Screening in Disease Prevention

What Works?

Walter W Holland, Susie Stewart

• Publisher: CRC Press
• Year: 2018
• ISBN:
  9781315345758
• Edition: 1
• Topic: Medicina
• Subtopic: Teoría, práctica y referencia médicas

Screening for disease has become a widely accepted concept in health care. Screening in Disease Prevention takes a critical look at the practice of screening throughout the various stages of life. The book highlights three current challenges: the increasing consumer, media and commercial focus on health in general and screening in particular; providing accurate and understandable information; and tackling the continuing variation in the uptake of screening between different areas of the country and different socio-economic groups. Screening in Disease Prevention is important reading for public health professionals, particularly those involved in screening programs. Policy makers and shapers, medical researchers, pressure groups and support organizations for people with screenable conditions will also find it a valuable reference.

Chapter 1

Historical background, current
definitions and criteria

Complete freedom from disease is almost incompatible with the process of living.^*

Introduction

The practice of screening in healthcare – that is, actively seeking to identify a disease or pre-disease condition in people who are presumed and presume themselves to be healthy – is one that grew rapidly during the twentieth century and now has wide acceptance in our society. In looking back over the years since our previous book on screening was published,¹ it is perhaps surprising how little appears to have changed in the provision of screening services or in the knowledge base of screening in the UK. Organisation and audit of existing programmes have undoubtedly improved and, importantly, there is now a UK National Screening Committee which acts as a central reference point for screening throughout the country. With the exception of genetic screening, where the possibilities have multiplied exponentially – although, as we shall show, there are major ethical and implementation issues in this area – we still have broadly the same programmes and services. What has changed, however, is the public perception and expectations of screening, the focus of media attention on health in general and screening in particular, and an increasing recognition, especially among health professionals, that screening can be harmful as well as helpful.

In this chapter we shall look at the historical background to screening, including the establishment of the National Screening Committee, restate acceptable definitions of the process, revisit the criteria that must be fulfilled before screening is introduced and consider briefly some political issues and public perceptions.

Historical background

The benefits of screening were first demonstrated by the use of mass miniature radiography (MMR) for the identification of individuals with tuberculosis. With the introduction of effective treatment for this condition after the end of the Second World War, the use of MMR became widespread in many western countries, particularly the USA and the UK.

In the late 1950s and early 1960s, special campaigns of mass radiography were used to good effect in Scotland – first in Glasgow and then throughout the country – to try and find the unknown and infectious sufferers from tuberculosis.² Andrew Semple, Medical Officer of Health in Liverpool from 1953 to 1974, set up a very successful MMR campaign in that city during which more than 80% of the adult population were screened. In 1953 he had noted that tuberculosis remained an intractable problem, with Liverpool having the highest rates in the country apart from Glasgow. By 1960, Semple was able to report a large reduction in cases, resulting from the campaign, and by 1966 it was possible to close the Central Chest Clinic.³

Other Medical Officers of Health, such as Robert Parry and Robert Wofinden with the William Budd Centre in Bristol, had developed the imaginative new concept of the health centre.⁴ These centres were intended to provide ‘lifetime’ preventive care and to develop screening services. Integrated care and screening for pregnant women from the antenatal period through birth in hospital or at home to care in the postnatal period were beginning in a few places, as were more co-ordinated care and surveillance for the elderly, the chronic sick and the mentally ill.

With the reduction in the burden of tuberculosis, the concept of screening began to be considered equally applicable to the control of other chronic diseases. This was shown in particular in the USA, where a law on the control of chronic diseases was passed in the late 1950s. A major review of screening in chronic disease was published in the Journal of Chronic Disease in 1955.⁵ One of the review’s editors, Lester Breslow – Head of the Division of Chronic Disease in the California State Health Department at the time – was a keen advocate of screening in this context. The Commission on Chronic Illness was founded in 1957 and started to publish copiously.⁶

In 1961, Thorner and Remein of the United States Public Health Service published the first comprehensive review of the principles of screening. Its evaluation still remains relevant.⁷

The initial push for screening was particularly evident in North America. One of the first examples of this was the enthusiastic introduction of screening for cancer of the cervix in British Columbia and California. This was reviewed critically by Ahluwalia and Doll,⁸ who did not consider that screening was justified on the basis of this experience.

One of the most ardent advocates of screening at this time was Morris Collen, Medical Director of the Kaiser Permanente Health Maintenance Organisation, who was interviewed 20 years later in connection with a history of the programme.⁹

Collen considered that regular screening of adults for a variety of conditions could reduce the costs and utilisation of medical services. As a result, regular screening – or preventive medical examination as it was described – was introduced as a component of subscribing to the Kaiser Permanente HMO, despite the inability to demonstrate clear benefits.

