Cost of multiple sclerosis by level of disability: a review of literature

We performed a review of the economic literature to identify what is known about the relationship between Expanded Disability Status Scale (EDSS) categories and cost of multiple sclerosis (MS). We sought cohort studies of patients with multiple sclerosis that described the costs attributed to each EDSS score and utilized specific inclusion criteria for the selection of 10 studies. We found that both direct and indirect costs rise continuously with increasing EDSS category, and this rise is qualitatively exponential. The rise in indirect costs appears at lower EDSS scores. The cost of a relapse occurring in any given EDSS category exceeds that associated with that particular EDSS category. Few studies comprehensively assessed the entire spectrum of the costs, and much of the literature is based on EDSS categories in coarse groupings. In spite of several variations between studies, one important conclusion that we can draw is that rise in cost is positively correlated to scores on the EDSS categories, and therefore agents with a capacity to prevent or arrest the rate of MS progression may affect the overall cost of MS.

Systematic review of CT and MR perfusion imaging for assessment of acute cerebrovascular disease

BACKGROUND AND PURPOSE

Perfusion imaging sequences are an important part of imaging studies designed to provide information to guide therapy for treatment of cerebrovascular disease. The purpose of this study was to perform a meta-analysis of the medical literature on perfusion imaging to determine its role in clinical decision making for patients with acute cerebral ischemia.

MATERIALS AND METHODS

We searched MEDLINE by using a strategy that combined terms related to perfusion imaging with terms related to acute cerebral ischemia and brain tumors. We identified 658 perfusion imaging articles and classified them according to the clinical usefulness criteria of Thornbury and Fryback. We found 59 articles with promise of indicating usefulness in clinical decision making. We devised and implemented a clinical decision making scoring scale more appropriate to the topic of acute cerebral ischemia.

RESULTS

Several articles provided important insights into the physiologic processes underlying acute cerebral ischemia by correlation of initial perfusion imaging deficits with clinical outcome or ultimate size of the infarct. However, most articles showed relatively low relevance to influencing decisions in implementing treatment.

CONCLUSION

Most perfusion imaging articles are oriented toward important topics such as optimization of imaging parameters, determination of ischemia penumbra, and prediction of outcome. However, information as to the role of perfusion imaging in clinical decision making is lacking. Studies are needed to demonstrate that use of perfusion imaging changes outcome of patients with acute cerebral ischemia.

Oxygen for relief of dyspnoea in mildly- or non-hypoxaemic patients with cancer: a systematic review and meta-analysis

The aim of this study was to determine the efficacy of palliative oxygen for relief of dyspnoea in cancer patients. MEDLINE and EMBASE were searched for randomised controlled trials, comparing oxygen and medical air in cancer patients not qualifying for home oxygen therapy. Abstracts were reviewed and studies were selected using Cochrane methodology. The included studies provided oxygen at rest or during a 6-min walk. The primary outcome was dyspnoea. Standardised mean differences (SMDs) were used to combine scores. Five studies were identified; one was excluded from meta-analysis due to data presentation. Individual patient data were obtained from the authors of the three of the four remaining studies (one each from England, Australia, and the United States). A total of 134 patients were included in the meta-analysis. Oxygen failed to improve dyspnoea in mildly- or non-hypoxaemic cancer patients (SMD=-0.09, 95% confidence interval -0.22 to 0.04; P=0.16). Results were stable to a sensitivity analysis, excluding studies requiring the use of imputed quantities. In this small meta-analysis, oxygen did not provide symptomatic benefit for cancer patients with refractory dyspnoea, who would not normally qualify for home oxygen therapy. Further study of the use of oxygen in this population is warranted given its widespread use.

Quality measures for the diagnosis and management of colorectal cancer

16031

Background: The huge burden of illness from colorectal cancer (CRC) can be reduced by improving the quality of care for CRC patients. Identifying appropriate quality measures that can assess the processes of care is the first step in this process. Therefore we conducted a comprehensive literature search to identify process measures available in the United States to assess the quality of care for diagnosing and managing patients with CRC and the extent to which they were field-ready. Methods: We conducted a standard literature search using MEDLINE and the Cochrane Database; also explored gray literature, and identified 3771 abstracts. By sequential exclusion, 74 of them were finally included. We included quality measures from traditional QI literature, and supplemented them with those included in studies where these measures were used as part of their research agenda. All measures were abstracted into evidence tables and evaluated using a set of standard criteria regarding their importance, usability, and scientific acceptability. In order to assess the extent to which they were field-ready, we devised a summary rating scale for each quality measure using three criteria: importance and usability, scientific acceptability, and extent of testing. Results: Overall, the coverage of general process measures in CRC is extensive. Process measures are available for diagnostic imaging, staging, surgical therapy, adjuvant chemotherapy, adjuvant radiation therapy, and colonoscopic surveillance. The highest rated measures were those related to chemotherapy (abstract submitted by Morse et al) and pathology reporting. There were no process measures for assessing the quality of: polyp removal, surgical management of stage IV rectal cancer, hepatic metastasis, chemotherapy for stage II colon cancer, stage IV rectal cancer, radiation for stage IV rectal cancer, and notes for endoscopy, surgery, chemotherapy and radiology - all because of lack of guidelines. Conclusions: Our evidence report suggests that we need to actively pursue the task of developing scientifically accurate quality measures for leverage points in the diagnosis and management of CRC; so we can evaluate the quality of care delivered by providers and initiate quality improvement activities, with the aim of providing better patient care.

No significant financial relationships to disclose.

TRIPSTAR: prioritizing oral triptan treatment attributes in migraine management

Migraine can be associated with severe pain and is often very disabling. Optimal treatment should provide rapid and sustained, complete pain relief, be well tolerated and restore normal function. The seven commercially available triptans show differences in performance on individual treatment attributes. The TRIPSTAR multiattribute decision model compares the profiles of the oral triptans, using efficacy and tolerability data weighted for importance, to identify if measurable differences are clinically relevant. Application of the TRIPSTAR model was demonstrated at the Migraine Trust International Symposium 2002, where delegates collectively prioritized treatment attributes according to the needs of a specific patient case history. The TRIPSTAR model identified the preferred triptans for this patient. These three triptans, almotriptan 12.5 mg, eletriptan 80 mg and rizatriptan 10 mg, standout in a triptan meta-analysis, three TRIPSTAR surveys and in a demonstration of the TRIPSTAR model at a symposium in the USA. Taken together the findings suggest that some differences amongst triptans may be relevant in clinical practice.

