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PubMed2004

Migraine is associated with magnetic resonance imaging white matter abnormalities: a meta-analysis.

BACKGROUND: There is controversy as to whether migraine is associated with white matter abnormalities (WMAs) on magnetic resonance images. These abnormalities may be important as a risk factor for future stroke. Further, it is controversial whether any increased risk of WMAs is attributable to comorbidities such as vascular disease. METHODS: A meta-analysis of published case-control studies was undertaken to address the relationship between migraine and magnetic resonance imaging WMAs. Seven studies were identified. Data from studies reporting the incidence of magnetic resonance imaging WMAs in those with migraine and appropriate control populations were used to calculate odds ratios for WMAs in migraine for each study. A stratified meta-analysis was performed using studies that did and did not exclude subjects with disease comorbidities. RESULTS: The summary odds ratio shows that those with migraine are at increased risk for WMAs (odds ratio, 3.9 [95% confidence interval, 2.26-6.72]). The risk does not differ between studies that included subjects with comorbidities and those that did not. CONCLUSION: This meta-analysis demonstrates that subjects with migraine are at higher risk of having WMAs on magnetic resonance images than those without migraine. This increased risk is present even in younger individuals who do not have co-occurring cerebrovascular disease risk factors. Prospective studies are needed to determine whether the increased risk of stroke in migraine is mediated or foreshadowed by the presence of WMAs.

Adult↗

PubMed2002

A meta-analysis of randomized controlled trials that compared neoadjuvant chemotherapy and surgery to surgery alone for resectable esophageal cancer.

BACKGROUND: Esophagectomy is often considered the standard treatment for resectable esophageal cancer but the rate of cure is low. Combining neoadjuvant chemotherapy with surgery has theoretical appeal and some clinical evidence suggests a benefit. We performed a meta-analysis of randomized controlled trials (RCTs) that compared neoadjuvant chemotherapy and surgery with surgery alone for esophageal cancer. METHODS: Medline and manual searches were done to identify all published RCTs that compared neoadjuvant chemotherapy and surgery to surgery alone for esophageal cancer. The selection process was inclusive; no trials were excluded. Trial validity assessment was done and a trial quality score was assigned. Outcomes assessed by meta-analysis included 1-, 2-, and 3-year survival, rate of resection, rate of complete resection, operative mortality, anastomotic leaks, postoperative pulmonary complications, all treatment mortality, local-regional cancer recurrence, distant cancer recurrence, and all cancer recurrence. A random-effects model was used and odds ratio was the principal measure of effect. Systematic quantitative review was done for outcomes unique to the neoadjuvant chemotherapy treatment group (clinical response, pathological complete response, and chemotherapy mortality). RESULTS: Eleven RCTs, which included 1,976 patients, were selected with quality scores ranging from 1 to 3 (5-point Jadad scale). Odds ratio (95% confidence interval [CI]; P value), expressed as chemotherapy and surgery versus surgery alone (treatment versus control; values <1 favor chemotherapy-surgery arm), was 1.00 (0.76, 1.30; P = 0.98) for 1-year survival, 0.88 (0.62, 1.24; P = 0.45) for 2-year survival, 0.77 (0.37, 1.59; P = 0.48) for 3-year survival, 1.71 (1.22, 2.40; P = 0.002) for rate of resection, 0.71 (0.58, 0.87; P = 0.001) for rate of complete resection, 0.94 (0.66, 1.35; P = 0.76) for operative mortality, 1.08 (0.45, 2.60; P = 0.87) for anastomotic leaks, 1.31 (0.77, 2.23; P = 0.32) for postoperative pulmonary complications, 1.36 (0.83, 2.25; P = 0.22) for all treatment mortality, 0.71 (0.36, 1.42; P = 0.33) for local-regional cancer recurrence, 0.79 (0.57, 1.10; P = 0.16) for distant cancer recurrence, and 0.63 (0.28, 1.41; P = 0.26) for all cancer recurrence. A clinical response to chemotherapy was observed in 31% of patients and 5% had a complete pathological response. Chemotherapy mortality (before surgery) was 1.6%. CONCLUSIONS: Compared with surgery alone, neoadjuvant chemotherapy and surgery is associated with a lower rate of esophageal resection but a higher rate of complete (R0) resection. It does not increase treatment related mortality. This meta-analysis did not demonstrate a survival benefit for the combination of neoadjuvant chemotherapy and surgery.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2003

Meta-analysis to determine the incidence of obstetric anal sphincter damage.

