. Muir Gray, CBE, DSc, MD, FRCP, FRCPSGlas, FCILIP
Programmes Director, UK National Screening Committee 1996– 2007
Anne Mackie, MB, BS, FFPH
Programmes Director, UK National Screening Committee
Angela E. Raffle, BSc (Hons), MB ChB, FFPH
Consultant to the National Screening Programmes
Endorsements
A readable, yet encyclopaedic guide to screening: its history, its key design elements,
its implementation and its policy challenges. Using case studies and simple figures,
Raffle, Mackie, and Gray illustrate the fundamental balance involved: many must be
tested, so that a few might benefit— while others will invariably be overdiagnosed and
treated needlessly. I was intrigued, in particular, by their delineation of two barriers to
balanced discussions of screening: first, the reassurance illusion— those with a normal
screening exam feel good, even though their risk has changed little; second, the popu-
larity paradox— the more overdiagnosis a screening programme causes, the more
popular it is— as more and more participants believe they owe it their life. A must- read
for clinicians, managers, and policy- makers who would like to assist Raffle, Mackie,
and Gray in achieving their goal: ‘to sort out the mess’.
Professor H. Gilbert Welch
Professor of Medicine
Dartmouth Institute for Health Policy and Clinical Practice
New Hampshire, USA
Important developments have taken place in the ten years since Raffle and Gray’s
highly regarded book Screening; evidence and practice was first published. The great
dangers of inadequately conceptualized, poorly assessed, and chaotically imple-
mented screening have become more widely appreciated. Harms are recognized from
overdiagnosis and overtreatment, from commercial promotion of multiphasic and
other unjustified screening, and sometimes even from misguided government intro-
duction of financially incentivized screening for conditions where no treatment exists.
This welcome second edition of Screening contains new and updated material, and
rigorous emphasis throughout on ‘screening programmes’ rather than ‘screening’ tout
simple. This provides a recurrent and important reminder that a screening programme
for conditions for which there is no beneficial intervention—w hat one epidemiologist
has referred to as ‘identifying dead people early’—w ill only very rarely be justified.
I commend this book for academics as well as practitioners, and for those in clinical
specialties as well as public health.
Sir Iain Chalmers
Editor, James Lind Library
Oxford, UK
It is obvious: detecting and treating disease early before symptoms appear will prevent
complications and prolong life. But Angela Raffle, Anne Mackie, and Muir Gray teach
us otherwise: screening may benefit some but will always harm others. Whether you
should undergo a screening test at your GP practice, or whether your government
should set up a national screening programme, needs careful assessment of the likely