Host immune responses and intestinal permeability in patients with jaundice

BACKGROUND

Systemic endotoxaemia is implicated in the development of complications associated with obstructive jaundice. The aims of these studies were to assess the systemic immune response to intervention in patients with jaundice and to compare the effects of surgical and non-surgical biliary drainage on host immune function and gut barrier function.

METHODS

In the first study, 18 jaundiced and 12 control patients were studied to assess systemic immune responses before and after intervention. In the second study, immune responses and gut barrier function were assessed following surgical and non-operative biliary decompression in 45 patients with jaundice.

RESULTS

Endotoxin antibody concentrations fell significantly in patients with jaundice immediately after surgical intervention, but not after non-operative biliary drainage. This decrease was associated with a significant increase in serum P(55) soluble tumour necrosis factor (sTNF) receptor concentration (5.3 versus 10.5 ng/ml; P < 0.001), urinary excretion of P(55) TNF receptors (21.4 versus 78.8 ng/ml; P = 0.002) and intestinal permeability (lactulose : mannitol ratio 0.032 versus 0.082; P = 0.048). Intestinal permeability was significantly increased in patients with jaundice compared with controls (0.033 versus 0.015; P = 0.002).

CONCLUSION

These data suggest that obstructive jaundice is associated with impaired gut barrier function and activation of host immune function that is exacerbated by intervention. Surgery causes an exaggerated pathophysiological disturbance not seen with non-operative biliary drainage procedures.

Oral sumatriptan for acute migraine

BACKGROUND

Migraine is a common neurovascular disorder characterized by recurrent episodes of disabling headache, autonomic nervous system dysfunction, and, in some patients, neurological aura symptoms. Sumatriptan is one of a class of selective serotonin 5-hydroxytryptamine (5-HT1B/1D) agonists (triptans) thought to relieve migraine attacks by several mechanisms, including cranial vasoconstriction and peripheral and central neural inhibition.

OBJECTIVES

To describe and assess the evidence from randomized controlled trials (RCTs) concerning the efficacy and tolerability of oral sumatriptan for the treatment of a single acute attack of migraine in adults.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (Cochrane Library, Issue 4, 2001), MEDLINE (1966 through November 2001), and reference lists of articles and books.

SELECTION CRITERIA

We included double-blind RCTs comparing oral sumatriptan (100 mg, 50 mg, 25 mg) with placebo, no intervention, other drug treatments, behavioral therapy, or physical therapy for the treatment of an acute attack of migraine in adults. Trials comparing different doses of sumatriptan or dosing regimens were also included. Outcomes considered were: 2-hour pain-free response, headache relief/headache intensity, and functional disability; headache recurrence; and adverse events.

DATA COLLECTION AND ANALYSIS

Data were abstracted by one reviewer and over-read by the other. The two reviewers independently assessed trial quality. Information on adverse events was collected from trial reports.

MAIN RESULTS

Twenty-five trials involving 16,200 participants were included. Methodological quality was generally good. Sixteen trials were placebo comparisons and showed that sumatriptan in doses of 100 mg (14 trials), 50 mg (five trials), and 25 mg (three trials) provided significantly better pain-free response (100 mg and 25 mg only), headache relief, and relief of disability at 2 hours. Numbers-needed-to-treat (NNTs) for pain-free response at 2 hours were 5.1 (3.9 to 7.1) for the 100-mg dose (n = 2221) and 7.5 (2.7 to 142) for the 25-mg dose (n = 131); there was no significant difference between the 50-mg dose and placebo for this outcome (n = 127). For headache relief at 2 hours, NNTs were 3.4 (3.0 to 4.0), 3.2 (2.4 to 5.1), and 3.4 (2.3 to 6.6) for sumatriptan 100 mg (n = 2940), 50 mg (n = 420), and 25 mg (n = 226), respectively. Precise estimates of the efficacy of the 50- and 25-mg doses relative to the 100-mg dose could not be obtained. Adverse events were more common with sumatriptan 100 mg than with placebo (risk difference [RD] = 0.14 [0.09 to 0.20]; number-needed-to-harm [NNH] = 7.1 [5.0 to 11.1]; n = 3172). RDs for the 50- and 25-mg vs. placebo comparisons were not statistically significant.

REVIEWER'S CONCLUSIONS

Oral sumatriptan has been shown to be an effective drug for the treatment of a single acute attack of migraine. It is well tolerated, though minor adverse events were not uncommon in the included trials. Other triptans were generally similar in efficacy and adverse events. Among non-triptan drugs, ergotamine + caffeine was significantly less effective than sumatriptan, and other drugs have been insufficiently studied to draw firm conclusions.

Anti-cholinergic bronchodilators versus beta2-sympathomimetic agents for acute exacerbations of chronic obstructive pulmonary disease

BACKGROUND

Inhaled bronchodilators form the mainstay of treatment for acute exacerbations of COPD. Two types of agent are used routinely, either singly or in combination: anticholinergic agents and beta2-sympathomimetic agonists.

OBJECTIVES

To assess the effect of anti-cholinergic agents on lung function and dyspnea in patients with acute exacerbations of COPD, compared with placebo or short-acting beta-2 agonists.

SEARCH STRATEGY

A comprehensive search of the literature was carried out on MEDLINE, EMBASE, CINAHL and the Cochrane COPD Trials Register, using the terms: bronchodilator* OR ipratropium OR oxitropium. References listed in each included trial were searched for additional trial reports.