BACKGROUND: The reported incidence of anal sphincter injury after first (11.5-35.0 per cent) and subsequent (3.4-12.1 per cent) vaginal deliveries varies widely. In addition, the reported incidence of associated faecal incontinence ranges from zero to 68.2 per cent. The aim of this study was to perform a meta-analysis of reported incidences of postpartum anal sphincter defect diagnosed by endoanal ultrasonography (EAUS) and associated incidences of faecal incontinence. METHODS: A Medline search yielded five studies with more than 100 subjects who underwent EAUS after childbirth for evaluation of anal sphincter disruption and who were questioned about symptoms of faecal incontinence, defined as any impairment in flatus and stool control but not including urgency of defaecation. A Bayesian meta-analysis was performed to produce one inference while accounting for potential heterogeneity among the five study populations. RESULTS: Meta-analysis of 717 vaginal deliveries revealed a 26.9 per cent incidence of anal sphincter defect in primiparous women and an 8.5 per cent incidence of new sphincter defects in multiparous women. Overall, 29.7 per cent of anal sphincter defects were symptomatic. Some 3.4 per cent of women experienced postpartum faecal incontinence without an anal sphincter defect. In a Bayesian calculation, the probability of postpartum faecal incontinence due to a sphincter defect was 76.8-82.8 per cent. CONCLUSION: : The incidence of occult anal sphincter disruption following vaginal delivery is much higher than commonly estimated. However, at least two-thirds of occult defects are asymptomatic postpartum. The probability of faecal incontinence associated with an anal sphincter defect was 76.8-82.8 per cent.

Anal Canal↗

PubMed2002

Meta-analysis of rates of erectile function after treatment of localized prostate carcinoma.

PURPOSE: The results of a 1997 meta-analysis of the rates of erectile function after external beam radiotherapy (EBRT) and radical prostatectomy have been widely used in patient and professional education materials and as a reference against which new findings are compared. With a number of recent publications, it is now possible to update this analysis and compare brachytherapy with or without EBRT with EBRT alone, standard and nerve-sparing radical prostatectomy, and cryotherapy. METHODS: A comprehensive literature review and subsequent meta-analysis of the rates of erectile dysfunction associated with the treatments of localized prostate carcinoma was conducted. A simple logistic regression analysis was used to combine the data from the 54 articles that met the selection criteria. RESULTS: The predicted probability of maintaining erectile function after brachytherapy was 0.76, after brachytherapy plus EBRT 0.60, after EBRT 0.55, after nerve-sparing radical prostatectomy 0.34, after standard radical prostatectomy 0.25, and after cryotherapy 0.13. When only studies reporting > or = 2 years follow-up were considered, the only significant change was a decline in the probability for nerve-sparing radical prostatectomy. No brachytherapy studies had a follow-up of > or = 2 years. When the probabilities were adjusted for age, the spread between the RT methods and surgical approaches was greater. CONCLUSION: The differences in the probability of maintaining erectile function after different treatments of localized prostate cancer are significant.

Aged↗

PubMed2005

Do pacifiers reduce the risk of sudden infant death syndrome? A meta-analysis.

