-
Systematic Reviews Jul 2014Assessment of design heterogeneity conducted prior to meta-analysis is infrequently reported; it is often presented post hoc to explain statistical heterogeneity.... (Review)
Review
BACKGROUND
Assessment of design heterogeneity conducted prior to meta-analysis is infrequently reported; it is often presented post hoc to explain statistical heterogeneity. However, design heterogeneity determines the mix of included studies and how they are analyzed in a meta-analysis, which in turn can importantly influence the results. The goal of this work is to introduce ways to improve the assessment and reporting of design heterogeneity prior to statistical summarization of epidemiologic studies.
METHODS
In this paper, we use an assessment of sugar-sweetened beverages (SSB) and type 2 diabetes (T2D) as an example to show how a technique called 'evidence mapping' can be used to organize studies and evaluate design heterogeneity prior to meta-analysis.. Employing a systematic and reproducible approach, we evaluated the following elements across 11 selected cohort studies: variation in definitions of SSB, T2D, and co-variables, design features and population characteristics associated with specific definitions of SSB, and diversity in modeling strategies.
RESULTS
Evidence mapping strategies effectively organized complex data and clearly depicted design heterogeneity. For example, across 11 studies of SSB and T2D, 7 measured diet only once (with 7 to 16 years of disease follow-up), 5 included primarily low SSB consumers, and 3 defined the study variable (SSB) as consumption of either sugar or artificially-sweetened beverages. This exercise also identified diversity in analysis strategies, such as adjustment for 11 to 17 co-variables and a large degree of fluctuation in SSB-T2D risk estimates depending on variables selected for multivariable models (2 to 95% change in the risk estimate from the age-adjusted model).
CONCLUSIONS
Meta-analysis seeks to understand heterogeneity in addition to computing a summary risk estimate. This strategy effectively documents design heterogeneity, thus improving the practice of meta-analysis by aiding in: 1) protocol and analysis planning, 2) transparent reporting of differences in study designs, and 3) interpretation of pooled estimates. We recommend expanding the practice of meta-analysis reporting to include a table that summarizes design heterogeneity. This would provide readers with more evidence to interpret the summary risk estimates.
Topics: Beverages; Diabetes Mellitus, Type 2; Dietary Sucrose; Humans; Information Storage and Retrieval; Meta-Analysis as Topic; Models, Theoretical; Review Literature as Topic
PubMed: 25055879
DOI: 10.1186/2046-4053-3-80 -
Journal of Gastrointestinal and Liver... Dec 2023Lactulose is the first-line drug for both treatment and secondary prophylaxis for overt hepatic encephalopathy (HE). The use of lactulose for the primary prophylaxis of... (Meta-Analysis)
Meta-Analysis
BACKGROUND AND AIMS
Lactulose is the first-line drug for both treatment and secondary prophylaxis for overt hepatic encephalopathy (HE). The use of lactulose for the primary prophylaxis of HE in patients with cirrhosis and acute upper gastrointestinal bleeding (AUGIB) has been debated. Hence, we conducted this meta-analysis to assess the role of lactulose in HE prophylaxis in patients with cirrhosis and AUGIB.
METHODS
A comprehensive search of literature from inception to December 2022 was performed of three databases for randomized studies comparing lactulose and placebo in patients with cirrhosis and AUGIB. Risk ratios (RR) with 95% confidence intervals were calculated for all the dichotomous outcomes.
RESULTS
A total of five studies were included in the final analysis, out of which three studies had a low risk of bias, and two had a moderate risk of bias. Lactulose therapy was associated with a significantly lower risk of OHE compared to placebo, with a RR of 0.38 (0.23-0.62) and a number needed to treat of 6. There was no difference in the risk of mortality between the groups, with a RR of 0.71 (0.29-1.76). The pooled incidence rates of overall adverse events (AEs) and diarrhea with the use of lactulose therapy were 53.2% (42.2- 64.2) and 34.7% (17.7-51.7), but a majority did not require drug discontinuation. The certainty of the evidence was moderate to low.
CONCLUSIONS
Prophylactic lactulose reduces the incidence of HE after AUGIB but has no effect on mortality. Diarrhea and abdominal discomfort are common AEs but do not need drug discontinuation.
