Systematic review and meta-analysis: Efficacy of patented probiotic, VSL#3, in irritable bowel syndrome

BACKGROUND

VSL#3 is a patented probiotic for which several clinical trials suggest benefits on motor function, bloating, and symptoms of irritable bowel syndrome (IBS).

OBJECTIVES

To quantify effects of VSL#3 on abdominal pain, stool consistency, overall response, abdominal bloating, and quality of life (QOL) in IBS through meta-analysis.

METHODS

MEDLINE (OvidSP and PubMed), EMBASE, Web of Science, and Scopus were searched up to May 2017. Using a fixed effects model, we pooled data from intention-to-treat analyses of randomized trials (RCTs) comparing VSL#3 to placebo in IBS. Data were reported as relative risk (RR), overall mean difference (MD), or standardized MD (SMD) with 95% confidence intervals (CI). Quality of evidence was rated using the GRADE approach.

KEY RESULTS

Among 236 citations, 5 RCTs (243 patients) were included. No significant differences were observed for abdominal pain (SMD = -0.03; 95% CI -0.29 to 0.22), bloating (SMD = -0.15; 95% CI -0.40 to 0.11), proportion of bowel movements with normal consistency (overall MD = 0; 95% CI -0.09 to 0.08), or IBS-QOL (SMD = 0.08; 95% CI -0.22 to 0.39). VSL#3 was associated with a nearly statistically significant increase in overall response (RR = 1.39; 95% CI 0.99-1.98).

CONCLUSIONS & INFERENCES

In this systematic review and meta-analysis, there was a trend toward improvement in overall response with VSL#3, but no clear evidence effectiveness for IBS. However, the number and sample sizes of the trials are small and the overall quality of evidence for 3 of the 5 outcomes was low. Larger trials evaluating validated endpoints in well-defined IBS patients are warranted.

A quantitative assessment of the risks and cost savings of forgoing histologic examination of diminutive polyps

BACKGROUND AND AIMS

Endoscopic prediction of polyp histology is rapidly improving to the point where it may not be necessary to submit all polyps for formal histologic assessment. This study aimed to quantify the expected costs and outcomes of removing diminutive polyps without subsequent pathologic assessment.

METHODS

Cross-sectional analysis of a colonoscopy database for polyp histology; decision models that quantify effects on guideline-recommended surveillance and subsequent costs and consequences. The database was composed of consecutive colonoscopies from 1999 to 2004 at a single-institution tertiary care center. Patients were those found to have at least one diminutive polyp removed during colonoscopy, irrespective of indication. The main outcome measurements include up-front cost savings resulting from forgoing pathologic assessment; frequency and cost of incorrect surveillance intervals based on errors in histologic assessment; number needed to harm (NNH) for perforation and/or interval cancer.

RESULTS

Incorrect surveillance intervals were recommended in 1.9% of cases when tissue was submitted for pathologic assessment and 11.8% of cases when it was not. Based on the annual volume of colonoscopy in the US, the annual up-front cost savings of forgoing the pathologic assessment would exceed a billion dollars. An upper estimate on the downstream costs and consequences of forgoing pathology suggests that less than 10% of the up-front savings would be offset and the NNH exceeds 11000.

CONCLUSION

Endoscopic diagnosis of polyp histology during colonoscopy and forgoing pathologic examination would result in substantial up-front cost savings. Downstream consequences of the resulting incorrect surveillance intervals appear to be negligible.

Surveillance approaches among colorectal cancer survivors after curative-intent

Intensive surveillance among colorectal cancer patients receiving curative-intent, particularly during the first 2 to 3 years of follow-up, has a beneficial impact upon all-cause survival at five years. Intensive surveillance appears to be associated with the early detection of recurrences, and more often accompanied by a clinical presentation enabling surgical resection. The optimal combination and frequency of surveillance tests is unknown. Imaging of the chest and abdomen have increasingly been recommended by professional organizations, in addition to CEA levels, in order to detect resectable recurrences. Metachronous cancers are relatively uncommon, nonetheless, surveillance colonoscopy is typically recommended. Cau-tion is warranted in further advancing the intensity of surveillance, as increasingly aggressive surveillance programs risk increased detection of pseudodisease. Different types of information will enhance our understanding of the impact of follow-up programs, including data regarding quality of life, cost, and patient preferences.

Evaluation of the Winthrop-University Hospital criteria to identify Legionella pneumonia

STUDY OBJECTIVE

To measure the ability of a set of clinical parameters, the Winthrop-University Hospital (WUH) criteria, to identify Legionella pneumonia while discriminating against bacteremic pneumococcal pneumonia at the time of hospitalization for community-acquired pneumonia (CAP).

DESIGN

Retrospective case-control study.

SETTING

An urban county hospital and a tertiary-care Veterans Affairs hospital.

PATIENTS

Thirty-seven patients with Legionella pneumonia (diagnosed by a positive result of a urinary Legionella antigen test) and 31 patients with bacteremic pneumococcal pneumonia. A subgroup of patients with all required laboratory criteria were studied further.

RESULTS

The WUH criteria correctly identified 29 of 37 patients with Legionella pneumonia (sensitivity, 78%; 95% confidence interval [CI], 61 to 90%), while successfully excluding legionellosis in 20 of 31 patients with bacteremic pneumococcal pneumonia (specificity, 65%; 95% CI, 45 to 80%). The positive and negative predictive values, adjusted for a relative prevalence of 1:3 between Legionella and Streptococcus pneumoniae bacteremia, were 42% (95% CI, 25 to 61%) and 90% (95% CI, 74 to 97%), respectively. In the subgroup analysis, the WUH criteria were successful in identifying 20 of 23 patients with Legionella pneumonia (sensitivity, 87%; 95% CI, 65 to 97%), while excluding legionellosis in 9 of 18 patients with bacteremic pneumococcal pneumonia (specificity, 50%; 95% CI, 27 to 73%). The adjusted positive and negative predictive values for a 1:3 relative prevalence were 37% (95% CI, 20 to 59%) and 92% (95% CI, 62 to 98%), respectively. The predictive values were changed in the directions expected for an increased relative prevalence of 1:1. The areas under the receiver operating characteristic curves were 0.72 +/- 0.06 for the entire study group and 0.68 +/- 0.09 for the subgroup.