OBJECTIVE: Pacifier use has been reported to be associated with a reduced risk of sudden infant death syndrome (SIDS), but most countries around the world, including the United States, have been reluctant to recommend the use of pacifiers because of concerns about possible adverse effects. This meta-analysis was undertaken to quantify and evaluate the protective effect of pacifiers against SIDS and to make a recommendation on the use of pacifiers to prevent SIDS. METHODS: We searched the Medline database (January 1966 to May 2004) to collect data on pacifier use and its association with SIDS, morbidity, or other adverse effects. The search strategy included published articles in English with the Medical Subject Headings terms "sudden infant death syndrome" and "pacifier" and the keywords "dummy" and "soother." Combining searches resulted in 384 abstracts, which were all read and evaluated for inclusion. For the meta-analysis, articles with data on the relationship between pacifier use and SIDS risk were limited to published original case-control studies, because no prospective observational reports were found; 9 articles met these criteria. Two independent reviewers evaluated each study on the basis of the 6 criteria developed by the American Academy of Pediatrics Task Force on Infant Positioning and SIDS; in cases of disagreement, a third reviewer evaluated the study, and a consensus opinion was reached. We developed a script to calculate the summary odds ratio (SOR) by using the reported ORs and respective confidence intervals (CI) to weight the ORs. We then pooled them together to compute the SOR. We performed the Breslow-Day test for homogeneity of ORs, Cochran-Mantel-Haenszel test for the null hypothesis of no effect (OR = 1), and the Mantel-Haenszel common OR estimate. The consistency of findings was evaluated and the overall potential benefits of pacifier use were weighed against the potential risks. Our recommendation is based on the taxonomy of the 5-point (A-E) scale adopted by the US Preventive Services Task Force. RESULTS: Seven studies were included in the meta-analysis. The SOR calculated for usual pacifier use (with univariate ORs) is 0.90 (95% confidence interval [CI]: 0.79-1.03) and 0.71 (95% CI: 0.59-0.85) with multivariate ORs. For pacifier use during last sleep, the SORs calculated using univariate and multivariate ORs are 0.47 (95% CI: 0.40-0.55) and 0.39 (95% CI: 0.31-0.50), respectively. CONCLUSIONS: Published case-control studies demonstrate a significant reduced risk of SIDS with pacifier use, particularly when placed for sleep. Encouraging pacifier use is likely to be beneficial on a population-wide basis: 1 SIDS death could be prevented for every 2733 (95% CI: 2416-3334) infants who use a pacifier when placed for sleep (number needed to treat), based on the US SIDS rate and the last-sleep multivariate SOR resulting from this analysis. Therefore, we recommend that pacifiers be offered to infants as a potential method to reduce the risk of SIDS. The pacifier should be offered to the infant when being placed for all sleep episodes, including daytime naps and nighttime sleeps. This is a US Preventive Services Task Force level B strength of recommendation based on the consistency of findings and the likelihood that the beneficial effects will outweigh any potential negative effects. In consideration of potential adverse effects, we recommend pacifier use for infants up to 1 year of age, which includes the peak ages for SIDS risk and the period in which the infant's need for sucking is highest. For breastfed infants, pacifiers should be introduced after breastfeeding has been well established.

Humans↗

PubMed1998

Review article: Overview of medical treatments in unresectable hepatocellular carcinoma--an impossible meta-analysis?

BACKGROUND: Controversies surrounding medical treatment in patients with unresectable hepatocellular carcinoma continue to persist. AIM: To perform a meta-analysis of therapeutic modalities which had been evaluated in two or more randomized trials. METHODS: Fifty-two randomized trials were studied; only 30 were included. This overview identified seven therapeutic modalities which had been evaluated in two or more trials: adriamycin, 5-fluorouracil, interferon, percutaneous ethanol injection, transarterial chemotherapy, the combination of lipiodol with transarterial chemotherapy, and tamoxifen. RESULTS: Comparisons of survival between control groups showed substantial heterogeneity. There was no survival benefit at 1 year with adriamycin (mean difference 4%), 5-fluorouracil (mean difference -3%), percutaneous ethanol injection (mean difference 6%) or transarterial chemotherapy (mean difference -2%). For interferon, the survival benefit was significant with the Der Simonian & Laird method (mean difference 9%, 95% CI = 1-18%, P = 0.04) but not with the Peto et al. method (2.4 mean odds ratio, 95% CI = 0.9-6.8). The meta-analysis of tamoxifen showed a borderline survival benefit (mean difference 25%, 95% CI = 0-49%, P = 0.05). However, in sensitivity analyses, the survival benefit of tamoxifen was no longer significant. CONCLUSIONS: No treatment has clearly proven efficacy in survival. 5-Fluorouracil, adriamycin and transarterial chemotherapy were not associated with survival benefit at 1 year. The number of randomized controlled trials was insufficient to enable a conclusion to be reached for interferon and percutaneous ethanol injection. Controversy persists concerning tamoxifen efficacy. Interferon and tamoxifen require new randomized controlled trials on a larger population of patients.

