849 resultados para Failure mode and effect analysis


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Background Three non-synonymous single nucleotide polymorphisms (Q223R, K109R and K656N) of the leptin receptor gene (LEPR) have been tested for association with obesity-related outcomes in multiple studies, showing inconclusive results. We performed a systematic review and meta-analysis on the association of the three LEPR variants with BMI. In addition, we analysed 15 SNPs within the LEPR gene in the CoLaus study, assessing the interaction of the variants with sex. Methodology/Principal Findings We searched electronic databases, including population-based studies that investigated the association between LEPR variants Q223R, K109R and K656N and obesity- related phenotypes in healthy, unrelated subjects. We furthermore performed meta-analyses of the genotype and allele frequencies in case-control studies. Results were stratified by SNP and by potential effect modifiers. CoLaus data were analysed by logistic and linear regressions and tested for interaction with sex. The meta-analysis of published data did not show an overall association between any of the tested LEPR variants and overweight. However, the choice of a BMI cut-off value to distinguish cases from controls was crucial to explain heterogeneity in Q223R. Differences in allele frequencies across ethnic groups are compatible with natural selection of derived alleles in Q223R and K109R and of the ancient allele in K656N in Asians. In CoLaus, the rs10128072, rs3790438 and rs3790437 variants showed interaction with sex for their association with overweight, waist circumference and fat mass in linear regressions. Conclusions Our systematic review and analysis of primary data from the CoLaus study did not show an overall association between LEPR SNPs and overweight. Most studies were underpowered to detect small effect sizes. A potential effect modification by sex, population stratification, as well as the role of natural selection should be addressed in future genetic association studies.

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The progression of liver fibrosis in chronic hepatitis C has long been considered to be independent from viral genotypes. However, recent studies suggest an association between Hepatitis C virus (HCV) genotype 3 and accelerated liver disease progression. We completed a systematic review and meta-analysis of studies evaluating the association between HCV genotypes and fibrosis progression. PubMed, Embase and ISI Web of Knowledge databases were searched for cohort, cross-sectional and case-control studies on treatment-naïve HCV-infected adults in which liver fibrosis progression rate (FPR) was assessed by the ratio of fibrosis stage in one single biopsy to the duration of infection (single-biopsy studies) or from the change in fibrosis stage between two biopsies (paired biopsies studies). A random effect model was used to derive FPR among different HCV genotypes. Eight single-biopsy studies (3182 patients, mean/median duration of infection ranging from 9 to 21 years) and eight paired biopsies studies (mean interval between biopsies 2-12 years) met the selection criteria. The odds ratio for the association of genotype 3 with accelerated fibrosis progression was 1.52 (95% CI 1.12-2.07, P = 0.007) in single-biopsy studies and 1.37 (95% CI 0.87-2.17, P = 0.17) in paired biopsy studies. In conclusion, viral genotype 3 was associated with faster fibrosis progression in single-biopsy studies. This observation may have important consequences on the clinical management of genotype 3-infected patients. The association was not significant in paired biopsies studies, although the latter may be limited by important indication bias, short observation time and small sample size.

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Thrombophilia has been associated with pregnancy complications and recurrent miscarriage. The aim of this systematic review was to evaluate the controversial association between thrombophilia and failures of assisted reproduction technology (ART). A systematic search of the literature for studies reporting on thrombophilia in women undergoing ART up to April 2011 yielded 33 studies (23 evaluating anti-phospholipid antibodies, 5 inherited thrombophilia, and 5 both) involving 6092 patients. Overall, methodologic quality of the studies was poor. Combined results from case-control studies showed that factor V Leiden was significantly more prevalent among women with ART failure compared with fertile parous women or those achieving pregnancy after ART (odds ratio = 3.08; 95% confidence interval, 1.77-5.36). The prothrombin mutation, methylenetetrahydrofolate reductase mutation, deficiency of protein S, protein C, or anti-thrombin were all not associated with ART failure. Women with ART failure tested more frequently positive for anti-phospholipids antibodies (odds ratio = 3.33; 95% confidence interval, 1.77-6.26) with evidence of high degree of between-study heterogeneity (I(2) = 75%; P < .00001). Prospective cohort studies did not show significant associations between thrombophilia and ART outcomes. Although case-control studies suggest that women experiencing ART failures are more frequently positive for factor V Leiden and anti-phospholipid antibodies, the evidence is inconclusive and not supported by cohort studies.

