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PubMed2004

Safety of botulinum toxin type A: a systematic review and meta-analysis.

OBJECTIVE: To define quantitatively the safety and tolerability profile of botulinum toxin type A (BTX-A) across all common therapeutic indications. The review was limited to the evaluation of the safety profile of one preparation of BTX-A (BOTOX) because distinct formulations of BTX-A are associated with different clinical profiles, requiring separate consideration for an analysis of safety. RESEARCH DESIGN AND METHODS: We identified randomized controlled trials of BTX-A through searches of the MEDLINE, EMBASE, and Cochrane Controlled Trial databases for the years 1966-2003. Studies were double-blind, randomized, crossover, or of parallel group design. The search strategy included the terms 'botulinum toxin', 'therapeutic use', 'randomized controlled trial', 'controlled clinical trial', 'randomized clinical trial', and 'placebo controlled trial'. Only randomized controlled trials of at least 7 days duration that reported adverse events were included in the analysis. MAIN OUTCOME MEASURE: Safety was assessed by means of a meta-analysis of the number and frequency of adverse events. RESULTS: Thirty-six studies involving 2309 subjects met the inclusion criteria. These reported on 1425 subjects receiving BTX-A treatment. No study reported any severe adverse events. The meta-analysis of any mild to moderate adverse events showed a rate of roughly 25% in the BTX-A-treated group (353/1425 patients) compared with 15% in the control group (133/884 patients, p < 0.001). Focal weakness was the only adverse event that occurred significantly more often with BTX-A treatment than control. CONCLUSION: The results of this meta-analysis and experience from long-term, open-label investigations demonstrate that the formulation of BTX-A evaluated here has a favorable safety and tolerability profile across a broad spectrum of therapeutic uses.

Botulinum Toxins, Type A↗

PubMed1999

Handedness in twins: a meta-analysis.

In the largest meta-analysis of twins and singletons conducted to date we have found a higher incidence of left-handedness in twins compared to singletons. Our analysis revealed no difference in the frequency of left-handedness among monozygotic versus dizygotic twins. However, identical twins were more likely to be concordant for hand preference than non-identical twins, which is consistent with a genetic model of handedness. Prior analyses have not revealed these findings consistently, and this has led to a number of conflicting models of handedness.

Journal Article↗

PubMed2003

Associations of stressors and uplifts of caregiving with caregiver burden and depressive mood: a meta-analysis.

In the present meta-analysis, we integrated findings from 228 studies on the association of six caregiving-related stressors and caregiving uplifts with burden and depressed mood. Care recipients' behavior problems showed stronger associations with caregiver outcomes than other stressors did. The size of the relationships varied by sample characteristics: Amount of care provided and care receivers' physical impairments were less strongly related to burden and depression for dementia caregivers than for caregivers of nondemented older adults. For spouse caregivers, physical impairments and care recipients' behavior problems had a stronger relationship to burden than for adult children. Furthermore, we found evidence that the association of caregiver burden with the number of caregiving tasks, perceived uplifts of caregiving, and the level of physical impairment of the care receiver were stronger in probability samples than in convenience samples.

Aged↗

PubMed1985

Efficacy of spinal manipulation/mobilization therapy. A meta-analysis.

A quantitative review (meta-analysis) was undertaken to synthesize existing evidence on the efficacy of joint mobilization and manipulation and expose consumers of rehabilitation research to the methods and procedures of quantitative reviewing. Potentially relevant studies were obtained through a computer-assisted bibliographic search of the Index Medicus data base and through examination of references contained in retrieved studies. A total of 57 titles were potentially relevant to manipulation/mobilization, but only nine met the prespecified criteria for inclusion in the quantitative review. Data analysis indicated that studies not employing random assignment were more likely to produce results supporting the use of manipulation/mobilization therapies. The effects in favor of manipulation and mobilization were greater when manual therapy was provided in conjunction with other forms of treatment and were also greater when the treatment effects were measured immediately following therapy. In addition, hypotheses tests appearing in journals published in the United States showed manipulation/mobilization less effective in comparison with reports appearing in English language journals published outside the United States. The results provided only limited empirical support for spinal mobilization and manipulation when used to treat pain, flexibility limitations, and impairment in physical activity.