Administration, Cutaneous↗

PubMed1998

Meta-analysis of fixed partial denture survival: prostheses and abutments.

STATEMENT OF PROBLEM: Few estimates of the probability of various outcomes associated with replacement of missing teeth with fixed partial dentures have been reported. Existing longitudinal studies have reported widely disparate results for the survival of fixed partial dentures, but these studies have used different definitions of failure and varying periods of follow-up. PURPOSE: This study used meta-analysis to formulate annual probability estimates for three categories of fixed partial denture or abutment survival. METHODS: A systematic review of the English language literature since 1960 identified eight studies that met the preset inclusion criteria. Estimated annual survival proportions were back-calculated based on the Kaplan-Meier model and these proportions were combined through a fixed effects model meta-analysis. The probabilities and corresponding 95% confidence intervals at 5, 10, and 15 years for the three categories of survival are reported. RESULTS: For the aggregate population represented by the limited longitudinal studies available, this meta-analysis indicated that less than 15% of fixed partial dentures were removed or in need of replacement at 10 years; whereas, nearly one third were removed or in need of replacement at 15 years. Less than 5% of abutments were removed at 10 years.

Confidence Intervals↗

PubMed1999

Randomised controlled trials of ursodeoxycholic-acid therapy for primary biliary cirrhosis: a meta-analysis.

BACKGROUND: Ursodeoxycholic acid (UDCA) is the only approved treatment for primary biliary cirrhosis, but its effect on disease progression and survival is uncertain. The aim of this study was to clarify the efficacy of UDCA in primary biliary cirrhosis. METHODS: A systematic review, including the use of meta-analysis, was done for the randomised and switch-over phases of trials comparing UDCA with placebo, obtained from Medline and Embase databases, and from manual searches derived from review articles and abstracts of major international meetings. All trials had more than a mean of 6 months' follow-up and only included patients with primary biliary cirrhosis (PBC) according to established diagnostic criteria. FINDINGS: 17 relevant articles were identified: 11 randomised controlled trials, including 1272 patients, and six reports of the switch-over phases. UCDA had a favourable effect on liver biochemistry in most of the studies but not on symptoms or the progression of histological stage; two studies did not assess survival, liver transplantation, or complications of liver disease. Meta-analysis showed no difference between UDCA and placebo in the incidence of death (odds ratio 1.21, 95% CI 0.71-2.04), liver related death (0.72, 0.22-2.32), liver transplantation (1.27, 0.78-2.07), death or liver transplantation (1.26, 0.87-1.82), and in the development of complications of liver disease (1.11, 0.64-1.92). With the primary end point defined by the authors (a combined end point in three studies, and death or liver transplantation in the others) an odds ratio of 1.53 (0.97-2.42) was obtained. Assessment of the switch-over phases, during which there was a longer follow-up, did not change the results of the meta-analysis. INTERPRETATION: Published randomised controlled trials of UDCA do not show evidence of therapeutic benefit in PBC and its use as standard therapy needs to be re-examined.

Evidence-Based Medicine↗

PubMed2026

Effects of phytosterols supplementation on hepatic lipid metabolism and metabolic outcomes in obese rodent models: a systematic review and meta-analysis.

