Improving GRADE evidence tables part 3: detailed guidance for explanatory footnotes supports creating and understanding GRADE certainty in the evidence judgments

Effectiveness of smoking cessation interventions among adults: an overview of systematic reviews

BACKGROUND

This overview of reviews aims to identify evidence on the benefits (i.e. tobacco use abstinence and reduction in smoking frequency) and harms (i.e. possible adverse events/outcomes) of smoking cessation interventions among adults aged 18 years and older.

METHODS

We searched Medline, Embase, PsycINFO, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, the CADTH Health Technology Assessment Database and several other websites for grey literature. Searches were conducted on November 12, 2018, updated on September 24, 2020, with publication years 2008 to 2020. Two reviewers independently performed title-abstract and full-text screening considering pre-determined inclusion criteria. Data extraction and quality assessments were initially completed by two reviewers independently (i.e. 73% of included studies (n = 22)) using A Measurement Tool to Assess Systematic Reviews-2 (AMSTAR 2), and the remainder done by one reviewer and verified by another due to resources and feasibility. The application of Grading of Recommendations Assessment, Development and Evaluation (GRADE) was performed by one independent reviewer and verified by another.

RESULTS

A total of 22 Cochrane systematic reviews evaluating the impact of smoking cessation interventions on outcomes such as tobacco use abstinence, reduction in smoking frequency, quality of life and possible adverse events were included. Pharmaceutical (i.e. varenicline, cytisine, nicotine replacement therapy (NRT), bupropion) and behavioural interventions (i.e. physician advice, non-tailored print-based self-help materials, stage-based individual counselling, etc.) showed to have increased smoking cessation; whereas, data for mobile phone-based interventions including text messaging, hypnotherapy, acupuncture, continuous auricular stimulation, laser therapy, electrostimulation, acupressure, St John's wort, S-adenosyl-L-methionine (SAMe), interactive voice response systems and other combination treatments were unclear. Considering harms related to smoking cessation interventions, small/mild harms (i.e. increased palpitations, chest pain, nausea, insomnia, headache) were observed following NRT, varenicline and cytisine use. There were no data on harms related to behavioural therapies (i.e. individual or group counselling self-help materials, internet interventions), combination therapies or other therapies (i.e. laser therapy, electrostimulation, acupressure, St John's wort, SAMe).

CONCLUSION

Results suggest that pharmacological and behavioural interventions may help the general smoking population quit smoking with observed small/mild harms following NRT or varenicline. Consequently, evidence regarding ideal intervention strategies and the long-term impact of these interventions for preventing smoking was unclear.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018099691.

Effects of non-pharmacological interventions on fatigue in people with stroke: a systematic review and meta-analysis

BACKGROUND

Fatigue, a common problem following a stroke, can have negative effects on a person's daily life. There are no good interventions thus far for alleviating fatigue among those affected.

OBJECTIVE

This review aimed to evaluate the effects of non-pharmacological interventions on fatigue among people with stroke.

METHODS

A search was conducted for articles in seven databases, clinical trial registry, and backward and forward citations of included publications. Randomized controlled trials, including feasibility and pilot trials, of non-pharmacological interventions for managing fatigue or promoting sleep or both in people with stroke were included. The standardized mean difference in scores for fatigue was analyzed using random effects models.

RESULTS

Ten studies, with 806 participants, were analyzed. The identified interventions included physical interventions, cognitive interventions, a combination of physical and cognitive interventions, oxygen therapy, and complementary interventions. Non-pharmacological interventions had no significant immediate, short-term and medium-term effects on fatigue. The adverse effects of falls and arrhythmia were each found in one participant in circuit training. The risk of bias was high in all studies. The certainty of the evidence ranged from very low to low.

CONCLUSIONS

The evidence in support of any non-pharmacological interventions for alleviating fatigue is still inconclusive in people with stroke. In view of the inadequacies of existing interventions and study designs, addressing the multidimensional characteristics of fatigue may be a possible direction in developing interventions. A robust study design with a larger sample size of people with stroke experiencing fatigue is required to evaluate the effects of interventions.

Calcium supplementation for people with overweight or obesity

BACKGROUND

Obesity is a major health problem worldwide as it can lead to high blood pressure, heart disease, stroke, diabetes, and insulin resistance. The prevalence of overweight and obesity is increasing worldwide across different age groups. There is evidence of an inverse relationship between calcium intake and body weight. The clinical relevance of a small reduction in body weight has been questioned. However, at a population level, a small effect could mitigate the observed global trends.

OBJECTIVES

To assess the effects of calcium supplementation on weight loss in individuals living with overweight or obesity.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, LILACS (Latin American and Caribbean Health Science Information database), and two clinical trials registries. The date of the last search of all databases (except Embase) was 10 May 2023. No language restrictions were applied.

SELECTION CRITERIA

We included randomised controlled trials evaluating the effect of calcium in participants with overweight or obesity of any age or gender. We excluded studies in participants with absorption problems. We included studies of any dose with a minimum duration of two months. We included the following comparisons: calcium supplementation versus placebo, calcium-fortified food or beverage versus placebo, or calcium-fortified food or beverage versus non-calcium-fortified food or beverage. We excluded studies that evaluated the effect of calcium and vitamin D or mixed minerals compared to placebo.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Our primary outcomes were body weight, health-related quality of life, and adverse events. Our secondary outcomes were anthropometric measures other than body weight, all-cause mortality, and morbidity.