SELECTION CRITERIA

Studies were included if the participants were adult patients with a known diagnosis of COPD and had symptoms consistent with criteria for acute exacerbation of COPD. All randomized controlled trials that compared inhaled ipratropium bromide or oxitropium bromide to appropriate controls were considered. Appropriate control treatments included placebo, other bronchodilating agents, or combination therapies. Studies of acute asthma or ventilated patients were excluded.

DATA COLLECTION AND ANALYSIS

All trials that appeared to be relevant were assessed by two reviewers who independently selected trials for inclusion. Differences were resolved by consensus.

MAIN RESULTS

Four trials compared the short-term effects of ipratropium bromide vs. a beta2-agonist. Short-term changes in FEV1 (up to 90 minutes) showed no significant difference between beta2-agonist and ipratropium bromide treated patients. The differences were similar among the studies and when combined: Weighted Mean Difference (WMD) 0.0 liters (95% Confidence Interval (95% CI) -0.19, 0.19). There was no significant additional increase in change in FEV1 on adding ipratropium to beta2-agonist: WMD 0.02 liter (95% CI -0.08, 0.12). Long-term effects (24 hours) of the ipratropium bromide and beta2-agonist treatment combination were similar: WMD 0.05 liters (95%CI -0.14, 0.05). Neither of two studies found significant changes in PaO2, either short- or long-term, with ipratropium vs. beta-agonist, although one showed an increase in PaO2 in subjects receiving ipratropium bromide at 60 minutes. Adverse drug reactions included dry mouth and tremor.

REVIEWER'S CONCLUSIONS

There was no evidence that the degree of bronchodilation achieved with ipratropium bromide was greater than that using a short-acting beta2-agonist. The combination of a beta2-agonist and ipratropium did not appear to increase the effect on FEV1 more than either used alone.

Butalbital in the treatment of headache: history, pharmacology, and efficacy

Analgesics containing butalbital compounded with aspirin, acetaminophen, and/or caffeine are widely used for the treatment of migraine and tension-type headache. The butalbital-containing compounds are efficacious in placebo-controlled trials among patients with episodic tension-type headaches. Despite their frequent clinical use for migraine, they have not been studied in placebo-controlled trials among patients with migraine. Barbiturates can produce intoxication, hangover, tolerance, dependence, and toxicity. Butalbital can result in intoxication that is clinically indistinguishable from that produced by alcohol. Butalbital-containing analgesics can produce drug-induced headache in addition to tolerance and dependence. Higher doses can produce withdrawal syndromes after discontinuation. Butalbital-containing analgesics may be effective as backup medications or when other medications are ineffective or cannot be used. Because of concerns about overuse, medication-overuse headache, and withdrawal, their use should be limited and carefully monitored.

Management of acute exacerbations of chronic obstructive pulmonary disease: a summary and appraisal of published evidence

PURPOSE

To review critically the available data on diagnostic evaluation, risk stratification, and therapeutic management of patients with acute exacerbations of chronic obstructive pulmonary disease (COPD).

DATA SOURCES

English-language articles were identified by searching MEDLINE (1966 to 2000, week 5), EMBASE (1974 to 2000, week 18), HealthStar (1975 to June 2000), and the Cochrane Controlled Trials Register (2000, Issue 1).

STUDY SELECTION

The best available evidence on each subtopic was selected for analysis. Randomized trials, sometimes buttressed by cohort studies, were used to evaluate therapeutic interventions. Cohort studies were used to evaluate diagnostic tests and risk stratification.

DATA EXTRACTION

Study design and results were summarized in evidence tables. Individual studies were rated by internal validity, external validity, and quality of design. Statistical analyses of combined data were not performed.

DATA SYNTHESIS

Data on the utility of most diagnostic tests are limited. However, chest radiography and arterial blood gas sampling seem useful while acute spirometry does not. Identifiable clinical variables are associated with risk for relapse and risk for death after hospitalization for an acute exacerbation. Evidence of efficacy was found for bronchodilators, corticosteroids, and noninvasive positive-pressure ventilation. There is also support for the use of antibiotics in patients with more severe exacerbations. On the basis of limited data, mucolytics and chest physiotherapy do not seem to be of benefit, and oxygen supplementation seems to increase the risk for respiratory failure only in an identifiable subgroup of patients.

CONCLUSIONS

Although suggestions for appropriate management can be made on the basis of available evidence, the supporting literature is scarce and further high-quality research is necessary. Such research will require an improved, generally acceptable, and transportable definition of acute exacerbation of COPD, as well as improved methods for observing and measuring outcomes.

Surgical trainees' attitudes to laparoscopic cholecystectomy: a regional survey

BACKGROUND AND STUDY AIMS

Since the introduction of laparoscopic cholecystectomy (LC), numerous articles have been written emphasising its many advantages over open cholecystectomy (OC). However, reports also highlight increased complications following LC such as bile-duct, vascular and bowel injuries. We aimed to study surgical trainees as a defined population of individuals who, with increasing exposure to cholecystectomy, would become fully aware of LC's advantages and controversies. We wished to test the hypothesis that, with increasing in-depth knowledge, they might opt for OC rather than LC if they themselves required cholecystectomy.

MATERIALS AND METHODS

We conducted a postal survey of all 133 Northern Ireland surgical trainees identified as having exposure to LC during their training. Trainees were asked whether they would undergo LC and if so with which preconditions. Similarly, if they stated a preference for open cholecystectomy they were asked to state the reason. A minimum time period of 18 months was considered adequate for trainees to become relatively more experienced in this field compared with their more junior counterparts.

RESULTS

A response rate of 80.5% (107/133) was achieved. A total of 51 of 107 trainees had at least 18 months' experience. Of the 107 who replied, 88.8% (95/107) would be willing to undergo LC. A total of 12 of 107 trainees would opt for OC, with twice as many experienced trainees (8 vs. 4) opting for this approach (n.s. [not significant]). Significantly more experienced trainees cited the use of laparoscopic cholangiography as a precondition for LC compared with their inexperienced counterparts (7 vs. 1, p = 0.020). Of 107 trainees, 19 would request use of the open first port (Hasson) technique; 14 of these had at least 18 months' experience (p = 0.009).