CONCLUSIONS

Although the WUH criteria discriminated fairly well between cases (mean +/- SE) and control subjects, the sensitivity is not high enough to exclude legionellosis confidently. These results suggest that empiric therapy for Legionella pneumonia should be included in the initial antibiotic regimen for hospitalized patients with CAP.

A meta-analysis of endoscopic variceal ligation for primary prophylaxis of esophageal variceal bleeding

Despite publication of several randomized trials of prophylactic variceal ligation, the effect on bleeding-related outcomes is unclear. We performed a meta-analysis of the trials, as identified by electronic database searching and cross-referencing. Both investigators independently applied inclusion and exclusion criteria, and abstracted data from each trial. Standard meta-analytic techniques were used to compute relative risks and the number needed to treat (NNT) for first variceal bleed, bleed-related mortality, and all-cause mortality. Among 601 patients in 5 homogeneous trials comparing prophylactic ligation with untreated controls, relative risks of first variceal bleed, bleed-related mortality, and all-cause mortality were 0.36 (0.26-0.50), 0.20 (0.11-0.39), and 0.55 (0.43-0.71), with respective NNTs of 4.1, 6.7, and 5.3. Among 283 subjects from 4 trials comparing ligation with beta-blocker therapy, the relative risk of first variceal bleed was 0.48 (0.24-0.96), with NNT of 13; however, there was no effect on either bleed-related mortality (relative risk [RR], 0.61; confidence interval [CI], 0.20-1.88) or all-cause mortality (RR, 0.95; CI, 0.56-1.62). In conclusion, compared with untreated controls, prophylactic ligation reduces the risks of variceal bleeding and mortality. Compared with beta-blockers, ligation reduces the risk for first variceal bleed but has no effect on mortality. Prophylactic ligation should be considered for patients with large esophageal varices who cannot tolerate beta-blockers. Subsequent research should further compare ligation and beta-blockers to determine the effect on mortality, and measure ligation's cost-effectiveness.

A cost-minimization analysis of alternative treatment strategies for achalasia

OBJECTIVE

The aim of this study is to compare the costs per cure of alternative strategies for the treatment of achalasia.

METHODS

A cost-minimization model compared three strategies for otherwise healthy adults of any age with achalasia: 1) laparoscopic Heller myotomy with fundoplication (LHM); 2) pneumatic dilation (PD), with LHM reserved for treatment failures; 3) botulinum toxin (Botox) injection of the lower esophageal sphincter, with PD reserved for treatment failures. Probabilities of short- and long-term efficacy, treatment failure, symptomatic recurrence rates, and complications were derived from the published literature. Only direct costs were considered during the 5-yr time horizon.

RESULTS

Respective reference case costs per cure of PD, Botox, and LHM strategies were $3,111, $3,723, and $10,792. Despite short- and long-term efficacy of 96% and 94%, respectively, the LHM strategy was most costly. Initial PD remained less costly than initial Botox, provided that rates of PD efficacy and perforation were > or = 70% and < 9.5%, respectively, and cost of a Botox session was > or = $450. The results were not sensitive to the probabilities of short- and long-term response to Botox, recurrence after PD, LHM efficacy, and post-LHM gastroesophageal reflux disease, nor to the costs of LHM and PD.

CONCLUSIONS

For otherwise healthy patients with achalasia, initial PD is the least costly strategy provided that the PD perforation rate remains < 10%. Initial Botox is less costly only when nonendoscopic-related costs decrease by 25%. Initial LHM is the most costly strategy under all clinically plausible scenarios. Subsequent analyses should include a longer time horizon and an assessment of patient ference for each strategy.

Need for validation of clinical decision aids: use of the AST/ALT ratio in predicting cirrhosis in chronic hepatitis C

OBJECTIVE

A value of > or = 1 for the ratio of aspartate amino-transferase to alanine aminotransferase (the AST/ALT ratio or AAR) has been shown to have a positive predictive value of 100% for the diagnosis of cirrhosis in patients with chronic hepatitis C. If validated on separate cohorts, an AAR > or = 1 might obviate the need for liver biopsy in some patients with hepatitis C.

METHODS

We attempted to validate the AAR by abstracting demographic and clinical data from a database of consecutive patients with hepatitis C who had a liver biopsy between 1993 and 1998. We used definitions, methods of data collection, and analyses comparable to those of the published study. A hepatopathologist blindly reviewed 49 liver biopsies for histological grade and stage.

RESULTS

The current cohort of 177 patients and the previous cohort of 139 patients were comparable in mean age (42.3 vs 43.8 yr), percentage of men (63 vs 67), percentage with an AAR > or =1 (20 vs 17), and Child-Pugh distribution, but differed in substantial use of ethanol (11% vs 3.6%; p = 0.01) and in the prevalence of cirrhosis (23% vs 34%, p = 0.06). Respective sensitivities of the AAR were 56% and 53%. An AAR > or =1 had a positive predictive value of 64% (95% confidence interval 48-78%) for the current cohort. Thirteen of 36 patients (36%) with an AAR > or =1 were incorrectly identified as having cirrhosis. Of these 13 patients, 6 had a normal AST and ALT, 5 had a minimally elevated AST or ALT, and 1 had advanced fibrosis without cirrhosis.

CONCLUSIONS

These results suggest that an AAR > or =1 may not be as useful for predicting cirrhosis in chronic hepatitis C as previously thought, and emphasizes the need for validation of clinical decision aids on independent patient cohorts.

