Strengths and limitations of meta-analysis: larger studies may be more reliable

Generic orphan drug substitution: a critical analysis of global practices and Saudi Arabia's perspective

In an era of cost pressure, substituting generic drugs represents one of the main cost-containment strategies of healthcare systems. Despite the obvious financial benefits, in a minority of cases, substitution may require caution or even be contraindicated. In most jurisdictions, to obtain approval, the bioequivalence of generic products with the brand-name equivalent needs to be shown via bioavailability studies in healthy subjects. Rare diseases, defined as medical conditions with a low prevalence, are a group of heterogenous diseases that are typically severe, disabling, progressive, degenerative, and life-threatening or chronically debilitating, and disproportionally affect the very young and elderly. Despite these unique features of rare diseases, generic bioequivalence studies are typically carried out with single doses and exclude children or the elderly. Furthermore, the excipients and manufacturing processes for generic/biosimilar products can differ from the brand products which may affect the shelf-life of the product, its appearance, smell, taste, bioavailability, safety and potency. This may result in approval of generics/biosimilars which are not bioequivalent/comparable in their target population or that meet bioequivalence but not therapeutic equivalence criteria. Another concern relates to the interchangeability of generics and biosimilars which cannot be guaranteed due to the phenomenon of biocreep. This review summarizes potential concerns with generic substitution of orphan drugs and discusses potentially problematic cases including narrow therapeutic index drugs or critical conditions where therapeutic failure could lead to serious complications or even death. Finally, we put forward the need for refining regulatory frameworks, with emphasis on Saudi Arabia, for generic substitution and recent efforts toward this direction.

Clinical Outcomes Following Surgical Management of Post-Traumatic Elbow Contractures in the Pediatric Age Group: A Meta-Analysis and Systematic Review

PURPOSE

Post-traumatic elbow stiffness is a common occurrence resulting in potentially substantial functional limitations in both daily activities and recreational endeavors. In children, this can be particularly difficult given the early stages of childhood and development and the challenges of rehabilitation. Several studies have reported favorable results of elbow contracture releases in children, resulting in improvements in outcomes. This meta-analysis aimed to determine the efficacy and safety of elbow contracture releases in the pediatric population (<18 years), along with subgroup analyses comparing age groups, operative approach, and post-traumatic versus nontraumatic etiologies.

METHODS

Meta-analysis was performed with a multidatabase search (PubMed, OVID, EMBASE, and Medline) according to Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines on September 25, 2020. Data from all published literature meeting inclusion criteria were extracted and analyzed.

RESULTS

Seven studies were included, comprising 114 post-traumatic elbow contractures. Mean age was 13.7 years. Contracture releases of the elbow led to improvements in flexion-extension arc of motion by 48º, and pronosupination arc of motion by 22º. Subgroup analysis comparing age groups of <10, 10-14 and 15-18 years showed greater improvements in flexion-extension arc in the older age group, whereas subgroup analysis comparing injury patterns revealed a larger improvement in pronosupination motion for radial head fractures. Comparing open and arthroscopic procedures, open releases had greater improvement in both flexion-extension and pronosupination motion by 18º and 21º, respectively, although there were limited patients in the arthroscopy group.

CONCLUSION

Operative management of pediatric elbow contractures is effective. Older children, children with radial head fractures, and those receiving open contracture releases may be more likely to have greater improvements.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Effectiveness of non-pharmacological interventions for fibromyalgia and quality of review methods: an overview of Cochrane Reviews

BACKGROUND

Fibromyalgia syndrome (FMS) is defined as chronic widespread pain associated with sleep disorders, cognitive dysfunction, and somatic symptoms present for at least three months and cannot be better explained by another diagnosis.

OBJECTIVES

To examine efficacy and safety of non-pharmacological interventions for FMS in adults reported in Cochrane Reviews, and reporting quality of reviews.

METHODS

Systematic reviews of randomised controlled trials (RCTs) of non-pharmacological interventions for FMS were identified from the Cochrane Database of Systematic Reviews (CDSR 2022, Issue 3 and CDSR 2023 Issue 6). Methodological quality was assessed using the AMSTAR-2 tool and a set of methodological criteria critical for analgesic effects. The primary efficacy outcomes of interest were clinically relevant pain relief, improvement in health-related quality of life (HRQoL), acceptability, safety, and reduction of mobility difficulties as reported by study participants. No pooled analyses were planned. We assumed a clinically relevant improvement was a minimal clinically important difference (MCID) between interventions and controls of 15%, or a SMD of more than 0.2, or a MD of more than 0.5, on a 0 to 10 scale.

RESULTS

Ten Cochrane reviews were eligible, reporting 181 randomized or quasi- randomized trials (11,917 participants, average trial size 66 participants). The reviews examined exercise training, acupuncture, transcutaneous electrical nerve stimulation, and psychological therapies. One review was rated moderate according to AMSTAR 2, seven were rated low and two were rated critically low. All reviews met most of the additional methodological quality criteria. All reviews included studies with patient-reported outcomes for pain. We found low certainty evidence of clinically relevant positive effects of aerobic and mixed exercise training and for cognitive behavioural therapies (CBTs) at reducing mobility difficulties and for mixed exercise training and CBTs for improving HRQoL at the end of the intervention. Number needed to treat for an additional beneficial outcome (NNTB) values for a MCID of 15% ranged between 4 and 9. We found low certainty evidence that was clinically relevant for mixed exercise and CBTs for reducing mobility difficulties at an average follow up of 24 weeks. We found low certainty evidence of clinically relevant positive effects of mixed exercise on HRQoL at an average follow up of 24 weeks. NNTB values for a MCID of 15% ranged from 5 to 11. The certainty of evidence of the acceptability (measured by dropouts) of the different non-pharmacological interventions ranged from very low to moderate and the dropout rate for any reason did not differ across the interventions or the controls, except for biofeedback and movement therapies. All the systematic reviews stated that the reporting of adverse events was inconsistent in the studies analysed (very low certainty evidence).

AUTHORS' CONCLUSIONS

There is low certainty evidence of clinically relevant reduction of mobility difficulties and of improvement of HRQoL among individuals with FMS by aerobic and mixed exercise training and by CBTs at the end of the intervention. There is low certainty evidence that CBTs and mixed exercise training reduces mobility difficulties post-treatment and that mixed exercise training improves HRQoL at follow-up by clinically meaningful scores.

Diabetes Mellitus as a risk factor for stroke among Nigerians: A systematic review and meta-analysis

Background

Diabetes mellitus is one of the modifiable risk factors for stroke. Stroke is common in Nigeria, but there is a paucity of national data on the frequency of diabetes in stroke. This study aimed to estimate to what extent diabetes a risk factor for stroke in Nigeria.

Methods

The study design is a systematic review, and the PRISMA guidelines were strictly followed. African Journal Online (AJOL), PubMed, SCOPUS and Google Scholar were systematically searched. The Newcastle-Ottawa scale was used to assess the quality, heterogeneity was determined with the I² statistic, and the DerSimonian Laird random effect model was selected for the meta-analysis.

Results

The studies were distributed across different regions of the country. The total sample size was 9397. The weighted average age of the patients with stroke was 53.7 years. The attributable risk of diabetes in stroke, among Nigerian patients, was 0.20 (95% CI: 0.17-0.22; p < 0.0001). The attributable risk has been rising steadily since the advent of the new century, and it is relatively higher in southern Nigeria.

Conclusion

The attributable risk of diabetes in stroke, among Nigerian patients is high. This varies across the regions but it is rising progressively nationally.

