Evidence-based practice

In the last 40 years, the needs of and demands for health care both in the UK and worldwide have increased dramatically. These increases are related to the population ageing, the development of new technologies and knowledge, rising patient expectations, and associated increases in professional expectations about the possibilities and potential of health care (Muir Gray 1997 ). In this period, the key policy concerns of the international health care community have been about containing costs and enabling equitable access to high quality health care, while also ensuring greater accountability, patient satisfaction, and improved public health (Lohr et al. 1998). Health care resources are finite and must be shared equitably on the basis of need, capacity to benefit, and effectiveness. The use of high quality research evidence and guidelines to inform individual patient care and population health care have become central to this process. In the mid-1970s, various writers began to question the effectiveness of medicine and the increasingly wider influence exerted by the medical profession on society. For example, McKeown (1976) mapped mortality rates for the main killer airborne diseases (tuberculosis, whooping cough, scarlet fever, diptheria, and smallpox) against contemporary advances in medicine from the mid-19th century to the early 1970s. He found that the declines in the incidence and prevalence of communicable diseases had occurred before their microbial cause had been identified and before an effective clinical intervention had been developed. McKeown concluded that the declines in mortality rates were not attributable to immunization and therapy and suggested the declines could more reasonably be attributed to better nutrition and improved housing conditions which had occurred over the period. Allied to McKeown’s historical analysis was the work of Archie Cochrane who evaluated contemporary clinical practice in the 1970s. In his seminal work Effectiveness and Efficiency , Cochrane (1972) showed that many medical treatments provided in the NHS were ineffective, inefficient, and founded on medical opinion rather than on a rigorous assessment of efficacy and effectiveness. Box 7.1 defines the terms efficacy, effective, and efficiency.