Biomedical subjects
R Deyo
Publications and source records attributed to R Deyo.
The limited state of technology assessment for medical devices: facing the issues.
Medical devices are an integral part of clinical practice and account for a substantial proportion of the national health budget. Clinical testing and regulation of medical devices, however, is vastly different from and inferior to the testing and regulation of drugs. As managed care organizations begin to exert controls on device use, providers are being caught between the policies of their organizations and the demands of device manufacturers and patients, who want wider access to devices. We outline several reasons for the poor state of medical device evaluations and the dangers of using devices without adequate information, and include the recently developed device assessment and reporting guidelines created by the Task Force on Technology Assessment of Medical Devices.
Chiropractic care for back pain.
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A brief introduction to the critical reading of the clinical literature.
Clinicians are bombarded by reports of new diagnostic tests or treatments for patients with spine problems. To provide the best possible patient care, clinicians need to be able to critically appraise the results of such studies for validity and relevance to patient care. Important questions to be asked of any description of diagnostic or treatment studies are the following questions: 1) Are the patients described in detail so that you can decide whether they are comparable to those that you see in your practice? 2) Are the treatments or assessments described well enough so that you could provide the same for your patients? 3) Was a clinically relevant endpoint measured? 4) Is there an appropriate comparison group? 5) Are potential sources of bias appropriately attended to? 6) Are the results clinically significant?
Patient outcomes after lumbar spinal fusions.
OBJECTIVES: To determine success and complication rates for lumbar spinal fusion surgery, predictors of good outcomes, and whether fusion improves success rates of laminectomy for specific low back disorders. DATA SOURCES: English-language journal articles published from 1966 through April 1991, identified through MEDLINE searching (spinal fusion plus limiting terms), bibliography review, and expert consultation. STUDY SELECTION: Articles were selected only if they reported at least 1 year of follow-up data enabling the classification of clinical outcomes as satisfactory or unsatisfactory for at least 30 patients. DATA EXTRACTION: Two reviewers independently extracted data on patient characteristics, surgical methods, patient outcomes, and quality of study methods. DATA SYNTHESIS: Of 47 articles, there were no randomized trials. Four nonrandomized studies compared surgery with and without fusion for herniated disks; three found no advantage for fusion. On average, 68% of patients had a satisfactory outcome after fusion, but the range was wide (16% to 95%), and the satisfactory outcome rate was lower in prospective than in retrospective studies. The most frequently reported complications were pseudarthrosis (14%) and chronic pain at the bone graft donor site (9%). Clinical outcomes did not differ by diagnosis or fusion technique, but were worse in studies with a greater number of previously operated patients. CONCLUSIONS: For several low back disorders no advantage has been demonstrated for fusion over surgery without fusion, and complications of fusions are common. Randomized controlled trials are needed to compare fusion, surgery without fusion, and nonsurgical treatments in rigorously defined patient groups.
Surgery for lumbar spinal stenosis. Attempted meta-analysis of the literature.
A meta-analysis was undertaken to determine the effects of surgery for lumbar spinal stenosis on pain and disability. Seventy-four journal articles met inclusion criteria and were independently reviewed by two readers. On average, 64% of patients treated surgically for lumbar spinal stenosis were reported to have good-to-excellent outcomes. However, there was wide variation across studies in the percentage with good outcomes. Few patient characteristics were found to predict outcome. Major deficits in study design, analysis, and reporting were common, and these precluded firm conclusions.
Geriatric evaluation and management: current status and future research directions.