Risk of advanced proximal neoplasms in asymptomatic adults according to the distal colorectal findings

BACKGROUND AND METHODS

The clinical significance of a distal colorectal polyp is uncertain. We determined the risk of advanced proximal neoplasia, defined as a polyp with villous features, a polyp with high-grade dysplasia, or cancer, among persons with distal hyperplastic or neoplastic polyps as compared with the risk among persons with no distal polyps. We analyzed data from 1994 consecutive asymptomatic adults (age, 50 years or older) who underwent colonoscopic screening for the first time between September 1995 and December 1998 as part of a program sponsored by an employer. The location and histologic features of all polyps were recorded. Colonoscopy to the level of the cecum was completed in 97.0 percent of the patients.

RESULTS

Sixty-one patients (3.1 percent) had advanced lesions in the distal colon, including 5 with cancer, and 50 (2.5 percent) had advanced proximal lesions, including 7 with cancer. Twenty-three patients with advanced proximal neoplasms (46 percent) had no distal polyps. The prevalence of advanced proximal neoplasia among patients with no distal polyps was 1.5 percent (23 cases among 1564 persons; 95 percent confidence interval, 0.9 to 2.1 percent). Among patients with distal hyperplastic polyps, those with distal tubular adenomas, and those with advanced distal polyps, the prevalence of advanced proximal neoplasia was 4.0 percent (8 cases among 201 patients), 7.1 percent (12 cases among 168 patients), and 11.5 percent (7 cases among 61 patients), respectively. The relative risk of advanced proximal neoplasia, adjusted for age and sex, was 2.6 for patients with distal hyperplastic polyps, 4.0 for those with distal tubular adenomas, and 6.7 for those with advanced distal polyps, as compared with patients who had no distal polyps. Older age and male sex were associated with an increased risk of advanced proximal neoplasia (relative risk, 1.3 for every five years of age and 3.3 for male sex).

CONCLUSIONS

Asymptomatic persons 50 years of age or older who have polyps in the distal colon are more likely to have advanced proximal neoplasia than are persons without distal polyps. However, if colonoscopic screening is performed only in persons with distal polyps, about half the cases of advanced proximal neoplasia will not be detected.

Pharmacologic treatment of the irritable bowel syndrome: a systematic review of randomized, controlled trials

PURPOSE

To evaluate the efficacy of pharmacologic agents for the irritable bowel syndrome.

DATA SOURCES

Electronic literature search of MEDLINE (1966 to 1999), EMBASE (1980 to 1999), PsycINFO (1967 to 1999), and the Cochrane controlled trials registry and a manual search of references from bibliographies of identified articles.

STUDY SELECTION

Randomized, double-blind, placebo-controlled, parallel, or crossover trials of a pharmacologic intervention for adult patients that reported outcomes of improvement in global or irritable bowel-specific symptoms.

DATA EXTRACTION

Qualitative and quantitative data reported on study groups, interventions, treatment outcomes, and trial methodologic characteristics.

DATA SYNTHESIS

70 studies met the inclusion criteria. The most common medication classes were smooth-muscle relaxants (16 trials), bulking agents (13 trials), prokinetic agents (6 trials), psychotropic agents (7 trials), and loperamide (4 trials). The strongest evidence for efficacy was shown for smooth-muscle relaxants in patients with abdominal pain as the predominant symptom. Loperamide seems to reduce diarrhea but does not relieve abdominal pain. Although psychotropic agents were shown to produce global improvement, the evidence is based on a small number of studies of suboptimal quality. Psychotropic drugs, 5-hydroxytryptamine (5-HT)-receptor antagonists, peppermint oil, and Chinese herbal medicine require further study.

CONCLUSIONS

Smooth-muscle relaxants are beneficial when abdominal pain is the predominant symptom. In contrast, the efficacy of bulking agents has not been established. Loperamide is effective for diarrhea. Evidence for use of psychotropic agents is inconclusive; more high-quality trials of longer duration are needed. Evidence for the efficacy of 5-HT-receptor antagonists seems favorable, although more studies are needed.

Predictors of large esophageal varices in patients with cirrhosis

OBJECTIVE

Recent guidelines recommend that all cirrhotics undergo screening upper endoscopy to identify those patients at risk for bleeding from varices. However, this practice may not be cost effective as large esophageal varices are seen only in 9-36% of these patients. The aim of this study was to determine whether clinical variables were predictive of the presence of large esophageal varices.

METHODS

This is a retrospective analysis of cirrhotics who had a screening upper endoscopy during an evaluation for liver transplantation at three different centers and who had not previously bled from varices. A multivariate model was derived on the combined cohort using logistic regression. Three hundred forty-six patients were eligible for the study.

RESULTS

The prevalence of large esophageal varices was 20%. On multivariate analysis, splenomegaly detected by computed tomographic scan (odds ratio: 4.3; 95% confidence interval: 1.6-11.5) or by physical examination (odds ratio: 2.0; 95% confidence interval: 1.1-3.8), and low platelet count were independent predictors of large esophageal varices. On the basis of these variables, cirrhotics were stratified into high- and low-risk groups for the presence of large esophageal varices. Patients with a platelet count of > or = 88,000/mm3 (median value) and no splenomegaly by physical examination had a risk of large esophageal varices of 7.2%. Those with splenomegaly or platelet count < 88,000/mm3 had a risk of large esophageal varices of 28% (p < 0.0001).

CONCLUSIONS

Our data show that clinical predictors could be used to stratify cirrhotic patients for the risk of large esophageal varices and such stratification could be used to improve the cost effectiveness of screening endoscopy.