This study aimed to synthesize and quantitatively assess the available evidence on the effects of phytosterol supplementation on hepatic lipid metabolism and obesity-related metabolic outcomes in obese rodent models, integrating biochemical, histological, and molecular evidence. A systematic search was conducted in electronic databases (PubMed, EMBASE, and Web of Science). Data on study design, population, intervention, outcomes, and risk of bias were extracted and analyzed. A quantitative meta-analysis was performed. Meta-analysis showed reductions in body weight, serum triglycerides, total cholesterol, LDL-C, VLDL-C, glucose, liver weight, hepatic cholesterol, hepatic triglycerides, and nonalcoholic fatty liver disease activity score. No significant changes were observed for adiposity index, HDL-C, insulin, or hepatic expression of PPARα, FAS, and SREBP1c. Conversely, CPT1A expression was significantly increased following PS supplementation. Subgroup analyses indicated that the beneficial effects on lipid and hepatic outcomes were generally consistent across rodent species (mice, rats, and hamsters), obesity induction models, and routes of administration, although the magnitude of responses varied between strains, with C57BL/6 mice showing more pronounced metabolic improvements. Additional analyses suggested that treatment duration and phytosterol composition may modulate specific outcomes, whereas dose-response meta-regression identified dose-dependent associations for serum and hepatic cholesterol, and PPARα expression in dietary supplementation studies. Overall, the available preclinical evidence suggests that phytosterol supplementation may improve several metabolic and hepatic outcomes in rodent models of obesity. However, the substantial heterogeneity across studies highlights the need for standardized experimental protocols and future clinical studies before these findings can be translated to human health.

Animals↗

PubMed1995

Radiologic, endoscopic, and surgical gastrostomy: an institutional evaluation and meta-analysis of the literature.

PURPOSE: To evaluate the effectiveness and safety of radiologic, percutaneous endoscopic (PEG), and surgical gastrostomy. MATERIALS AND METHODS: This project involved 5,752 patients (837 patients underwent radiologic gastrotomy; 4,194, PEG; and 721, surgical gastrostomy). Seventy-two (47 male, 25 female; age range, 12-94 years) underwent gastrostomy within 1 year in this series (radiologic gastrostomy, n = 33; PEG, n = 35; surgical gastrostomy, n = 4). A meta-analysis of 5,680 additional cases from literature published from 1980 to the present was also performed. RESULTS: Rates of successful tube placement were higher for radiologic gastrostomy than for PEG in our series and in the meta-analysis (99.2% vs 95.7%, P < .001). Major complications occurred less frequently after radiologic gastrostomy in our series and in the meta-analysis (5.9% vs 9.4% for PEG and 19.9% for surgery, P < .001). Thirty-day procedure-related mortality rates were highest for surgery (2.5% vs 0.3% for radiologic gastrostomy and 0.53% for PEG, P < .001). CONCLUSION: Radiologic gastrostomy is associated with a higher success rate than is PEG and less morbidity than either PEG or surgery.

Adolescent↗

PubMed2006

[Meta-analysis of the association of the LRP C766T polymorphism with the risk of Alzheimer's disease].

A C-to-T polymorphism in exon 3 of the low density lipoprotein receptor-related protein 1 (LPR-1) gene has been implicated as a risk factor for Alzheimer's disease (AD). The authors performed a meta-analysis to investigate the association between the C766T polymorphism in the LPR-1 gene and the risk for AD. Nineteen references were retrieved through Medline, Cochran Library and CBM search from 1997 to 2004. Similar search strategies were applied to each of these databases. Studies which were eligible for the meta-analysis should meet the following inclusion criteria: presentation of original data and a cross-sectional design, AD as the outcome of interest, an odds ratio (or enough information to calculate it) reported to quantify the association between the frequencies of genotypes and/or alleles of LPR-1 gene C766T polymorphism and the risk for AD. All analyses were performed with Review Manager 4.2. A total of 3,560 AD patients and 3,476 control subjects were analyzed according to the random effect model because some between-study heterogeneity was found (P<0.01). The combined data statistics revealed that there was no statistical difference (test for overall effect: Z=1.74, P=0.08, OR=1.17, 95% CI: 0.98-1.39; Z=1.31, P=0.19, OR=1.11, 95% CI: 0.95-1.31) in the frequencies of allele and genotype between the AD patients and the controls. The meta-analysis showed that the LPR-1 polymorphism was not a major risk factor for AD, although a small effect of the polymorphism for AD risk could not be excluded.