Back Pain↗

PubMed1987

Perioperative parenteral nutrition: a meta-analysis.

We used a meta-analysis protocol to evaluate the results of 18 controlled trials that measured the effectiveness of perioperative total parenteral nutrition. The pooled results of 11 trials that were randomized or quasi-randomized showed trends suggesting that total parenteral nutrition reduced the risk for complications from major surgery (p = 0.21) and fatalities (p = 0.21). Consideration of these pooled estimates of the effectiveness of this intervention must be offset by the poor quality of the trials' methodologies and the iatrogenic complications (pneumothorax, septicemia) that occurred at a pooled rate of 0.067. Alternately, other design flaws, such as the failure to exclude patients who were not malnourished from the trials, may have limited the ability of these trials to show the effectiveness of total parenteral nutrition. The evidence available up to August 1986 shows that the routine use of perioperative total parenteral nutrition in unselected patients having major surgery is not justified; however, this intervention may be helpful in subgroups of these patients who are at high risk.

Clinical Trials as Topic↗

PubMed2006

Combined use of electroconvulsive therapy and antipsychotics in schizophrenia: the Indian evidence. A review and a meta-analysis.

BACKGROUND: Combined use of electroconvulsive therapy (ECT) and antipsychotics in acute phases of schizophrenia remains controversial and inadequately investigated. AIM: This study tried to examine whether the ECT-antipsychotic combination was more efficacious than antipsychotic drugs used alone in the acute phase treatment of schizophrenia, by way of an open review and an exploratory meta-analysis of the Indian studies on the subject. METHOD: Eleven studies (n = 651) and 4 controlled trials (n = 113) were selected for the open review and the meta-analysis, respectively. For the meta-analysis, a standard chi analysis was undertaken to check for heterogeneity. Brief Psychiatric Rating Scale scores were used to estimate treatment effects. RESULTS: The open review suggested that the ECT-antipsychotic combination was more efficacious than antipsychotic drugs used alone in the first few weeks of treatment of schizophrenia. The meta-analysis, using the Inverse Weighted Variance Model, showed that the ECT-antipsychotic combination provides an advantage of approximately 5 Brief Psychiatric Rating Scale points over antipsychotic drugs, in the first 4 to 5 weeks of treatment of schizophrenia (mean treatment effect, 4.89; 95% confidence intervals, 0.50-9.38). CONCLUSIONS: The studies reviewed thus indicated that ECT-antipsychotic combinations might be better than antipsychotic drugs used alone in the first few weeks of treatment of schizophrenia; the main benefit seemed to be an acceleration of treatment response. Although the evidence was not conclusive because of several methodological difficulties, it does suggest that further research is required to determine the usefulness of the ECT-antipsychotic combination in the acute treatment of schizophrenia.

Antipsychotic Agents↗

PubMed2006

Quasi-empirical Bayes methodology for improving meta-analysis.

This article addresses the problem of heterogeneity among various studies to be combined in a meta-analysis. We adopt quasi-empirical Bayes methodology to predict the odds ratios for each study. As a result, the predicted odds ratios are pulled toward the estimated common odds ratio of the various studies under consideration. With strong heterogeneity among the studies, we jointly consider the display of the 95% CIs of the ORs and a Dixon's test (1950) for "outliers" to exclude the "extreme" estimated ORs. We demonstrate the effectiveness of our methodology based on the data analyzed by Thompson and Pocock (1987) demonstrating the power of the new approach to meta-analysis to find statistical agreement in what looks like great disagreement via a chi-squared test. We believe our technique (i.e., minimum mean-square sense) will go a long way toward increasing the trustworthiness of meta-analysis.

Bayes Theorem↗

PubMed2006

A meta-analysis of teen cigarette smoking cessation.