Diagnostic Performance of Six Ultrasound Risk Stratification Systems for Thyroid Nodules: A Systematic Review and Network Meta-Analysis

BACKGROUND. Risk stratification systems for evaluating thyroid nodules on ultrasound use varying approaches to classify levels of suspicion for malignancy, leading to variable performance. OBJECTIVE. The purpose of this study was to perform a network meta-analysis comparing six risk stratification systems used to evaluate thyroid nodules on ultrasound in terms of their diagnostic performance for the detection of thyroid cancer. EVIDENCE ACQUISITION. Five bibliometric databases were searched for studies published through August 31, 2022, that compared at least two of six ultrasound risk stratification systems (the American Association of Clinical Endocrinologists, American College of Endocrinology, and Associazione Medici Endocrinologi [AACE/ACE/AME] system; American College of Radiology Thyroid Imaging Reporting and Data System [ACR TI-RADS]; the American Thyroid Association [ATA] risk stratification system; European Thyroid Association Thyroid Imaging Reporting and Data System [EU-TIRADS]; the Korean Thyroid Imaging Reporting and Data System [K-TIRADS] endorsed by the Korean Thyroid Association and the Korean Society of Thyroid Radiology; and the Thyroid Imaging Reporting and Data System developed by Kwak et al. [Kwak TIRADS]) in terms of their diagnostic performance for the detection of thyroid cancer, with cytologic or histologic evaluation used as a reference standard. The studies' risk of bias was evaluated using the Newcastle-Ottawa Scale. A meta-analysis of each system was performed to identify the risk category threshold that had the highest accuracy as well as the highest sensitivity and specificity at this threshold. Network meta-analysis was used to perform hierarchic ranking and identify the systems having the highest sensitivities and specificities at each system's most accurate threshold. EVIDENCE SYNTHESIS. The analysis included 39 studies with 49,661 patients. All studies were of fair (n = 17) or good (n = 22) quality. The most accurate risk category thresholds were class 3 (high risk) for the AACE/ACE/AME system, TR5 (highly suspicious) for ACR TI-RADS, EU-TIRADS 5 (high risk) for EU-TIRADS, 4c (moderate concern but not classic for malignancy) for Kwak TIRADS, K-TIRADS 5 (high suspicion) for K-TIRADS, and high suspicion for the ATA system. At these thresholds, the systems had sensitivity of 64-77% and specificity of 82-90%. Network meta-analysis identified the highest sensitivity and highest specificity for ACR TI-RADS, followed by K-TIRADS. CONCLUSION. Of six risk stratification systems, ACR TI-RADS had the highest diagnostic performance for the detection of thyroid nodules on ultrasound. CLINICAL IMPACT. This network meta-analysis can inform decisions regarding implementation of the risk stratification systems and can aid future system updates.

Flawed, futile, and fabricated-features that limit confidence in clinical research in pain and anaesthesia: a narrative review

The randomised controlled trial is the foundation of clinical research; yet there is concern that many trials have flaws in design, conduct, and reporting that undermine trustworthiness. Common flaws in trials include high risk of bias, small size, outcomes irrelevant to clinical care and patient's experience, and inability to detect efficacy even if present. These flaws carry forward into systematic reviews, which can confer the label of 'high-quality evidence' on inadequate data. Trials can be futile because their flaws mean that they cannot deliver any meaningful result in that different results in a small number of patients would be sufficient to change conclusions. Some trials have been discovered to be fabricated, the number of which is growing. The fields of anaesthesia and pain have more fabricated trials than other clinical fields, possibly because of increased vigilance. This narrative review examines these themes in depth whilst acknowledging an inescapable conclusion: that much of our clinical evidence is in trouble, and special measures are needed to bolster quality and confidence.

Primary headache epidemiology in children and adolescents: a systematic review and meta-analysis

INTRODUCTION

Headache is the most prevalent neurological manifestation in adults and one of the leading causes of disability worldwide. In children and adolescents, headaches are arguably responsible for a remarkable impact on physical and psychological issues, yet high-quality evidence is scarce.

MATERIAL AND METHODS

We searched cross-sectional and cohort studies in Embase, Medline, Web of Science, and Cochrane databases from January 1988 to June 2022 to identify the prevalence of headaches in 8-18 years old individuals. The risk of bias was examined with the Joanna Briggs Institute (JBI) scale. A random-effects model was used to estimate the pooled prevalence of pediatric headache. Subgroup analyses based on headache subtypes were also conducted.

RESULTS

Out of 5,486 papers retrieved electronically, we identified 48 studies that fulfilled our inclusion criteria. The pooled prevalence of primary headaches was 11% for migraine overall [95%CI: 9-14%], 8% for migraine without aura (MwoA) [95%CI: 5-12%], 3% for migraine with aura (MwA) [95%CI:2-4%] and 17% for tension-type headache (TTH) [95% CI: 12-23%]. The pooled prevalence of overall primary headache in children and adolescents was 62% [95% CI: 53-70%], with prevalence in females and males of 38% [95% CI: 16-66%] and 27% [95% CI: 11-53%] respectively. After the removal of studies ranked as low-quality according to the JBI scale, prevalence rates were not substantially different. Epidemiological data on less common primary headaches, such as trigeminal autonomic cephalalgias, were lacking.

CONCLUSION

We found an overall remarkably high prevalence of primary headaches in children and adolescents, even if flawed by a high degree of heterogeneity. Further up-to-date studies are warranted to complete the picture of pediatric headache-related burden to enhance specific public interventions.

The efficacy and safety of peri-tonsillar administrated agents on pain treatment after pediatric tonsillectomy: A network meta-analysis

OBJECTIVES

We assessed the pain control efficacies and associated morbidities of drugs administered locally (around the tonsils) in pediatric patients undergoing a tonsillectomy.

METHODS

Randomized controlled trials up to April 2022 were retrieved from six databases. The treatment networks featured six interventions (ropivacaine, bupivacaine, levobupivacaine, ketamine, tramadol, and dexamethasone) and a control (placebo). The outcomes were the postoperative pain scores, the time to use of the first analgesic drugs, and postoperative nausea/vomiting. Both pairwise and network meta-analyses were performed.

RESULTS

All treatments controlled pain at 1 h and 1 day postoperatively. Although all agents tended to delay the time to the first analgesic drug, only bupivacaine, dexamethasone, ketamine, and tramadol significantly reduced the need for analgesics. No agent caused significant postoperative nausea or vomiting. The ranking hierarchy revealed that tramadol was superior in terms of pain control 1 h postoperatively, the time to the first analgesic drug, and the number of analgesic doses required; however, it ranked third in terms of operative time.

CONCLUSION

All drugs reduced postoperative pain. Tramadol was optimal in pain control, and dexamethasone also afforded good pain control with low incidences of nausea and vomiting.

Auditory Stimulation Improves Gait and Posture in Cerebral Palsy: A Systematic Review with Between- and Within-Group Meta-Analysis

The past decade has seen an increased interest in the implementation of auditory stimulation (AStim) for managing gait and postural deficits in people with cerebral palsy. Although existing reviews report beneficial effects of AStim on the spatiotemporal and kinematic parameters of gait, there are still numerous limitations that need to be addressed to correctly interpret these results. For instance, existing reviews have failed to characterize the effects of AStim by conducting separate between and within-group meta-analyses, these reviews have not evaluated the influence of AStim on postural outcomes, and nor have included several high-quality existing trials. In this study, we conducted between- and within-group meta-analyses to establish a state of evidence for the influence of AStim on gait and postural outcomes in people with cerebral palsy. We searched the literature according to PRISMA-P guidelines across 10 databases. Of 1414 records, 14 studies, including a total of 325 people with cerebral palsy, met the inclusion criterion. We report a significant enhancement in gait speed, stride length, cadence, and gross motor function (standing and walking) outcomes with AStim compared to conventional physiotherapy. The findings from this analysis reveal the beneficial influence of AStim on the spatiotemporal and kinematic parameters of gait and postural stability in people with cerebral palsy. Furthermore, we discuss the futurized implementation of smart wearables that can deliver person-centred AStim rehabilitation in people with cerebral palsy.