In the UK, possibly because of fewer financial resources for health, screening lagged behind. However, Sir George Godber, the Chief Medical Officer from 1960 to 1973, quickly recognised that screening was an important possible method of delivering preventive healthcare.¹⁰ He therefore despatched Dr JMG Wilson, a senior medical officer in the Ministry of Health, to North America to review and learn about the possibilities and problems. Wilson developed his views and these were later written up with Jungner, a Swedish biochemist, and published as a World Health Organization monograph. This remains a landmark contribution to the field of screening.¹¹

The ‘women’s movement’ was also growing at this time, with a particular focus on women’s health. As a result of the North American experience and the hope that cervical cytology could prevent cancer of the cervix, demand for a national screening programme began to make itself felt. With the development of family planning and women’s health services, cervical smears began to be taken increasingly. The ease of performing these smears meant that they were very popular, and there was little concern at this stage about the effectiveness of the procedure or the need for it. Pathology services, particularly cytology, became overwhelmed with the large number of smears needing examination. At that time, most specimen reporting was carried out by medically qualified pathologists. As a result, other aspects of pathology work, such as post-mortems, were neglected. It has been suggested that the demand for cervical cytology in the 1960s was responsible for the great diminution in the number of post-mortem investigations, which had hitherto been more or less routine.

Stimulated by Wilson, the Ministry of Health and various other groups began to consider the implications of screening as a part of healthcare. The Nuffield Provincial Hospitals Trust, for example, convened a Working Party under the chairmanship of Professor T McKeown, which published its findings in 1968.¹²

That group reached two main conclusions. First, evaluation of ten screening procedures showed that, in six of these, evidence was severely deficient with regard to one or more of the following elements: the natural history of the disease; methods of diagnosis and treatment; operational problems; assessment of benefits and costs.

Secondly, examination of screening procedures in Britain suggested that the existing research and administrative framework for screening should be strengthened. Developments appeared to be needed in three main areas:

1. sharper definition of the requirements of screening and of the state of evidence concerning current programmes
2. promotion of those types of research (large-scale, prolonged, applied and economic) that were not readily accommodated within the present framework
3. meticulous attention to the introduction and development of screening programmes to ensure that they were reliable and co-ordinated within the whole range of health services.

Screening was now at the forefront of the health agenda.

That same year the Ministry of Health had created a Joint Standing Sub-Committee on Screening in Medical Care with the remit of reviewing the evidence for any screening programme and making recommendations on what needed to be done before a programme could be introduced into the National Health Service – the lessons of the problems created by the unmanaged introduction of cervical screening seemed to have been learned. This committee was a subcommittee of the Standing Medical Advisory Committee (SMAC) and thus its authority was limited. Its terms of reference were as follows:

1. to review the field of diagnostic screening of the population for disease
2. to identify areas of needed research (co-operating where indicated with other Departmental Advisory Committees)
3. to consider the implications for resources
4. to advise the Standing Medical Advisory Committees of the Secretary of State for Social Services and the Secretary of State for Scotland (Scottish Health Services Planning Council) on the justification for and operation of screening services.

The first meeting was held in January 1969 and the sub-committee continued until September 1980, when no further meeting was scheduled ‘pending SMAC’s consideration of the future of the Sub-Committee.’

The National Screening Committee

There was then a planning gap on screening until the United Kingdom National Screening Committee (NSC) was established in 1996 and an effective mechanism was set up – covering the four countries of the UK – both to influence the implementation of effective programmes and to identify areas for further research.

The remit and terms of reference of the NSC are as follows.

1. The UK National Screening Committee will advise Ministers, the devolved national assemblies and the Scottish Parliament on:
   • the case for implementing new population screening programmes not presently purchased by the NHS within each of the countries of the UK
   • screening technologies that are of proven effectiveness but which require controlled and well-managed introduction
   • the case for continuing, modifying or withdrawing existing population screening programmes, in particular programmes that have been inadequately evaluated or which are of doubtful effectiveness, quality or value.
2. The NSC will call on sound evidence to inform its advice and recommend...

Table of contents

• Cover
• Title Page
• Copyright Page
• Contents
• About the authors
• The Nuffield Trust
• List of Trustees
• Acknowledgements
• 1 Historical background, current definitions and criteria
• 2 Key issues in screening: genetics, information and economics
• 3 Key issues in screening: ethics and audit
• 4 Antenatal and neonatal screening
• 5 Screening and surveillance in childhood and adolescence
• 6 Screening in adults
• 7 Screening in the elderly
• 8 Screening practices in Europe
• 9 Overview and recommendations