CONCLUSION

Our survey confirms that the majority of trainees would be willing to undergo LC. However, increased experience of LC may alter an individual's expectations about how LC should ideally be performed.

Management of acute exacerbations of COPD: a summary and appraisal of published evidence

STUDY OBJECTIVES

To critically review the available data on the diagnostic evaluation, risk stratification, and therapeutic management of patients with acute exacerbations of COPD.

DESIGN, SETTING, AND PARTICIPANTS

English-language articles were identified from the following databases: MEDLINE (from 1966 to week 5, 2000), EMBASE (from 1974 to week 18, 2000), HealthStar (from 1975 to June 2000), and the Cochrane Controlled Trials Register (2000, issue 1). The best available evidence on each subtopic then was selected for analysis. Randomized trials, sometimes buttressed by cohort studies, were used to evaluate therapeutic interventions. Cohort studies were used to evaluate diagnostic tests and risk stratification. Study design and results were summarized in evidence tables. Individual studies were rated as to their internal validity, external validity, and quality of study design. Statistical analyses of combined data were not performed.

MEASUREMENT AND RESULTS

Limited data exist regarding the utility of most diagnostic tests. However, chest radiography and arterial blood gas sampling appear to be useful, while short-term spirometry measurements do not. In terms of the risk of relapse and the risk of death after hospitalization for an acute exacerbation, there are identifiable clinical variables that are associated with these outcomes. Therapies for which there is evidence of efficacy include bronchodilators, corticosteroids, and noninvasive positive-pressure ventilation. There is also support for the use of antibiotics in patients with more severe exacerbations. Based on limited data, mucolytics and chest physiotherapy do not appear to be of benefit, and oxygen supplementation appears to increase the risk of respiratory failure in an identifiable subgroup of patients.

CONCLUSIONS

Although suggestions for appropriate management can be made based on available evidence, the supporting literature is spotty. Further high-quality research is needed and will require an improved, generally acceptable, and transportable definition of the syndrome "acute exacerbation of COPD" and improved methods for observing and measuring outcomes.

Setting the target for a better cervical screening test: characteristics of a cost-effective test for cervical neoplasia screening

OBJECTIVE

To determine the potential effects on costs and outcomes of changes in sensitivity and specificity with new screening methods for cervical cancer.

METHODS

Using a Markov model of the natural history of cervical cancer, we estimated the effects of sensitivity, specificity, and screening frequency on cost-effectiveness. Our estimates of conventional Papanicolaou test sensitivity of 51% and specificity of 97% were obtained from a meta-analysis. We estimated the effect of reducing false-negative rates from 40-90% and increasing false-positive rates by up to 20%, independently and jointly. We varied the marginal cost of improving sensitivity from $0 to $15.

RESULTS

When specificity was held constant, increasing sensitivity of the Papanicolaou test increased life expectancy and costs. When sensitivity was held constant, decreasing specificity of the Papanicolaou test increased costs, an effect that was more dramatic at more frequent intervals. Decreased specificity had a substantial effect on cost-effectiveness estimates of improved Papanicolaou test sensitivity. Most of those effects are related to the cost of evaluation and treatment of low-grade lesions.

CONCLUSION

Policies or technologies that increased sensitivity of cervical cytologic screening increased overall costs, even if the cost of the technology was identical to that of conventional Papanicolaou smears. These effects appear to be caused by relatively high prevalence of low-grade lesions and are magnified at frequent screening intervals. Efficient cervical cancer screening requires methods with greater ability to detect lesions that are most likely to become cancerous.

Mathematical model for the natural history of human papillomavirus infection and cervical carcinogenesis

The authors constructed a Markov model as part of a systematic review of cervical cytology conducted at the Duke University Evidence-based Practice Center (Durham, North Carolina) between October 1997 and September 1998. The model incorporated states for human papillomavirus infection (HPV), low- and high-grade squamous intraepithelial lesions, and cervical cancer stages I-IV to simulate the natural history of HPV infection in a cohort of women from ages 15 to 85 years. The age-specific incidence rate of HPV, and regression and progression rates of HPV and squamous intraepithelial lesions, were obtained from the literature. The effects of varying natural history parameters on cervical cancer incidence were evaluated by using sensitivity analysis. The base-case model resulted in a lifetime cervical cancer risk of 3.67% and a lifetime cervical cancer mortality risk of 1.26%, with a peak incidence of 81/100,000 at age 50 years. Age-specific distributions of precursors were similar to reported data. Lifetime risk of cancer was most sensitive to the incidence of HPV and the probability of rapid HPV progression to high-grade lesions (two- to threefold variations in risk). The model approximates the age-specific incidence of cervical cancer and provides a tool for evaluating the natural history of HPV infection and cervical cancer carcinogenesis as well as the effectiveness and cost-effectiveness of primary and secondary prevention strategies.

Accuracy of the Papanicolaou test in screening for and follow-up of cervical cytologic abnormalities: a systematic review

PURPOSE

To evaluate the accuracy of conventional and new methods of Papanicolaou (Pap) testing when used to detect cervical cancer and its precursors.

DATA SOURCES

Systematic search of English-language literature through October 1999 using MEDLINE, EMBASE, other computerized databases, and hand searching.

STUDY SELECTION

All studies that compared Pap testing (conventional methods, computer screening or rescreening, or monolayer cytology) with a concurrent reference standard (histologic examination, colposcopy, or cytology).

DATA EXTRACTION

Two reviewers independently reviewed selection criteria and completed 2 x 2 tables for each study.

DATA SYNTHESIS

94 studies of the conventional Pap test and three studies of monolayer cytology met inclusion criteria. No studies of computerized screening were included. Data were organized by cytologic and histologic thresholds used to define disease. For conventional Pap tests, estimates of sensitivity and specificity varied greatly in individual studies. Methodologic quality and frequency of histologic abnormalities also varied greatly between studies. In the 12 studies with the least biased estimates, sensitivity ranged from 30% to 87% and specificity ranged from 86% to 100%.