OBJECTIVE: This article presents a meta-analysis of 48 teen cigarette smoking cessation studies, the 1st meta-analysis of its kind. The authors conducted searches of electronic databases and unpublished manuscripts from 1970 to 2003. Fifty contextual elements were coded from each article. A weighted least squares random effects method was used to pool results from individual study net effects estimates. Multilevel random coefficients modeling was applied to control for the intrastudy variation. MAIN OUTCOME MEASURES: The primary outcome for the present analysis was quit rate. Data were entered as intent-to-treat (ITT) quit rates (not compliance sample rates). Overall treatment effect size and treatment effect sizes as a function of program content, modality, number of sessions, and length of follow-up were examined. RESULTS: Across studies, program conditions, compared with control conditions, appeared to give smokers a 2.90% (95% confidence interval = 1.47-4.35%) absolute advantage in quitting, increasing the probability of quitting by approximately 46% (9.14% vs. 6.24%). Relatively higher quit rates were found in programs that included a motivation enhancement component, cognitive-behavioral techniques, and social influence approaches. Also, relatively higher quit rates were found in school-based clinic and classroom modalities. Furthermore, relatively higher quit rates were found for programs consisting of at least 5 quit sessions. Data also indicated that the effects were maintained at short-term (1 year or less) and longer term (longer than 1 year) follow-ups. CONCLUSION: Much more teen smoking cessation research is needed, but teen smoking cessation programming is effective, and the present study provides a framework to move forward.

Adolescent↗

PubMed2001

Recombinant or urinary follicle-stimulating hormone? A cost-effectiveness analysis derived by particularizing the number needed to treat from a published meta-analysis.

OBJECTIVE: To demonstrate that particularizing pooled results of a meta-analysis can derive incremental cost effectiveness of superovulation with recombinant follicle-stimulating hormones (rFSH) vs. the highly purified urinary form (uFSH) for assisted conception. DESIGN: A retrospective study. SETTING: An assisted conception unit in the United Kingdom. PATIENT(S): One hundred forty-five fresh in vitro fertilization (IVF) and 58 fresh intracytoplasmic sperm injection (ICSI) cycles. INTERVENTION(S): rFSH vs. uFSH. MAIN OUTCOME MEASURE(S): Incremental cost-effectiveness (i.e., cost needed to treat, or CNT) and budget-impact analyses of rFSH vs. uFSH. RESULT(S): In women less than 30 years old, the clinical pregnancy rate was 37.7% (95% CI 24.8%-52.1%), the particularized number needed to treat (pNNT) was -19, and the cost needed to treat was 5070.51 pounds sterling (3660.53 pounds sterling to 7619.32 pounds sterling). For the 30- to 35-year-old age group, the clinical pregnancy rate was 29.9% (95% CI 20.0%--41.4%), the particularized number needed to treat was -24, and CNT was 7335.59 pounds stering (5284.11 pounds sterling to 10,941.22 pounds sterling). For the 36- to 40-year-old age group, the clinical pregnancy rate was 30.6.0% (95% CI 19.6%--43.7%), the particularized number needed to treat was -23.0, and the CNT was 8569.67 pounds sterling (5998.70 pounds sterling to 13,413.24 pounds sterling). CONCLUSION(S): The CNT and thus the budget impact analyses (the extra number of cycles that can be funded by the CNT) both increase directly with age of the patient, and inversely with the clinical pregnancy rate.

Adult↗

PubMed1999

The treatment of tardive dyskinesia--a systematic review and meta-analysis.