Topics: Humans; Lactulose; Randomized Controlled Trials as Topic; Hepatic Encephalopathy; Liver Cirrhosis; Diarrhea; Gastrointestinal Hemorrhage
PubMed: 38147599
DOI: 10.15403/jgld-4975 -
Journal of Clinical Gastroenterology Jan 2022Hepatic encephalopathy (HE) is a complex neuropsychiatric syndrome associated with liver failure and/or portal systemic shunting. Polyethylene glycol (PEG) electrolyte... (Meta-Analysis)
Meta-Analysis
Comparative Effectiveness and Safety of Polyethylene Glycol Electrolyte Solution Versus Lactulose for Treatment of Hepatic Encephalopathy: A Systematic Review and Meta-analysis.
BACKGROUND
Hepatic encephalopathy (HE) is a complex neuropsychiatric syndrome associated with liver failure and/or portal systemic shunting. Polyethylene glycol (PEG) electrolyte solution is a commonly used for catharsis of gut, which has been demonstrated to relieve HE in a number of randomized controlled trials. The aim of this paper was to evaluate the comparative efficacy and safety of PEG with lactulose for current HE treatment.
METHODS
PEG electrolyte solution versus lactulose of HE was deeply studied by conducting a systematic search in electronic databases and other sources until December 31, 2020. The PRISMA statement recommended the use of meta-analysis with 95% confidence interval (CI), relative risk (RR), and weighted mean deviation (WMD) as the estimated effect size. A sensitivity analysis was performed comprehensively to present the risk of bias and the source of heterogeneity.
RESULTS
A total of 434 patients were involved in 7 randomized studies. It is found that there was a significant advantage of PEG therapy in the increase of clinical efficacy (RR=1.46; 95% CI: 1.26-1.68; P=0.000; I2=0.0%) and the decrease of hospital stay (WMD=-1.78; 95% CI: -2.72 to 0.85; P=0.000; I2=90.1%). There was no significant difference in the incidence of adverse events (RR=0.75; 95% CI: 0.48-1.19; P=0.222>0.05; I2=7.2%) and the level of serum ammonia (WMD=9.02; 95% CI: -14.39 to 32.43; P=0.45>0.05; I2=84.9%) after 24 hours between the 2 groups.
CONCLUSIONS
The results prove that PEG has a beneficial effect on the treatment of HE. Compared with lactulose, PEG can lead to more rapid HE resolution during the first 24 hours and shorten the length of stay without increasing the rate of adverse effects.
Topics: Electrolytes; Hepatic Encephalopathy; Humans; Lactulose; Polyethylene Glycols; Randomized Controlled Trials as Topic; Treatment Outcome
PubMed: 34739404
DOI: 10.1097/MCG.0000000000001621 -
The Cochrane Database of Systematic... Jun 2018Venous leg ulcers are open skin wounds on the lower leg which can be slow to heal, and are both painful and costly. The point prevalence of open venous leg ulcers in the... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Venous leg ulcers are open skin wounds on the lower leg which can be slow to heal, and are both painful and costly. The point prevalence of open venous leg ulcers in the UK is about 3 cases per 10,000 people, and many people experience recurrent episodes of prolonged ulceration. First-line treatment for venous leg ulcers is compression therapy, but a wide range of dressings and topical treatments are also used. This diversity of treatments makes evidence-based decision-making challenging, and a clear and current overview of all the evidence is required. This review is a network meta-analysis (NMA) which assesses the probability of complete ulcer healing associated with alternative dressings and topical agents.
OBJECTIVES
To assess the effects of (1) dressings and (2) topical agents for healing venous leg ulcers in any care setting and to rank treatments in order of effectiveness, with assessment of uncertainty and evidence quality.
SEARCH METHODS
In March 2017 we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE; Ovid MEDLINE (In-Process & Other Non-Indexed Citations); Ovid Embase and EBSCO CINAHL Plus. We also scanned reference lists of relevant included studies as well as reviews, meta-analyses, guidelines and health technology reports to identify additional studies. There were no restrictions with respect to language, date of publication or study setting. We updated this search in March 2018; as a result several studies are awaiting classification.