CONCLUSIONS

Insufficient high-quality data exist to estimate test operating characteristics of new cytologic methods for cervical screening. Future studies of these technologies should apply adequate reference standards. Most studies of the conventional Pap test are severely biased: The best estimates suggest that it is only moderately accurate and does not achieve concurrently high sensitivity and specificity. Cost-effectiveness models of cervical cancer screening should use more conservative estimates of Pap test sensitivity.

Getting meaningful informed consent from older adults: a structured literature review of empirical research

OBJECTIVES

To perform a structured literature review of the published empirical research on informed consent with older adults in order to make recommendations to improve the informed consent process and to highlight areas needing further examination.

DESIGN

Relevant literature was identified by searching electronic databases (AGELINE, BIOETHICSLINE, CancerLit, Ethics Index, Health, LegalTrac, MEDLINE, PAIS International, PsycInfo, and Sociofile). Studies were included if they were reports of primary research data about informed consent and, if patients or other subjects were used, older subjects were included in the sample. Data related to the aspect of informed consent under study (recruitment, decision-making capacity, voluntariness, disclosure of information, understanding of information, consent forms, authorization, and policies and procedures) were abstracted and entered into a specially designed database.

MEASUREMENTS

Characterization of the population, age of subjects, setting, whether informed consent was being studied in the context of research or treatment, study design, the nature of outcome or dependent variables, independent variables (e.g., experimental conditions in a randomized controlled trial or patient/subject characteristics in a nonrandomized comparison), and results according to the aspect of informed consent under study.

RESULTS

A total of 99 articles met all the inclusion criteria and posed 289 unique research questions covering a wide range of aspects of informed consent: recruitment (60); decision making capacity (21); voluntariness (6); disclosure (30); understanding (139); consent forms (7); authorization (11); policies (13); and other (2). In the secondary analyses of numerous studies, diminished understanding of informed consent information was associated with older age and fewer years of education. Older age was also sometimes associated with decreased participation in research. Studies of disclosure of informed consent information suggest strategies to improve understanding and include a variety of novel formats (e.g., simplified, storybook, video) and procedures (e.g., use of health educators, quizzing subjects, multiple disclosure sessions).

CONCLUSIONS

A systematic review of the published literature on informed consent reveals evidence for impaired understanding of informed consent information in older subjects and those with less formal education. Effective strategies to improve the understanding of informed consent information should be considered when designing materials, forms, policies, and procedures for obtaining informed consent. Other than empirical research that has investigated disclosure and understanding of informed consent information, little systematic research has examined other aspects of the informed consent process. This deficit should be rectified to ensure that the rights and interests of patients and of human subjects who participate in research are adequately protected.

Influence of projected complication rates on estimated appropriate use rates for carotid endarterectomy. Appropriateness Project Investigators. Academic Medical Center Consortium

OBJECTIVE

To examine specifically the influence of estimated perioperative mortality and stroke rate on the assessment of appropriateness of carotid endarterectomy.

DATA SOURCES/STUDY SETTING

An expert panel convened to rate the appropriateness of a variety of potential indications for carotid endarterectomy based on various rates of perioperative complications. We then applied these ratings to the charts of 1,160 randomly selected patients who had carotid endarterectomy in one of the 12 participating academic medical centers.

STUDY DESIGN

An expert panel evaluated indications for carotid endarterectomy using the modified Delphi approach. Charts of patients who received surgery were abstracted, and clinical indications for the procedure as well as perioperative complications were recorded. To examine the impact of surgical risk assessment on the rates of appropriateness, three different definitions of risk strata for combined perioperative death or stroke were used: Definition A, low risk < 3 percent; Definition B, low risk < 5 percent; and Definition C, low risk < 7 percent.

PRINCIPAL FINDINGS

Overall hospital-specific mortality ranged from 0 percent to 4.0 percent and major complications, defined as death, stroke, intracranial hemorrhage, or myocardial infarction, varied from 2.0 percent to 11.1 percent. Most patients (72 percent) had surgery for transient ischemic attack or stroke; 24 percent of patients were asymptomatic. Most patients (82 percent) had surgery on the side of a high-grade stenosis (70-99 percent). When the thresholds for operative risk were placed at the values defined by the expert panel (Definition A), only 33.5 percent of 1,160 procedures were classified as "appropriate." When the definition of low risk was shifted upward, the proportion of cases categorized as appropriate increased to 58 percent and 81.5 percent for Definitions B and C, respectively.

CONCLUSIONS

Despite the high proportion of procedures performed for symptomatic patients with a high degree of ipsilateral extracranial carotid artery stenosis and generally low rates of surgical complications at the participating institutions, the overall rate of "appropriateness" using a perioperative complication rate of < 3 percent was low. However, the rate of "appropriateness" was extremely sensitive to judgments about a single clinical feature, surgical risk. These data show that before applying such "appropriateness" ratings, it is crucial to perform sensitivity analyses in order to assess the stability of the results. Results that are robust to moderate in variation in surgical risk provide a much sounder basis for policy making than those that are not.

Treatment considerations for persons with metastatic prostate cancer: survival versus out-of-pocket costs

OBJECTIVES

Treatment decisions for metastatic prostate cancer require the consideration of factors such as survival, quality of life, costs of care, and toxicities. In this study, we queried physicians who had extensive experience with prostate cancer about features of metastatic prostate cancer, patients' quality of life, and factors influencing their decision to prescribe flutamide.

METHODS

Data were gathered through physician surveys and focus group discussions. Demographic information on the physicians and their patients was collected. Physicians made assessments of five health states related to metastatic prostate cancer, based on the time trade-off technique, and on the desirability of flutamide, based on average expected improvement in survival free of progressive disease, side effects, and drug cost.

RESULTS

Physicians were internally consistent in their judgments of the factors most important to quality of life for individuals with metastatic prostate cancer. Physicians considered bone pain and weight loss/anorexia the most important factors. Physicians who cared for a higher proportion of older persons or Medicare recipients rated each scenario as less undesirable than did physicians with a lower proportion of these patients. Out-of-pocket cost was the major factor predicting whether a physician would prescribe flutamide. Physicians working for health maintenance organizations were more likely to prescribe flutamide but were more sensitive to out-of-pocket costs than were other physicians.

