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Despite a large number of published randomized prospective controlled clinical trials the indications for perioperative parenteral and enteral nutrition support remain controversial. This article reviews the reports of several recently published consensus conference reports and prospective randomized controlled trials evaluating nutritional therapy in surgical patients.
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When existing evaluations find little or no evidence of consensus recommendations leading to action, one can justifiably ask why so much of this review was dedicated to analyzing alternative ways of producing such "words without action." There are, however, at least two reasons why consensus recommendations should be produced with care and attention to validity. First, recommendations do sometimes have an impact on behavior as a consequence of mere dissemination activity--the Dutch program, for instance, was more successful than most. This success may occur when the target audience is already particularly receptive to change and the message is timely and delivered by a credible source in a clinically relevant way. Thus, although "such a conjunction of favorable conditions is probably the exception rather than the rule for consensus topics" (46, 240) it does happen. Second, the output from consensus processes is increasingly a potential input to other processes. Consensus recommendations can be used as the criteria for evaluation and appraisal aimed at changing practice behavior, making administrative decisions on resource allocation, or defining research protocols. For instance, quality assurance activities, such as peer assessment, practitioner certification, or utilization review, are actively seeking criteria with which to make judgments and elicit changes in practice to improve the quality of care. Funding agencies are looking for information to help make reimbursement, capital expenditure, or fee-for-service decisions on cessation of insurance for particular procedures or approaches. These uses of the consensus criteria are potentially major and controversial. Therefore, even if dissemination rarely leads to action, consensus processes should still be done carefully and with valid techniques. The use of their recommendations embedded within other activities may well lead to (forced) changes in behavior. On ethical grounds alone, we should be as sure as possible that the behavior changes being implied and encouraged are indeed advisable. For these reasons, the review describes the decision points in the production process for consensus recommendations as a start on the development of a set of recognized standards. The review offers a critical appraisal of the various methodological choices available at each decision point. The seven decision points are selecting a topic, picking the consensus group, providing background preparation, identifying information inputs, choosing a group judgment process, defining the criteria for recommendations, and choosing a report preparation procedure and format. At least two important points emerged from this review. First, the research is often not well enough developed to give clear indications for many of the choices on what is the "best" alternative.(ABSTRACT TRUNCATED AT 400 WORDS)
PURPOSE: Prostate-specific antigen (PSA) is a glycoprotein that is found almost exclusively in normal and neoplastic prostate cells. For patients with metastatic disease, changes in PSA will often antedate changes in bone scan. Furthermore, many but not all investigators have observed an association between a decline in PSA levels of 50% or greater and survival. Since the majority of phase II clinical trials for patients with androgen-independent prostate cancer (AIPC) have used PSA as a marker, we believed it was important for investigators to agree on definitions and values for a minimum set of parameters for eligibility and PSA declines and to develop a common approach to outcome analysis and reporting. We held a consensus conference with 26 leading investigators in the field of AIPC to define these parameters. RESULT: We defined four patient groups: (1) progressive measurable disease, (2) progressive bone metastasis, (3) stable metastases and a rising PSA, and (4) rising PSA and no other evidence of metastatic disease. The purpose of determining the number of patients whose PSA level drops in a phase II trial of AIPC is to guide the selection of agents for further testing and phase III trials. We propose that investigators report at a minimum a PSA decline of at least 50% and this must be confirmed by a second PSA value 4 or more weeks later. Patients may not demonstrate clinical or radiographic evidence of disease progression during this time period. Some investigators may want to report additional measures of PSA changes (ie, 75% decline, 90% decline). Response duration and the time to PSA progression may also be important clinical end point. CONCLUSION: Through this consensus conference, we believe we have developed practical guidelines for using PSA as a measurement of outcome. Furthermore, the use of common standards is important as we determine which agents should progress to randomized trials which will use survival as an end point.
Adjuvant endocrine therapy is a vitally important modality for treatment of women with resected hormone-sensitive breast cancer as indicated by the presence of estrogen and/or progesterone receptors in the tumor. It is not recommended in those patients whose tumors lack these hormone receptors. Tamoxifen for 5 years has been shown to reduce the risk of recurrence and death irrespective of menopausal status or use of adjuvant chemotherapy. In postmenopausal women, the major research emphasis relates to the use of third-generation aromatase inhibitors in sequence with, instead of, and in combination with tamoxifen. In premenopausal women, ovarian ablation/suppression has demonstrated efficacy comparable with some chemotherapy regimens, but its role in women receiving chemotherapy remains to be determined.