This systematic review aimed to collate randomized controlled trials (RCTs) of various interventions used to treat tardive dyskinesia (TD) and, where appropriate, to combine the data for meta-analysis. Clinical trials were identified by electronic searches, handsearches and contact with principal investigators. Data were extracted independently by two reviewers, for outcomes related to improvement, deterioration, side-effects and drop out rates. Data were pooled using the Mantel-Haenzel Odds Ratio (fixed effect model). For treatments that had significant effects, the number needed to treat (NNT) was calculated. From 296 controlled clinical trials, data were extracted from 47 trials. For most interventions, we could identify no RCT-derived evidence of efficacy. A meta-analysis showed that baclofen, deanol and diazepam were no more effective than a placebo. Single RCTs demonstrated a lack of evidence of any effect for bromocriptine, ceruletide, clonidine, estrogen, gamma linolenic acid, hydergine, lecithin, lithium, progabide, seligiline and tetrahydroisoxazolopyridinol. The meta-analysis found that five interventions were effective: L-dopa, oxypertine, sodium valproate, tiapride and vitamin E; neuroleptic reduction was marginally significant. Data from single RCTs revealed that insulin, alpha methyl dopa and reserpine were more effective than a placebo. There was a significantly increased risk of adverse events associated with baclofen, deanol, L-dopa, oxypertine and reserpine. Meta-analysis of the impact of placebo (n=485) showed that 37.3% of participants showed an improvement. Interpretation of this systematic review requires caution as the individual trials identified tended to have small sample sizes. For many compounds, data from only one trial were available, and where meta-analyses were possible, these were based on a small number of trials. Despite these concerns, the review facilitated the interpretation of the large and diverse range of treatments used for TD. Clinical recommendations for the treatment of TD are made, based on the availability of RCT-derived evidence, the strength of that evidence and the presence of adverse effects.

Double-Blind Method↗

PubMed2005

[The multi-level Meta analysis model combining individual level data with aggregative level data].

OBJECTIVE: To explore the multi-level Meta analysis model combining individual level data with aggregative level data and its application in medicine. METHODS: The difference in respect to "decreased hemoglobin A(1c)" between treatment with roglizatone and treatment without roglizatone was obtained by combining individual level data from clinical trial of roglizatone natrium with aggregative level data from literatures. This endeavor was regarded as an example to construct the multi-level Meta analysis model combining individual level data with aggregative level data. RESULTS: The baseline hemoglobin A(1c) was 9% and the dose of drug was 4 mg per day. The average difference in "decreased hemoglobin A(1c)" between treatment with and without roglizatone was 0. 464%, with a 95% CI from 0.168% to 0.760%. CONCLUSION: In case that individual data are available, the multi-level Meta analysis model combining individual level data with aggregative level data can utilize the data resources adequately and the results obtained should be more accurate.

Data Interpretation, Statistical↗

PubMed2006

Methylenetetrahydrofolate reductase gene and susceptibility to breast cancer: a meta-analysis.

The methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms have been linked to the risk of developing breast cancer. A meta-analysis of 18 case-control studies investigating the association between the C677T and the A1298C polymorphisms of the MTHFR gene and breast cancer (BC) was carried out. The meta-analysis included genotype data on 5467/7336 and 3768/5276 cases/controls for C677T and A1298C, respectively. In the meta-analysis, the consistency of genetic effects across different ethnicities and the effect of menopausal status for various genetic contrasts were investigated. The overall analysis for investigating the association between the C677T allele T and the risk of developing BC showed significant heterogeneity (p = 0.08, I2 = 34%) and non-significant association [odds ratio (OR) 1.02; 95% confidence interval (0.95-1.10)]. The allele contrast was not significant in Caucasians (nine studies) and in East Asians (four studies) [OR 1.03 (0.93-1.14) and OR 0.96 (0.81-1.15), respectively] or in pre-menopausal (five studies) and post-menopausal (four studies) groups [OR 1.10 (0.94-1.29) and OR 1.06 (0.95-1.18), respectively]. The genotype contrast of the homozygotes (TT vs CC) produced significant results only for pre-menopausal cases [OR 1.46 (1.05-2.03)]. The recessive model for allele T produced significant association only in pre-menopausal cases [OR 1.49 (1.09-2.03)]. The dominant model for the effect of allele T produced no significant results, overall and in each subgroup. For the A1298C polymorphism, all genotype contrasts showed lack of association, overall and in Caucasians. In summary, the accumulated evidence supports an association in pre-menopausal women. BC is a complex disease with multifactorial etiology, and therefore, case-control studies that investigate gene-environment interaction might elucidate further the genetics of the disease.