Age of Onset↗

PubMed2001

Epoetin treatment of anemia associated with cancer therapy: a systematic review and meta-analysis of controlled clinical trials.

Epoetin treatment offers an attractive but costly alternative to red blood cell transfusion for managing anemia associated with cancer therapy. The goal of this review is to facilitate more efficient use of epoetin by 1) quantifying the effects of epoetin on the likelihood of transfusion and on quality of life in patients with cancer treatment-related anemia and 2) evaluating whether outcomes are superior when epoetin treatment is initiated at higher hemoglobin thresholds. Two independent reviewers followed a prospective protocol for identifying studies. Outcomes data were combined with the use of a random-effects meta-analysis model. Double-blind, randomized, controlled trials that minimized patient exclusions were defined as higher quality for sensitivity analysis; randomized but unblinded trials and trials with excessive exclusions were included in the meta-analysis but were defined as lower quality. Twenty-two trials (n = 1927) met inclusion criteria, and 12 (n = 1390) could be combined for estimation of odds of transfusion. Epoetin decreased the percentage of patients transfused by 9%-45% in adults with mean baseline hemoglobin concentrations of 10 g/dL or less (seven trials; n = 1080), by 7%-47% in those with hemoglobin concentrations greater than 10 g/dL but less than 12 g/dL (seven trials; n = 431), and by 7%-39% in those with hemoglobin concentrations of 12 g/dL or higher (five trials; n = 308). In sensitivity analysis, the combined odds ratio for transfusion in epoetin-treated patients as compared with controls was 0.45 (95% confidence interval [CI] = 0.33 to 0.62) in higher quality studies and 0.14 (95% CI = 0.06 to 0.31) in lower quality studies. The number of patients needed to treat to prevent one transfusion is 4.4 for all studies, 5.2 for higher quality studies, and 2.6 for lower quality studies. Only studies with mean baseline hemoglobin concentrations of 10 g/dL or less reported statistically significant effects of epoetin treatment on quality of life; quality-of-life data were insufficient for meta-analysis. No studies addressed epoetin's effects on anemia-related symptoms. We conclude that epoetin reduces the odds of transfusion for cancer patients undergoing therapy. Evidence is insufficient to determine whether initiating epoetin earlier spares more patients from transfusion or results in better quality of life than waiting until hemoglobin concentrations decline to nearly 10 g/dL.

Anemia↗

PubMed1997

Antimicrobial prophylaxis prior to shock wave lithotripsy in patients with sterile urine before treatment: a meta-analysis and cost-effectiveness analysis.

OBJECTIVES: To determine the efficacy and cost-effectiveness of routine antimicrobial prophylaxis prior to shock wave lithotripsy (SWL) in patients with a sterile pretreatment urine culture. METHODS: A structured MedLine search revealed eight prospective, randomized, controlled trials (RCTs) of active treatment versus placebo or no treatment (n = 885) and six clinical series (non-RCTs; n = 597) addressing the use of antimicrobial prophylaxis for SWL. A meta-analysis was performed on the eight RCTs, with the primary outcome being the diagnosis of a urinary tract infection (UTI) post-SWL. A cost analysis was performed comparing a prophylactic strategy (prophylaxis for every patient and treatment for post-SWL UTIs) with a treatment-only strategy for post-SWL UTIs using various antimicrobial combinations and the median probability of post-SWL UTIs determined by meta-analysis. RESULTS: The incidence of post-SWL UTIs ranged from 0% to 28% in the control group and from 0% to 7.7% in the patients who underwent prophylaxis. Combining the placebo/no-drug treatment arms in the six RCTs by meta-analysis (Bayesian analysis) resulted in a median probability of a post-SWL UTI of 5.7% (95% confidence interval [CI] 3.8% to 8.4%). For the drug treatment arms, the median probability of a UTI was 2.1% (95% CI 0.9% to 3.6%). Relative risk (RR) analysis resulted in an overall RR of post-SWL UTIs with prophylaxis versus without prophylaxis of 0.45 (95% CI 0.22 to 0.93) (P = 0.0005). Depending on the antimicrobial regimen used for prophylaxis and treatment, a prophylactic strategy added minimally to the overall treatment cost of SWL, and proved cost beneficial when taking into consideration serious UTIs requiring inpatient treatment. CONCLUSIONS: A policy of antibiotic prophylaxis prior to SWL in patients with sterile pretreatment urine cultures is efficacious in reducing the rate of post-SWL UTIs. Discounting inpatient episodes for sepsis and acute pyelonephritis, however, the strategy is not cost-effective. In contrast, using literature-derived incidence estimates for post-SWL urosepsis or pyelonephritis necessitating inpatient treatment, prophylaxis becomes both efficacious and cost-effective, and thus constitutes a dominant strategy.