SELECTION CRITERIA
We included published or unpublished randomised controlled trials (RCTs) that enrolled adults with venous leg ulcers and compared the effects of at least one of the following interventions with any other intervention in the treatment of venous leg ulcers: any dressing, or any topical agent applied directly to an open venous leg ulcer and left in situ. We excluded from this review dressings attached to external devices such as negative pressure wound therapies, skin grafts, growth factors and other biological agents, larval therapy and treatments such as laser, heat or ultrasound. Studies were required to report complete wound healing to be eligible.
DATA COLLECTION AND ANALYSIS
Two review authors independently performed study selection, 'Risk of bias' assessment and data extraction. We conducted this NMA using frequentist meta-regression methods for the efficacy outcome; the probability of complete healing. We assumed that treatment effects were similar within dressings classes (e.g. hydrocolloid, foam). We present estimates of effect with their 95% confidence intervals (CIs) for individual treatments focusing on comparisons with widely used dressing classes, and we report ranking probabilities for each intervention (probability of being the best, second best, etc treatment). We assessed the certainty (quality) of the body of evidence using GRADE for each network comparison and for the network as whole.
MAIN RESULTS
We included 78 RCTs (7014 participants) in this review. Of these, 59 studies (5156 participants, 25 different interventions) were included in the NMA; resulting in 40 direct contrasts which informed 300 mixed-treatment contrasts.The evidence for the network as a whole was of low certainty. This judgement was based on the sparsity of the network leading to imprecision and the general high risk of bias in the included studies. Sensitivity analyses also demonstrated instability in key aspects of the network and results are reported for the extended sensitivity analysis. Evidence for individual contrasts was mainly judged to be low or very low certainty.The uncertainty was perpetuated when the results were considered by ranking the treatments in terms of the probability that they were the most effective for ulcer healing, with many treatments having similar, low, probabilities of being the best treatment. The two most highly-ranked treatments both had more than 50% probability of being the best (sucralfate and silver dressings). However, the data for sucralfate was from one small study, which means that this finding should be interpreted with caution. When exploring the data for silver and sucralfate compared with widely-used dressing classes, there was some evidence that silver dressings may increase the probability of venous leg ulcer healing, compared with nonadherent dressings: RR 2.43, 95% CI 1.58 to 3.74 (moderate-certainty evidence in the context of a low-certainty network). For all other combinations of these five interventions it was unclear whether the intervention increased the probability of healing; in each case this was low- or very low-certainty evidence as a consequence of one or more of imprecision, risk of bias and inconsistency.
AUTHORS' CONCLUSIONS
More research is needed to determine whether particular dressings or topical agents improve the probability of healing of venous leg ulcers. However, the NMA is uninformative regarding which interventions might best be included in a large trial, largely because of the low certainty of the whole network and of individual comparisons.The results of this NMA focus exclusively on complete healing; whilst this is of key importance to people living with venous leg ulcers, clinicians may wish to take into account other patient-important outcomes and factors such as patient preference and cost.
Topics: Aged; Aged, 80 and over; Anti-Ulcer Agents; Bandages; Bandages, Hydrocolloid; Female; Humans; Male; Middle Aged; Network Meta-Analysis; Randomized Controlled Trials as Topic; Sensitivity and Specificity; Silver; Sucralfate; Varicose Ulcer; Wound Healing
PubMed: 29906322
DOI: 10.1002/14651858.CD012583.pub2 -
International Journal of Surgery... Jun 2018The aim of this work was to determine the best preservation solutions for allografts for liver transplantation by quantitative network meta-analysis. (Meta-Analysis)
Meta-Analysis Review
AIMS
The aim of this work was to determine the best preservation solutions for allografts for liver transplantation by quantitative network meta-analysis.
METHODS
Global electronic databases including PubMed, EMBASE, and Cochrane Library were searched for relevant randomized controlled trials. Seven pieces of parametric data were extracted from included studies for pooled estimation. A consistency model was used for direct and indirect comparisons. The cumulative probability P value was utilized to rank the solutions. A node-splitting model was utilized for testing the consistency of final data. Quality of evidence was assessed using the GRADE (Grades of Recommendations Assessment, Development and Evaluation) system.