Genome-scale metabolic modeling reveals increased reliance on valine catabolism in clinical isolates of Klebsiella pneumoniae

Infections due to carbapenem-resistant Enterobacteriaceae have recently emerged as one of the most urgent threats to hospitalized patients within the United States and Europe. By far the most common etiological agent of these infections is Klebsiella pneumoniae, frequently manifesting in hospital-acquired pneumonia with a mortality rate of ~50% even with antimicrobial intervention. We performed transcriptomic analysis of data collected previously from in vitro characterization of both laboratory and clinical isolates which revealed shifts in expression of multiple master metabolic regulators across isolate types. Metabolism has been previously shown to be an effective target for antibacterial therapy, and genome-scale metabolic network reconstructions (GENREs) have provided a powerful means to accelerate identification of potential targets in silico. Combining these techniques with the transcriptome meta-analysis, we generated context-specific models of metabolism utilizing a well-curated GENRE of K. pneumoniae (iYL1228) to identify novel therapeutic targets. Functional metabolic analyses revealed that both composition and metabolic activity of clinical isolate-associated context-specific models significantly differs from laboratory isolate-associated models of the bacterium. Additionally, we identified increased catabolism of L-valine in clinical isolate-specific growth simulations. These findings warrant future studies for potential efficacy of valine transaminase inhibition as a target against K. pneumoniae infection.

Efficacy of Imaging Methods in the Detection and Diagnosis of Cerebrospinal Fluid Rhinorrhea

OBJECTIVE

To assess the diagnostic efficacy of various imaging methods in patients with suspected cerebrospinal fluid (CSF) rhinorrhea.

DATA SOURCES

The PubMed, EMBASE, SCOPUS, Web of Science, Cochrane Trials, and Google Scholar databases were searched up to December 2021.

REVIEW METHODS

Diagnostic accuracy was compared among seven radiological methods: computed tomography (CT), CT cisternography (CTC), magnetic resonance imaging (MRI), magnetic resonance cisternography (MRC), CT + MRI, radionuclide cisternography, and intrathecal gadolinium (Gd)-MRC. Sensitivity, specificity, and accuracy were used as outcomes of the analysis. Both a traditional pairwise meta-analysis and a network meta-analysis were performed.

RESULTS

Twenty-three trials were included in the analysis. The results of a network meta-analysis performed on a network consisting of seven diagnostic methods showed that all imaging modalities had greater diagnostic accuracy than CT, with the exception of CTC, which had lower sensitivity. Only intrathecal Gd-MRC was significantly superior to other imaging methods with regard to sensitivity and accuracy. Gd-MRC also showed the greatest surface under the cumulative ranking curve values for all of the outcomes (sensitivity: 0.9200; specificity: 0.8364; accuracy: 0.8920).

CONCLUSION

This network meta-analysis demonstrates that intrathecal Gd-MRC is the most useful diagnostic method to detect CSF rhinorrhea. Laryngoscope, 2022.

Meta-analysis of QTLs and candidate genes associated with seed germination in rice (Oryza sativa L.)

Seed germination is one of the critical stages of plant life, and many quantitative trait loci (QTLs) control this complex trait. Meta-analysis of QTLs is a powerful computational technique for estimating the most stable QTLs regardless of the population's genetic background. Besides, this analysis effectively narrows down the confidence interval (CI) to identify candidate genes (CGs) and marker development. In the current study, a comprehensive genome-wide meta-analysis was performed on QTLs associated with germination in rice. This analysis was conducted based on the data reported over the last two decades. In this case, various analyses were performed, including seed germination rate, plumule length, radicle length, germination percentage, coleoptile length, coleorhiza length, radicle fresh weight, germination potential, and germination index. A total of 67 QTLs were projected onto a reference map for these traits and then integrated into 32 meta-QTLs (MQTLs) to provide a genetic framework for seed germination. The average CI of MQTLs was considerably reduced from 15.125 to 8.73 cM compared to the initial QTLs. This situation identified 728 well-known functionally characterized genes and novel putative CGs for investigated traits. The fold change calculation demonstrated that 155 CGs had significant changes in expression analysis. In this case, 112 and 43 CGs were up-regulated and down-regulated during germination, respectively. This study provides an overview and compares genetic loci controlling traits related to seed germination in rice. The findings can bridge the gap between QTLs and CGs for seed germination.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12298-022-01232-1.

Emerging Therapies for COVID-19: The Value of Information From More Clinical Trials

OBJECTIVES

The COVID-19 pandemic necessitates time-sensitive policy and implementation decisions regarding new therapies in the face of uncertainty. This study aimed to quantify consequences of approving therapies or pursuing further research: immediate approval, use only in research, approval with research (eg, emergency use authorization), or reject.

METHODS

Using a cohort state-transition model for hospitalized patients with COVID-19, we estimated quality-adjusted life-years (QALYs) and costs associated with the following interventions: hydroxychloroquine, remdesivir, casirivimab-imdevimab, dexamethasone, baricitinib-remdesivir, tocilizumab, lopinavir-ritonavir, interferon beta-1a, and usual care. We used the model outcomes to conduct cost-effectiveness and value of information analyses from a US healthcare perspective and a lifetime horizon.

RESULTS

Assuming a $100 000-per-QALY willingness-to-pay threshold, only remdesivir, casirivimab-imdevimab, dexamethasone, baricitinib-remdesivir, and tocilizumab were (cost-) effective (incremental net health benefit 0.252, 0.164, 0.545, 0.668, and 0.524 QALYs and incremental net monetary benefit $25 249, $16 375, $54 526, $66 826, and $52 378). Our value of information analyses suggest that most value can be obtained if these 5 therapies are approved for immediate use rather than requiring additional randomized controlled trials (RCTs) (net value $20.6 billion, $13.4 billion, $7.4 billion, $54.6 billion, and $7.1 billion), hydroxychloroquine (net value $198 million) is only used in further RCTs if seeking to demonstrate decremental cost-effectiveness and otherwise rejected, and interferon beta-1a and lopinavir-ritonavir are rejected (ie, neither approved nor additional RCTs).

CONCLUSIONS

Estimating the real-time value of collecting additional evidence during the pandemic can inform policy makers and clinicians about the optimal moment to implement therapies and whether to perform further research.

Association between lead source exposure and blood lead levels in some lead manufacturing countries: A systematic review and meta-analysis

Lead is one of the 10 most toxic chemicals of greatest concern for its effects on public health. Predominantly, in undeveloped countries, high blood lead levels (BLLs) persist in the population. To develop intervention strategies that may reduce lead exposure in populations, it is a priority to know the sources of lead pollution. The objective of this critical review and meta-analysis is to assess whether there is an association between different sources of lead exposure and the mean difference in blood lead levels in people exposed. To identify the major lead source exposure, a statistical analysis was performed on selection studies. This investigation reveals the limited information available on the sources of lead in Mexico and other lead producer countries, such as Croatia, Ecuador, Brazil, South Korea, India, Nigeria, Turkey, and China. Meta-analysis could be performed only in battery, smelting mining, and glazed ceramic workers. Battery manufacturing workers have the highest mean difference level of lead in their blood worldwide. Mexico has the second highest mean difference BLL in battery workers in the world. An interesting difference between the mean difference in BLL in mining workers from uncontrolled industry (-39.38) and controlled industry (-5.68) was found. This difference highlighted the success of applying strict control of lead sources and community education to reduce BLL and its potential harmful effects on human health and the environment. Children living near mining sites have the highest mean difference BLL (-11.1). This analysis may aid in assessing the source of lead exposure associated with a range of BLLs in people. Furthermore, this review highlights several social and cultural patterns associated with lead exposure and lead levels in control populations. These results could help to develop international lead regulations and appropriate public health guidelines to protect people around the world.

Comparison between Analgesia Nociception Index (ANI) and self-reported measures for diagnosing pain in conscious individuals: a systematic review and meta-analysis

The Analgesia Nociception Index (ANI), an objective measure of pain based on heart rate variability (HRV), has its usefulness in awake patients still unclear. This systematic review and meta-analysis aimed to assess ANI's accuracy compared to self-reported pain measures in conscious individuals undergoing medical procedures or painful stimuli. PubMed, Ovid, Web of Science, Scopus, Embase, and grey literature were searched until March 2021. Of the 832 identified citations, 16 studies complied with the eligibility criteria. A meta-analysis including nine studies demonstrated a weak negative correlation between ANI and NRS for pain assessment in individuals in the post-anesthetic recovery room (r = − 0.0984, 95% CI = − 0.397 to 0.220, I² = 95.82%), or in those submitted to electrical stimulus (r = − 0.089; 95% CI = − 0.390 to 0.228, I² = 0%). The evidence to use ANI in conscious individuals is weak compared to self-report measures of pain, yet ANI explains a part of self-report. Therefore, some individuals may be benefited from the use of ANI during procedures or in the immediate postoperative period.

