Clinical trials methods and the practice of medicine

An important potential byproduct from clinical trials is validated clinical methods applicable to clinical practice. The potential for improved patient care is separate from the scientific and intellectual answers gained in such trials. The current mechanisms for the transfer of methodological information from clinical trials are inefficient and have identifiable barriers. Methods validated in clinical trials must be recognized and accentuated as a valuable resource. A central repository of clinical trials' methods and a retrieval system dedicated to this unique body of scientific literature is warranted. Reports of methodological advances from clinical trials should be published in the literature read by clinical practitioners. The effective transfer of methods information from clinical trials to the office of the clinical practitioner is possible but requires increased efforts on the part of clinical trials scientists.

Physicians' reasons for not entering eligible patients in a randomized clinical trial of surgery for breast cancer

We studied the reasons surgical principal investigators chose not to enter patients in a large, multicenter trial sponsored by a cooperative group. In 1976 the National Surgical Adjuvant Project for Breast and Bowel Cancers (NSABP) initiated a clinical trial to compare segmental mastectomy and postoperative radiation, or segmental mastectomy alone, with total mastectomy. Because the low rates of accrual were threatening to close the trial prematurely, we mailed a questionnaire to the 94 NSABP principal investigators, asking why they were not entering eligible patients in the trial. A response rate of 97 per cent was achieved. Physicians who did not enter all eligible patients offered the following explanations: (1) concern that the doctor-patient relationship would be affected by a randomized clinical trial (73 per cent), (2) difficulty with informed consent (38 per cent), (3) dislike of open discussions involving uncertainty (22 per cent), (4) perceived conflict between the roles of scientist and clinician (18 per cent), (5) practical difficulties in following procedures (9 per cent), and (6) feelings of personal responsibility if the treatments were found to be unequal (8 per cent). Further investigation into the behavioral aspects of the investigator-patient relationship is particularly pressing, since fear of change in this relationship was the most common reason given for not entering eligible patients in the trial.

An additional basic science for clinical medicine: II. The limitations of randomized trials

Although highly successful in investigating remedial therapy, randomized clinical trials have sometimes created rather than clarified controversy when the treatments were given for the complex problems involved in studying either the primary prevention of disease or the secondary prevention of adverse progression for an established disease. Another source of difficulty has been the inevitable conflicts created by two legitimate and justifiable but opposing policies regarding the fastidious or pragmatic goals of the trials. These problems limit the scope of clinical questions that can be answered successfully by randomized trials, but other limitations are produced by problems in logistics or ethics. Randomized trials are unfeasible for studying multiple therapeutic candidates, minor changes in therapy, "instabilities" due to rapid technologic improvements in available treatment, long-term adverse effects, studies of etiologic or other suspected "noxious" agents, and the diverse clinical roles of diagnostic technology. Consequently, despite the magnificent scientific achievements of randomized clinical trials, the foundation for a basic science of patient care will also require major attention to the events and observations that occur in the ordinary circumstances of clinical practice.

A decade of experience with chemotherapy for prostate cancer

Chemotherapy for prostate cancer has been demonstrated by the Clinical Trials Program of the NPCP and by other cooperative and individual studies both as single antitumor agents and combinations of agents to provide additional benefit to patients with advanced disease that no longer respond to hormonal therapy, markedly more so than could be provided by a host of palliative and real or synthetic hormonal agents commonly used in this type of patient. There is also some evidence to support the premise that adding antitumor agents to hormones as initial treatment for metastatic disease is more effective than waiting for the ultimate hormone failure, at least in patients with poorer prognosis.

Clinical trials and the community physician

Further important advances in cancer treatment, and the development of regimens with fewer side-effects, may largely depend upon the subtle manipulations of available agents and comparison of results only possible in large numbers of patients. More than 80% of all cancer patients are treated within their own communities, and the opportunity to increase the overall cure rate significantly above the current estimate of 41% depends upon our ability to conduct clinical trials in these communities. A variety of models have evolved for the integration of the community physician into clinical cancer research. Abundant evidence exists that the quality of clinical research data generated by the community physician is usually not different from that of data generated by university hospitals or Cancer Centers. While the protocol which provides instructions for the clinical trial is often a formidable document, newly developed computer systems permit a highly simplified interaction between the physician or nurse and the office computer terminal. The process of randomization, which is often essential to eliminating bias in studies comparing treatments, has been difficult for community practitioners to accept. A new statistical technique, pre-randomization, may solve this problem. Even where patients do not formally enter a clinical trial, the introduction of protocols into a practice provides the benefits of all known technology. Thus, community participation in clinical research is a superb method for delivering optimal patient care.

Progress of therapy in acute leukemia 1948-1981: randomized versus nonrandomized clinical trials

This paper gives a review of selected clinical studies in acute leukemia over the last 33 years and addresses two questions: What advances in the practice of medicine have resulted from clinical trials, both randomized and nonrandomized? What generalizations can be made about clinical trials which have led to advances in treatment? The review demonstrates that nonrandomized studies have been the primary mechanism for establishing the efficacy of new therapies. Such studies have also been utilized to determine patient characteristics related to prognosis and some important concepts of treatment (e.g., independent action of some drugs). Randomized studies have tended to yield positive results concerning treatment differences when there were prior suggestions of activity from nonrandomized studies. Analyses of randomized studies have been made to determine patient features related to prognosis and concepts for the treatment of patients (e.g., independent action of some drugs and the importance of treating patients in a disease-free state).

[Drug testing today]

According to the new West German drug legislation, new drugs will only be registered if their quality, effectiveness and safety is ensured. Safety means a favourable ratio of therapeutic value and risk of side-effects. Effectiveness can usually be verified most objectively in adequate and well-controlled clinical investigations (phase II and phase III of drug evaluation), which are preceded by pharmacological and toxicological experiments in animals and preliminary pharmakokinetic and pharmakodynamic studies in volunteers (phase I). In phase III and IV, rare but important adverse drug effects are looked for.