Cost-effectiveness analysis of hepatitis A vaccination strategies for adults

Our objective in this study was to determine the cost-effectiveness of hepatitis A vaccination strategies in healthy adults in the United States. We constructed a decision model simulating costs and health consequences for otherwise healthy adults with respect to hepatitis A prevention. Three strategies were compared: (1) no intervention, (2) vaccination against hepatitis A, and (3) testing for antibodies to hepatitis A and vaccinating those without antibodies. Costs and probabilities were obtained from the published literature. One- and two- way sensitivity analyses were performed. Under baseline conditions, the "test" strategy cost $230,100 per life-year saved compared with the "no intervention" strategy. The incremental cost-effectiveness of the "vaccination" strategy compared with the "test" strategy was $20.1 million per life-year saved. The "test" strategy was cost-effective when the hepatitis A case fatality rate exceeded 17% (baseline 2.7%). The "vaccination" strategy was cost-effective when 1 dose of vaccine cost $7 or less (baseline $57). Under baseline conditions, neither the "test" nor the "vaccination" strategies are considered cost-effective according to current standards. Large changes in hepatitis A incidence, mortality rates, or vaccine cost are required for either of the intervention strategies to approach potentially cost-effectiveness. Such conditions may occur in areas in which hepatitis A is endemic, and/or under mass-vaccination scenarios.

Patients willing to try colonoscopy without sedation: associated clinical factors and results of a randomized controlled trial

BACKGROUND

Sedation causes most of the complications of colonoscopy. Sedation is used selectively in some countries but is routine in the United States.

METHODS

Cross-sectional survey and randomized controlled trial were used to identify patient factors associated with willingness to try colonoscopy without sedation and to compare pain and satisfaction scores and willingness to return to the same physician in patients randomized to receive routine sedation versus as needed sedation. A single colonoscopist invited 250 consecutive eligible outpatients to be randomized to routine sedation versus as needed sedation. Seventeen who preferred no sedation and 163 who preferred sedation refused. Seventy accepted and were randomized.

RESULTS

Male gender (odds ratio 4.33; 95% CI [2.27, 8.26]), increasing age (odds ratio for 10-year increase 1.28; 95% CI [1.01, 1.06]), and absence of abdominal pain (odds ratio 5.13; 95% CI [1.68, 15.63]) were associated with willingness to be randomized. Total colonoscopy was achieved without sedation in 94% of those who received sedation only as needed. Pain scores were higher in the sedation as needed arm. All 35 patients in the routine sedation arm were "very satisfied". In the sedation as needed arm, 31 of the 34 were "very satisfied" and 3 were "somewhat satisfied". All randomized patients said they would return to the same colonoscopist. Patients in the sedation as needed arm had less decline in blood pressure, less hypoxemia, and lower charges than those in the routine sedation arm.

CONCLUSIONS

Experienced colonoscopists should consider offering colonoscopy without sedation to selected patients.

The utility of clinical and radiographic features in the diagnosis of cytomegalovirus central nervous system disease in AIDS patients

BACKGROUND

Polymerase chain reaction (PCR) assays of cerebrospinal fluid (CSF) for cytomegalovirus (CMV) DNA have facilitated the diagnosis of CMV-associated central nervous system disease in AIDS patients. We attempt to correlate clinical and radiographic features that are associated with CMV PCR- positivity in CSF from AIDS patients with neurologic disease.

METHODS AND RESULTS

A retrospective case controlled comparison was made of CMV PCR-positive and PCR-negative patients.

RESULTS

CMV PCR-positive patients were significantly more likely to have nystagmus, prior CMV retinitis, and CSF protein levels.90 mg/dL. Of patients with 0, 1, and $2 of these features, 5.6%, 55.2%, and 88.9%, respectively, were PCR-positive. Ependymal enhancement was present by magnetic resonance imaging in 9 of 12 PCR-positive, and in 8 of 30 PCR-negative patients.

CONCLUSION

These clinical and radiographic features may serve as useful adjuncts toward the establishment of the diagnosis of CMV-associated neurologic disease in AIDS patients.

Meta-analysis and cost comparison of polyethylene glycol lavage versus sodium phosphate for colonoscopy preparation

BACKGROUND

Although polyethylene glycol lavage solutions are widely used for colonoscopy preparation, evidence suggests that sodium phosphate is better tolerated and has similar efficacy. The purpose of this study was to compare compliance with and efficacy of polyethylene glycol and sodium phosphate using meta-analysis and to compare the cost of colonoscopy with both methods.

METHODS

We used Medline to identify all randomized controlled trials comparing the two preparations. Study methods were evaluated, and quantitative data were abstracted independently, including inability to complete the preparation and preparation quality, rated as adequate or excellent. A random effects model was used to calculate the pooled relative risk. Direct costs and literature-based probability estimates were used to compare costs.

RESULTS

Among 1286 subjects from eight colonoscopist-blinded trials, the pooled relative risk of inability to complete the preparation was 0.23 (95% CI [0.18-0.28]) in favor of sodium phosphate. Although the best estimate of the relative risk for an adequate quality preparation revealed therapeutic equivalence (relative risk = 1.06: 95% CI [0.95-1.19]), an excellent quality preparation was more likely with sodium phosphate (relative risk = 1.72: 95% CI [1.16-2.53]). Assuming reexamination rates from published literature of 3% and 8% for sodium phosphate and polyethylene glycol, respectively, direct costs of colonic examination were $465 and $503. There were no clinically important adverse effects with either method.

CONCLUSION

The results suggest that sodium phosphate is as effective and less costly, with a more easily completed preparation, compared with polyethylene glycol and is the preferred method of preparation for colonoscopy for certain patient subgroups.

Somatostatin or octreotide compared with H2 antagonists and placebo in the management of acute nonvariceal upper gastrointestinal hemorrhage: a meta-analysis

PURPOSE

To determine the efficacy of somatostatin or octreotide for the treatment of acute nonvariceal upper gastrointestinal hemorrhage.

DATA SOURCE

Database searches of English-language articles published between 1966 and 1996 and the bibliographies of all related articles and textbook chapters.

STUDY SELECTION

Randomized clinical trials comparing somatostatin or octreotide with H2 blockers or placebo in patients with a clinical or endoscopic diagnosis of acute nonvariceal upper gastrointestinal hemorrhage.

