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Biomedical subjects

E B Bass

Publications and source records attributed to E B Bass.

At least 37 records · Page 2Linked to original sources
PubMed2000

Relation between prepublication release of clinical trial results and the practice of carotid endarterectomy.

CONTEXT: Little is known about how clinical practice is affected by disseminating results of clinical trials prior to publication in peer-reviewed journals. OBJECTIVE: To determine whether prepublication release of carotid endarterectomy (CEA) trial results via National Institutes of Health Clinical Alerts was associated with prompt changes in patient care that were consistent with the new medical evidence. DESIGN, SETTING, AND PATIENTS: Longitudinal data series analysis using acute care hospital discharge data from the Healthcare Cost and Utilization Project for patients who had CEA performed in acute care hospitals in 7 states (New York, California, Pennsylvania, Florida, Colorado, Illinois, and Wisconsin). The trials were the North American Symptomatic Carotid Endarterectomy Trial (NASCET clinical alert released February 1991) and the Asymptomatic Carotid Atherosclerosis Study (ACAS clinical alert released September 1994). MAIN OUTCOME MEASURE: Carotid endarterectomy rate during each month from 1989 (2 years before the NASCET clinical alert) to 1996 (2 years after the ACAS clinical alert), adjusted for age and sex. Because both trials were limited to patients 80 years or younger in hospitals with low mortality, we also stratified CEA rates by patient age and hospital mortality rate. RESULTS: From 1989 through 1996, 272849 CEAs were performed in the acute care hospitals in these 7 states, with the annual number increasing from 22300 to 51 495. Afterthe NASCET clinical alert, the adjusted CEA rate increased 3.4% per month (95% confidence interval [CI], 1.6%-5.3%) during the following 6 months and then increased 0.5% per month (95% CI, 0.2%-0.8%; P<.04) after journal publication of the NASCET study. After the ACAS clinical alert, the CEA rate increased 7.3 % per month (95% CI, 6.0%-8.5%) during the following 7 months and then decreased by 0.44% per month (95% CI, -0.86% to -0.0002%; P<.04) after journal publication of the ACAS study. After the ACAS clinical alert, the CEA rate increased more in patients aged 80 years or older than in younger patients; whereas, after journal publication of ACAS, the CEA rate decreased more rapidly in the older population. The overall proportion of CEAs performed in low-mortality hospitals did not change substantially after release of the clinical alerts or after journal publication. CONCLUSION: In this study, prepublication dissemination of CEA trial results with clinical alerts was associated with prompt and substantial changes in medical practice, but the observed changes suggest that the results were extrapolated to patients and settings not directly supported by the trials.

Aged↗
PubMed2000

The value of routine preoperative medical testing before cataract surgery. Study of Medical Testing for Cataract Surgery.

BACKGROUND: Routine preoperative medical testing is commonly performed in patients scheduled to undergo cataract surgery, although the value of such testing is uncertain. We performed a study to determine whether routine testing helps reduce the incidence of intraoperative and postoperative medical complications. METHODS: We randomly assigned 19,557 elective cataract operations in 18,189 patients at nine centers to be preceded or not preceded by a standard battery of medical tests (electrocardiography, complete blood count, and measurement of serum levels of electrolytes, urea nitrogen, creatinine, and glucose), in addition to a history taking and physical examination. Adverse medical events and interventions on the day of surgery and during the seven days after surgery were recorded. RESULTS: Medical outcomes were assessed in 9408 patients who underwent 9626 cataract operations that were not preceded by routine testing and in 9411 patients who underwent 9624 operations that were preceded by routine testing. The most frequent medical events in both groups were treatment for hypertension and arrhythmia (principally bradycardia). The overall rate of complications (intraoperative and postoperative events combined) was the same in the two groups (31.3 events per 1000 operations). There were also no significant differences between the no-testing group and the testing group in the rates of intraoperative events (19.2 and 19.7, respectively, per 1000 operations) and postoperative events (12.6 and 12.1 per 1000 operations). Analyses stratified according to age, sex, race, physical status (according to the American Society of Anesthesiologists classification), and medical history revealed no benefit of routine testing. CONCLUSIONS: Routine medical testing before cataract surgery does not measurably increase the safety of the surgery.