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The use of self-etch primers has increased steadily because of their time savings and greater simplicity; however, overall benefits and potential disadvantages and harms have not been assessed systematically. In this study, we reviewed randomized controlled trials to assess the risk of attachment failure, bonding time, and demineralization adjacent to attachments between 1-stage (self-etch) and 2-stage (acid etch) bonding in orthodontic patients over a minimum follow-up period of 12 months.

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This systematic review and meta-analysis compared the efficacy of different anthracyclines and anthracycline dosing schedules for induction therapy in acute myeloid leukaemia in children and adults younger than 60 years of age. Twenty-nine randomized controlled trials were eligible for inclusion in the review. Idarubicin (IDA), in comparison to daunorubicin (DNR), reduced remission failure rates (risk ratio (RR) 0·81; 95% confidence interval (CI), 0·66-0·99; P = 0·04), but did not alter rates of early death or overall mortality. Superiority of IDA for remission induction was limited to studies with a DNR/IDA dose ratio <5 (ratio <5: RR 0·65; 95% CI, 0·51-0·81; P < 0·001; ratio ≥5: RR 1·03; 95% CI, 0·91-1·16; P = 0·63). Higher-dose DNR, compared to lower-dose DNR, was associated with reduced rates for remission failure (RR 0·75; 95% CI, 0·60-0·94; P = 0·003) and overall mortality (RR 0·83; 95% CI, 0·75-0·93; P < 0·001), but not for early death. Comparisons of several other anthracycline derivates did not reveal significant differences in outcomes. Survival estimates in adults suggest that both high-dose DNR (90 mg/m(2) daily × 3 or 50 mg/m(2) daily × 5) and IDA (12 mg/m(2) daily × 3) can achieve 5-year survival rates of between 40 and 50 percent.

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Whilst estimation of the marginal (total) causal effect of a point exposure on an outcome is arguably the most common objective of experimental and observational studies in the health and social sciences, in recent years, investigators have also become increasingly interested in mediation analysis. Specifically, upon establishing a non-null total effect of the exposure, investigators routinely wish to make inferences about the direct (indirect) pathway of the effect of the exposure not through (through) a mediator variable that occurs subsequently to the exposure and prior to the outcome. Although powerful semiparametric methodologies have been developed to analyze observational studies, that produce double robust and highly efficient estimates of the marginal total causal effect, similar methods for mediation analysis are currently lacking. Thus, this paper develops a general semiparametric framework for obtaining inferences about so-called marginal natural direct and indirect causal effects, while appropriately accounting for a large number of pre-exposure confounding factors for the exposure and the mediator variables. Our analytic framework is particularly appealing, because it gives new insights on issues of efficiency and robustness in the context of mediation analysis. In particular, we propose new multiply robust locally efficient estimators of the marginal natural indirect and direct causal effects, and develop a novel double robust sensitivity analysis framework for the assumption of ignorability of the mediator variable.

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OBJECTIVE: To compare the effectiveness and safety of intraarticular high-molecular hylan with standard preparations of hyaluronic acids in osteoarthritis of the knee. METHODS: We performed a systematic review and meta-analysis of randomized controlled trials comparing hylan with a hyaluronic acid in patients with knee osteoarthritis. Trials were identified by systematic searches of Central, Medline, EMBase, Cinahl, the Food and Drug Administration, and Science Citation Index supplemented by hand searches of conference proceedings and reference lists (last update November 2006). Literature screening and data extraction were performed in duplicate. Effect sizes were calculated from differences in means of pain-related outcomes between treatment and control groups at the end of the trial, divided by the pooled standard deviation. Trials were combined using random-effects meta-analysis. RESULTS: Thirteen trials with a pooled total of 2,085 patients contributed to the meta-analysis. The pooled effect size was -0.27 (95% confidence interval [95% CI] -0.55, 0.01), favoring hylan, but between-trial heterogeneity was high (I(2) = 88%). Trials with blinded patients, adequate concealment of allocation, and an intent-to-treat analysis had pooled effect sizes near null. The meta-analyses on safety revealed an increased risk associated with hylan for any local adverse events (relative risk [RR] 1.91; 95% CI 1.04, 3.49; I(2) = 28%) and for flares (RR 2.04; 95% CI 1.18, 3.53; I(2) = 0%). CONCLUSION: Given the likely lack of a superior effectiveness of hylan over hyaluronic acids and the increased risk of local adverse events associated with hylan, we discourage the use of intraarticular hylan in patients with knee osteoarthritis in clinical research or practice.