DATA EXTRACTION

Methods and quality of the studies were evaluated, and quantitative data on outcomes, including continued bleeding, rebleeding during the treatment period, need for surgery, and transfusion requirement, were extracted.

DATA SYNTHESIS

Among 1829 patients from 14 trials, the relative risk (RR) for continued bleeding or rebleeding was 0.53 (95% CI, 0.43 to 0.63) in favor or somatostatin, with a number needed to treat (NNT) of 5. Among 7 investigator-blinded trials, the relative risk was 0.73 (CI, 0.64 to 0.81) and the NNT was 11. Somatostatin was efficacious for peptic ulcer bleeding (RR, 0.48 [CI, 0.39 to 0.59]; NNT, 4) and showed a trend toward efficacy for non-peptic ulcer bleeding (RR, 0.62 [CI, 0.39 to 1.002]). Although the overall results suggested a decreased need for surgery in the somatostatin group, a subgroup analysis of investigator-blinded trials revealed a more modest effect that was not statistically significant (RR, 0.94 [CI, 0.87 to 1.001]).

CONCLUSION

Somatostatin may reduce the risk for continued bleeding from acutely bleeding peptic ulcer disease. Somatostatin may be useful either as an adjunct treatment before endoscopy or when endoscopy is unsuccessful, contraindicated, or unavailable.

Primary prophylaxis of variceal bleeding in cirrhosis: a cost-effectiveness analysis

BACKGROUND & AIMS

Prophylaxis against the first variceal bleeding has been proposed to reduce morbidity and mortality in cirrhotic patients. No previous information is available regarding the cost-effectiveness of prophylaxis. The aim of this study was to compare the cost-effectiveness of variceal bleeding prophylaxis with propranolol, sclerotherapy, and shunt surgery in cirrhotic patients stratified by bleeding risk.

METHODS

A hypothetical cohort was stratified according to bleeding risk. The natural history of cirrhosis with esophageal varices was simulated using a Markov model. Transitional probabilities extracted from published studies and costs were obtained from our institution's billing department. Sensitivity analyses were performed for important variables.

RESULTS

Propranolol results in cost savings ranging between $450 and $14,600 over a 5-year period. The extent of cost savings depended on the individual patient's bleeding risk. In addition, propranolol increased the quality-adjusted life expectancy by 0.1-0.4 years. Sclerotherapy was significantly less cost-effective than propranolol and had no advantage on quality of life. Shunt surgery was effective therapy for prevention of bleeding but decreased life expectancy and quality of life in some risk groups and was not cost-effective.

CONCLUSIONS

Propranolol is the only cost-effective form of prophylactic therapy for preventing initial variceal bleeding in cirrhosis regardless of bleeding risk.

A cost analysis of alternative treatments for duodenal ulcer

OBJECTIVE

To compare the costs of alternative strategies for the treatment of duodenal ulcer.

DESIGN

A cost comparison using decision analysis.

METHODS

A decision model was used to compare the costs per cure of an endoscopically documented duodenal ulcer for three initial treatment strategies: 1) H2-receptor antagonist therapy for 8 weeks, 2) antibiotic therapy for Helicobacter pylori infection plus H2-receptor antagonist therapy, and 3) urease test-based treatment. For symptomatic recurrences, secondary treatment strategies included empiric retreatment with the same or other regimen, and treatment based on repeat endoscopy-guided urease test or biopsy, with an assumption of subsequent cure. The cohort modeled for this analysis consisted of patients at low risk for a malignant ulcer. Probability estimates were derived from published clinical trials, cohort studies, and expert opinion. Side effects from combination therapy with antibiotics and H2-receptor antagonists and resulting costs were included from the perspective of a group practice model health maintenance organization.

RESULTS

For all secondary treatment strategies, initial therapy with antibiotics for H. pylori infection plus an H2-receptor antagonist resulted in the lowest average costs per symptomatic cure when the prevalence or likelihood of H. pylori infection exceeded 66% to 76%; the costs ranged from $284 for secondary (re)treatment with empiric antibiotic and H2-receptor antagonist therapy to $398 for endoscopy-guided secondary treatment. Initial treatment with an H2-receptor antagonist resulted in the highest costs, ranging from $372 for secondary treatment with empiric antibiotic and H2-receptor antagonist therapy to $679 for endoscopy-guided secondary treatment. The results were not sensitive to the rates of duodenal ulcer recurrence after either treatment, to the cost of either treatment, or to prevalence of H. pylori.

CONCLUSIONS

This cost analysis indicates that, regardless of the secondary treatment used for ulcer recurrence, initial therapy with antibiotics for H. pylori infection plus an H2-receptor antagonist provides the lowest costs per symptomatic cure. These cost savings and the lower recurrence rates associated with this treatment favor eradication of H. pylori as part of the initial treatment of duodenal ulcer.

A meta-analysis of somatostatin versus vasopressin in the management of acute esophageal variceal hemorrhage

BACKGROUND & AIMS

Although sclerotherapy is the current standard therapy for bleeding esophageal varices, the best method for initial control is unclear. The aim of this meta-analysis was to compare the efficacy and toxicity of somatostatin and vasopressin in short-term treatment of hemorrhage from esophageal varices.

METHODS

Using MEDLINE, all randomized trials comparing somatostatin with vasopressin in subjects with endoscopically documented acute esophageal variceal bleeding were identified. The quality of each study was critically and independently evaluated, and quantitative data for initial cessation of bleeding, sustained control of bleeding, and major adverse effects were abstracted. The relative risk (RR) and number needed to be treated were calculated.

RESULTS

The RR or likelihood of achieving initial control of bleeding with somatostatin vs. vasopressin was 1.62 (95% confidence interval [CI], 1.37-1.93), and the number needed to be treated was 3.7, i.e., between 3 and 4 patients would have to be treated with somatostatin for 1 patient to derive additional benefit over vasopressin. For trials that measured sustained control of bleeding, somatostatin was superior to vasopressin (RR, 1.28 [95% CI, 1.00-1.65]; number needed to be treated, 8.8). The risk of adverse effects was greater for subjects given vasopressin (10% vs. 0%; P = 0.00007).

