Screening: Evidence and practice

Screening is the routine testing of populations to identify individuals who may have a particular medical condition or disease. It is carried out by both government and private organisations with the aims of: better prognosis/outcome for individuals; to protect society from contagious disease; to allow rational allocation of resources; to allow selection of healthy individuals; and for research purposes. About £500 million is spent on screening each year in Britain alone, and it is an issue that has relevance in health systems and for the general public and media.

For many years, screening was practised without debate, but in the 1960s serious challenges were raised about standard screening procedures. Benefits of screening must be judged against negative side-effects, and concern was raised about potential and actual harm arising when people without a health problem received dangerous and unnecessary investigations and treatments as a result of 'routine' screening tests. Controversy raged and only now 50 years later, is there widespread recognition that quality assured service delivery and proper consumer information are essential. In addition to debate over health risks, the cost-effectiveness of such results also has to be considered, making this a highly contested issue.

This book serves as a non-technical, introductory guide to all aspects of screening. The first section deals with concepts, methodology and evidence, explaining what screening is and how to evaluate it. The second section describes practical management, for example how to make policy and how to deliver it to a high quality. It includes many examples and case histories, a glossary to make medical terms accessible to the non-medic, and each chapter concludes with a summary and self-test questions. Although reference is made to the UK NHS, a world leader in screening, the book remains internationally relevant as the principles, knowledge and skills of screening are applicable in any setting. The controversies, paradoxes, uncertainties and ethical dilemmas of screening are explained in a balanced way. Muir Gray and Angela Raffle have been at the forefront of achieving improvements in screening over recent years, and they bring their wealth of experience to this essential text.

Sir Muir Gray has been the driving force behind the transformation of screening in the UK. In the 1980s he secured £25,000 from the Department of Health to resolve the problematic cervical screening programme; by harnessing the experience and commitment of pathologists, public health physicians, and gynaecologists throughout the service he transformed it into the quality assured public health programme it is today. Muir also masterminded the implementation of a nationwide breast screening programme. He then turned his attention to wider screening, setting up the National Screening Programmes which brought evidence, order and effectiveness to a disparate set of public health risk reduction programmes. Muir has also established the National Library for Health, been instrumental in helping establish the Cochrane Collaboration, and has brought accessible evidence-based information to the fingertips and desktops of all clinicians by publications such as Clinical Evidence. Dr Angela Raffle became involved in screening in 1985 when she took on responsibility for the cervical screening programme in and around Bristol and Bath. Working with Dr Elisabeth Mackenzie, she analysed the screening records for the 250,000 women in the programme. The results were worrying, demonstrating the scale of overdetection and overtreatment inherent in cervical screening. She articulated her findings, not as a polemicist from outside the programme, but as a professional involved in screening, committed to serving the women who participated. Angela became part of the National Coordinating Network, has worked on a wide range of screening policy issues for the National Screening Programmes, and has continued her commitment to teaching nationally and internationally. In Bristol she is responsible for all aspects of cancer services including the cancer screening programmes. She has also been a major player in the Smoke-free Bristol campaign and palliative care services at the end of life.