Aged↗
PubMed2000

Injectable versus topical anesthesia for cataract surgery: patient perceptions of pain and side effects. The Study of Medical Testing for Cataract Surgery study team.

OBJECTIVE: To compare patient reports of intraoperative pain and postoperative side effects by different anesthesia strategies for cataract surgery. DESIGN: Prospective cohort study. PARTICIPANTS: Men and women 50 years of age and older undergoing 19,250 cataract surgeries at nine centers in the United States and Canada from June 1995 through June 1997. INTERVENTION: Topical anesthesia or anesthesia with injection, with or without sedatives, opioid analgesia, hypnotics, and diphenhydramine (Benadryl). MAIN OUTCOME MEASURES: Patient ratings of intraoperative pain, satisfaction with pain management, and early postoperative side effects (drowsiness, nausea, vomiting, or a combination thereof). RESULTS: Twenty-six percent of surgeries were performed using topical anesthesia alone, and the remainder were performed with peribulbar, retrobulbar, or facial nerve block, or a combination thereof. Local anesthesia by injection with sedatives and diphenhydramine resulted in the lowest reporting of any intraoperative pain (1.3%), with postoperative drowsiness (9.6%) and nausea, vomiting, or both (1.5%) comparable with those administered topical anesthesia alone. Among those receiving topical anesthesia, use of sedatives and opioids reduced reports of any pain during surgery by 56% (95% confidence interval [CI], 34%, 70%), but increased nausea and vomiting (odds ratio, 2.27; 95% CI, 1.26, 4.09) compared with those administered topical anesthesia alone, after adjusting for age, gender, race, American Society of Anesthesiologists risk class, self-reported health status, and duration of surgery. Among those receiving local injections, use of opioids reduced reports of any pain among those receiving sedatives by 37% (95% CI, 15%, 54%), but did not increase postoperative side effects. The use of diphenhydramine among those receiving sedatives decreased reports of any pain by 59% (95% CI, 33%, 75%) and also reduced drowsiness and nausea and vomiting by 57% (95% CI, 48%, 65%) and by 60% (95% CI, 36%, 75%), respectively. Use of hypnotics with sedatives was associated with increased reports of any pain during surgery and increased nausea and vomiting after surgery. CONCLUSIONS: Patient reports of any pain during cataract surgery (5%) and postoperative side effects (16% drowsiness and 4% nausea and vomiting) were low, but varied by anesthesia strategy. Patient perceptions of pain and side effects can be helpful in guiding the appropriate choice of anesthesia strategy.

Administration, Topical↗
PubMed2000

Prevention of thromboembolism in atrial fibrillation. A meta-analysis of trials of anticoagulants and antiplatelet drugs.

OBJECTIVE: Appropriate use of drugs to prevent thromboembolism in patients with atrial fibrillation (AF) involves comparing the patient's risk of stroke and risk of hemorrhage. This review summarizes the evidence regarding the efficacy of these medications. METHODS: We conducted a meta-analysis of randomized controlled trials of drugs used to prevent thromboembolism in adults with nonpostoperative AF. Articles were identified through the Cochrane Collaboration's CENTRAL database and MEDLINE until May 1998. MAIN RESULTS: Eleven articles met criteria for inclusion in this review. Warfarin was more efficacious than placebo for primary stroke prevention (aggregate odds ratio [OR] of stroke = 0.30, 95% confidence interval [CI] 0.19, 0.48), with moderate evidence of more major bleeding (OR 1.90; 95% CI 0.89, 4.04). Aspirin was inconclusively more efficacious than placebo for stroke prevention (OR 0.56, 95% CI 0.19, 1.65), with inconclusive evidence regarding more major bleeds (OR 0.81, 95% CI 0.37, 1.77). For primary prevention, assuming a baseline risk of 45 strokes per 1,000 patient-years, warfarin could prevent 30 strokes at the expense of only 6 additional major bleeds. Aspirin could prevent 17 strokes, without increasing major hemorrhage. In direct comparison, there was evidence suggesting fewer strokes among patients on warfarin than among patients on aspirin (aggregate OR 0.64, 95% CI 0.43, 0.96), with only suggestive evidence for more major hemorrhage (OR 1.60, 95% CI 0.77,3.35). However, in younger patients, with a mean age of 65 years, the absolute reduction in stroke rate with warfarin compared with aspirin was low (5.5 per 1,000 person-years) compared with an older group (15 per 1,000 person-years). CONCLUSION: In general, the evidence strongly supports warfarin for patients with AF at average or greater risk of stroke. Aspirin may prove to be useful in subgroups with a low risk of stroke, although this is not definitively supported by the evidence.

