221 research outputs found
Validity of observational evidence on putative risk and protective factors:appraisal of 3744 meta-analyses on 57 topics
BACKGROUND: The validity of observational studies and their meta-analyses is contested. Here, we aimed to appraise thousands of meta-analyses of observational studies using a pre-specified set of quantitative criteria that assess the significance, amount, consistency, and bias of the evidence. We also aimed to compare results from meta-analyses of observational studies against meta-analyses of randomized controlled trials (RCTs) and Mendelian randomization (MR) studies. METHODS: We retrieved from PubMed (last update, November 19, 2020) umbrella reviews including meta-analyses of observational studies assessing putative risk or protective factors, regardless of the nature of the exposure and health outcome. We extracted information on 7 quantitative criteria that reflect the level of statistical support, the amount of data, the consistency across different studies, and hints pointing to potential bias. These criteria were level of statistical significance (pre-categorized according to 10-6, 0.001, and 0.05 p-value thresholds), sample size, statistical significance for the largest study, 95% prediction intervals, between-study heterogeneity, and the results of tests for small study effects and for excess significance. RESULTS: 3744 associations (in 57 umbrella reviews) assessed by a median number of 7 (interquartile range 4 to 11) observational studies were eligible. Most associations were statistically significant at P < 0.05 (61.1%, 2289/3744). Only 2.6% of associations had P < 10-6, ≥1000 cases (or ≥20,000 participants for continuous factors), P < 0.05 in the largest study, 95% prediction interval excluding the null, and no large between-study heterogeneity, small study effects, or excess significance. Across the 57 topics, large heterogeneity was observed in the proportion of associations fulfilling various quantitative criteria. The quantitative criteria were mostly independent from one another. Across 62 associations assessed in both RCTs and in observational studies, 37.1% had effect estimates in opposite directions and 43.5% had effect estimates differing beyond chance in the two designs. Across 94 comparisons assessed in both MR and observational studies, such discrepancies occurred in 30.8% and 54.7%, respectively. CONCLUSIONS: Acknowledging that no gold-standard exists to judge whether an observational association is genuine, statistically significant results are common in observational studies, but they are rarely convincing or corroborated by randomized evidence
Thread Detection and Response Generation using Transformers with Prompt Optimisation
Conversational systems are crucial for human-computer interaction, managing
complex dialogues by identifying threads and prioritising responses. This is
especially vital in multi-party conversations, where precise identification of
threads and strategic response prioritisation ensure efficient dialogue
management. To address these challenges an end-to-end model that identifies
threads and prioritises their response generation based on the importance was
developed, involving a systematic decomposition of the problem into discrete
components - thread detection, prioritisation, and performance optimisation
which was meticulously analysed and optimised. These refined components
seamlessly integrate into a unified framework, in conversational systems.
Llama2 7b is used due to its high level of generalisation but the system can be
updated with any open source Large Language Model(LLM). The computational
capabilities of the Llama2 model was augmented by using fine tuning methods and
strategic prompting techniques to optimise the model's performance, reducing
computational time and increasing the accuracy of the model. The model achieves
up to 10x speed improvement, while generating more coherent results compared to
existing models.Comment: 6 pages, 4 figures, submitted to 2024 IEEE International Conference
on Signal Processing and Communications (SPCOM
Mandated reporters\u27 experiences with reporting child maltreatment: A meta-synthesis of qualitative studies
Objective To systematically search for research about the effectiveness of mandatory reporting of child maltreatment and to synthesise qualitative research that explores mandated reporters\u27 (MRS) experiences with reporting. Design As no studies assessing the effectiveness of mandatory reporting were retrieved from our systematic search, we conducted a meta-synthesis of retrieved qualitative research. Searches in Medline (Ovid), Embase, PsycINFO, Cumulative Index to Nursing and Allied Health Literature, Sociological Abstracts, Education Resources Information Center, Criminal Justice Abstracts and Cochrane Library yielded over 6000 citations, which were deduplicated and then screened by two independent reviewers. English-language, primary qualitative studies that investigated MRS\u27 experiences with reporting of child maltreatment were