Extraction of third molars is the operation most frequently performed by oral and maxillofacial surgeons. The American National Institute of Health (1979) and the American Association of Oral and Maxillofacial Surgeons (1993) have organised consensus conferences to systematically analyse the scientific evidence and provide official guidelines for the management of third molars. However, some clinical aspects are still controversial: indications for preventive extraction, early extraction, prognosis of impacted teeth, continuous follow-up, relationship with anterior crowding and temporo-mandibular disorders. This article reviews the conclusions from the consensus conferences and integrates them with more recent data. The actual trend seems to justify a more conservative clinical approach rather than an aggressive extraction policy.
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As of the early 1980s, despite the wealth of evidence from experimental animal models, the extensive epidemiologic evidence, the powerful genetic evidence, and the strongly suggestive clinical intervention trial results, most clinicians still remained unpersuaded regarding the relevance of the lipid hypothesis. What was needed was a well-designed, large-scale, long-term, double-blind study demonstrating a statistically significant impact of treatment on coronary heart disease events. The National Institutes of Health (NIH) had laid the groundwork for such a study as early as 1970, but the study was not completed and the results published until 1984. This study, the Coronary Primary Prevention Trial, showed that treatment with a bile acid binding resin reduced major coronary events in hypercholesterolemic men by 19%, with a P value of 0.05. The NIH followed this up with a national Consensus Development Conference on Lowering Blood Cholesterol to Prevent Heart Disease. For the first time, the NIH now went on record advocating screening for hypercholesterolemia and urging aggressive treatment for those at high risk. The Institute initiated a national cooperative program to that end, the National Cholesterol Education Program. For the first time, preventing coronary heart disease became a national public health goal.
The Ancillary Therapy and Supportive Care Working Group had 3 goals: (1) to establish guidelines for ancillary therapy and supportive care in chronic graft-versus-host disease (GVHD), including treatment for symptoms and recommendations for patient education, preventive measures, and appropriate follow-up; (2) to provide guidelines for the prevention and management of infections and other common complications of treatment for chronic GVHD; and (3) to highlight the areas with the greatest need for clinical research. The definition of "ancillary therapy and supportive care" embraces the most frequent immunosuppressive or anti-inflammatory interventions used with topical intent and any other interventions directed at organ-specific control of symptoms or complications resulting from GVHD and its therapy. Also included in the definition are educational, preventive, and psychosocial interventions with this same objective. Recommendations are organized according to the strength and quality of evidence supporting them and cover the most commonly involved organs, including the skin, mouth, female genital tract, eyes, gastrointestinal tract, and lungs. Recommendations are provided for prevention of infections, osteoporosis, and steroid myopathy and management of neurocognitive and psychosocial adverse effects related to chronic GVHD. Optimal care of patients with chronic GVHD often requires a multidisciplinary approach.
Several diverse genetically engineered mouse models of pancreatic exocrine neoplasia have been developed. These mouse models have a spectrum of pathologic changes; however, until now, there has been no uniform nomenclature to characterize these changes. An international workshop, sponsored by The National Cancer Institute and the University of Pennsylvania, was held from December 1 to 3, 2004 with the goal of establishing an internationally accepted uniform nomenclature for the pathology of genetically engineered mouse models of pancreatic exocrine neoplasia. The pancreatic pathology in 12 existing mouse models of pancreatic neoplasia was reviewed at this workshop, and a standardized nomenclature with definitions and associated images was developed. It is our intention that this nomenclature will standardize the reporting of genetically engineered mouse models of pancreatic exocrine neoplasia, that it will facilitate comparisons between genetically engineered mouse models and human pancreatic disease, and that it will be broad enough to accommodate newly emerging mouse models of pancreatic neoplasia.