Antibiotic Prophylaxis↗

PubMed2006

Post-tympanostomy tube otorrhea: a meta-analysis.

INTRODUCTION: Post-tympanostomy tube otorrhea is the most common complication of tympanostomy tube placement. The incidence of this problem varies from 3.4% to 74%. Trials that study post-tympanostomy tube otorrhea may involve valid randomization "by patient" or "by ear." In an attempt to define "best practice," we conduct a meta-analysis to quantify the benefit of using topical prophylactic antibiotic drops in the postoperative period. We then compare our findings with previous results found in the literature. METHODS: We selected randomized studies for which antibiotic drops had been used for at least 48 hours after tympanostomy tube insertion. Nine studies, 3 "by ear" and 6 "by patient," met our inclusion criteria. The odds ratio and 95% confidence intervals were calculated for each to conduct the meta-analysis. RESULTS: Overall, prophylaxis appears to be effective at reducing the incidence of post-tympanostomy tube otorrhea. The odds ratios for all studies were less than 1.0. However, none of the 3 "by ear" studies and only 3 of the 6 "by patient" studies were statistically significant. The mean odds ratio was 52%, suggesting that prophylaxis may reduce the incidence of post-tympanostomy tube otorrhea by half. CONCLUSION: This meta-analysis suggests that routine post-tympanostomy tube prophylaxis is beneficial, but this finding is dependent on selection criteria used. EBM RATING: A-1a.

Cerebrospinal Fluid Otorrhea↗

PubMed1998

Erythrocyte Na+/Li+ countertransport and Na+/K+-2Cl- co-transport measurement in essential hypertension: useful diagnostic tools or failure? A meta-analysis of 17 years of literature.

1.A meta-analysis of 17 years of literature on erythrocyte Na+/Li+ countertransport (NLCT) and Na+/K+ co-transport (COT) measurements in relation to essential hypertension is presented. The analysis aimed to answer two questions: (i) Which clinical or laboratory variables influence NLCT and COT flux values? (ii) How useful are NLCT and COT measurements as a diagnostic aid in essential hypertension?2. Regression analysis was performed on the mean flux values and relevant clinical and laboratory values. Studies in both normotensive and hypertensive subjects were stratified for variables which showed a significant association with the measured flux. For hypertensive subjects the studies were also stratified for medication. Means of strata were calculated after weighing the mean of a study by the inverse of its own variance and were compared in normotensive as well as hypertensive subjects using a t-test.3.The analysis did not demonstrate systematic effects of laboratory variables for either NLCT or COT. It was found that essential hypertension, family history of hypertension, gender and antihypertensive medication are main determinants for the flux values of both transport systems. After stratification for these determinants, significant differences in weighed mean flux values between normotensive and hypertensive subjects were demonstrated. However, these differences are much smaller than the variance in the weighed mean flux values, suggesting the existence of other unknown variables that strongly affect the flux rates.4.In conclusion, NLCT and COT measurements cannot be of diagnostic use in essential hypertension.

Antihypertensive Agents↗

PubMed2006

Cross-platform array comparative genomic hybridization meta-analysis separates hematopoietic and mesenchymal from epithelial tumors.