included. Critical appraisal involved a modified checklist from the Critical Appraisal Skills Programme and qualitative meta-synthesis was used to combine results from the primary studies. Setting All healthcare and social-service settings implicated by mandatory reporting laws were included. Included studies crossed nine high-income countries (USA, Australia, Sweden, Taiwan, Canada, Norway, Finland, Israel and Cyprus) and three middle-income countries (South Africa, Brazil and El Salvador). Participants: The studies represent the views of 1088 MRS. Outcomes Factors that influence MRS\u27 decision to report and MRS\u27 views towards and experiences with mandatory reporting of child maltreatment. Results Forty-four articles reporting 42 studies were included. Findings indicate that MRS struggle to identify and respond to less overt forms of child maltreatment. While some articles (14%) described positive experiences MRS had with the reporting process, negative experiences were reported in 73% of articles and included accounts of harm to therapeutic relationships and child death following removal from their family of origin. Conclusions The findings of this meta-synthesis suggest that there are many potentially harmful experiences associated with mandatory reporting and that research on the effectiveness of this process is urgently needed
World Allergy Organization (WAO) diagnosis and rationale for action against cow\u27s milk allergy (DRACMA) guideline update – XI – milk supplement/replacement formulas for infants and toddlers with CMA – systematic review
Background: Cow\u27s milk allergy (CMA) is the most complex and common food allergy in infants. Elimination of cow\u27s milk from the diet and replacement with a specialized formula for infants with cow\u27s milk allergy who cannot be breastfed is an established approach to minimize the risk of severe allergic reactions while avoiding nutritional deficiencies. Given the availability of multiple options, such as extensively hydrolyzed cow\u27s milk-based formula (eHF-CM), aminoacid formula (AAF), hydrolyzed rice formula (HRF), and soy formula (SF), there is some uncertainty regarding which formula might represent the most suitable choice with respect to health outcomes. The addition of probiotics to a specialized formula has also been proposed as a potential approach to possibly increase the benefit. We systematically reviewed specialized formulas for infants with CMA to inform the updated World Allergy Organization (WAO) DRACMA guidelines.
Objective: To systematically review and synthesize the available evidence about the use of specialized formulas for the management of individuals with CMA.
Methods: We searched from inception PubMed, Medline, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL), and the websites of selected allergy organizations, for randomized and non-randomized trials of any language investigating specialized formulas with or without probiotics. We included all studies irrespective of the language of the original publication. The last search was conducted in January 2024. We synthesized the identified evidence quantitatively or narratively as appropriate and summarized it in the evidence profiles. We conducted this review following the PRISMA, Cochrane methods, and the GRADE approach.
Results: We identified 3558 records including 14 randomized trials and 7 observational studies. Very low certainty evidence suggested that in infants with IgE-mediated CMA, eHF-CM, compared with AAF, might have higher probability of outgrowing CMA (risk ratio (RR) 2.32; risk difference (RD) 25 more per 100), while showing potentially lower probability of severe vomiting (RR 0.12, 95% CI 0.02 to 0.88; RD 23 fewer per 100, 95% CI 3 to 26) and developing food protein-induced enterocolitis syndrome (FPIES) (RR 0.15, 95% CI 0.03 to 0.82; RD 34 fewer per 100, 95% CI 7 to 39). We also found, however, that eHF-CM might be inferior to AAF in supporting a physiological growth, with respect to both weight (−5.5% from baseline, 95%CI -9.5% to −1.5%) and length (−0.7 z-score change, 95%CI -1.15 to −0.25) (very low certainty). We found similar effects for eHF-CM, compared with AAF, also in non-IgE CMA. When compared with SF, eHF-CM might favor weight gain for IgE CMA infants (0.23 z-score change, 95%CI 0.01 to 0.45), and tolerance acquisition (RR 1.86, 95%CI 1.03 to 3.37; RD 27%, 95%CI 1%–74%) for non-IgE CMA (both at very low certainty of the evidence (CoE)). The comparison of eHF-CM vs. HRF, and HRF vs. SF, showed no difference in effect (very low certainty). For IgE CMA patients, low certainty evidence suggested that adding probiotics (L. rhamnosus GG, L. casei CRL431 and B. lactis Bb-12) might increase the probability of developing CMA tolerance (RR 2.47, 95%CI 1.03 to 5.93; RD 27%, 95%CI 1%–91%), and reduce the risk of severe wheezing (RR 0.12, 95%CI 0.02 to 0.95; RD -23%, 95%CI -8% to −0.4%). However, in non-IgE CMA infants, the addition of probiotics (L. rhamnosus GG) showed no significant effect, as supported by low to very low CoE.