CONCLUSIONS

Physicians-varied in their perceptions of quality of life for persons with metastatic prostate cancer and in their willingness to prescribe flutamide. These perceptions and prescribing preferences are strongly influenced by factors other than health status or specific health benefits. In deciding to prescribe flutamide, concerns over out-of-pocket expenditures loom large for most clinicians. It would be important to know the degree to which these concerns are shared by patients and whether prescribing preferences differ for Medicare managed-care patients who have pharmaceutical benefits.

Stroke prevention: the emerging strategies

Warfarin prophylaxis in patients with nonvalvular atrial fibrillation may be one of the most valuable public-health interventions. Barriers to its optimal utilization include wariness about bleeding complications and concern about age-related sensitivity to the drug. The risks, however, may be minimized by creation of anticoagulation clinics to ensure optimal dosing and follow-up.

Comparison and meta-analysis of randomized trials of endarterectomy for symptomatic carotid artery stenosis

OBJECTIVE

Comparison and meta-analysis of randomized trials of carotid endarterectomy for symptomatic stenosis of the extracranial carotid artery.

BACKGROUND

Randomized trials (North American Symptomatic Carotid Endarterectomy Trial [NASCET], the European Carotid Surgery Trial [ECST], and the VA Cooperative Study [VACS]) each show that carotid endarterectomy improves outcomes in selected symptomatic patients with high-grade extracranial carotid artery stenosis. Direct comparisons among the studies have not been possible because of differing methodologies, endpoints, and formats of data reporting.

DESIGN/METHODS

Data for specified endpoints and corresponding person-years at risk were obtained for each trial. The rates of nonfatal stroke, nonfatal myocardial infarction, or death for surgically or medically treated patients in the perioperative period (30 days) and thereafter were compared (both including and excluding perioperative events) and then combined using meta-analytic techniques. Data from NASCET and ECST were also analyzed for differences in outcomes by sex.

RESULTS

Event rate estimates (with 95% confidence intervals [95% CI]) for the first 30 days (events per person-year, primarily nonfatal stroke) for medically treated patients were 0.44 (0.22 to 0.76) for NASCET, 0.15 (0.04 to 0.38) for ECST, and 0.27 (0.03 to 0.96) for VACS. For surgically treated patients, the corresponding rates (per person-year) were 0.78 (0.49 to 1.19), 0.63 (0.41 to 0.94), and 1.27 (0.58 to 2.43). Event rates per year after 30 days were higher for medically treated patients (0.20 [0.16 to 0.25] versus 0.08 [0.05 to 0.11] for NASCET; 0.12 [0.10 to 0.15] versus 0.07 [0.06 to 0.09] for ECST; and 0.15 [0.07 to 0.25] versus 0.07 [0.03 to 0.16] for VACS). There were no significant differences among the trials, with an overall benefit for surgical therapy (risk ratio estimate, RR = 0.67, 95% CI = 0.54 to 0.83). There were no significant sex-based differences between NASCET and ECST and the overall benefit was not significantly different for men and women (RR = 0.58, 95% CI = 0.45 to 0.74 for men; RR = 0.84, 95% CI = 0.57 to 1.25 for women).

CONCLUSIONS

Adjusting for primary endpoints and duration of follow-up, carotid endarterectomy has a similar benefit for symptomatic patients across trials and a similar benefit for men and women.

Physician attitudes about anticoagulation for nonvalvular atrial fibrillation in the elderly

BACKGROUND

Our goal was to determine whether patient age affects a physician's reported likelihood of using anticoagulant therapy or the intensity of anticoagulant therapy for patients with nonvalvular atrial fibrillation.

METHODS

We surveyed a nationwide sample of 1189 randomly selected office-based practitioners in three strata: primary care (geriatrics, internal medicine, family practice, and general practice), cardiology, and neurology. A vignette-based questionnaire was used to measure attitudes and beliefs regarding anticoagulation risks and effectiveness, barriers to anticoagulation in clinical practice, and likelihood of using anticoagulation and target intensity of anticoagulation at three patient ages (55, 65, and 75 years) for four clinical scenarios (chronic non-valvular atrial fibrillation with mild left atrial enlargement, intermittent or paroxysmal atrial fibrillation, recent-onset atrial fibrillation, and atrial fibrillation with recent [3 months] embolic stroke).

RESULTS

The overall response rate was 38%. The mean likelihoods of using anticoagulation for the three ages were unequal (P < .0001) for each scenario. Most physicians were "very" or "somewhat" likely to use anticoagulant therapy for a 65-year-old with left atrial enlargement (71%), intermittent or paryoxysmal atrial fibrillation (68%), recent-onset atrial fibrillation (86%), or embolic stroke (96%). Fewer physicians were likely to use anticoagulant therapy for a 75-year-old with left atrial enlargement (63%), intermittent or paroxysmal atrial fibrillation (56%), recent-onset atrial fibrillation (80%), or embolic stroke (93%). Among physicians equally likely to use anticoagulation for 65- and 75-year-old patients, intensity of anticoagulant therapy (target international normalized ratio or prothrombin time ratio) was lower (P < .04) for the 75-year-old.

CONCLUSION

Anticoagulant therapy may be less often and less intensively used for elderly patients with nonvalvular atrial fibrillation.

Meta-analytic tools for medical decision making: a practical guide

This paper is an extension of notes used for the short course in meta-analysis given at the 13th and 14th annual meetings of the Society for Medical Decision Making. The material covers both standard and evolving methods of meta-analysis. The methods include those for combining p-values, for analyzing general fixed-effects models, for analyzing contingency tables, and for analyzing count and continuous outcomes. For each general method, the authors present simplified formulas first, followed by more precise formulas when necessary. Similarly, both classic and Bayesian methods are presented where appropriate. Actual examples are used for methods.