Systematic reviews do not (yet) represent the 'gold standard' of evidence: A position paper

The low quality of included trials, insufficient rigour in review methodology, ignorance of key pain issues, small size, and over-optimistic judgements about the direction and magnitude of treatment effects all devalue systematic reviews, supposedly the 'gold standard' of evidence. Available evidence indicates that almost all systematic reviews in the published literature contain fatal flaws likely to make their conclusions incorrect and misleading. Only 3 in every 100 systematic reviews are deemed to have adequate methods and be clinically useful. Examples of research waste and questionable ethical standards abound: most trials have little hope of providing useful results, and systematic review of hopeless trials inspires no confidence. We argue that results of most systematic reviews should be dismissed. Forensically critical systematic reviews are essential tools to improve the quality of trials and should be encouraged and protected.

A comparison of surgical practice and operative outcomes between retroperitoneal and transperitoneal laparoscopic nephrectomies – 6 years of data from the BAUS Nephrectomy database

Objectives:

While the choice of surgical approach for laparoscopic nephrectomy is broadly split between transperitoneal and retroperitoneal options, the evidence for the impact of this decision on perioperative outcomes is built on relatively small volume data, with often inconsistent findings and conclusions. We aimed to assess the impact of operative approach on perioperative outcomes for laparoscopic radical, partial and simple nephrectomy and nephroureterectomy through analysis of the British Association of Urological Surgeons (BAUS) Nephrectomy database.

Patients and methods:

All patients added to the BAUS Nephrectomy database with laparoscopic surgery between 2012 and 2017 inclusively were included and subdivided by operation and surgical approach. Preoperative patient and tumour characteristics, as well as intraoperative and post-operative short-term outcomes, were assessed.

Results:

Overall, 26,682 operations were documented over the review window (81.6% transperitoneal). Small increases in blood loss ( p = 0.001), transfusion rate ( p = 0.02) and operative length ( p = 0.01) were seen for transperitoneal radical nephrectomies and longer hospital stays seen for retroperitoneal procedures (radical nephrectomy p = 0.00l; partial nephrectomy p = 0.04). Retroperitoneal procedures were associated with increased rates of conversion for simple nephrectomy ( p = 0.02), nephroureterectomy ( p = 0.03) and most notably partial nephrectomy (10.5% versus 4.4%; p = 0.001). No further variation in intraoperative complications, post-operative complications, tumour margin positivity rates, unintended ITU admission, or likelihood of death was identified related to surgical approach.

Conclusion:

Observed variations in perioperative outcomes were generally modest in nature, and little ground is seen to support a change in operative technique for those committed to one approach. A caveat to this exists with open conversion for retroperitoneal partial nephrectomies and requires careful consideration of patient selection by the individual surgeon.

Level of evidence:

4

Greater risk of all-cause revisions and complications for obese patients in 3 106 381 total knee arthroplasties: a meta-analysis and systematic review

BACKGROUND

Obesity is a major public health issue and has considerable implications on outcomes of total knee arthroplasty (TKA). However, there has been conflicting evidence and conclusions on the effects of obesity on TKA. This meta-analysis compares the outcomes, complications, and peri-operative parameters of TKA in the obese (body mass index [BMI] ≥ 30 kg/m² ) versus non-obese (BMI < 30 kg/m² ) population as well as subgroup analysis of morbidly obese (BMI ≥ 40 kg/m² ) versus non-obese population.

METHODS

A meta-analysis was conducted with a multi-database search according to PRISMA guidelines on 12 September 2019. Data from all published literature meeting inclusion criteria were extracted and analysed.

RESULTS

Ninety-one studies were included, consisting of 917 447 obese and 2 188 834 non-obese TKA. Obese patients had higher risk of all-cause revisions (odds ratio [OR] = 1.15, 95% CI: 1.08-1.24, p < 0.0001), all complications (OR = 1.21, 95% CI: 1.06-1.38, p = 0.004), deep infections (OR = 1.47, 95% CI: 1.27-1.69, p < 0.0001), superficial infections (OR = 1.59, 95% CI: 1.32-1.91, p < 0.0001), wound dehiscence (OR = 1.46, 95% CI: 1.24-1.72, p < 0.0001) and readmissions (OR = 1.21, 95% CI: 1.05-1.40, p = 0.009). Subgroup analysis of morbidly obese patients revealed greater risks of all-cause revisions (OR = 1.25, 95% CI: 1.10-1.43, p = 0.0009), deep infections (OR = 1.98, 95% CI: 1.05-3.75, p = 0.04), superficial infections (OR = 2.44, 95% CI: 2.08-2.88, p < 0.0001) and readmissions (OR = 1.33, 95% CI: 1.20-1.47, p < 0.0001). No analysis was performed on patient reported outcome measures due to heterogeneous reporting methods.

CONCLUSION

Obese and morbidly obese patients have higher risks of revisions and infections post TKA. Surgeons should counsel patients of these risks during the informed consenting process and adopt preventative strategies into clinical practice to reduce risks where possible. In conclusion, obesity is a significant, modifiable risk factor for increased complications following TKA.

A treatment in search of a disease? Challenges in mindfulness research and practice

'Mindfulness' has become a mainstream component of American culture and a successful business worth more than 1 billion dollars. Born out of Buddhist contemplative traditions that reached the West in the mid-1960s, secular mindfulness programs have spread both geographically (to the US and Europe) and socially (to healthcare, academia, politics, the military, and finance). The diffusion of mindfulness practice to domains that are culturally and socially so different from its original Buddhist context has had important consequences. This manuscript will examine some of these consequences as well as some challenges generated by the encounter between the American culture and Eastern millennial contemplative traditions. With the purpose of increasing awareness about these issues and to generate a debate within the mindfulness community, some suggestions on how to face such challenges are then offered to mindfulness researchers, instructors, and health care providers interested in alleviating the suffering of their patients using mindfulness meditation.

An Abductive Inference Approach to Assess the Performance-Enhancing Effects of Drugs Included on the World Anti-Doping Agency Prohibited List

Some have questioned the evidence for performance-enhancing effects of several substances included on the World Anti-Doping Agency's Prohibited List due to the divergent or inconclusive findings in randomized controlled trials (RCTs). However, inductive statistical inference based on RCTs-only may result in biased conclusions because of the scarcity of studies, inter-study heterogeneity, too few outcome events, or insufficient power. An abductive inference approach, where the body of evidence is evaluated beyond considerations of statistical significance, may serve as a tool to assess the plausibility of performance-enhancing effects of substances by also considering observations and facts not solely obtained from RCTs. Herein, we explored the applicability of an abductive inference approach as a tool to assess the performance-enhancing effects of substances included on the Prohibited List. We applied an abductive inference approach to make inferences on debated issues pertaining to the ergogenic effects of recombinant human erythropoietin (rHuEPO), beta₂-agonists and anabolic androgenic steroids (AAS), and extended the approach to more controversial drug classes where RCTs are limited. We report that an abductive inference approach is a useful tool to assess the ergogenic effect of substances included on the Prohibited List-particularly for substances where inductive inference is inconclusive. Specifically, a systematic abductive inference approach can aid researchers in assessing the effects of doping substances, either by leading to suggestions of causal relationships or identifying the need for additional research.

Efficacy of non-invasive diagnostic methods in the diagnosis and screening of oral cancer and precancer

INTRODUCTION

Traditional meta-analyses on the diagnostic accuracy of oral lesions have been conducted, but they were inherently limited to direct pairwise comparisons between a single method and a single alternative, while multiple diagnostic options and the ranking thereof were methodologically not possible.