Breast Neoplasms↗

PubMed1999

Meta-analysis: an adolescent in need of evidence and a watchful eye.

Meta-analysis is a relatively new development in medicine. It is conceptually appealing, summarizing the medical literature in a rigorous manner and providing clinicians with a global picture regarding the merits of interventions. This process can help clinicians choose appropriate, evidence-based management options for their patients. The early enthusiasm for this approach has more recently been called into question. The reliability, and therefore the usefulness, of meta-analysis will improve as more evidence concerning the rigorous ways to conduct and report such studies is developed.

Cost-Benefit Analysis↗

PubMed2005

Effects of testosterone on sexual function in men: results of a meta-analysis.

OBJECTIVES: The role of androgen decline in the sexual activity of adult males is controversial. To clarify whether sexual function would benefit from testosterone (T) treatment in men with partially or severely reduced serum T levels, we conducted a systematic review and meta-analysis of placebo-controlled studies published in the past 30 years. The aim of this study was to assess and compare the effects of T on the different domains of sexual life. DATA SOURCE: A comprehensive search of all published randomized clinical trials was performed in MEDLINE, the Cochrane Library, EMBASE and Current Contents databases. REVIEW METHODS: Guided by prespecified criteria, software-assisted data abstraction and quality assessed by two independent reviewers, a total of 17 randomized placebo-controlled trials were found to be eligible. For each domain of sexual function we calculated the standardized mean difference relative to T and reported the results of pooled estimates of T treatment using the random effect model of meta-analysis. Heterogeneity, reproducibility and consistency of the findings across studies were explored using sensitivity and meta-regression analysis. RESULTS: Overall, 656 subjects were evaluated: 284 were randomized to T, 284 to placebo (P) and 88 treated in cross-over. The median study length was 3 months (range 1-36 months). Our meta-analysis showed that in men with an average T level at baseline below 12 nmol/l, T treatment moderately improved the number of nocturnal erections, sexual thoughts and motivation, number of successful intercourses, scores of erectile function and overall sexual satisfaction, whereas T had no effect on erectile function in eugonadal men compared to placebo. Heterogeneity was explored by grouping studies according to the characteristics of the study population. A cut-off value of 10 nmol/l for the mean T of the study population failed to predict the effect of treatment, whereas the presence of risk factors for vasculogenic erectile dysfunction (ED), comorbidities and shorter evaluation periods were associated with greater treatment effects in the studies performed in hypogonadal, but not in eugonadal, men. Meta-regression analysis showed that the effects of T on erectile function, but not libido, were inversely related to the mean baseline T concentration. The meta-analysis of available studies indicates that T treatment might be useful for improving vasculogenic ED in selected subjects with low or low-normal T levels. The evidence for a beneficial effect of T treatment on erectile function should be tempered with the caveats that the effect tends to decline over time, is progressively smaller with increasing baseline T levels, and long-term safety data are not available. The present meta-analysis highlights the need, and pitfalls, for large-scale, long-term, randomized controlled trials to formally investigate the efficacy of T replacement in symptomatic middle-aged and elderly men with reduced T levels and ED.

Adult↗

PubMedDate not supplied

Nursing intervention and smoking cessation: meta-analysis update.

OBJECTIVE: The study objective was to determine through meta-analysis the effects of nursing-delivered smoking-cessation interventions. RESULTS: Thirty-four studies met inclusion criteria in this updated meta-analysis. Twenty-six studies compared a nursing intervention with a control or usual care group of adults and found interventions of high and low intensity to modestly increase the odds of quitting (1.36, 95% confidence interval 1.22-1.51). The study results demonstrated heterogeneity; using a random effects model did not make a difference. There was evidence that interventions were most effective for hospital inpatients with cardiovascular disease than for patients with other conditions (odds ratio 2.14, confidence interval 1.39-3.31). Interventions in nonhospitalized adults were beneficial as well; no effect was found for additive intervention components. Counseling during health-screening programs or as part of multifactorial secondary preventions programs was found to be the least effective. The challenge will be to incorporate smoking-cessation interventions into evidence-based nursing practice.