Conclusions: Currently available studies comparing eHF-CM, AAF, HRF, and SF provide very low certainty evidence about their effects in infants with IgE-mediated and non-IgE-mediated CMA. Our review revealed several limitations in the current body of evidence, primarily arising from concerns related to the quality of studies, the limited size of the participant populations and most importantly the lack of diversity and standardization in the compared interventions. It is therefore imperative for future studies to be methodologically rigorous and investigate a broader spectrum of available interventions. We encourage clinicians and researchers to review current World Allergy Organization (WAO) Diagnosis and Rationale for Action against Cow\u27s Milk Allergy (DRACMA) Guidelines for suggestions on how to use milk replacement formulas in clinical practice and what additional research would be the most beneficial
Mandated reporters' experiences with reporting child maltreatment: a meta-synthesis of qualitative studies.
OBJECTIVE: To systematically search for research about the effectiveness of mandatory reporting of child maltreatment and to synthesise qualitative research that explores mandated reporters' (MRs) experiences with reporting. DESIGN: As no studies assessing the effectiveness of mandatory reporting were retrieved from our systematic search, we conducted a meta-synthesis of retrieved qualitative research. Searches in Medline (Ovid), Embase, PsycINFO, Cumulative Index to Nursing and Allied Health Literature, Sociological Abstracts, Education Resources Information Center, Criminal Justice Abstracts and Cochrane Library yielded over 6000 citations, which were deduplicated and then screened by two independent reviewers. English-language, primary qualitative studies that investigated MRs' experiences with reporting of child maltreatment were included. Critical appraisal involved a modified checklist from the Critical Appraisal Skills Programme and qualitative meta-synthesis was used to combine results from the primary studies. SETTING: All healthcare and social-service settings implicated by mandatory reporting laws were included. Included studies crossed nine high-income countries (USA, Australia, Sweden, Taiwan, Canada, Norway, Finland, Israel and Cyprus) and three middle-income countries (South Africa, Brazil and El Salvador). PARTICIPANTS: The studies represent the views of 1088 MRs. OUTCOMES: Factors that influence MRs' decision to report and MRs' views towards and experiences with mandatory reporting of child maltreatment. RESULTS: Forty-four articles reporting 42 studies were included. Findings indicate that MRs struggle to identify and respond to less overt forms of child maltreatment. While some articles (14%) described positive experiences MRs had with the reporting process, negative experiences were reported in 73% of articles and included accounts of harm to therapeutic relationships and child death following removal from their family of origin. CONCLUSIONS: The findings of this meta-synthesis suggest that there are many potentially harmful experiences associated with mandatory reporting and that research on the effectiveness of this process is urgently needed
Viscosupplementation for knee osteoarthritis: systematic review and meta-analysis
Objective: To evaluate the effectiveness and safety of viscosupplementation for pain and function in patients with knee osteoarthritis.
Design: Systematic review and meta-analysis of randomised trials.
Data sources Searches were conducted of Medline, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL) databases from inception to 11 September 2021. Unpublished trials were identified from the grey literature and trial registries.
Eligibility criteria for study selection: Randomised trials comparing viscosupplementation with placebo or no intervention for knee osteoarthritis treatment.
Main outcome measures: The prespecified primary outcome was pain intensity. Secondary outcomes were function and serious adverse events. Pain and function were analysed as standardised mean differences (SMDs). The prespecified minimal clinically important between group difference was −0.37 SMD. Serious adverse events were analysed as relative risks.
Methods: Two reviewers independently extracted relevant data and assessed the risk of bias of trials using the Cochrane risk of bias tool. The predefined main analysis was based only on large, placebo controlled trials with ≥100 participants per group. Summary results were obtained through a random effects meta-analysis model. Cumulative meta-analysis and trial sequential analysis under a random effects model were also performed.
