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This month’s edition of Healthcare Review – OnlineTM is the first in a series examining population screening for disease.
The choice by public authorities to recommend screening is associated with a substantial degree of responsibility. Clear evidence should exist that the disease in question can be identified at an earlier and more treatable stage in its natural history and the resulting fall in mortality or morbidity should be achieved without too great a burden of adverse effects, from either diagnostic procedures or treatments. 1
Three authors consider these and other issues relating to decisions to screen for disease across the general population. Two authors review the issues related to the decision to establish a programme for colorectal cancer screening. The third author draws on experience in the transition from opportunistic cervical screening to an organised public health programme programme for cervical screening during the 1990s in Australia.
Associate Professor James St John, Director, Department of Gastroenterology, The Royal Melbourne Hospital, Australia, considers the case for population screening for colorectal cancer in Australia.
St John notes that there is a trend towards endorsement of screening. For example, in 1997, the Australian Health Technology Advisory Committee recommended the development of a programme for the introduction of population screening for colorectal cancer by faecal occult blood testing (FOBT) for the average risk population in Australia, beginning with pilot and feasibility studies. However, such screening has not been recommended for New Zealand, Canada has opposed screening and many other countries remain uncommitted.
St John acknowledges the controversy over screening for colorectal cancer but notes that the case for screening has been strengthened by the availability of level 1 controlled trial evidence of a significant reduction in mortality from colorectal cancer in those offered FOBT.
St John examines the criteria that need to be met to justify a screening programme. He reviews the processes used to make decisions about undertaking population screening for colorectal cancer in Australia and considers the question of who should be involved in the decision-making process. With respect to the latter, he notes that all interested groups should participate in discussions and decision-making, and that, in order to achieve high levels of participation, general practitioners, in particular, must be convinced that screening is worthwhile.
In reviewing the case for establishing a colorectal cancer screening programme for Australia, St John considers each of the principles for early disease detection adopted by the World Health Organisation. In this, he considers such issues as the availability of a suitable screening test, test acceptability and the cost-effectiveness of screening.
St John considers reasons why colorectal cancer screening has become so controversial, including the failure to understand the concept of screening. St John concludes by noting that the immediate challenge is to involve medical practitioners and the target population in FOBT-based screening, to educate them about the concept of screening and to promote an understanding of the potentially important role of colorectal cancer screening as a public health measure.
Dr Peter Bampton, Staff Specialist in the Department of Gastroenterology, Flinders Medical Centre, South Australia, presents the paper "Colorectal Cancer - An Ideal Tumour to Screen?".
In keeping with St John, he sets out four criteria that determine the ability of a screening programme to change the burden of disease in terms of its mortality and morbidity rates:
He considers each of these factors in turn for the case of colorectal cancer.
Bampton then identifies five elements vital to the successful implementation of a screening programme: the initial approach to the population, the registration of screenees with the programme, the successful application of the screening tool, a method that ensures that abnormal results are followed up and the continuation of the programme (ie, re-screening). He considers these elements in the cases of Germany, Japan and the US where FOBT is available free of charge, with or without a structured screening programme.
Bampton concludes that the question for colorectal cancer screening is no longer why, but how and when.
Dr Heather Mitchell, Medical Director, Victorian Cervical Cytology Registry, Australia, considers the transition during the 1990s in Australia from opportunistic cervical screening to an organised public health programme. Mitchell reviews the impetus for the change, the decision-making process that was adopted, and how the change was implemented.
Key to the change was a review of cervical screening in Australia, commissioned in 1988 in response to limited success from opportunistic screening and critical feedback on cervical screening internationally. This review engaged a wide audience in the debate about cervical screening and involved a diverse range of activities beyond simply the taking and reporting of a Pap smear and the management of abnormalities. For example, recruitment programmes, an information infrastructure pilot and a review of quality assurance in pathology laboratories were included in the review activities. A Steering Committee was established to oversee the review and was chaired by Mitchell during its period of operation in 1988-1991.
The establishment of a National Advisory Committee (NAC) to advise government on policy and operational matters in relation to cervical screening was also critical in the programme’s development. Mitchell has been a member of the NAC since its inception and has chaired this Committee since 1998.
Major achievements of the organised programme have included:
- adoption of uniform terminology for reporting on Pap smears and for management protocols for women with abnormal or unsatisfactory smears
- establishment of Pap Test Registers in all States and Territories of Australia
- systematic efforts to increase the level of participation in cervical screening
- development and implementation of quantitative performance standards for the pathology laboratories reporting Pap smears.
Mitchell outlines new challenges that have arisen. These include issues related to low cost efficiency of screening and to management of poor laboratory performance. She sees that the new challenges, like the challenges successfully faced in the early stages of developing the programme, have applicability beyond cervical screening.
Mitchell concludes by summarising the three essential ingredients for the successful changes that have occurred: forming and maintaining critical coalitions across diverse disciplines and interest groups; leadership by government and; the provision of funding to trial new approaches. She considers that Australia will need to maintain these three ingredients if it is to achieve even more success in its cervical screening programme.
References
- McNeil JJ, O’Brien PE. Screening, case finding and evidence-based guidelines. Med J Aust 1999; 171: 344-345
