SECTION CONTENTS

In this section we will examine some of the basic characteristics of the scientific method. A ‘method’, in the present context, refers to a system for acquiring knowledge and establishing its truth. Health providers justify their theories and practices on the grounds that they are ‘scientific’, that is, based on scientific methodology. The scientific method is essential for conducting research and evaluation aimed at producing evidence, improving the effect-iveness and cost-effectiveness of health services.

A common view of the scientific method is that it enables us to describe, predict, explain and perhaps to control events in the world. As an example, consider how researchers and practitioners in the health care system responded to the outbreak of the acquired immuno-deficiency syndrome (AIDS) epidemic in the early 1980s. One of the first signs of this epidemic was the clinical observation that young men presented with a deadly cancer (Kaposi’s sarcoma) which was previously found only in the elderly. This was the initial evidence which indicated that further facts and explanations were required. It was hypothesized that the premature failure of the immune system was responsible for the disorder. Subsequent clinical evidence supported this hypothesis, leading to a clear definition of the disease as ‘AIDS’. As more cases of AIDS were identified it became evident that some groups in the population were most at risk: persons who were involved in multiple homosexual relationships or who were intravenous drug users, or those who required blood products, for example, for haemophilia. An important development was the confirmation of the hypothesis that the disease was caused by a specific virus labelled ‘HIV’ (human immuno-deficiency virus). On the basis of the above clinical, epidemiological and virological evidence it was hypothesized that the HIV was transmitted through body fluids such as blood or semen. In this way it became possible to predict which practices in the population involved a high level of risk for transmitting the virus.

The above findings and hypotheses contributed to constructing theories of AIDS, providing systematic and integrated conceptual frameworks for explaining the transmission and the clinical features of the disorder. These theories also inform current practices aimed at controlling the epidemic, such as testing blood products for HIV, or promoting ‘safe sex’ behaviours. The effectiveness of these practices (at least in some countries) for containing the epidemic provided evidence confirming the accuracy of our understanding of the problem. At the same time, we remain sceptical about certain aspects of our theories, recognizing that there are as yet no vaccines or pharmacological cures for AIDS.

You might have recognized that the above brief account of attempting to contain AIDS is deficient in an essential way: it excludes evidence concerning the personal experiences and actions of persons at risk of or having HIV. The above account represented a quantitative approach to the scientific method aiming to provide a mechanistic or reductionistic explanation of health and illness. This method is not appropriate for researching and theorizing how persons, their families and the community respond to health-related issues and problems. Research methods should also include qualitative or interpretive approaches to discover the personal meanings involved in being at risk of or suffering from diseases or disabilities. Qualitative methods are also appropriate for researching the cultural context and social construction of a dis-order; for instance, discovering the images of AIDS sufferers communicated by the media in a given community.

The position taken in the present book is that the scientific method, as applied to health care, must include both quantitative and qualitative methods. These methods are used to produce evidence for solving health-related problems. Regardless of controversies regarding the nature of science and its methodology, there is a broad consensus concerning the principles and rules for producing scientific evidence. Our goal is to convey these principles and rules to our readers.