Performance of the serum cobalamin assay for diagnosis of cobalamin deficiency

The authors' objective, with this study, was to determine the use in routine clinical practice of the cobalamin serum assay in evaluating patients suspected of having cobalamin deficiency. The design was a prospective observational study of a diagnostic test compared with a criterion gold standard. The setting was the Veterans Affairs hospital inpatient wards and outpatient clinics. The authors prospectively identified all patients who had serum cobalamin measured and enrolled all those with cobalamin < 133 pmol/L (180 pg/mL) and a random sample of patients with cobalamin greater than or equal to 133 pmol/L (N = 168). There were no interventions. To identify cobalamin deficiency, subjects underwent blinded clinical and laboratory examinations, Schilling test, and urinary methylmalonic acid assay, with a trial of cobalamin replacement, if needed. Of 1,599 patients assayed, 84 (5.2%) had low cobalamin levels. After evaluation, 16 of those with low cobalamin levels, but none of those with normal cobalamin levels, were confirmed as deficient. Positive predictive value of a low cobalamin level in this population was 22.2% (95% confidence interval, 12.6-31.8%). After correcting for sampling procedure, the calculated sensitivity rate was 100% (95% confidence interval, 20.6-100%), and specificity rate was 95.8% (95% confidence interval, 95.2-100%). The authors conclude that in routine use, the positive predictive value of the cobalamin assay is low. Low cobalamin levels should not be used alone to justify a lifetime of parenteral therapy or to rule out other conditions that mimic cobalamin deficiency.

Modulation of immune function and weight loss by L-arginine in obstructive jaundice in the rat

Jaundiced surgical patients have a high incidence of postoperative complications. Many causative factors have been identified including cachexia and immune suppression. The amino acid L-arginine has anabolic and immunostimulatory properties. It was hypothesized that dietary supplementation with L-arginine would diminish the weight loss and immune suppression of obstructive jaundice. Sixteen male Wistar rats rendered jaundiced by bile duct ligation were allocated to two groups. The test group (n = 8) received drinking water supplemented with 1.8 percent L-arginine ad libitum and the control group (n = 8) received a solution of isonitrogenous glycine. Both groups had free access to standard chow. Body-weight, and fluid and food intake were recorded. After 21 days, delayed-type hypersensitivity to 2,4-dinitrofluorobenzene was assessed. Animals receiving L-arginine consumed more food than controls (mean(s.e.m.) 414(16) versus 360(13) g, P < 0.05) and lost less weight (mean(s.e.m.) proportion of initial body-weight lost 7.8(1.2) versus 14.8(1.4) percent, P < 0.05). The delayed-type hypersensitivity response was significantly greater in rats receiving L-arginine (mean(s.e.m.) increase in ear thickness 23.9(2.7) versus 9.4(2.1) percent, P < 0.05). In this animal model of obstructive jaundice dietary supplementation with L-arginine diminished both weight loss and immune suppression.

Medical treatment for stroke prevention

PURPOSE

To review the effectiveness of medical treatments for stroke prevention in patients at elevated risk for stroke.

DATA SOURCES

English-language articles published after 1977 and indexed in MEDLINE under the following Medical Subject Heading terms: anticoagulants, aspirin, dipyridamole, ticlopidine, or sulfinpyrazone, combined with cerebrovascular disorders.

STUDY SELECTION

Randomized controlled trials of anticoagulant or platelet antiaggregant treatment reporting subsequent stroke and myocardial infarction, death, or complications in persons with asymptomatic carotid stenosis or bruit, transient ischemic attack (TIA), previous stroke, nonvalvular atrial fibrillation, or other vascular diseases.

DATA EXTRACTION

Of 900 articles identified, 33 were selected by two independent reviewers and abstracted for outcome events and person-years of follow-up.

RESULTS

In patients with nonvalvular atrial fibrillation, warfarin is highly effective in reducing stroke and death but may result in more complications. Aspirin appears to be less effective and less risky than anticoagulation. In patients with TIA or minor stroke, both aspirin and ticlopidine reduce the risk for stroke. In patients who have had myocardial infarction, warfarin is effective but had high complication rates in the reviewed studies. Aspirin slightly reduces the risk for stroke.

CONCLUSIONS

Warfarin is strongly recommended for persons with nonvalvular atrial fibrillation who are older than 60 years or who have additional risk factors for stroke. Aspirin is recommended for persons at elevated risk for bleeding while receiving anticoagulants. For persons with TIA or minor stroke, aspirin should be used first. Patients who do not respond to or tolerate aspirin or who have had a major stroke are reasonable candidates for ticlopidine. For patients who have had myocardial infarction, aspirin is recommended for the prevention of secondary myocardial infarction but not of stroke.

Multicenter review of preoperative risk factors for carotid endarterectomy in patients with ipsilateral symptoms

BACKGROUND AND PURPOSE

Randomized clinical trials have shown that carotid endarterectomy decreases the risk of subsequent stroke in patients with high-grade carotid stenosis and ipsilateral transient ischemic attack or minor stroke. The benefit of surgery is highly dependent on surgical risk. We previously found that patients with ipsilateral hemispheric symptoms were at greater risk of carotid endarterectomy complications compared with those who were asymptomatic or had nonipsilateral symptoms. The goals of the present study were (1) to identify preoperative clinical factors that may increase the risk of complications after carotid endarterectomy in patients with ipsilateral hemispheric symptoms and (2) to develop a risk index based on this patient-level data.

METHODS

Records from 1160 carotid endarterectomies performed at 12 academic medical centers composed the primary data set. Hospital charts for the admission during which carotid endarterectomy was performed were systematically reviewed by abstractors using a defined protocol. The present analysis was carried out on data from the subset of patients who had carotid endarterectomy for ipsilateral hemispheric symptoms. Candidate variables were identified based on univariate Fisher's exact tests or chi 2 tests. A risk index was then developed using those variables with a greater than 90% probability of being associated with adverse outcomes.