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OBJECTIVES: The role of statin use in the treatment of acute coronary syndromes (ACS) is not clear. The aim of our study was to evaluate the role of statins in ACS. METHODS: Using data from the Acute Myocardial Infarction in Switzerland (AMIS Plus) Project, we compared the effects of chronic statin use, statin therapy after admission and no statin therapy on presentation mode and outcomes in ACS. RESULTS: Available data from the period 2001-2006 including 11,603 patients were analyzed. Major cardiac event rates and in-hospital mortality were more common in statin-naive patients compared to patients who received statins. CONCLUSIONS: Our results support the importance of statin treatment in ACS. Chronic statin therapy seems to alter the initial presentation of ACS but it is questionable whether it provides an additional effect on early outcomes compared to the establishment of statin therapy after admission in statin-naive patients.

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BACKGROUND: Multidimensional preventive home visit programs aim at maintaining health and autonomy of older adults and preventing disability and subsequent nursing home admission, but results of randomized controlled trials (RCTs) have been inconsistent. Our objective was to systematically review RCTs examining the effect of home visit programs on mortality, nursing home admissions, and functional status decline. METHODS: Data sources were MEDLINE, EMBASE, Cochrane CENTRAL database, and references. Studies were reviewed to identify RCTs that compared outcome data of older participants in preventive home visit programs with control group outcome data. Publications reporting 21 trials were included. Data on study population, intervention characteristics, outcomes, and trial quality were double-extracted. We conducted random effects meta-analyses. RESULTS: Pooled effects estimates revealed statistically nonsignificant favorable, and heterogeneous effects on mortality (odds ratio [OR] 0.92, 95% confidence interval [CI], 0.80-1.05), functional status decline (OR 0.89, 95% CI, 0.77-1.03), and nursing home admission (OR 0.86, 95% CI, 0.68-1.10). A beneficial effect on mortality was seen in younger study populations (OR 0.74, 95% CI, 0.58-0.94) but not in older populations (OR 1.14, 95% CI, 0.90-1.43). Functional decline was reduced in programs including a clinical examination in the initial assessment (OR 0.64, 95% CI, 0.48-0.87) but not in other trials (OR 1.00, 95% CI, 0.88-1.14). There was no single factor explaining the heterogenous effects of trials on nursing home admissions. CONCLUSION: Multidimensional preventive home visits have the potential to reduce disability burden among older adults when based on multidimensional assessment with clinical examination. Effects on nursing home admissions are heterogeneous and likely depend on multiple factors including population factors, program characteristics, and health care setting.

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To assess the effect of self-monitoring of blood glucose (SMBG) on glycaemic control in non-insulin treated patients with type 2 diabetes by means of a systematic review and meta-analysis.