CONCLUSIONS

This meta-analysis suggests that somatostatin is more efficacious in controlling acute hemorrhage from esophageal varices and has a lower risk of adverse effects than vasopressin.

Are cytotoxic agents beneficial in idiopathic membranous nephropathy? A meta-analysis of the controlled trials

The use of cytotoxic agents for the treatment of idiopathic membranous nephropathy is controversial. Although several controlled trials have been published, both the comparison groups and the study findings have varied, resulting in clinical uncertainty. To explore this uncertainty, a meta-analysis of controlled trials of treatment with cyclophosphamide or chlorambucil was performed in patients with idiopathic membranous nephropathy and nephrotic-range proteinuria. Patients in the control groups received only symptomatic treatment or corticosteroids. Descriptive and quantitative data from each trial were abstracted independently. Outcomes included effects of treatment on renal function and proteinuria, with a complete remission (CR) or partial remission (PR) defined as the complete or partial resolution of proteinuria without deterioration of renal function. For patients having either any response (CR or PR) or only a CR, both the relative risk (RR) and the number needed to be treated were calculated. The five trials that satisfied criteria for inclusion in the analysis were clinically and statistically homogeneous. There were no placebo-controlled trials that met the criteria for inclusion. Among the 228 patients in these studies, the RR of achieving any response with cytotoxic agents was 2.3 (95% confidence interval, 1.7 to 3.2) and the RR for a CR was 4.6 (95% confidence interval, 2.2 to 9.3), with respective numbers needed to be treated of 2.9 and 4.7, meaning that between three and five patients would need to be treated with cytotoxic agents to achieve one response. Exclusion of the only nonrandomized trial had no significant effect on the results. Both chlorambucil and cyclophosphamide showed similar beneficial effects.(ABSTRACT TRUNCATED AT 250 WORDS)

A meta-analysis of methods to prevent venous thromboembolism following total hip replacement

OBJECTIVE

While several methods of prophylaxis have been shown to reduce the risk of venous thromboembolism following total hip replacement, the safest and most effective agent is unclear. To clarify this issue, we performed a meta-analysis of the randomized trials of methods used to prevent venous thromboembolism following total hip replacement.

DATA SOURCE

English-language human studies articles from 1966 through 1993 were obtained from a MEDLINE database search with indexing terms including thromboembolism, hip replacement or hip prosthesis, and randomized controlled trials. Additional references were obtained from study bibliographies.

STUDY SELECTION

The following criteria were used to select studies for inclusion: study design--randomized clinical trial; study population--patients undergoing elective total hip replacement; interventions--aspirin, warfarin, dextran, heparin, low-molecular-weight heparin, compression stockings; and outcomes--venous thromboembolism, major hemorrhage.

DATA EXTRACTION

Methodological and descriptive data from each study were abstracted by one author who was blinded to quantitative outcomes data.

DATA SYNTHESIS

Ninety-one treatment groups and 25 control groups were identified from 56 trials. Four treatment groups were excluded because of rarely used combinations. Trial populations were clinically homogeneous. When compared with the control arm, all treatments except aspirin reduced the risk of all deep venous thromboses (risk differences range, 0.18 to 0.31; all P values < .05). All treatments except aspirin reduced the risk of proximal venous thrombosis (risk differences range, 0.09 to 0.18; all P values < .05). Only low-molecular-weight heparin and stockings reduced the risk of pulmonary embolism, both with risk differences equal to 0.02. The crude risks of clinically important bleeding as defined by the individual trials were 0% for stockings, 0.3% for controls, and 1.8% for low-molecular-weight heparin.

CONCLUSIONS

The results suggest that low-molecular-weight heparin and compression stockings have the greatest relative efficacy in preventing venous thromboembolism following total hip replacement. Low-molecular-weight heparin may be more effective, though at a small risk of clinically important bleeding.

Use of the alveolar-arterial oxygen gradient in the diagnosis of pulmonary embolism

BACKGROUND

Arterial blood gas (ABG) values and the alveolar-arterial oxygen (A-a) gradient are sensitive indicators of pulmonary pathology. Alone, they are not diagnostic of pulmonary embolism (PE), but they may be useful in excluding the diagnosis of PE if their values fall within the normal range. The purpose of this study was to determine the diagnostic value of a normal A-a gradient in ruling out PE.

PATIENTS AND METHODS

The Derivation Set came from the records of all patients at Cleveland MetroHealth Medical Center who received a ventilation/perfusion (V/Q) scan for suspected PE in 1988 or 1989. Demographic and clinical data were obtained that included risk factors, symptoms, signs, and laboratory tests. A-a gradients were calculated using a standard equation; a normal gradient was defined as less than or equal to (age/4 + 4). The A-a gradient was examined before and after controlling for PE risk factors. The Validation Set was comprised of patients who had V/Q scans in 1987 and 1990.

RESULTS

Among the 873 patients in the Derivation Set, 540 had simultaneous room air ABG determinations. Of these patients, 109 (20%) had a discharge diagnosis of PE. Only 1 of 57 (1.8%; 95% confidence interval [CI]: 0.9%-10.7%) patients without a history of PE or deep venous thrombosis (DVT) and with a normal A-a gradient had PE. Among the 805 V/Q patients in the Validation Set, 489 had simultaneous room air/ABG determinations. Of these, 75 (15%) had PE. Only 1 of 54 (1.9%; 95% CI: 0.1%-11.2%) patients without a history of PE or DVT and with a normal A-a gradient had PE.

CONCLUSIONS

A normal A-a gradient among patients without a history of PE or DVT makes the diagnosis of PE unlikely. Further diagnostic evaluation may be unnecessary in this subgroup of patients.