RESULTS
Eleven 2-arm trials including 1319 patients and 5 different solutions were finally included. HTK (Histidine-tryptophan-ketoglutarate) solution exhibited the best efficacy for decreasing the primary dysfunction rate, biliary complications and ICU-stay time (probability P = 0.43, 0.45 and 0.58, respectively). Celsior solution significantly decreased the rate of rejection and early retransplantation (probability P = 0.73 and 0.38, respectively), and enhanced patient and graft survival (probability P = 0.90 and 0.98, respectively) more than did other solutions. Overall, the quality of evidence was rated high or moderate.
CONCLUSIONS
We suggested that HTK solution may offer the best safety during the perioperative period. However, Celsior solution led to better graft tolerance and exhibited greater benefit for long-term outcomes. And our conclusions still need to be further validated.
Topics: Allografts; Disaccharides; Electrolytes; Glucose; Glutamates; Glutathione; Graft Survival; Histidine; Humans; Liver; Liver Transplantation; Mannitol; Network Meta-Analysis; Organ Preservation; Organ Preservation Solutions; Potassium Chloride; Procaine
PubMed: 29684666
DOI: 10.1016/j.ijsu.2018.04.024 -
Italian Journal of Pediatrics May 2018Despite the rising of the Functional Gastrointestinal Disorders (FGIDs)' incidence in the last years, the etio-pathogenesis of FGIDs remains unclear. The diet seems to... (Review)
Review
Does a low FODMAPs diet reduce symptoms of functional abdominal pain disorders? A systematic review in adult and paediatric population, on behalf of Italian Society of Pediatrics.
BACKGROUND
Despite the rising of the Functional Gastrointestinal Disorders (FGIDs)' incidence in the last years, the etio-pathogenesis of FGIDs remains unclear. The diet seems to play an important role in these disorders. Indeed, at least two thirds of adult patients with Irritable Bowel Syndrome (IBS) and of children with FGIDs perceive their GI symptoms to be food-related. In particular, in the last years, more interest has been focused in the low Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyol (FODMAPs) diet.
AIMS
To provide a systematic review on the efficacy of a low FODMAPs diet in reducing symptoms associated with functional abdominal pain disorders.
METHODS
Cochrane Library, MEDLINE (via Pubmed), and EMBASE databases from inception to June 2017 were searched. We included randomized controlled trials (RCTs), prospective and retrospective studies, systematic reviews and meta-analyses, reporting the efficacy of the FODMAPs diet intervention in FGIDs patients.
RESULTS
Nineteen studies were eligible. A FODMAPs-restricted diet is beneficial in 12/13 intervention trials. The low FODMAPs diet improves overall GI symptoms, especially abdominal pain and bloating. In children, only one study reported positive results of a low FODMAPs diet. No effect was found for the lactose free diet whilst fructose-restricted diet was effective in 3/4 studies. The duration of the intervention was very different among the studies, ranging from 2 days to 16 months, and from 3 and 9 weeks for the RCTs. The majority of the trials presented differences in symptoms scoring scales, diet, food diaries, and food frequencies questionnaire.
CONCLUSIONS
The FODMAPs-restricted diet may be an effective dietary intervention for reducing IBS symptoms in adults. In children, there are promising data, although only one randomized double-blind study exists and further data are needed to better clarify the role of FODMAPs and fructose-restricted diet in IBS. The current evidence does not support the use of a lactose-restricted diet in children with FGIDs.
Topics: Abdominal Pain; Adult; Child; Disaccharides; Fermentation; Humans; Irritable Bowel Syndrome; Monosaccharides; Oligosaccharides; Polymers
PubMed: 29764491
DOI: 10.1186/s13052-018-0495-8 -
Mayo Clinic Proceedings Dec 2019To determine the association of total and added fructose-containing sugars on cardiovascular (CVD) incidence and mortality. (Meta-Analysis)
Meta-Analysis
Relation of Total Sugars, Sucrose, Fructose, and Added Sugars With the Risk of Cardiovascular Disease: A Systematic Review and Dose-Response Meta-analysis of Prospective Cohort Studies.
OBJECTIVE
To determine the association of total and added fructose-containing sugars on cardiovascular (CVD) incidence and mortality.