OBJECTIVE

To evaluate the diagnostic values of various methods in patients with oral potential malignant disease by performing a network meta-analysis.

METHODS

Two authors independently searched the databases (MEDLINE, SCOPUS, the Cochrane Register of Controlled Trials, and Google scholar) up to June 2020 for studies comparing the diagnostic accuracy of various tools (autofluorescence, chemiluminescence, cytology, narrow band imaging, and toluidine blue) with visual examination or other tools. The outcomes of interest for this analysis were sensitivity, specificity, negative predictive value, positive predictive value and accuracy. Both a standard pairwise meta-analysis and network meta-analysis were conducted.

RESULTS

Treatment networks consisting of six interventions were defined for the network meta-analysis. The results of traditional meta-analysis showed that, among six methods, narrow band imaging showed higher sensitivity, specificity, negative predictive value, positive predictive value, and accuracy compared to visual examination. The results of network meta-analysis showed that autofluorescence, chemiluminescence, and narrow band imaging had higher sensitivity compared with visual examination, and that chemiluminescence and narrow band imaging had higher negative predictive value compared with visual examination. However, autofluorescence and chemiluminescence had lower specificity compared with visual examination. There were no significant differences in positive predictive value and accuracy among the six interventions.

CONCLUSION

This study demonstrated that narrow banding imaging has superiority in terms of sensitivity and negative predictive value compared with the other five tested agents.

The bigger, the better? When multicenter clinical trials and meta-analyses do not work

Courtesy of the development of the Internet, bursts of information technology, and globalization, huge multicenter studies along with meta-analyses have been introduced to the medical sciences society. Meta-analyses and multicenter studies revolutionized modern medicine and drug development, and empowered evidence based medicine by providing extremely high levels of evidence. Nevertheless, there are occasions that while results of local multi/single center studies showed efficacy of a new treatment, larger multicenter studies or meta-analyses failed to show efficacy, and vice versa. Generally, bigger studies are more powerful and we rely on their results in clinical decision making. Nevertheless, we should keep in mind that in certain circumstances, single center studies are of great importance, and are preferred to multicenter studies and meta-analyses. In order to have a better understanding of why and when multicenter studies along with meta-analyses might not be the best options, we have discussed three different scenarios.

The efficacy of intraoperative ICG fluorescence angiography on anastomotic leak after resection for colorectal cancer: a meta-analysis

OBJECTIVE

The purpose of this study was to investigate whether intraoperative indocyanine green fluorescence angiography can reduce the incidence of anastomotic leak.

METHODS

Present authors conducted a systematic search of PubMed, EMBASE, and Cochrane databases for randomized controlled trials (RCTs), prospective nonrandomized trials, and retrospective trials up to March 2020. Eleven papers fulfilling the screening criteria were included.

INTERVENTION

Indocyanine green was injected intravenously after the division of the mesentery and colon but before anastomosis. The primary outcome measure was AL rate with at least 3 months of follow-up. Secondary outcome measure was operation time, postoperative complications, surgical site infection, reoperation, and ileus rate. The results were analyzed using STATA 12.0 software (Stata Corp, College Station, TX, USA).

RESULT

A total of 3137 patients were collected in 11 studies. Meta-analysis showed that compared with conventional surgery, the ICG fluorescence angiography resulted in a fewer AL rate (OR = 0.31; 95% CI 0.21 to 0.44; P < 0.0001), postoperative complications (OR = 0.70; 95% CI 0.51 to 0.96; P < 0.025), and reoperation rate (OR = 0.334; 95% CI 0.16 to 0.68; P = 0.003). Operation time (weighted mean difference - 25.162 min; 95% CI - 58.7 to 8.375; P = 0.141), surgical site infection rate (OR = 1.11; 95% CI 0.59 to 2.09; P = 0.742) did not differ between the two groups.

CONCLUSION

The result revealed that indocyanine green was associated with a lower anastomotic leakage rate after colorectal cancer resection. However, larger, multicentered, high-quality randomized controlled trials are needed to confirm the benefit of indocyanine green fluorescence angiography.

Milk Consumption for the Prevention of Fragility Fractures

Results indicating that a high milk intake is associated with both higher and lower risks of fragility fractures, or that indicate no association, can all be presented in the same meta-analysis, depending on how it is performed. In this narrative review, we discuss the available studies examining milk intake in relation to fragility fractures, highlight potential problems with meta-analyses of such studies, and discuss potential mechanisms and biases underlying the different results. We conclude that studies examining milk and dairy intakes in relation to fragility fracture risk need to study the different milk products separately. Meta-analyses should consider the doses in the individual studies. Additional studies in populations with a large range of intake of fermented milk are warranted.

The Efficacy of Hypotensive Agents on Intraoperative Bleeding and Recovery Following General Anesthesia for Nasal Surgery: A Network Meta-Analysis

OBJECTIVES

A systematic review of the literature was conducted to evaluate hypotensive agents in terms of their adverse effects and associations with perioperative morbidity in patients undergoing nasal surgery.

METHODS

Two authors independently searched databases (Medline, Scopus, and Cochrane databases) up to February 2020 for randomized controlled trials comparing the perioperative administration of a hypotensive agent with a placebo or other agent. The outcomes of interest for this analysis were intraoperative morbidity, operative time, intraoperative bleeding, hypotension, postoperative nausea/vomiting, and postoperative pain. Both a standard pairwise meta-analysis and network meta-analysis were conducted.

RESULTS

Our analysis was based on 37 trials. Treatment networks consisting of six interventions (placebo, clonidine, dexmedetomidine, beta-blockers, opioids, and nitroglycerine) were defined for the network meta-analysis. Dexmedetomidine resulted in the greatest differences in intraoperative bleeding (-0.971; 95% confidence interval [CI], -1.161 to -0.781), intraoperative fentanyl administration (-3.683; 95% CI, -4.848 to -2.518), and postoperative pain (-2.065; 95% CI, -3.170 to -0.960) compared with placebo. The greatest difference in operative time compared with placebo was achieved with clonidine (-0.699; 95% CI, -0.977 to -0.421). All other agents also had beneficial effects on the measured outcomes. Dexmedetomidine was less likely than other agents to cause adverse effects.

CONCLUSION

This study demonstrated the superiority of the systemic use of dexmedetomidine as a perioperative hypotensive agent compared with the other five tested agents. However, the other agents were also superior to placebo in improving operative time, intraoperative bleeding, and postoperative pain.

Virtual reality training enhances gait poststroke: a systematic review and meta-analysis

Virtual reality (VR)-based interventions are gaining widespread attention for managing neurological disorders such as stroke. A metastatistical consensus regarding the intervention is strongly warranted. In this study, we attempt to address this gap in the literature and provide the current state of evidence for the effects of VR on gait performance. We conducted both between- and within-group meta-analyses to provide a state of evidence for VR. Moreover, we conducted a search adhering to PRISMA guidelines on nine databases. Out of 1866 records, 32 studies involving a total of 809 individuals were included in this review. Considering all included studies, significant enhancements in gait parameters were observed with VR-based interventions compared with conventional therapy. A between-group meta-analysis reported beneficial significant medium effects of VR training on cadence (Hedge's g = 0.55), stride length ((STrL; Hedge's g = 0.46), and gait speed (Hedge's g = 0.30). Similarly, a within-group meta-analysis further revealed positive medium effects of VR on cadence (Hedge's g = 0.76), STrL (Hedge's g = 0.61), and gait speed (Hedge's g = 0.69). Additional subgroup analyses revealed beneficial effects of joint application of VR and robot-assisted gait training on gait speed (Hedge's g = 0.50). Collectively, findings from this review provide evidence for the effectiveness of VR-based gait training for stroke survivors.