Anticoagulants↗
PubMed2000

Evaluation of a national curriculum reform effort for the medicine core clerkship.

BACKGROUND: In 1995, the Society of General Internal Medicine (SGIM) and the Clerkship Directors in Internal Medicine (CDIM) developed and disseminated a new model curriculum for the medicine core clerkship that was designed to enhance learning of generalist competencies and increase interest in general internal medicine. OBJECTIVE: To evaluate the dissemination and use of the resulting SGIM/CDIM Core Medicine Clerkship Curriculum Guide. DESIGN: Survey of internal medicine clerkship directors at the 125 medical schools in the United States. MEASUREMENTS AND MAIN RESULTS: The questionnaire elicited information about the use and usefulness of the Guide and each of its components, barriers to effective use of the Guide, and outcomes associated with use of the Guide. Responses were received from 95 clerkship directors, representing 88 (70%) of the 125 medical schools. Eighty-seven (92%) of the 95 respondents were familiar with the Guide, and 80 respondents had used it. The 4 components used most frequently were the basic generalist competencies (used by 83% of those familiar with the Guide), learning objectives for these competencies (used by 83%), learning objectives for training problems (used by 70%), and specific training problems (used by 67%); 74% to 85% of those using these components found them moderately or very useful. The most frequently identified barriers to use of the Guide were insufficient faculty time, insufficient number of ambulatory care preceptors and training sites, and need for more faculty development. About 30% or more of those familiar with the Guide reported that use of the Guide was associated with improved ability to meet clerkship accreditation criteria, improved performance of students on the clerkship exam, and increased clerkship time devoted to ambulatory care. CONCLUSION: This federally supported initiative that engaged the collaborative efforts of the SGIM and the CDIM was successful in facilitating significant changes in the medicine core clerkship across the United States.

Baltimore↗
PubMed2000

US nephrologists' recommendation of dialysis modality: results of a national survey.

Selection of a dialysis modality for persons with end-stage renal disease (ESRD) has important lifestyle and occupational implications. The factors affecting modality choice remain unclear, resulting in a low rate of peritoneal dialysis (PD) in the United States compared with other countries. A national survey of 271 US nephrologists was conducted from June 1997 to June 1998 to assess the relative importance of nonclinical and clinical factors related to dialysis modality selection for patients with ESRD. Hypothetical patient scenarios were randomly assigned to nephrologists to determine their recommendation for dialytic therapy based on patient demographic, clinical, and social factors. US nephrologists were more likely to recommend PD for men with ESRD compared with women (39% versus 33%; P: < 0.05; adjusted odds ratio, 1.44; 95% confidence interval, 1.15 to 1.80), as well as for patients with good compliance (adjusted odds ratio, 11.80; 95% confidence interval, 9.29 to 15.01), weight less than 200 lb (adjusted odds ratio, 2.3; 95% confidence interval, 1.8 to 2.9), residual renal function (adjusted odds ratio, 2.14; 95% confidence interval, 1.71 to 2.70), absence of diabetes (adjusted odds ratio, 2.0; 95% confidence interval, 1.6 to 2.5), and living with family (adjusted odds ratio, 1.7; 95% confidence interval, 1.4 to 2.1). Nephrologists in practice for 11 or more years were less likely to recommend PD. The association of male sex with PD therapy suggests a potential bias or sensitivity to women's perception of body image. Race was not associated with PD recommendations after controlling for other demographic and clinical characteristics. Because the incident US ESRD population is increasingly characterized by factors associated with not selecting PD (diabetes, obesity, malnourishment, living alone, and substance abuse problems), our results suggest that PD use may decrease over time.

Adult↗
PubMed2000

Formal literature review of quality-of-life instruments used in end-stage renal disease.