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INTRODUCTION Light cure of resin-based adhesives is the mainstay of orthodontic bonding. In recent years, alternatives to conventional halogen lights offering reduced curing time and the potential for lower attachment failure rates have emerged. The relative merits of curing lights in current use, including halogen-based lamps, light-emitting diodes (LEDs), and plasma arc lights, have not been analyzed systematically. In this study, we reviewed randomized controlled trials and controlled clinical trials to assess the risks of attachment failure and bonding time in orthodontic patients in whom brackets were cured with halogen lights, LEDs, or plasma arc systems. METHODS Multiple electronic database searches were undertaken, including MEDLINE, EMBASE, and the Cochrane Oral Health Group's Trials Register, CENTRAL. Language restrictions were not applied. Unpublished literature was searched on ClinicalTrials.gov, the National Research Register, Pro-Quest Dissertation Abstracts, and Thesis database. Search terms included randomized controlled trial, controlled clinical trial, random allocation, double blind method, single blind method, orthodontics, LED, halogen, bond, and bracket. Authors of primary studies were contacted as required, and reference lists of the included studies were screened. RESULTS Randomized controlled trials and clinical controlled trials directly comparing conventional halogen lights, LEDs, or plasma arc systems involving patients with full arch, fixed, or bonded orthodontic appliances (not banded) with follow-up periods of a minimum of 6 months were included. Using predefined forms, 2 authors undertook independent extraction of articles; disagreements were resolved by discussion. The assessment of the risk of bias of the randomized controlled trials was based on the Cochrane Risk of Bias tool. Ten studies met the inclusion criteria; 2 were excluded because of high risk of bias. In the comparison of bond failure risk with halogen lights and plasma arc lights, 1851 brackets were included in both groups. Little statistical heterogeneity was observed in this analysis (I(2) = 4.8%; P = 0.379). There was no statistical difference in bond failure risk between the groups (OR, 0.92; 95% CI, 0.68-1.23; prediction intervals, 0.54, 1.56). Similarly, no statistical difference in bond failure risk was observed in the meta-analysis comparing halogen lights and LEDs (OR, 0.96; 95% CI, 0.64-1.44; prediction intervals, 0.07, 13.32). The pooled estimates from both comparisons were OR, 0.93; 95% CI, 0.74-1.17; and prediction intervals, 0.69, 1.17. CONCLUSIONS There is no evidence to support the use of 1 light cure type over another based on risk of attachment failure.

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Sexual dysfunction is highly prevalent in the general population and associated with psychological distress and impaired sexual satisfaction. Psychological interventions are promising treatment options, as sexual dysfunction is frequently caused by and deteriorates because of psychological factors. However, research into the efficacy of psychological interventions is rather scarce and an up-to-date review of outcome studies is currently lacking. Therefore, we conducted a systematic review and meta-analysis of all available studies from 1980 to 2009 to examine the efficacy of psychological interventions for patients with sexual dysfunction. A total of 20 randomized controlled studies comparing a psychological intervention with a wait-list were included in the meta-analysis. The overall post-treatment effect size for symptom severity was d = 0.58 (95% CI: 0.40 to 0.77) and for sexual satisfaction d = 0.47 (95% CI: 0.27 to 0.70). Psychological interventions were shown to especially improve symptom severity for women with Hypoactive Sexual Desire Disorder and orgasmic disorder. Our systematic review of 14 studies comparing at least two active interventions head-to-head revealed that very few comparative studies are available with large variability in effect sizes across studies (d between -0.69 and 2.29 for symptom severity and -0.56 and 14.02 for sexual satisfaction). In conclusion, psychological interventions are effective treatment options for sexual dysfunction. However, evidence varies considerably across single disorders. Good evidence exists to date for female hypoactive sexual desire disorder and female orgasmic disorder. Further research is needed on psychological interventions for other sexual dysfunctions, their long-term and comparative effects.

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INTRODUCTION Erectile dysfunction (ED) is an increasing health problem that demands effective treatment. There is evidence that phosphodiesterase-5 inhibitors (PDE5-Is) and psychological intervention (PI) are effective treatment options; however, little is known about their comparative efficacy and the efficacy of combined treatments. AIM The aim of this systematic review and meta-analysis is to evaluate the comparative efficacy of PI, PDE5-Is, and their combination in the treatment of ED. MAIN OUTCOME MEASURES Primary outcome was ED symptoms, and secondary outcome was sexual satisfaction of the patient. METHODS A systematic literature search was conducted in order to identify relevant articles published between 1998 and 2012. We included randomized controlled trials and controlled trials comparing PI with PDE5-I treatment or one of them against a combination of both. RESULTS Eight studies with a total number of 562 patients were included in the meta-analysis. The results of the included studies are inconclusive, though they show a trend towards a larger effect of combined treatment compared with PI or PDE5-I treatment alone. The meta-analysis found that, overall, combined treatment was more efficacious for ED symptoms than PDE5-I treatment or PI alone. Combined treatment was more efficacious than PDE5-I use alone on sexual satisfaction. No differences were found between PDE5-Is and PI as stand-alone treatments. None of the moderators (treatment duration, methodological quality, or researcher allegiance) altered the effects. CONCLUSIONS The combination of PI and PDE5-Is is a promising strategy for a favorable outcome in ED and can be considered as a first-choice option for ED patients. Stronger RCTs are required to confirm this initial finding. Schmidt HM, Munder T, Gerger H, Frühauf S, and Barth J. Combination of psychological intervention and phosphodiesterase-5 inhibitors for erectile dysfunction: A narrative review and meta-analysis. J Sex Med **;**:**-**.