An overview of the efficacy and safety of fenfluramine and mazindol in the treatment of obesity

OBJECTIVE

To assess the validity of the perceptions that appetite-suppressant drugs are ineffective, potentially addictive, and fraught with side effects, we reviewed the effectiveness and safety of two such drugs with purported low abuse potential in the treatment of obesity: mazindol and fenfluramine hydrochloride.

DATA SOURCES

Relevant studies in English published before September 1991 were identified using MEDLINE, accompanied by a cross-referenced manual search.

STUDY SELECTION

All randomized clinical trials conducted with adults for at least 6 weeks' duration with weight change as an outcome.

DATA EXTRACTION

Data extracted from each report included key study characteristics, clinical information, co-interventions, and outcomes, including dropouts due to either adverse drug effects or perceived lack of effect.

DATA SYNTHESIS

Of 36 acceptable trials, 35 were double-blinded, 32 were placebo-controlled, and 13 were cross-over. Median duration of drug therapy was 12 weeks. In studies reporting such data, mean patient age was 41 years, and mean baseline weight was 84 kg (143% of ideal body weight). Among 1163 patients receiving drug therapy and 866 patients receiving placebo, mean weight loss across all trials was 5.2 and 1.9 kg, respectively (P < .001). Among 32 direct comparisons between drug and placebo, the mean weight loss by sample size was 3.0 kg greater in the treatment group (P < .001), and did not vary in subgroup analyses of trial type, drug, or dose. Similar proportions of treatment and placebo groups dropped out (20% vs 22%; P = .34); however, overall dropout rates were higher in parallel trials (25% vs 9% for crossover trials). Dropouts due to adverse drug effects were more common in the treatment group (7% vs 2%; P < .001), while those due to perceived lack of effect were more common in the placebo group (6% vs 2%; P < .001). Mazindol resulted in fewer dropouts due to adverse drug effects (4% vs 9%; P < .001) and a perceived lack of effect (1% v 3%; P = .04). No drug addiction or adverse drug effects requiring medical intervention were reported.

CONCLUSION

The apparent short-term efficacy of these appetite-suppressant drugs and the lack of severe adverse drug effects or addiction suggest that they may be useful in the treatment of obesity. Further study of these agents with attention to long-term efficacy, safety, and health consequences is warranted.

The acute effect of phenylpropanolamine and brompheniramine on blood pressure in controlled hypertension: a randomized double-blind crossover trial

STUDY OBJECTIVE

To determine the acute effect of phenylpropanolamine, 75 mg, and brompheniramine, 12 mg, in combination (PPA/B) on blood pressure in patients with controlled hypertension, using ambulatory blood pressure monitoring (ABPM).

DESIGN

Randomized double-blind crossover trial.

SETTING

Outpatient clinic at one medical center.

PARTICIPANTS

13 healthy volunteers aged 36 to 64 years, receiving medication for hypertension.

INTERVENTIONS

Following 24-hour baseline ABPM, participants were randomized to receive either placebo or PPA/B every 12 hours for three doses, while ABPM continued. After a 24-hour washout period, all participants received the crossover regimen.

MEASUREMENTS AND MAIN RESULTS

No clinically important or statistically significant difference was noted for mean systolic and diastolic blood pressures during the baseline (125/75), PPA/B (127/72), and placebo (126/73) phases of the study. Within the first four hours of treatment, the mean change in systolic blood pressure from baseline between PPA/B and placebo phases was 1.7 mm Hg (95% CI -5.3 to 8.7), and mean change in diastolic blood pressure was 0.9 mm Hg (95% CI -1.6 to 3.5), excluding a first-dose pressor effect.

CONCLUSION

When used as recommended, PPA/B, a commonly used over-the-counter cold medication, has no significant acute effect on blood pressure in patients with controlled hypertension.

A meta-analysis of low-dose aspirin for the prevention of pregnancy-induced hypertensive disease

BACKGROUND

--Pregnancy-induced hypertension (PIH), defined as either isolated hypertension after the 20th week of gestation or hypertension with proteinuria (preeclampsia), occurs in 5% to 15% of pregnancies and is associated with maternal and neonatal morbidity. Previous clinical trials with small numbers of patients have suggested that aspirin in doses of 60 to 150 mg/d during the second and third trimesters reduces the risk of PIH and improves maternal and neonatal outcomes.

OBJECTIVE

--We performed a meta-analysis of the six published controlled trials to estimate more precisely (1) the magnitude of protection of aspirin from PIH; (2) the effect of aspirin on severe low-birth-weight infants, cesarean section, and perinatal mortality; and (3) the risk of adverse effects.

METHODS

--We critically and independently evaluated study methods, assigned a quality score to each trial, and abstracted quantitative outcomes data. For each outcome, both relative risk (RR) and the number needed to be treated were calculated.

RESULTS

--Among 394 subjects from six trials, the RR of PIH among women who took aspirin was 0.35 (95% confidence interval [CI], 0.22 to 0.55) and the number needed to be treated was 4.4, meaning that between four and five high-risk women would need to be treated with aspirin to prevent one case of PIH. Aspirin reduced the risk of severe low birth weight among newborns by 44% (RR = 0.56; 95% CI, 0.36 to 0.88) and reduced the risk of cesarean section by 66% overall (RR = 0.34; 95% CI, 0.25 to 0.48), although the specific indications for cesarean section were generally not described. There was no effect on fetal and neonatal death (RR = 0.88; 95% CI, 0.32 to 2.46), and there were no maternal or neonatal adverse effects associated with taking aspirin.

CONCLUSION

--This meta-analysis suggests that low-dose aspirin reduces the risks of PIH and severe low birth weight, with no observed risk of maternal or neonatal adverse effects.

Do corticosteroids reduce mortality from alcoholic hepatitis? A meta-analysis of the randomized trials

PURPOSE

To determine whether corticosteroids affect short-term mortality from alcoholic hepatitis.