Although quality-of-life assessment is an important complement to conventional clinical evaluation, there are limited opportunities for researchers in end-stage renal disease (ESRD) to examine evidence for a range of quality-of-life measures. To better understand how quality of life has been conceptualized, measured, and evaluated for ESRD, we conducted a structured literature review. Eligible articles were identified from a MEDLINE search, expert input, and review of references from eligible articles. A standardized instrument was created for article review and included type of measure, instrument development process, study sample characteristics, quality-of-life domains, and reliability and validity testing. From 436 citations, 78 articles were eligible for final review, and of those, 47 articles contained evidence of reliability or validity testing. Within this set, there were 113 uses of 53 different instruments: 82% were generic and 18% were disease specific. Only 32% defined quality of life. The most frequently assessed domains were depression (41%), social functioning (32%), positive affect (30%), and role functioning (27%). Testing was completed for test-retest reliability (20%), interrater reliability (13%), internal consistency (22%), content validity (24%), construct validity (41%), criterion validity (55%), and responsiveness (59%). Few articles measuring quality of life in ESRD defined quality-of-life domains or adequately described instrument development and testing. Generic measures, such as the Sickness Impact Profile, and disease-specific measures, such as the Kidney Disease Questionnaire, had been tested more thoroughly than others. Standardized reporting and more rigorous testing could help researchers make informed choices about instruments that would best serve their own and their patients' needs.

Humans↗
PubMed2000

The evidence regarding the drugs used for ventricular rate control.

OBJECTIVE: Our goal was to determine what drugs are most efficacious for controlling the ventricular rate in patients with atrial fibrillation. SEARCH STRATEGY: We conducted a systematic review of the literature published before May 1998, beginning with searches of The Cochrane Collaboration's CENTRAL database and MEDLINE. SELECTION CRITERIA: We included English-language articles describing randomized controlled trials of drugs used for heart rate control in adults with atrial fibrillation. DATA COLLECTION/ANALYSIS: Abstracts of trials were reviewed independently by 2 members of the study team. We reviewed English-language abstracts of non-English-language publications to assess qualitative consistency with our results. MAIN RESULTS: Forty-five articles evaluating 17 drugs met our criteria for review. In the 5 trials of verapamil and 5 of diltiazem, heart rate was reduced significantly (P <.05), both at rest and with exercise, compared with placebo, with equivalent or improved exercise tolerance in 6 of 7 comparisons. In 7 of 12 comparisons of a beta-blocker with placebo, the beta-blocker was efficacious for control of resting heart rate, with evidence that the effect is drug specific, as nadolol and atenolol proved to be most efficacious. All 9 comparisons demonstrated good heart rate control with beta-blockers during exercise, although exercise tolerance was compromised in 3 of 9 comparisons. In 7 of 8 trials, digoxin administered alone slowed the resting heart rate more than placebo, but it did not significantly slow the rate during exercise in 4 studies. The trials evaluating other drugs yielded insufficient evidence to support their use, but those drugs may yet be promising. CONCLUSIONS: The calcium-channel blockers verapamil or diltiazem, or select beta-blockers are efficacious for heart rate control at rest and during exercise for patients with atrial fibrillation without a clinically important decrease in exercise tolerance. Digoxin is useful when rate control during exercise is less a concern.

Adrenergic beta-Antagonists↗
PubMed2000

Efficacy of agents for pharmacologic conversion of atrial fibrillation and subsequent maintenance of sinus rhythm: a meta-analysis of clinical trials.