BACKGROUND: Three important events in the history of breast cancer treatment occurred between 1983 and 1995: a large clinical trial, first lady Nancy Reagan's choice of mastectomy and the publishing of an NIH consensus statement. OBJECTIVE: To assess the effects of these events on use of breast conserving surgery (BCS). RESEARCH DESIGN: Data from the cohort study of the surveillance, epidemiology and end results (SEER) Program from 1983 to 1995 were divided into four periods: Baseline, Trial, Celebrity, and Consensus. SUBJECTS: Of the women, 169,466 diagnosed with early stage breast cancer in nine SEER areas. MEASURES: Monthly percentages of BCS. RESULTS: A linear regression model generated a separate intercept and slope term for four time periods, adjusting for demographic characteristics of breast cancer patients. For the Baseline, Celebrity and Consensus Periods, slopes indicated an increasing use of BCS which varied between 0.24% and 0.28% per month. Slopes for these three periods were not statistically different (p = 0.120). In contrast, there was no change in use of BCS during the trial period (p = 0.247). We tested the magnitude of discontinuity between periods. At the beginning of the trial, celebrity and consensus periods, there were increases in BCS of 5.54% (p < 0.001), -3.55% (p < 0.001), and 2.37% (p < 0.001), respectively. CONCLUSIONS: The use of BCS was substantially affected by the reports of a clinical trial of BCS and by celebrity action. These effects were abrupt but transient. The NIH consensus statement stimulated a small change in use of BCS and may be an important intervention for maintaining the increasing trend in use of BCS since the 1990s.
The incidence of newly acquired hepatitis C infection has diminished in the United States. This decline is largely because of a decrease in cases among IDUs for reasons that are unclear and, to a lesser extent, to testing of blood donors for HCV. The virus is transmitted by blood, and such transmission now occurs primarily through injection drug use, sex with an infected partner or multiple partners, and occupational exposure. Most infections become chronic, and therefore the prevalence of HCV infections is high, with about 3 million Americans estimated, to be chronically infected. HCV is a leading cause of cirrhosis, a common cause of HCC and the leading cause of liter transplantation in the United States. The disease spectrum associated with HCV infection varies greatly. Various studies have suggested that 3% to 10% of chronically infected patients will develop cirrhosis over a 20-year period, and these patients are at risk for HCC. Persons who are older at the time of infection, patients with continuous exposure to alcohol, and those coinfected with HIV or HBV demonstrate accelerated progression to more advanced liver disease. Conversely, individuals infected at a younger age have little or no disease progression over several decades. The diagnosis of chronic hepatitis C infection often is suggested by abnormalities in ALT levels and is established by EIA followed by confirmatory determination of HCV RNA. Several sensitive and specific assays are automated partly for the purposes of detecting HCV RNA and quantifying the viral level. Although there is little correlation between viral level and disease manifestations, these assays have proven useful in identifying those patients who are more likely to benefit from treatment and, particularly, in demonstrating successful response to treatment as defined by an SVR. Liver biopsy is useful in defining baseline abnormalities of liver disease and in enabling patients and healthcare providers to reach a decision regarding antiviral therapy. Noninvasive tests do not provide the information that can be obtained through liver biopsy. Information on the genotype of the virus is important to guide treatment decisions. Genotype 1, most commonly found in the United States, is less amenable to treatment than genotypes 2 or 3. Therefore, clinical trials of antiviral therapies require genotyping information for appropriate stratification of subjects. Recent therapeutic trials in defined, selected populations have shown clearly that combinations of interferons and ribavirin are more effective than monotherapy. Moreover, trials using pegylated interferons have yielded improved SVR rates with similar toxicity profiles. Results continue to show, however, that the SVR rate is less common in patients with genotype 1 infections, higher HCV RNA levels, or more advanced stages of fibrosis. Genotype 1 infections require therapy for 48 weeks, whereas shorter treatment is feasible in genotype 2 and 3 infections. In genotype 1, the lack of an early virologic response (< 2 log decrease in HCV RNA) is associated with failure to achieve an SVR. The SVR is lower in patients with advanced liver disease than in patients without cirrhosis. Ongoing trials are exploring the usefulness of combination therapy in various populations. Preliminary experience in IDUs, individuals coinfected with HIV, children, and other special groups suggests similar responses are achievable in these populations. Patients with acute hepatitis C may be treated, but specific recommendations for antiviral treatment must await further evaluation of the rate of spontaneous clearance of the virus and determination of the optimal time to initiate treatment. Preventive measures beyond blood-banking practices include prompt identification of infected individuals, awareness of the potential for perinatal transmission, implementation of safe injection practices, linkage of drug users to drug treatment programs. and implementation of community-based education and support programs to modify risk behavior. Some of these measures have been implemented successfully in the control of HIV infections, and it stands to reason that they would be valuable for reducing HCV transmission. Future advances in the diagnosis and management of hepatitis C require continued vigilance concerning the transmission of this infection, extending treatment to populations not evaluated previously in treatment trials, and the introduction of more effective therapies.
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