A discrete emotion with discrete effects: effects of anger on depth of information processing

There is relative paucity in the comprehensive study of anger and information processing. Emotions can impact the depth of information processing and anger is a powerful high-certainty emotion. Yet, the magnitude of the effects of anger on the depth of information processing has not been summarized. This scholarship performs a meta-analytic synthesis to report the effect of anger on the depth of information processing as compared to one of the four contrast groups: neutral control, sadness, happiness, and fear. A systematic search identified 26 articles with a total of 39 unique studies and 113 effect sizes. The evaluation revealed that anger did not have a significant effect on depth of information processing for any of the emotional comparison groups. Furthermore, the presence of publication bias was only found for one analysis. These complex results indicate that anger is an exceedingly nuanced emotion. The implications of the study and future scholarship are discussed.

Assessment of the Dose-Response Relationship Between Folate Exposure and Cognitive Impairment: Synthesizing Data from Documented Studies

The dose-response relationship between folate levels and cognitive impairment among individuals with vitamin B12 deficiency is an essential component of a risk-benefit analysis approach to regulatory and policy recommendations regarding folic acid fortification. Epidemiological studies provide data that are potentially useful for addressing this research question, but the lack of analysis and reporting of data in a manner suitable for dose-response purposes hinders the application of the traditional evidence synthesis process. This study aimed to estimate a quantitative dose-response relationship between folate exposure and the risk of cognitive impairment among older adults with vitamin B12 deficiency using "probabilistic meta-analysis," a novel approach for synthesizing data from observational studies. Second-order multistage regression was identified as the best-fit model for the association between the probability of cognitive impairment and serum folate levels based on data generated by randomly sampling probabilistic distributions with parameters estimated based on summarized information reported in relevant publications. The findings indicate a "J-shape" effect of serum folate levels on the occurrence of cognitive impairment. In particular, an excessive level of folate exposure is predicted to be associated with a higher risk of cognitive impairment, albeit with greater uncertainty than the association between low folate exposure and cognitive impairment. This study directly contributes to the development of a practical solution to synthesize observational evidence for dose-response assessment purposes, which will help strengthen future nutritional risk assessments for the purpose of informing decisions on nutrient fortification in food.

Individual Patient Data Pooled Analysis of Randomized Trials of Bivalirudin versus Heparin in Acute Myocardial Infarction: Rationale and Methodology

BACKGROUND

 Individual randomized controlled trials (RCTs) of periprocedural anticoagulation with bivalirudin versus heparin during percutaneous coronary intervention (PCI) have reported conflicting results. Study-level meta-analyses lack granularity to adjust for confounders, explore heterogeneity, or identify subgroups that may particularly benefit or be harmed.

OBJECTIVE

 To overcome these limitations, we sought to develop an individual patient-data pooled database of RCTs comparing bivalirudin versus heparin.

METHODS

 We conducted a systematic review to identify RCTs in which ≥1,000 patients with acute myocardial infarction (AMI) undergoing PCI were randomized to bivalirudin versus heparin.

RESULTS

 From 738 identified studies, 8 RCTs met the prespecified criteria. The principal investigators of each study agreed to provide patient-level data. The data were pooled and checked for accuracy against trial publications, with discrepancies addressed by consulting with the trialists. Consensus-based definitions were created to resolve differing antithrombotic, procedural, and outcome definitions. The project required 3.5 years to complete, and the final database includes 27,409 patients (13,346 randomized to bivalirudin and 14,063 randomized to heparin).

CONCLUSION

 We have created a large individual patient database of bivalirudin versus heparin RCTs in patients with AMI undergoing PCI. This endeavor may help identify the optimal periprocedural anticoagulation regimen for patient groups with different relative risks of adverse ischemic versus bleeding events, including those with ST-segment and non-ST-segment elevation MI, radial versus femoral access, use of a prolonged bivalirudin infusion or glycoprotein inhibitors, and others. Adherence to standardized techniques and rigorous validation processes should increase confidence in the accuracy and robustness of the results.

Growth mindsets and psychological distress: A meta-analysis

We investigated if growth mindsets-the belief in the malleable nature of human attributes-are negatively related to psychological distress and if they are positively related to treatment value and active coping. In the meta-analysis, we included articles published between 1988 and 2019, written in English, that reported on mindsets as well as a qualifying dependent variable and included information required to calculate an effect size. With a random effects approach, meta-analytic results (k = 72 samples, N = 17,692) demonstrated that mindsets relate, albeit with minimal effects, to distress, treatment and coping. Specifically, there is a negative relation between growth mindsets and psychological distress (r = -0.220), a positive relation between growth mindsets and treatment value (r = 0.137) and a positive relation between growth mindsets and active coping (r = 0.207). Differences in mindset domain, assessment method of mindsets and timing of assessments moderated effects. There were not differences based on operationalization of psychological distress outcome or sample characteristics (i.e., developmental stage, diagnostic status, ethnicity). We discuss theoretical and practical applications of the findings.

Fostering Scientific Meta-analyses with Knowledge Graphs: A Case-Study

A meta-analysis is a Science of Science method widely used in the medical and social sciences to review, aggregate and quantitatively synthesise a body of studies that address the same research question. With the volume of research growing exponentially every year, conducting meta-analyses can be costly and inefficient, as a significant amount of time and human efforts needs to be spent in finding studies meeting research criteria, annotating them, and properly performing the statistical analyses to summarise the findings. In this work, we show these issues can be tackled with semantic representations and technologies, using a social science scenario as case-study. We show how the domain-specific content of research outputs can be represented and used to facilitate their search, analysis and synthesis. We present the very first representation of the domain of human cooperation, and the application we built on top of this to help experts in performing meta-analyses semi-automatically. Using few application scenarios, we show how our approach supports the various phases meta-analyses, and more in general contributes towards research replication and automated hypotheses generation.

Greater risks of complications, infections, and revisions in the obese versus non-obese total hip arthroplasty population of 2,190,824 patients: a meta-analysis and systematic review

BACKGROUND

Obesity is an epidemic, especially in developed countries. This affects the general health of these patients, especially when they are having a major surgical procedure such as total hip arthroplasty (THA). Several articles have described the effects of obesity on THA with varying conclusions. This meta-analysis aims to compare the outcomes, complications, and peri-operative parameters of THA in the obese (BMI≥30 kg/m²) vs non-obese (BMI<30 kg/m²) population as well as a subgroup analysis of morbidly obese (BMI≥40 kg/m²) vs non-obese population.

METHODS

A multi-database search was performed according to PRISMA guidelines. Data from studies assessing the outcomes and complications of THA in the obese and non-obese population were extracted and analyzed.

RESULTS

Sixty-seven studies were included in this meta-analysis, consisting of 581,012 obese and 1,609,812 non-obese patients. Meta-analysis could not be performed on patient reported outcome measures due to heterogeneous reporting methods. Obese patients had a higher risk of all complications (OR = 1.53, 95%CI: 1.30-1.80, P < 0.001), deep infections (OR = 2.71, 95%CI: 2.08-3.53, P < 0.001), superficial infections (OR = 1.99, 95%CI: 1.55-2.55, P < 0.001), dislocations (OR = 1.72, 95%CI: 1.66-1.79, P < 0.001), reoperations (OR = 1.61, 95%CI: 1.40-1.85, P < 0.001), revisions (OR = 1.44, 95%CI: 1.32-1.57, P < 0.001), and readmissions (OR = 1.37, 95%CI: 1.15-1.63, P < 0.001). When sub-group analysis of morbidly obese (BMI≥40 kg/m²) patients was performed, the risks of all these parameters were even greater.

CONCLUSION

Obese and morbidly obese patients are at higher risks of complications post THA than non-obese patients. Surgeons should be aware of these risks in order to counsel patients and adopt prophylactic strategies to reduce these risks where applicable.

Impact of whole egg intake on blood pressure, lipids and lipoproteins in middle-aged and older population: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND AIM

Effects of whole egg consumption on cardiovascular diseases (CVD) risk in the middle-aged and older population remain unclear due to inconsistent findings from observational and randomized controlled trials (RCTs). This meta-analysis aimed to assess the impacts of whole egg and egg category (whole eggs versus egg substitutes) intake quantity on CVD risk factors from systematically searched RCTs. Egg substitutes were hypothesized to have minimal effects of the blood lipid and lipoprotein profile as they are void of dietary cholesterol.