CONTEXT: Physicians have little evidentiary guidance for pharmacologic agent selection for atrial fibrillation (AF). OBJECTIVE: To assess antiarrhythmic agent efficacy for AF conversion and subsequent maintenance of sinus rhythm (MSR). DATA SOURCE: We searched the clinical trial database of the Cochrane Collaboration and MEDLINE encompassing literature from 1948 to May 1998. STUDY SELECTION: We selected 36 (28%) articles eligible as randomized trials of nonpostoperative AF conversion or MSR in adults. DATA EXTRACTION: Study quality; rates of conversion, MSR, and adverse events were extracted. DATA SYNTHESIS: Compared with control treatment (placebo, verapamil, diltiazem, or digoxin), the odds ratio (OR) for conversion was greatest for ibutilide/dofetilide (OR=29.1; 95% confidence interval [CI], 9.8-86.1) and flecainide (OR=24.7; 95% CI, 9.0-68.3). Less strong but conclusive evidence existed for propafenone (OR=4.6; 95% CI, 2.6-8.2). Quinidine (OR=2.9; 95% CI, 1.2-7.0) had moderate evidence of efficacy for conversion. Disopyramide (OR=7.0; 95% CI, 0.3-153.0) and amiodarone (OR=5.7; 95% CI, 1.0-33.4) had suggestive evidence of efficacy. Sotalol (OR=0.4; 95% CI, 0.0-3.0) had suggestive evidence of negative efficacy. For MSR, strong evidence of efficacy existed for quinidine (OR=4.1; 95% CI, 2.5-6.7), disopyramide (OR=3.4; CI, 1.6-7.1), flecainide (OR=3.1; 95% CI, 1.5-6.2), propafenone (OR=3.7; 95% CI, 2.4-5.7), and sotalol (OR=7.1; 95% CI, 3.8-13.4). The only amiodarone data, from comparison with disopyramide, provided moderate evidence of efficacy for MSR. No trial evaluated procainamide. Direct agent comparisons and adverse event data were limited. CONCLUSIONS: Although multiple antiarrhythmic agents had strong evidence of efficacy compared with control treatment for MSR, ibutilide/dofetilide and flecainide had particularly strong evidence of efficacy compared with control treatment for AF conversion. There is sparse and inconclusive evidence on direct agent comparisons and adverse event rates. Obtaining information regarding these relative efficacies should be a research priority.

Aged↗
PubMed1999

Complex gastrointestinal surgery: impact of provider experience on clinical and economic outcomes.

BACKGROUND: Commonly performed elective gastrointestinal surgical procedures are carried out with low morbidity and mortality in hospitals throughout the United States. Complex operative procedures on the alimentary tract are performed with a relatively low frequency and are associated with higher mortality. Volume and experience of the surgical provider team have been correlated with better clinical and economic outcomes for one complex gastrointestinal surgical procedure, pancreaticoduodenectomy. This study evaluated whether provider volume and experience were important factors influencing clinical and economic outcomes for a variety of complex gastrointestinal surgical procedures in one state. STUDY DESIGN: Complex high-risk gastrointestinal surgical procedures were defined as those with statewide in-hospital mortality of > or = 5%, frequency of greater than 200 per year in the state, and requiring special surgical skill and expertise. Six procedures met these criteria. Using publicly available discharge data, all patients discharged from Maryland hospitals from July 1989 to June 1997 with a primary procedure code for one of the six study procedures were selected. Hospitals were classified into one of six groups based on the average number of study procedures per year: 10 or less; 11 to 20; 21 to 50; 51 to 100; 101 to 200; and 201 or more procedures per year. A hospital was included if at least one procedure was performed there during the study period. No providers fell within the 51 to 100, and 101 to 200 groups, so all analyses were performed for the remaining four volume groups that were classified, respectively, as minimal (10 or fewer procedures), low (11 to 20 procedures), medium (21 to 50 procedures), and high-volume groups (201 or more procedures). Poisson regression was used to assess the relationship between in-hospital mortality and hospital volume after case-mix adjustment. Multiple linear regression models were used to assess differences in average length-of-stay and average total hospital charges among hospital volume groups. We further analyzed mortality, length-of-stay, and charges at the procedural level to understand these subgroups of complex gastrointestinal patients. We also examined the relationship between provider volume and outcomes for malignant versus benign diagnosis groups. RESULTS: Complex gastrointestinal surgical procedures were performed on 4,561 patients in Maryland from July 1989 through June 1997. The study population averaged 61.6 years of age, was 55% male, 71% Caucasian, and had predominantly Medicare as a payment source. After case-mix adjustment, patients who underwent complex gastrointestinal surgical procedures at the medium-, low-, and minimal-volume provider groups had a 2.1, 3.3, and 3.2 times greater risk of in-hospital death, respectively, than patients at the high-volume provider (p < 0.001 for all comparisons); longer lengths-of-stay, 16.1, 15.7, and 15.5 days at the low-, medium-, and minimal-volume groups, respectively, versus 14.0 days for the high-volume provider (p < 0.001 for all comparisons). Similarly, adjusted charges at the high-volume provider were, on average, 14% less than those of the low-volume group, which had the next lowest charges. Although mortality rates differed by procedure type, for each procedure, mortality increased as provider volume decreased, following the pattern found in the aggregate analysis. After case-mix adjustment, the risk of in-hospital death for patients with malignant diagnoses was significantly higher for the medium-, low-, and minimal-volume groups compared with patients at the high-volume provider, relative risk of 3.1, 4.0, and 4.2, respectively, (p < 0.001 for all comparisons). CONCLUSIONS: This study demonstrates that increased hospital experience is associated with a marked decrease in hospital mortality. The decreased mortality at the high-volume provider was also associated with shorter lengths-of-stay and lower hospital char