RESULTS

Of the 697 patients with ipsilateral symptoms, 8.5% had either stroke, myocardial infarction, or died during the postoperative period of hospitalization. Those over the age of 75 had a greater risk of myocardial infarction (6.6% versus 2.3%, P = .024) but not of stroke or death (P > .10). The overall frequencies of adverse outcomes were also higher in the 5 patients with complete ipsilateral carotid occlusions (40% versus 8.2%, P < .01), the 28 patients with ipsilateral intraluminal thrombus (17.9% versus 8.1%, P = .07), and the 65 patients with ipsilateral carotid siphon stenosis (13.9% versus 7.9%, P = .10). There were no differences in adverse outcomes among those with different degrees of ipsilateral stenosis (30% to 49%, 50% to 69%, and 70% to 99%). Adverse outcome rates were similar regardless of the type of symptom (transient ischemic attack, recent ipsilateral minor stroke, remote ipsilateral minor stroke). There were no significant differences in adverse outcome rates based on sex, race, history of angina, recent myocardial infarction, congestive heart failure, chronic obstructive pulmonary disease, hypertension, degree of stenosis of the contralateral carotid artery, or presence of ulceration in the ipsilateral artery (Fisher's exact tests, P > .10). A count of variables with greater than 90% probability of being associated with adverse outcomes (age > or = 75 years or angiographic evidence of ipsilateral carotid occlusion, stenosis in the region of the carotid siphon, or intraluminal thrombus) was used to form a simple risk index. "High-risk" patients (one or more risk factors) had more than two times the risk of complications compared with "low-risk" patients who had no risk factors (odds ratio, 2.18; 95% confidence interval, 1.25 to 3.81).

CONCLUSIONS

Certain preoperative clinical variables may place patients with ipsilateral symptoms at greater risk of perioperative complications after carotid endarterectomy. Prospective validation of a simple risk index would provide an additional method for assessing preoperative risk in endarterectomy candidates.

Prospective study of postoperative renal function in obstructive jaundice and the effect of perioperative dopamine

A prospective study was undertaken to assess postoperative renal dysfunction in patients with obstructive jaundice and to determine the effectiveness of dopamine in reducing its incidence. A total of 23 patients undergoing surgical relief of obstructive jaundice (serum bilirubin level above 100 mumol l-1) were randomized into two groups. Those in the control group (n = 10) received 3 litres 5 per cent dextrose intravenously during the 24 h before surgery plus a bolus of intravenous frusemide 1 mg kg-1 at induction of anaesthesia. The second group (n = 13) received a similar fluid and frusemide regimen plus an infusion of dopamine 3 micrograms kg-1 min-1 starting at induction of anaesthesia and continuing for 48 h after surgery. Postoperative oliguria occurred in two of the ten patients in the control group and in three of the 13 given dopamine (P = 0.74). No patient developed acute renal failure. There was no significant difference in mean levels of serum bilirubin, urea and creatinine, creatinine clearance and 24-h urinary output, on the day before and on days 1-5 after operation, between the two groups. It is concluded that, with careful preoperative resuscitation and control of fluid and electrolyte balance, the incidence of postoperative renal dysfunction in patients with obstructive jaundice is not as high as in some previous studies and is unaltered by administration of perioperative low-dose dopamine.

Predicting complications of carotid endarterectomy

BACKGROUND AND PURPOSE

Carotid endarterectomy has been shown to be beneficial in patients with high-grade carotid stenosis and ipsilateral transient ischemic attack or stroke. This benefit will be realized only if the operation is performed safely. We sought to determine the extent to which clinically significant adverse events occurring after carotid endarterectomy can be predicted from clinical data available before surgery.

METHODS

Eleven hundred sixty patients were randomly selected from all patients who underwent carotid endarterectomy and were discharged during the calendar years 1988, 1989, and 1990 in 12 academic medical centers in 10 states. Clinical data abstracted from hospital charts were analyzed retrospectively. A model was developed and validated to predict the occurrence of stroke, myocardial infarction, or death during the postoperative period of hospitalization.

RESULTS

Eight patients (6.9%) suffered at least one adverse event. Rates for individual complications were as follows: death, 1.4%; nonfatal stroke, 3.4%; nonfatal myocardial infarction, 2.1%; and nonfatal stroke or death, 4.8%. Significant predictors of adverse events were age 75 years or older, symptom status (ipsilateral symptoms versus asymptomatic or nonipsilateral symptoms), severe hypertension (preoperative diastolic blood pressure of greater than 110 mm Hg), carotid endarterectomy performed in preparation for coronary artery bypass surgery, history of angina, evidence of internal carotid artery thrombus, and internal carotid artery stenosis near the carotid siphon. The presence of two or more of these risk factors was associated with a nearly twofold increase in risk of an adverse event (relative risk, 1.7; 95% confidence interval, 1.0 to 3.0).

CONCLUSIONS

Clinical data can be used to stratify patients undergoing carotid endarterectomy according to risk of postoperative in-hospital stroke, myocardial infarction, or death.

Biliary drainage in obstructive jaundice: experimental and clinical aspects

Jaundiced patients undergoing invasive diagnostic and therapeutic procedures are at increased risk of complications and death. Despite the large number of clinical and experimental investigations carried out to identify relevant risk factors, no single parameter has been found to be consistently useful in predicting morbidity or mortality. Biliary decompression was initially employed by surgeons and subsequently by interventional radiologists. More recently, endoscopic retrograde cholangiopancreatography has provided an alternative route for decompression of the biliary tree and preliminary data using this method are encouraging. Although there are enthusiastic proponents of various therapeutic techniques, controlled trials have not been convincing in highlighting the benefits of biliary drainage or in determining the best approach. This article reviews the literature pertaining to this complex surgical problem; an attempt has been made to balance the advantages and disadvantages of biliary decompression as palliation and/or preliminary treatment for extrahepatic biliary obstruction.

The effect of sleeved arms on oscillometric blood pressure measurement

The authors measured the blood pressures of 36 subjects who had bare and sleeved arms to determine the effect of wearing sleeves on automatic oscillometric blood pressure measurements. They found no statistically significant effect of sleeves on the measurement of either systolic or diastolic blood pressure (p > 0.15). However, based on confidence intervals of possible sleeve effects, the authors recommend repeating blood pressure measurements on bared arms when the sleeved-arm oscillometric measurements are at least 86 mm Hg diastolic or 135 mm Hg systolic.