METHODS AND RESULTS

As many as 434 studies identified from PubMed, Cochrane Library, CINAHL and Medline (Ovid) databases were screened and data were extracted from 8 selected RCTs. Quality of the selected studies were assessed and the overall effect sizes of weighted mean differences (WMD) were calculated using a random effects model. Non-differential effects in blood pressures, lipids and lipoproteins were observed when >4 whole eggs/week compared to ≤4 whole eggs/week were consumed. Intake of >4 whole eggs/week compared to equivalent amounts of egg substitutes caused greater elevations in blood total cholesterol (WMD: 0.198 mmol/L; 95% CIs: 0.056, 0.339), HDL cholesterol (WMD: 0.068 mmol/L; 95% CIs: 0.006, 0.130) and LDL cholesterol (WMD: 0.171 mmol/L; 95% CIs: 0.028, 0.315) but did not differentially affect triglycerides concentration.

CONCLUSION

Overall, the results support the notion that quantity of whole egg intake does not affect CVD risk factors and consuming egg substitutes may also be beneficial compared to whole eggs on lowering CVD risk in the middle-aged and older population.

The Impact of Domain-Specific Experience on Chess Skill: Reanalysis of a Key Study

How important are training and other forms of domain-relevant experience in predicting individual differences in expertise? To answer this question, we used structural equation modeling to reanalyze data from a study of chess by Charness, Tuffiash, Krampe, Reingold, and Vasyukova (2005). Latent variables reflecting serious chess activity and formal instruction, along with a manifest variable indexing serious starting age, accounted for 63% of the variance in peak rating. Serious starting age had a significant negative effect on peak rating (β = –.15), even after we controlled for domain-specific experience, indicating an advantage for starting earlier. We also tested the prediction that formal instruction increases the effectiveness of serious study (Ericsson & Charness, 1994) using moderated regression. This claim was not supported. Overall, the results affirm that serious study and other forms of domain-specific experience are important pieces of the expertise puzzle, but other factors must matter too.

Supplemental materials are available at https://www.press.uillinois.edu/journals/ajp/media/chess_skill

McGurk Effect by Individuals with Autism Spectrum Disorder and Typically Developing Controls: A Systematic Review and Meta-analysis

By synthesizing existing behavioural studies through a meta-analytic approach, the current study compared the performances of Autism spectrum disorder (ASD) and typically developing groups in audiovisual speech integration and investigated potential moderators that might contribute to the heterogeneity of the existing findings. In total, nine studies were included in the current study, and the pooled overall difference between the two groups was significant, g = - 0.835 (p < 0.001; 95% CI - 1.155 to - 0.516). Age and task scoring method were found to be associated with the inconsistencies of the findings reported by previous studies. These findings indicate that individuals with ASD show weaker McGurk effect than typically developing controls.

Systematic Review and Meta-analysis: Sometimes Bigger Is Indeed Better

Clinicians encounter an ever increasing and frequently overwhelming amount of information, even in a narrow scope or area of interest. Given this enormous amount of scientific information published every year, systematic reviews and meta-analyses have become indispensable methods for the evaluation of medical treatments and the delivery of evidence-based best practice. The present basic statistical tutorial thus focuses on the fundamentals of a systematic review and meta-analysis, against the backdrop of practicing evidence-based medicine. Even if properly performed, a single study is no more than tentative evidence, which needs to be confirmed by additional, independent research. A systematic review summarizes the existing, published research on a particular topic, in a well-described, methodical, rigorous, and reproducible (hence "systematic") manner. A systematic review typically includes a greater range of patients than any single study, thus strengthening the external validity or generalizability of its findings and the utility to the clinician seeking to practice evidence-based medicine. A systematic review often forms the basis for a concomitant meta-analysis, in which the results from the identified series of separate studies are aggregated and statistical pooling is performed. This allows for a single best estimate of the effect or association. A conjoint systematic review and meta-analysis can provide an estimate of therapeutic efficacy, prognosis, or diagnostic test accuracy. By aggregating and pooling the data derived from a systemic review, a well-done meta-analysis essentially increases the precision and the certainty of the statistical inference. The resulting single best estimate of effect or association facilitates clinical decision making and practicing evidence-based medicine. A well-designed systematic review and meta-analysis can provide valuable information for researchers, policymakers, and clinicians. However, there are many critical caveats in performing and interpreting them, and thus, like the individual research studies on which they are based, there are many ways in which meta-analyses can yield misleading information. Creators, reviewers, and consumers alike of systematic reviews and meta-analyses would thus be well-served to observe and mitigate their associated caveats and potential pitfalls.

Guidelines on How to Perform a Meta-Analysis in Spine Surgery: Strengths and Weaknesses of Design

There are many questions in the literature that remain unanswered due to the paucity of available subjects or the large sample size needed to detect a difference. A meta-analysis consists of integrating together data from multiple studies into one larger data set in order to increase the subject size and power of a paper. In essence, it is a systematic review in which one uses statistical methods to summarize the results of these studies. It is important that a meta-analysis be performed in a systematic and orderly manner with the assistance of a statistician. When carried out correctly, these studies serve as powerful tools to help us better address our knowledge. Because of their complexity, they are prone to bias at multiple levels. This article will discuss the steps involved in performing a meta-analysis, select good studies, as well as explain the statistics conducted in these studies. Furthermore, we will discuss examples from the literature that demonstrate a good meta-analysis.

Perioperative intravenous ketamine for acute postoperative pain in adults

BACKGROUND

Inadequate pain management after surgery increases the risk of postoperative complications and may predispose for chronic postsurgical pain. Perioperative ketamine may enhance conventional analgesics in the acute postoperative setting.

OBJECTIVES

To evaluate the efficacy and safety of perioperative intravenous ketamine in adult patients when used for the treatment or prevention of acute pain following general anaesthesia.

SEARCH METHODS

We searched CENTRAL, MEDLINE and Embase to July 2018 and three trials registers (metaRegister of controlled trials, ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP)) together with reference checking, citation searching and contact with study authors to identify additional studies.

SELECTION CRITERIA

We sought randomised, double-blind, controlled trials of adults undergoing surgery under general anaesthesia and being treated with perioperative intravenous ketamine. Studies compared ketamine with placebo, or compared ketamine plus a basic analgesic, such as morphine or non-steroidal anti-inflammatory drug (NSAID), with a basic analgesic alone.

DATA COLLECTION AND ANALYSIS

Two review authors searched for studies, extracted efficacy and adverse event data, examined issues of study quality and potential bias, and performed analyses. Primary outcomes were opioid consumption and pain intensity at rest and during movement at 24 and 48 hours postoperatively. Secondary outcomes were time to first analgesic request, assessment of postoperative hyperalgesia, central nervous system (CNS) adverse effects, and postoperative nausea and vomiting. We assessed the evidence using GRADE and created a 'Summary of findings' table.