Adult↗

PubMed2006

An updated meta-analysis of genome scans for hypertension and blood pressure in the NHLBI Family Blood Pressure Program (FBPP).

A meta-analysis of the results from a multicenter genome-wide linkage study for hypertension and blood pressure (BP) based on an initial sample of 6,245 individuals was published in 2003. We report here a combined linkage analysis of hypertension and BP using the complete Family Blood Pressure Program (FBPP) dataset, which includes a total of 12,028 genotyped individuals. Genome-wide linkage analyses for hypertension and BP were first performed in each of the studied ethnic group within each network and the results were combined with a meta-analysis using a modified Fisher's method of combining P values. Our meta-analysis of genome scans for the latest FBPP dataset reveals suggestive linkage for hypertension and BP at several regions on the human genome. Strong evidence for linkage at two of these regions, 2p14 and 3p14.1, have also been published in previous meta-analyses, making them good candidate locations for susceptibility variants.

Adult↗

PubMed1998

Meta-analysis of studies assessing the efficacy of projective techniques in discriminating child sexual abuse.

OBJECTIVE: This meta-analysis of 12 studies assesses the efficacy of projective techniques to discriminate between sexually abused children and nonsexually abused children. METHOD: A literature search was conducted to identify published studies that used projective instruments with sexually abused children. Those studies that reported statistics that allowed for an effect size to be calculated, were then included in the meta-analysis. There were 12 studies that fit the criteria. The projectives reviewed include The Rorschach, The Hand Test, The Thematic Apperception Test (TAT), the Kinetic Family Drawings, Human Figure Drawings, Draw Your Favorite Kind of Day, The Rosebush: A Visualization Strategy, and The House-Tree-Person. RESULTS: The results of this analysis gave an over-all effect size of d = .81, which is a large effect. Six studies included only a norm group of nondistressed, nonabused children with the sexual abuse group. The average effect size was d = .87, which is impressive. Six studies did include a clinical group of distressed nonsexually abused subjects and the effect size lowered to d = .76, which is a medium to large effect. CONCLUSION: This indicates that projective instruments can discriminate distressed children from nondistressed subjects, quite well. In the studies that included a clinical group of distressed children who were not sexually abused, the lower effect size indicates that the instruments were less able to discriminate the type of distress. This meta-analysis gives evidence that projective techniques have the ability to discriminate between children who have been sexually abused and those who were not abused sexually. However, further research that is designed to include clinical groups of distressed children is needed in order to determine how well the projectives can discriminate the type of distress.

Adolescent↗

PubMedDate not supplied

Meta-analysis of case-referent studies of specific environmental or occupational pollutants on lung cancer.

BACKGROUND: Meta-analysis is a statistical tool for combining and integrating the results of independent studies of a given scientific issue. The present investigation was initiated to investigate case-referent studies of lung cancer risk from specific environmental and occupational pollutants, using detailed individual exposure data. MATERIALS AND METHODS: To examine the risk of lung cancer associated with environmental and occupational pollutants, a meta-analysis of published case-control studies was undertaken using a random effects model. For this study, the papers were selected for review from electronic search of PubMed, Medline and Google Scholar during 1990-2006. The principal outcome measure was the odds ratio for the risk of lung cancer. Twelve study reports detailing the relationship between the lung cancer and the type of exposure were identified. RESULTS: The odds ratio of asbestos, cooking fuel, cooking fumes, motor and diesel exhaust related to lung cancer were 1.67, 1.99, 2.52 and 1.42 (P < 0.001), respectively. The odds ratio of metal fumes related to lung cancer was 1.28 (0.001 P < 0.01). The combined odds ratio for the environmental and occupational exposure related to lung cancer was 1.67 (P < 0.001). CONCLUSIONS: The meta-analysis of the present study shows the magnitude association between asbestos, cooking fumes, cooking fuels, motor and diesel exhaust, with lung cancer risk. Lung cancer risk may be reduced by controlling exposure levels.

Case-Control Studies↗