Clinical Competence↗
PubMed1999

Patient preferences for early discharge after laparoscopic cholecystectomy.

UNLABELLED: Patients may have concerns about their ability to manage postoperative symptoms at home after ambulatory surgery. We assessed patients' attitudes toward postoperative care at home or in the hospital after laparoscopic cholecystectomy. Thirty-eight patients undergoing elective laparoscopic cholecystectomy were pre- and postoperatively (within a week each) presented with scenarios describing symptoms of differing severity in either a home or hospital setting and were asked to rank and rate the relative desirability of the scenarios using rating scale, standard gamble, and willingness-to-pay techniques. Preoperatively, 16 (42%), 21 (55%), and 30 (79%) patients ranked pain of mild, moderate, and severe levels, respectively, as worse than the respective levels of nausea and vomiting. Of 24 patients, 19 (79%) preferred home care to hospital care for mild symptoms, and 12 of 22 patients (55%) preferred home care to hospital care for moderate symptoms. The average ratings were 20, 53, and 90 for mild, moderate, and severe symptoms, respectively, where 0 = no symptoms and 100 = the worst symptoms possible. Patients who preferred care outside the home indicated that they were willing to pay a mean of $142 (maximum $410) as a maximal copayment to have postoperative care in the hospital and a mean of $255 to receive care in a medical hotel-like facility. Postoperative assessment correlated highly with the preoperative assessment (correlation coefficient >0.6 for rating, standard gamble, and willingness-to-pay assessments). We conclude that patients vary in their attitudes toward where they would like to receive postoperative care. Attitudes assessed preoperatively may predict their attitudes postoperatively. IMPLICATIONS: Patients preferred to be at home for mild postoperative symptoms but in the hospital for worse postoperative symptoms. Preferences did not change with different methods of asking and were the same pre- and postoperatively. If patients made choices for their care before their procedure, they would still be happy with those decisions postoperatively.

Adult↗
PubMed1999

Outpatient-based bone marrow transplantation for hematologic malignancies: cost saving or cost shifting?

PURPOSE: To determine whether a shift in care from an inpatient-based to an outpatient-based bone marrow transplantation (BMT) program decreased charges to payers without increasing clinical complications or out-of-pocket costs to patients. PATIENTS AND METHODS: This nonrandomized prospective cohort study compared clinical and economic outcomes for 132 consecutive BMT patients with hematologic malignancies who received either inpatient- or outpatient-based BMT care. RESULTS: Seventeen of 132 BMT patients underwent outpatient-based BMT. Compared with the inpatient-based group, the outpatient-based group had a markedly lower mean number of inpatient hospital days (22 v 47; P <.001) and decreased mean inpatient facility charges ($61,059 less per patient; P <.0001) but had higher mean outpatient facility charges ($49,732 higher; P <. 0001). Total professional fees were similar for the groups. The mean total charge to payers was only 7% less ($12,652; P =.21) for outpatient-based BMT than for inpatient-based BMT, but total charge was 34% less for outpatient compared with inpatient BMT ($54,240; P = 0.056) in a subset of patients who had a standard rather than high risk of treatment failure. There was no significant difference between groups in out-of-pocket costs for transportation, lodging, meals, home nursing, household assistance, child care, medication expenses, or unreimbursed medical bills. There also was no significant difference between groups in reported income lost, involuntary unemployment, or months of disability. The two groups had similar rates of major complications, including death, significant acute graft-versus-host disease, and veno-occlusive disease of the liver. CONCLUSION: Increased use of outpatient-based BMT should produce substantial cost savings for payers without adverse effects on patients for those patients who do not have a high risk of treatment failure.

Adult↗