DATA IDENTIFICATION

Studies published from 1966 to 1989 were identified through a MEDLINE computer search and an extensive manual search of the bibliographies of identified articles.

STUDY SELECTION

We found 11 randomized studies (10 of which were placebo controlled) that assessed mortality in hospitalized patients diagnosed with acute alcoholic hepatitis and treated with corticosteroids.

DATA EXTRACTION

Two critical appraisers independently evaluated trial quality and abstracted quantitative data on clinical characteristics of the populations, interventions, and all-cause mortality.

RESULTS OF DATA SYNTHESIS

Overall, the protective efficacy (or percent reduction in mortality) of corticosteroids was 37% (95% CI, 20% to 50%). Protective efficacy was higher among trials with higher quality scores and trials that excluded subjects with active gastrointestinal bleeding. In subjects with hepatic encephalopathy, protective efficacy was 34% overall (CI, 15% to 48%). It was also higher among trials with higher quality scores and trials excluding subjects with acute gastrointestinal bleeding, but was not present among trials with lower quality scores or trials that did not exclude subjects with acute gastrointestinal bleeding. In subjects without hepatic encephalopathy, corticosteroids had no protective effect, and this lack of efficacy was consistent across all trial subgroups.

CONCLUSIONS

These results suggest that corticosteroids reduce short-term mortality in patients with acute alcoholic hepatitis who have hepatic encephalopathy, that the protective effect depends on the exclusion criterion of acute gastrointestinal bleeding and is influenced by trial quality, and that corticosteroids are of no benefit in patients without hepatic encephalopathy.

Does prophylaxis prevent postdental infective endocarditis? A controlled evaluation of protective efficacy

PURPOSE

Despite the American Heart Association's (AHA) recommendations for antibiotic prophylaxis to prevent infective endocarditis, no controlled clinical evidence exists for the effectiveness of this intervention. The purpose of this case-control study was to determine whether antibiotic prophylaxis for a dental procedure reduces the risk of infective endocarditis in persons with high-risk cardiac lesions.

PATIENTS AND METHODS

Cases consisted of eight subjects with high-risk lesions (six mitral, one aortic, one uncorrected tetralogy) whose first-time, native-valve infective endocarditis occurred within 12 weeks of a dental procedure and was diagnosed between 1980 and 1986. For each case subject, three control subjects were chosen from patients who underwent echocardiographic evaluation between 1980 and 1986, and who were matched for the specific high-risk lesion and age. Use of antibiotic prophylaxis, which was determined by interviews with patients and supplemented by the dentists, was defined as antibiotic taken both before and after the dental procedure.

RESULTS

Antibiotic prophylaxis was used by only one of eight (13%) case subjects compared with 15 of 24 (63%) control subjects, for an odds ratio of 0.09, which is clinically impressive (indicating 91% protective efficacy) and statistically significant (p = 0.025).

CONCLUSION

Although this report does not specifically assess the value of antibiotic prophylaxis for the current AHA recommendations, the use of antibiotic prophylaxis in persons with high-risk cardiac lesions is supported by the magnitude of protective efficacy observed in this study.

Scientific standards and the design of case-control research

A new controversy has emerged over the results of a case-control study alleging a causal relationship between certain non-steroidal anti-inflammatory agents (NSAIAs) and the risks of agranulocytosis and aplastic anemia. After describing the methods and results of the International Agranulocytosis and Aplastic Anemia (IAAA) study, we review the distinctive methodologic challenges of this study and the requirements for avoiding bias, and then reconcile the study results with the principles of case-control design. As a result of our analysis, we believe that the IAAA study's most important and reliable finding is its documentation of the infrequent occurrences of aplastic anemia and agranulocytosis with analgesic use. In contrast, a causal association between NSAIAs and blood dyscrasias has not been suitably established, and may well have resulted from several distinctive sources of bias. These include the effects of diagnostic-suspicion bias in case determination, of exclusion bias in choosing controls, of recall bias in determining exposure, and of publicity bias in both case selection and ascertainment of exposure. These problems could have been avoided and a more valid result obtained with closer attention to the experimental paradigm for case-control research.

Aortic stenosis, idiopathic gastrointestinal bleeding, and angiodysplasia: is there an association? A methodologic critique of the literature

To assess the reported association between colonic angiodysplasia and aortic stenosis, we performed a quantitative and methodologic analysis of the literature. In four controlled studies that support an association between aortic stenosis and idiopathic gastrointestinal bleeding there are major methodologic deficiencies including the following: nonblinded data collection, noncomparable diagnostic examination, nonblinded ascertainment of exposure, and noncomparable demographic susceptibility. None of the studies directly assesses angiodysplasia. Additional case reports about aortic valve replacement used to treat bleeding from angiodysplasia are limited in number and in duration of follow-up. We conclude that the existing literature does not demonstrate an association between aortic stenosis and angiodysplasia. Further controlled evaluation of this topic would be useful.

Preadmission screening of Medicare patients. The clinical impact of reimbursement disapproval

The clinical impact of a statewide Medicare preadmission certification program was assessed with a retrospective survey of Connecticut physicians. In a three-month period, only 100 (0.37%) of 28,450 Medicare admission requests were disapproved for reimbursement. Following disapproval, 22 patients were admitted immediately, 44 received outpatient care, and eight additional outpatients were not evaluated or treated. The remaining 26 patients subsequently were admitted with preadmission approval due to changed clinical condition or failed outpatient plan. Although some patients had minor problems that their physicians believed would have been avoided by immediate admission, no severe morbidity resulted from admission delay. Many physicians expressed concern about preadmission certification program-related patient anxiety and inconvenience. Although this limited survey provides preliminary evidence that preadmission certification programs can be implemented without major deleterious short-term medical effects, continued monitoring of physicians and patients involved in disapproved admissions is necessary to evaluate potential medical and psychosocial problems.