Do we have the will, the power of innovation, to lift ourselves above our own creations and control them? This is the central question of modern medicine, a question which for some time has dominated current discourse in health care and which gave rise in the early 1970s to the field of technology assessment. The technologic armory that has been developed over the past one and a half centuries is vast, formidable, and expanding. Its presence must be reckoned with, and to do this we must begin by understanding our relationship to it.

There are many ongoing activities in the United States that can be characterized as strategies in technology assessment and implementation. A comprehensive strategy, however, is lacking. The richness and diversity of the groups with a stake in technology assessment is in part responsible for the inability to move to a comprehensive strategy. Important conflicts within and across groups must be resolved before a comprehensive program of technology assessment can be put in place.

No European country (as far as the author knows) has a comprehensive strategy for technology assessment and implementation. Many countries undertake some aspects of such a strategy, but none cover all of them. Such a strategy would need to include the technical, clinical, economic and social evaluation of technologies, and the use of this information to set policies and to ensure that they are implemented. Despite the considerable differences in health systems financing and organization there is a surprising degree of similarity in the way we approach technology assessment; more variability exists in the mechanisms used to regulate and control the introduction and use of medical technologies.

The term “assessment of medical technologies” does not appear to have a unique meaning that always applies to its use. It seems wise, then, to state what will be meant by the term in this chapter. “Medical technology” is regarded here as including drugs, devices, procedures, (whether preventive, diagnostic, or therapeutic) that bear more or less directly on patients. Thus, an educational program for patients might be a technology, but a training program for dietitians would not. A surgical procedure or a prosthesis would; but a scale for assessing quality of life would not. “Assessment,” as used here, refers to a complex set of activities that comprise data acquisition, analysis, and interpretation concerning properties of medical technologies. Assessment tends to be comparative, either explicitly (as to a control group) or implicitly (as looking toward “usual experience”). In any case, the goal of assessment is to increase understanding of such properties of a medical technology as its applicability, convenience, efficacy, safety, effectiveness, cost, etc.

Few would argue that the randomized clinical trial is the most definitive instrument available for measuring the safety and efficacy of a new medical technology, be it drug, device, or procedure. Randomization removes the potential for bias in the allocation of subjects to the intervention group or to the control group. In addition, randomization tends to produce comparable groups which can be further strengthened by stratification and by stratified analyses. The randomized controlled trial guarantees validity of statistical tests, as long as the sample size is large enough to avoid type-II error.

Economic techniques have been used for several years to evaluate health care expenditures, and there is reasonable agreement amongst economists as to the appropriate methodology. Comprehensive reviews of techniques and applications can be found in Drummond (3,4), Culyer and Horisberger (2) and a report from the Office of Technology Assessment (7). More recently Williams (13) has addressed the problems of evaluating a developing technology and Wagner (10) the specific problems of diagnostic technologies.

The standard way to assess medical technologies is to conduct a randomized clinical trial. Patients are randomly assigned to groups receiving alternative treatments, and outcomes are monitored over a long period of time. For example, some victims of left main coronary artery disease may undergo coronary artery bypass surgery, and others may receive medical treatment with nitroglycerine and beta blockers. Comparison of five-year mortality and morbidity in the two groups helps to determine the relative appropriateness of the two procedures. In addition, information about quality of life and cost can also be collected and compared.

The consensus development program for health care is an American invention which dates back to 1977. It is derived out of concern for the appropriate use of medical technology and designed to formalize the process by which research pertinent to health care is disseminated and used.

The Medicare prospective payment system (PPS) for inpatient hopital service was enacted in 1983. It uses a classification based on diagnosis-related groups (DRGs) to determine payment for services provided.

Over the past decade the Office of Medical Application of Research (OMAR) of the National Institutes of Health has developed the consensus development conference (18) to assess technologies in cases where the scientific community has been unable, or unwilling, to reach a firm position as to efficacy but which require some better form of assessment than expert opinion (8). Another paper in this issue describes the principles that underlie such conferences (9).

“Technology assessment” is still a relatively new concept, and its application to the field of medicine is even more recent. This results not only from an important effort to develop the scientific basis for health care, but also as a consequence of the growing concern about medical care costs (19). The term refers basically to the evaluation of the costs and effects of a medical technology. The most important methodological approach in this area has been, and still is, the traditional clinical trial, defined by Bradford Hill as “A carefully and ethically designed experiment with the aim of answering some precisely framed question,” including random allocation of the subjects in the trial (4).

Since 1977, the Consensus Development Program of the Office of Medical Applications of Research (OMAR), part of the National Institutes of Health (NIH), has sponsored more than 50 consensus development conferences (CDCs) on the safety and efficacy of important biomedical technologies. The aim of these conferences, described fully elsewhere (4), is to inform the health care community, and to some extent the public, of the status of emerging biomedical technologies and the need for change in the use of existing health-related technologies. OMAR has therefore, worked diligently to publicize conference findings among these audiences. Further, OMAR has sought to improve the effectiveness of these transfer activities by conducting assessments of the impact of CDCs on their primary audience, U.S. physicians.

The role and the place of technology assessment, in relation to health policy making, are gradually changing. These changes have implications for the transfer of assessment findings to the parties involved in the process of policy making.

It is the aim of the present paper to emphasize the uniformity of ethical principles which are applied in the large variety of methods for technology assessment, ranging from the level of the individual citizen to that of society as a whole. A further aim is to emphasize that the application of such ethical principles is necessary not only for assessment situations comprised within the classical doctor-patient relationship, but also for assessing mass applications of preventive interventions (a type of application which is not to be confused with the widespread post-assessment application of already-tested methods).

Percutaneous lithotripsy has achieved widespread diffusion throughout the medical community and is described by many authors as the manipulative treatment of choice in an increasing number of patients with renal stones. Appropriate use of percutaneous lithotripsy is not an isolated event of patient management but is considered to be one episode in the medical#surgical management of nephrolithiasis. Medical management must be initiated at the first determination of the presence of the stone or at the time of the diagnosis of one of the underlying conditions which predispose to stone formation. In spite of the fact that no randomized prospective trial studies are available, the overall preponderance of the available information is that percutaneous lithotripsy for the treatment of kidney stones is a safe and efficacious procedure. In addition, it has achieved widespread acceptance and is generally employed throughout the country. Cooperation between the physician responsible for medical management of the patient, the urologist, and the radiologist appears to be an essential ingredient for successful management. Long-term studies are indicated to determine the true incidence of complications and the long-range effects of the procedures employed by the percutaneous route.

The available information on transurethral ureteroscopic ultrasound and electrohydraulic wave lithotripsy in the surgical treatment of upper renal tract stones is presented above. It is significant that most reports add only 2–5 case studies to the literature and no large series of cases are reported. This approach to the surgical care of renal stones will have to be considered over the next several years against a backdrop of the current rapid spread in the use of percutaneous lithotripsy and the potential rapid diffusion of ESWL in the United States.