A series of studies have been published that evaluate the chromosomal copy number changes of different tumor classes using array comparative genomic hybridization (array CGH); however, the chromosomal aberrations that distinguish the different tumor classes have not been fully characterized. Therefore, we performed a meta-analysis of different array CGH data sets in an attempt to classify samples tested across different platforms. As opposed to RNA expression, a common reference is used in dual channel CGH arrays: normal human DNA, theoretically facilitating cross-platform analysis. To this aim, cell line and primary cancer data sets from three different dual channel array CGH platforms obtained by four different institutes were integrated. The cell line data were used to develop preprocessing methods, which performed noise reduction and transformed samples into a common format. The transformed array CGH profiles allowed perfect clustering by cell line, but importantly not by platform or institute. The same preprocessing procedures used for the cell line data were applied to data from 373 primary tumors profiled by array CGH, including controls. Results indicated that there is no apparent feature related to the institute or platform and that array CGH allows for unambiguous cross-platform meta-analysis. Major clusters with common tissue origin were identified. Interestingly, tumors of hematopoietic and mesenchymal origins cluster separately from tumors of epithelial origin. Therefore, it can be concluded that chromosomal aberrations of tumors from hematopoietic and mesenchymal origin versus tumors of epithelial origin are distinct, and these differences can be picked up by meta-analysis of array CGH data. This suggests the possibility of prospectively using combined analysis of diverse copy number data sets for cancer subtype classification.

Chromosome Aberrations↗

PubMed1999

The effectiveness of protraction face mask therapy: a meta-analysis.

This study examined the effectiveness of maxillary protraction with orthopedic appliances in Class III patients. A meta-analysis of relevant literature was performed to determine whether a consensus exists regarding controversial issues such as the timing of treatment and the use of adjunctive intraoral appliances. An initial search identified 440 articles relating to Class III malocclusion. Among those articles, 11 studies in English and 3 studies in foreign languages met the previously established selection criteria. Data from the selected studies were categorized by age and appliance groups for the meta-analysis. The sample sizes were comparable between the groups. The statistical synthesis of changes before and after treatment in selected cephalometric landmarks showed no distinct difference between the palatal expansion group and nonexpansion group except for 1 variable, upper incisor angulation, which increased to a greater degree in the nonexpansion group. This finding implies that more skeletal effect and less dental change are produced in the expansion appliance group. Examination of the effects of age revealed greater treatment changes in the younger group. Results indicate that protraction face mask therapy is effective in patients who are growing, but to a lesser degree in patients who are older than 10 years of age, and that protraction in combination with an initial period of expansion may provide more significant skeletal effects. Overall mean values and corresponding standard deviations for the studies selected can also be used to estimate mean treatment effects expected from the use of protraction face mask.

Age Factors↗

PubMed1988

Decreased neonatal serum bilirubin with plain agar: a meta-analysis.

Neonatal jaundice is one of the most common problems leading to prolonged hospitalization of the newborn. Therefore, an effective low-risk, low-cost therapy reducing hospitalization is highly desirable. Plain dried agar, an extract of seaweed, is low cost and low risk; it can bind bilirubin in the gut, decreasing its enterohepatic circulation, thereby decreasing serum levels. Because of conflicting conclusions in the studies of agar's effectiveness in the prevention and treatment of neonatal jaundice, a meta-analysis of their methodologies was done. Criteria for assessing prospective controlled therapeutic trials of agar were established in six areas: hypothesis and clinical outcome, patient selection, treatment group allocation, therapeutic maneuver, use of cotherapies, and data analysis. Nine prospective clinical trials of agar therapy were evaluated using these six criteria. The seven studies with negative conclusions regarding agar's efficacy failed to meet the criteria in several categories: patient selection, therapeutic maneuver, use of cotherapies, or data analysis. All of the studies, including the positive studies, were at risk for biased treatment allocation. Although the pooled data analysis suggests that prophylactic agar treatment is associated with reduced peak serum bilirubin levels, this observation must be interpreted cautiously in light of heterogenous patient populations and the methodologic problems described. Based on this meta-analysis, agar therapy for neonatal jaundice can neither be recommended nor rejected. The methodologic analysis gives clear guidance for future research concerning the effectiveness of agar in treating neonatal jaundice and provides a model for meta-analysis of other prospective trials in pediatrics.

Agar↗