METHODS
MEDLINE, EMBASE and Cochrane Library were searched from January 1, 1980, to July 31, 2018. Prospective cohort studies assessing the association of reported intakes of total, sucrose, fructose and added sugars with CVD incidence and mortality in individuals free from disease at baseline were included. Risk estimates were pooled using the inverse variance method, and dose-response analysis was modeled.
RESULTS
Eligibility criteria were met by 24 prospective cohort comparisons (624,128 unique individuals; 11,856 CVD incidence cases and 12,224 CVD mortality cases). Total sugars, sucrose, and fructose were not associated with CVD incidence. Total sugars (risk ratio, 1.09 [95% confidence interval, 1.02 to 1.17]) and fructose (1.08 [1.01 to 1.15]) showed a harmful association for CVD mortality, there was no association for added sugars and a beneficial association for sucrose (0.94 [0.89 to 0.99]). Dose-response analyses showed a beneficial linear dose-response gradient for sucrose and nonlinear dose-response thresholds for harm for total sugars (133 grams, 26% energy), fructose (58 grams, 11% energy) and added sugars (65 grams, 13% energy) in relation to CVD mortality (P<.05). The certainty of the evidence using GRADE was very low for CVD incidence and low for CVD mortality for all sugar types.
CONCLUSION
Current evidence supports a threshold of harm for intakes of total sugars, added sugars, and fructose at higher exposures and lack of harm for sucrose independent of food form for CVD mortality. Further research of different food sources of sugars is needed to define better the relationship between sugars and CVD. REGISTRATION: clinicaltrials.gov, NCT01608620.
Topics: Cardiovascular Diseases; Fructose; Humans; Sucrose; Sugars; Sweetening Agents
PubMed: 31806098
DOI: 10.1016/j.mayocp.2019.05.034 -
The Journal of Nutrition Jun 2020The reward value of palatable foods is often cited as an important influence on eating behaviors, including intake of sugars. However, human neuroimaging studies have... (Meta-Analysis)
Meta-Analysis
BACKGROUND
The reward value of palatable foods is often cited as an important influence on eating behaviors, including intake of sugars. However, human neuroimaging studies have generated conflicting evidence on the basic neural representation of taste and reward responses to caloric sweeteners (sucrose and glucose), and most relevant studies have used small subject numbers.
OBJECTIVE
We conducted a systematic review and a coordinate-based meta-analysis of studies reporting brain responses to oral sugar solutions.
METHODS
A systematic search of MEDLINE, Scopus, and PsycINFO through October 2019 identified fMRI studies (in healthy human adults, including those with overweight or obesity) assessing differences in responses to purified sweet and nonsweet taste stimuli. Data were extracted with the primary objective of quantifying evidence for the activation of brain regions associated with caloric sweet taste sensation. We used activation likelihood estimation meta-analysis methods. We also performed multiple sensitivity analyses to assess the generality of effects.
RESULTS
Of 455 unique articles, 15 met the criteria for inclusion. These contributed to 2 primary meta-analyses: 1) sucrose (13 experiments, 179 coordinates, n = 241) and 2) sucrose + glucose (16 experiments, 209 coordinates, n = 262). Consistent activation was apparent in primary taste areas: insula (69.2% of studies) and opercular cortex (76.9% of studies), precentral gyri (53.9% of studies), and globus pallidus and postcentral gyrus (30.8% of studies for each). Evidence of reward activity (caudate) was seen in the primary analyses (30.8% of studies) but not in sensitivity analysis.
CONCLUSIONS
We confirm the importance of primary taste areas for gustatory processing in human adults. We also provide tentative evidence for reward-related caudate activity in relation to the sweet taste of caloric sugars. A number of factors affect the observation and interpretation of brain responses, including reward-related activity. Firm conclusions require confirmation with large data set studies.
Topics: Humans; Likelihood Functions; Magnetic Resonance Imaging; Sucrose; Sweetening Agents; Taste
PubMed: 32271923
DOI: 10.1093/jn/nxaa071 -
Alimentary Pharmacology & Therapeutics Apr 2015Interventional treatment for overt hepatic encephalopathy (OHE), includes non-absorbable disaccharides, neomycin, rifaximin, L-ornithine-L-aspartate and branched chain... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Interventional treatment for overt hepatic encephalopathy (OHE), includes non-absorbable disaccharides, neomycin, rifaximin, L-ornithine-L-aspartate and branched chain amino acids (BCAA). However, the optimum regimen remains inconclusive.