Results: 169 trials provided data on 21 163 randomised participants. Evidence of small study effects and publication biases was observed for pain and function (Egger’s tests with P<0.001 and asymmetric funnel plots). Twenty four large, placebo controlled trials (8997 randomised participants) included in the main analysis of pain indicated that viscosupplementation was associated with a small reduction in pain intensity compared with placebo (SMD −0.08, 95% confidence interval −0.15 to −0.02), with the lower bound of the 95% confidence interval excluding the minimal clinically important between group difference. This effect corresponds to a difference in pain scores of −2.0 mm (95% confidence interval −3.8 to −0.5 mm) on a 100 mm visual analogue scale. Trial sequential analysis for pain indicated that since 2009 there has been conclusive evidence of clinical equivalence between viscosupplementation and placebo. Similar conclusions were obtained for function. Based on 15 large, placebo controlled trials on 6462 randomised participants, viscosupplementation was associated with a statistically significant higher risk of serious adverse events than placebo (relative risk 1.49, 95% confidence interval 1.12 to 1.98).
Conclusion: Strong conclusive evidence indicates that viscosupplementation leads to a small reduction in knee osteoarthritis pain compared with placebo, but the difference is less than the minimal clinically important between group difference. Strong conclusive evidence indicates that viscosupplementation is also associated with an increased risk of serious adverse events compared with placebo. The findings do not support broad use of viscosupplementation for the treatment of knee osteoarthritis
Efficacy and safety of blood transfusion in obstetric patients: systematic review of the literature
Objectives: To evaluate the efficacy of blood transfusion compared to no intervention in obstetric patients. Material and methods: A systematic review was performed with Cochrane Database of Clinical Trials, PubMed, EMBASE and LILACS databases searched as of September, 2016. Two authors independently selected relevant clinical trials, assessed their methodological quality and extracted data, using the GRADE approach.
Results: Five studies within a total of 6,297 met the inclusion criteria, with women generally aged 20–40 years. Three included studies allocated women to receive blood transfusion or no intervention. Two other studies allocated women with either restricted or full blood supplies. The major issue regarding risk of bias was the extent of concealment of randomization and blinding. There was no statistically significant difference between blood transfusion versus no transfusion or restricted blood supply on mortality (relative risk 0.82 [95% confidential interval 0.32 to 2.09], p = 0.68; two studies; I2 = not applicable). Conclusions: Very low-quality evidence suggests no significant difference between blood transfusion and no intervention in obstetric patients, underlining the need for more robust clinical trials evaluating this area
Electronic nicotine delivery systems and/or electronic non-nicotine delivery systems for tobacco smoking cessation or reduction: a systematic review and meta-analysis
Objective A systematic review and meta-analysis to investigate the impact of electronic nicotine delivery systems (ENDS) and/or electronic non-nicotine delivery systems (ENNDS) versus no smoking cessation aid, or alternative smoking cessation aids, in cigarette smokers on long-term tobacco use. Data sources Searches of MEDLINE, EMBASE, PsycInfo, CINAHL, CENTRAL and Web of Science up to December 2015. Study selection Randomised controlled trials (RCTs) and prospective cohort studies. Data extraction Three pairs of reviewers independently screened potentially eligible articles, extracted data from included studies on populations, interventions and outcomes and assessed their risk of bias. We used the Grading of Recommendations Assessment, Development and Evaluation approach to rate overall certainty of the evidence by outcome. Data synthesis Three randomised trials including 1007 participants and nine cohorts including 13?115 participants proved eligible. Results provided by only two RCTs suggest a possible increase in tobacco smoking cessation with ENDS in comparison with ENNDS (RR 2.03, 95% CI 0.94 to 4.38; p=0.07; I2=0%, risk difference (RD) 64/1000 over 6 to 12?months, low-certainty evidence). Results from cohort studies suggested a possible reduction in quit rates with use of ENDS compared with no use of ENDS (OR 0.74, 95% CI 0.55 to 1.00; p=0.051; I2=56%, very low certainty). Conclusions There is very limited evidence regarding the impact of ENDS or ENNDS on tobacco smoking cessation, reduction or adverse effects: data from RCTs are of low certainty and observational studies of very low certainty. The limitations of the cohort studies led us to a rating of very low-certainty evidence from which no credible inferences can be drawn. Lack of usefulness with regard to address the question of e-cigarettes\u27 efficacy on smoking reduction and cessation was largely due to poor reporting. This review underlines the need to conduct well-designed trials measuring biochemically validated outcomes and adverse effects
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