MAIN RESULTS

We included 130 studies with 8341 participants. Ketamine was given to 4588 participants and 3753 participants served as controls. Types of surgery included ear, nose or throat surgery, wisdom tooth extraction, thoracotomy, lumbar fusion surgery, microdiscectomy, hip joint replacement surgery, knee joint replacement surgery, anterior cruciate ligament repair, knee arthroscopy, mastectomy, haemorrhoidectomy, abdominal surgery, radical prostatectomy, thyroid surgery, elective caesarean section, and laparoscopic surgery. Racemic ketamine bolus doses were predominantly 0.25 mg to 1 mg, and infusions 2 to 5 µg/kg/minute; 10 studies used only S-ketamine and one only R-ketamine. Risk of bias was generally low or uncertain, except for study size; most had fewer than 50 participants per treatment arm, resulting in high heterogeneity, as expected, for most analyses. We did not stratify the main analysis by type of surgery or any other factor, such as dose or timing of ketamine administration, and used a non-stratified analysis.Perioperative intravenous ketamine reduced postoperative opioid consumption over 24 hours by 8 mg morphine equivalents (95% CI 6 to 9; 19% from 42 mg consumed by participants given placebo, moderate-quality evidence; 65 studies, 4004 participants). Over 48 hours, opioid consumption was 13 mg lower (95% CI 10 to 15; 19% from 67 mg with placebo, moderate-quality evidence; 37 studies, 2449 participants).Perioperative intravenous ketamine reduced pain at rest at 24 hours by 5/100 mm on a visual analogue scale (95% CI 4 to 7; 19% lower from 26/100 mm with placebo, high-quality evidence; 82 studies, 5004 participants), and at 48 hours by 5/100 mm (95% CI 3 to 7; 22% lower from 23/100 mm, high-quality evidence; 49 studies, 2962 participants). Pain during movement was reduced at 24 hours (6/100 mm, 14% lower from 42/100 mm, moderate-quality evidence; 29 studies, 1806 participants), and 48 hours (6/100 mm, 16% lower from 37 mm, low-quality evidence; 23 studies, 1353 participants).Results for primary outcomes were consistent when analysed by pain at rest or on movement, operation type, and timing of administration, or sensitivity to study size and pain intensity. No analysis by dose was possible. There was no difference when nitrous oxide was used. We downgraded the quality of the evidence once if numbers of participants were large but small-study effects were present, or twice if numbers were small and small-study effects likely but testing not possible.Ketamine increased the time for the first postoperative analgesic request by 54 minutes (95% CI 37 to 71 minutes), from a mean of 39 minutes with placebo (moderate-quality evidence; 31 studies, 1678 participants). Ketamine reduced the area of postoperative hyperalgesia by 7 cm² (95% CI -11.9 to -2.2), compared with placebo (very low-quality evidence; 7 studies 333 participants). We downgraded the quality of evidence because of small-study effects or because the number of participants was below 400.CNS adverse events occurred in 52 studies, while 53 studies reported of absence of CNS adverse events. Overall, 187/3614 (5%) participants receiving ketamine and 122/2924 (4%) receiving control treatment experienced an adverse event (RR 1.2, 95% CI 0.95 to 1.4; high-quality evidence; 105 studies, 6538 participants). Ketamine reduced postoperative nausea and vomiting from 27% with placebo to 23% with ketamine (RR 0.88, 95% CI 0.81 to 0.96; the number needed to treat to prevent one episode of postoperative nausea and vomiting with perioperative intravenous ketamine administration was 24 (95% CI 16 to 54; high-quality evidence; 95 studies, 5965 participants).

AUTHORS' CONCLUSIONS

Perioperative intravenous ketamine probably reduces postoperative analgesic consumption and pain intensity. Results were consistent in different operation types or timing of ketamine administration, with larger and smaller studies, and by higher and lower pain intensity. CNS adverse events were little different with ketamine or control. Perioperative intravenous ketamine probably reduces postoperative nausea and vomiting by a small extent, of arguable clinical relevance.

Correction for Partial Volume Effect Is a Must, Not a Luxury, to Fully Exploit the Potential of Quantitative PET Imaging in Clinical Oncology

The partial volume effect (PVE) is considered as one of the major degrading factors impacting image quality and hampering the accuracy of quantitative PET imaging in clinical oncology. This effect is the consequence of the limited spatial resolution of whole-body PET scanners, which results in blurring of the generated images by the scanner's response function. A number of strategies have been devised to deal with partial volume effect. However, the lack of consensus on the clinical relevance of partial volume correction and the most appropriate technique to be used in the context of clinical oncology limited their application in clinical setting. This issue is debated in this commentary.

Pharmacological therapies for fibromyalgia in adults ‐ an overview of Cochrane Reviews

This is a protocol for a Cochrane Review (Overview). The objectives are as follows:

To provide an overview of the therapeutic efficacy of pharmacological therapies for fibromyalgia, and to report on adverse events associated with their use. The major comparison of interest will be with placebo.

Antibiotic de-escalation in patients with pneumonia in the intensive care unit: A systematic review and meta-analysis

OBJECTIVES OF THE REVIEW

Antibiotic de-escalation is part of an antibiotic stewardship strategy to achieve adequate therapy for infections while avoiding the prolonged use of broad-spectrum antibiotics. However, there is a paucity of clinical evidence on the clinical impact of this strategy in pneumonia patients in the intensive care unit (ICU). This review aimed to evaluate the impact of antibiotic de-escalation therapy for adult patients diagnosed with pneumonia in the ICU.

METHODS USED TO CONDUCT THE REVIEW

This review was conducted in accordance with the Meta-analysis of Observational Studies in Epidemiology (MOOSE) recommendation. Electronic databases including MEDLINE, CINAHL, PubMed, Embase, Cochrane Databases and Cochrane Central Register of Controlled Trials were searched up to March 2017 for relevant trials. The methodological quality of included trials was assessed by using a modified version of the Newcastle-Ottawa Quality Assessment Scale for Case-Control and Cohort Studies. A meta-analysis was conducted using the random-effect model to combine the rate of mortality and length of stay outcomes.

FINDINGS OF THE REVIEW

Nine observational trials involving 2128 patients were considered eligible for inclusion. Although based on low quality evidence, there was a statistically significant difference in favour of the impact of de-escalation on hospital stay but not mortality (MD -5.96 days; 95% CI -8.39 to -3.52).

INTERPRETATIONS AND IMPLICATIONS OF THE FINDINGS

This review highlights the need for more rigorous studies to be carried out before a firm conclusion on the benefit of de-escalation therapy is supported.

Cognitive behavioural therapy for fear of falling and balance among older people: a systematic review and meta-analysis

BACKGROUND

fear of falling is prevalent among older people and associated with various health outcomes. A growing number of studies have examined the effects of interventions designed to reduce the fear of falling and improve balance among older people, yet our current understanding is restricted to physiological interventions. Psychological interventions such as cognitive behavioural therapy (CBT) have not been reviewed and meta-analysed.

OBJECTIVE

to perform a systematic review and meta-analysis evaluating the effects of CBT on reducing fear of falling and enhancing balance in community-dwelling older people.

METHOD

randomised controlled trials (RCTs) addressing fear of falling and balance were identified through searches of six electronic databases, concurrent registered clinical trials, forward citation and reference lists of three previous systematic reviews.

RESULTS

a total of six trials involving 1,626 participants were identified. Four studies used group-based interventions and two adopted individual intervention. Intervention period ranged from 4 to 20 weeks, and the number and duration of face-to-face contact varied. Core components of the CBT intervention included cognitive restructuring, personal goal setting and promotion of physical activities. The risk of bias was low across the included studies. Our analysis suggests that CBT interventions have significant immediate and retention effects up to 12 months on reducing fear of falling, and 6 months post-intervention effect on enhancing balance.

CONCLUSIONS

CBT appears to be effective in reducing fear of falling and improving balance among older people. Future researches to investigate the use of CBT on reducing fear of falling and improving balance are warranted.

Development and validation of Image Stimuli for Emotion Elicitation (ISEE): A novel affective pictorial system with test-retest repeatability

The aim of this study was to develop a novel set of pictorial stimuli for emotion elicitation. The Image Stimuli for Emotion Elicitation (ISEE), are the first set of stimuli for which there was an unbiased initial selection method and with images specifically selected for high retest correlation coefficients and high agreement across time. In order to protect against a researcher's subjective bias in screening initial pictures, we crawled 10,696 images from the biggest image hosting website (Flickr.com) based on a computational selection method. In the initial screening study, participants rated stimuli twice for emotion elicitation across a 1-week interval and 1620 images were selected based on the number of ratings of participants and retest reliability of each picture. Using this set of stimuli, a second phase of the study was conducted, again having participants rate images twice with a 1-week interval, in which we found a total of 158 unique images that elicited various levels of emotionality with both good reliability and good agreement over time. The newly developed pictorial stimuli set is expected to facilitate cumulative science on human emotions.