AIM
To compare interventions in terms of patients' adverse events and major clinical outcomes.
METHODS
Literature search of PubMed, Embase, Scopus, and Cochrane Library studies published up to July 31 2014. RCTs of above interventions in OHE patients were included. Network meta-analysis combined direct and indirect evidence to estimate odds ratios (ORs) and mean difference (MD) between treatments and the probabilities of ranking for treatment based on clinical outcomes.
RESULTS
Twenty eligible RCTs were included. When compared with observation, only L-ornithine-L-aspartate (OR 3.71, P < 0.001) and BCAA (OR 3.37, P < 0.001) improved clinical efficacy significantly. However, when L-ornithine-L-aspartate was compared with BCAA, non-absorbable disaccharides and neomycin, there was a trend suggesting that L-ornithine-L-aspartate may be the most effective intervention with respect to clinical improvement (OR 1.10), rifaximin (OR 1.31), non-absorbable disaccharides (OR 2.75), neomycin (OR 2.22). In addition, L-ornithine-L-aspartate (MD -20.18, 95% CI -40.12 to -0.27) provided a significant reduction in blood ammonia concentration compared with observation. Neomycin appeared to be associated with more adverse events in comparison with non-absorbable disaccharides (OR 10.15), rifaximin (OR 17.31), L-ornithine-L-aspartate (OR 3.16) or BCAA (OR 7.69).
CONCLUSIONS
L-ornithine-L-aspartate treatment may show a trend in superiority for clinical efficacy among standard interventions for OHE. Rifaximin shows the greatest reduction in blood ammonia concentration, and treatment with neomycin demonstrates a higher probability in causing adverse effects among the five compared interventions.
Topics: Amino Acids, Branched-Chain; Ammonia; Dipeptides; Disaccharides; Gastrointestinal Agents; Hepatic Encephalopathy; Humans; Mental Health; Neomycin; Randomized Controlled Trials as Topic; Rifamycins; Rifaximin
PubMed: 25684317
DOI: 10.1111/apt.13122 -
Obesity Reviews : An Official Journal... Nov 2015Sugar-sweetened beverage (SSB) consumption is associated with adverse health outcomes. Improved understanding of the determinants will inform effective interventions to... (Review)
Review
Sugar-sweetened beverage (SSB) consumption is associated with adverse health outcomes. Improved understanding of the determinants will inform effective interventions to reduce SSB consumption. A total of 46,876 papers were identified through searching eight electronic databases. Evidence from intervention (n = 13), prospective (n = 6) and cross-sectional (n = 25) studies on correlates/determinants of SSB consumption was quality assessed and synthesized. Twelve correlates/determinants were associated with higher SSB consumption (child's preference for SSBs, TV viewing/screen time and snack consumption; parents' lower socioeconomic status, lower age, SSB consumption, formula milk feeding, early introduction of solids, using food as rewards, parental-perceived barriers, attending out-of-home care and living near a fast food/convenience store). Five correlates/determinants were associated with lower SSB consumption (parental positive modelling, parents' married/co-habiting, school nutrition policy, staff skills and supermarket nearby). There was equivocal evidence for child's age and knowledge, parental knowledge, skills, rules/restrictions and home SSB availability. Eight intervention studies targeted multi-level (child, parents, childcare/preschool setting) determinants; four were effective. Four intervention studies targeted parental determinants; two were effective. One (effective) intervention targeted the preschool environment. There is consistent evidence to support potentially modifiable correlates/determinants of SSB consumption in young children acting at parental (modelling), child (TV viewing) and environmental (school policy) levels.
Topics: Australia; Beverages; Child; Child Nutritional Physiological Phenomena; Child, Preschool; Cross-Sectional Studies; Dietary Sucrose; Europe; Humans; Nutrition Policy; Nutritive Value; Parents; Pediatric Obesity; Prospective Studies; Schools; Sweetening Agents; United States
PubMed: 26252417
DOI: 10.1111/obr.12310