In the last decade the concept of geriatric evaluation and management (GEM) has been widely discussed in the literature. Studies of GEM have occurred primarily in three settings: inpatient units, outpatient clinics, and specialized types of home care. We have reviewed the literature, focusing on randomized trials, to determine the strength of the evidence for the efficacy of these interventions. Two single-site randomized controlled trials of inpatient GEM units have been conducted and indicate that such units that provide care to targeted disabled older patients probably have a favorable impact on subsequent physical function, rates of institutionalization, and mortality. Two randomized trials of inpatient GEM consultation teams have been conducted. The trial that did not target high-risk individuals showed no benefit while the trial that did target an at-risk group showed that those receiving the service had improvements in mental status and short-term mortality. The results of randomized trials of outpatient GEM clinics to date have been unimpressive. Two trials of in-home GEM by a trained observer tended to show that the service resulted in a reduction in mortality. To date randomized trials of GEM have been very heterogeneous in terms of the type of assessment and subsequent care, the site in which services are delivered, and the manner in which patients are selected for the studies. This limits the ability to compare and extrapolate across studies. In the future there is a need to better clarify the selection of study participants, the exact structure of the assessment intervention provided, and the elements of successful interventions that may be most critical to insuring a good outcome.
Working group recommendations: measuring outcomes of care in geriatric evaluation and management units.
Issues related to measuring outcomes of care in geriatric evaluation and management (GEM) units were identified by the outcomes working group of the GEM evaluation conference. GEM units have as a major goal the improvement or maintenance of both physical and psychosocial function. Suggested outcome measures for physical health included survival, restricted activity days, general health perceptions, comprehensive physical function, and miscellaneous specific types of functioning. In the area of psycho-social function, the working group suggested measuring cognitive function, affect/life satisfaction, social function, and satisfaction with care. The patient's caregiver (eg, spouse or child) is often an important target of GEM care, and the group suggested measuring caregiver burden, life satisfaction, and assessment of patient behavior problems. While the primary goal of GEM units is to improve health status, their effects on the utilization and cost of health care are important to decisions about wide-spread implementation and funding. The group therefore suggested a comprehensive assessment of these outcomes. Among the large array of recommended outcomes, the most important were thought to be mortality, function, and cost.
Research strategies for geriatric evaluation and management: conference summary and recommendations.
In this paper, we present the consensus statement from a national conference on research priorities and methodologies for studying geriatric evaluation and management (GEM) programs. These conclusions, discussion points, and recommendations resulted from discussions of plenary papers, working group deliberations, and a final session in which findings were synthesized by the conference co-chairmen and presented to conference participants for final review. Major conclusions included: (1) The importance of linking geriatric evaluation with care management in future studies; (2) The need for multi-center trials of inpatient units to establish efficacy; (3) The importance of studying criteria for targeting GEM care on patients who are most likely to benefit; (4) The need for further developmental studies of outpatient GEM clinics; (5) The importance of assessing a range of outcomes including mortality, patient function, satisfaction, caregiver burden, and cost; and (6) The need to define more carefully the nature of the intervention that is being studied to aid in comparing and extrapolating findings. The following research priorities for GEMS were formulated based on the conference: (1) Within the VA health care system, a multi-site randomized trial of inpatient GEM units should be initiated; (2) Multi-site studies of inpatient GEM units and consultation teams linked to outpatient care should be initiated in non-VA settings; (3) Studies should identify the components of GEM that are most critical to outcome; (4) Studies should explore efficacy of GEM in settings that have not been well studied to date such as nursing homes; and (5) Studies are needed to test screening methods and targeting criteria for GEM in all settings.
Nimodipine alters acquisition of a visual discrimination task in chicks.
Chicks 5 days old received intraperitoneal injections of nimodipine 30 min before training on either a visual discrimination task (0, 0.5, 1.0, or 5.0 mg/kg) or a test of separation-induced distress vocalizations (0, 0.5, or 2.5 mg/kg). Chicks receiving 1.0 mg/kg nimodipine made significantly fewer visual discrimination errors than vehicle controls by trials 41-60, but did not differ from controls 24 h later. Chicks in the 5 mg/kg group made significantly more errors when compared to controls both during acquisition of the task and during retention. Nimodipine did not alter separation-induced distress vocalizations at any of the doses tested, suggesting that nimodipine's effects on learning cannot be attributed to a reduction in separation distress. These data indicate that nimodipine's facilitation of learning in young subjects is dose dependent, but nimodipine failed to enhance retention.
Production of achlorhydria in rats by direct irradiation of the stomach.
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