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Genetic evidence has indicated that the segmentation gene runt plays a key role in regulating gene expression of the pair-rule genes hairy, even-skipped, and fushi tarazu. In contrast to other pair-rule genes, sequence data of the runt open reading frame did not reveal homologies to DNA-binding motifs of known transcriptional regulatory proteins. This thesis project examined several properties of the runt gene based on the sequence of the transcription unit, including the subcellular localization of the protein in vivo, its ability to bind DNA, and the functionality of a putative nucleotide binding domain.^ A runt-specific antibody was generated and used to demonstrate that runt is localized in the nucleus. Since the precise overlap of the pair-rule stripes is thought to be critical for the determination of cellular identity along the anterior-posterior axis, phasing of early runt expression in the blastoderm was examined with regard to the segmentation genes hairy, even-skipped, and fushi tarazu. runt was also expressed at later stages of embryogenesis, including expression in neuroblasts, and ganglion mother cells of the developing nervous system. Expression at this stage was required for the subsequent formation of specific neurons and runt was extensively expressed in the central and peripheral nervous systems.^ Several experiments were done to address the biochemical function of the runt protein. A direct interaction of runt with DNA was first examined. Although bacterial expressed runt was found to bind dsDNA-cellulose, subsequent experiments failed to detect sequence-specific interactions with DNA. Inter-species conservation of the putative nucleotide binding domain suggested that this region was functionally important, and runt protein bound a labeled ATP analog with high affinity in vitro. Finally, the effect of substitution of a critical residue of the nucleotide binding domain on runt activity was examined in vivo. Ectopic expression of the mutant protein indicated that this conserved substitution altered, but did not eliminate, runt activity as evaluated by segmentation phenotype and viability. ^

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Congenital Adrenal Hyperplasia (CAH), due to 21-Hydroxylase deficiency, has an estimated incidence of 1:15,000 births and can result in death, salt-wasting crisis or impaired growth. It has been proposed that early diagnosis and treatment of infants detected from newborn screening for CAH will decrease the incidence of mortality and morbidity in the affected population. The Texas Department of Health (TDH) began mandatory screening for CAH in June, 1989 and Texas is one of fourteen states to provide neonatal screening for the disorder.^ The purpose of this study was to describe the cost and effect of screening for CAH in Texas during 1994 and to compare cases first detected by screen and first detected clinically between January 1, 1990 and December 31, 1994. This study used a longitudinal descriptive research design. The data was secondary and previously collected by the Texas Department of Health. Along with the descriptive study, an economic analysis was done. The cost of the program was defined, measured and valued for four phases of screening: specimen collection, specimen testing, follow-up and diagnostic evaluation.^ There were 103 infants with Classical CAH diagnosed during the study and 71 of the cases had the more serious Salt-Wasting form of the disease. Of the infants diagnosed with Classical CAH, 60% of the cases were first detected by screen and 40% were first detected because of clinical findings before the screening results were returned. The base case cost of adding newborn screening to an existing program (excluding the cost of specimen collection) was $357,989 for 100,000 infants. The cost per case of Classical CAH diagnosed, based on the number of infants first detected by screen in 1994, was \$126,892. There were 42 infants diagnosed with the more benign Nonclassical form of the disease. When these cases were included in the total, the cost per infant to diagnose Congenital Adrenal/Hyperplasia was $87,848. ^