MAIN RESULTS

We found 18 studies that evaluated the effect of calcium compared to placebo or control, with a total of 1873 randomised participants (950 participants in the calcium supplementation groups and 923 in the control groups). All included studies gave oral calcium supplementation as the intervention. We did not find any studies evaluating calcium-fortified foods. We excluded 38 studies, identified four ongoing studies, and listed one study as 'awaiting classification'. Sixteen studies compared calcium supplementation to placebo; two studies compared different doses of calcium supplementation. Doses ranged from very low (0.162 g of calcium/day) to high (1.5 g of calcium/day). Most studies were performed in the USA and Iran, lasted less than six months, and included only women. Low-certainty evidence suggests that calcium supplementation compared to placebo or control may result in little to no difference in body weight (mean difference (MD) -0.15 kg, 95% confidence interval (CI) -0.55 to 0.24; P = 0.45, I2 = 46%; 17 studies, 1317 participants; low-certainty evidence). We downgraded the certainty of the evidence by two levels for risk of bias and heterogeneity. None of the included studies reported health-related quality of life, all-cause mortality, or morbidity/complications as outcomes. Only five studies assessed or reported adverse events. Low-certainty evidence suggests a low frequency of adverse events, with no clear difference between intervention and control groups. Moderate-certainty evidence shows that calcium supplementation compared to placebo or control probably results in a small reduction in body mass index (BMI) (MD -0.18 kg/m2,95% CI -0.22 to -0.13; P < 0.001, I2 = 0%; 9 studies, 731 participants) and waist circumference (MD -0.51 cm, 95% CI -0.72 to -0.29; P < 0.001, I2 = 0%; 6 studies, 273 participants). Low-certainty evidence suggests that calcium supplementation compared to placebo or control may result in a small reduction in body fat mass (MD -0.34 kg, 95% CI -0.73 to 0.05; P < 0.001, I2 = 97%; 12 studies, 812 participants).

AUTHORS' CONCLUSIONS

Calcium supplementation for eight weeks to 24 months may result in little to no difference in body weight in people with overweight or obesity. The current evidence is of low certainty, due to concerns regarding risk of bias and statistical heterogeneity. We found that the degree of heterogeneity might be partly explained by calcium dosage, the presence or absence of a co-intervention, and whether an intention-to-treat analysis was pursued. While our analyses suggest that calcium supplementation may result in a small reduction in BMI, waist circumference, and fat mass, this evidence is of low to moderate certainty. Future studies could investigate the effect of calcium supplementation on lean body mass to explore if there is a change in body composition.

Vowel onset measures and their reliability, sensitivity and specificity: A systematic literature review

OBJECTIVE

To systematically evaluate the evidence for the reliability, sensitivity and specificity of existing measures of vowel-initial voice onset.

METHODS

A literature search was conducted across electronic databases for published studies (MEDLINE, EMBASE, Scopus, Web of Science, CINAHL, PubMed Central, IEEE Xplore) and grey literature (ProQuest for unpublished dissertations) measuring vowel onset. Eligibility criteria included research of any study design type or context focused on measuring human voice onset on an initial vowel. Two independent reviewers were involved at each stage of title and abstract screening, data extraction and analysis. Data extracted included measures used, their reliability, sensitivity and specificity. Risk of bias and certainty of evidence was assessed using GRADE as the data of interest was extracted.

RESULTS

The search retrieved 6,983 records. Titles and abstracts were screened against the inclusion criteria by two independent reviewers, with a third reviewer responsible for conflict resolution. Thirty-five papers were included in the review, which identified five categories of voice onset measurement: auditory perceptual, acoustic, aerodynamic, physiological and visual imaging. Reliability was explored in 14 papers with varied reliability ratings, while sensitivity was rarely assessed, and no assessment of specificity was conducted across any of the included records. Certainty of evidence ranged from very low to moderate with high variability in methodology and voice onset measures used.

CONCLUSIONS

A range of vowel-initial voice onset measurements have been applied throughout the literature, however, there is a lack of evidence regarding their sensitivity, specificity and reliability in the detection and discrimination of voice onset types. Heterogeneity in study populations and methods used preclude conclusions on the most valid measures. There is a clear need for standardisation of research methodology, and for future studies to examine the practicality of these measures in research and clinical settings.

Identification of depression and anxiety during pregnancy: A systematic review and meta-analysis of test accuracy

INTRODUCTION

Depression and anxiety are significant contributors to maternal perinatal morbidity and a range of negative child outcomes. This systematic review and meta-analysis aimed to review and assess the diagnostic test accuracy of selected screening tools (Edinburgh Postnatal Depression Scale [EPDS], EPDS-3A, Patient Health Questionnaire [PHQ-9]-, PHQ-2, Matthey Generic Mood Question [MGMQ], Generalized Anxiety Disorder scale [GAD-7], GAD-2, and the Whooley questions) used to identify women with antenatal depression or anxiety in Western countries.

MATERIAL AND METHODS

On January 16, 2023, we searched 10 databases (CINAHL, Cochrane Library, CRD Database, Embase, Epistemonikos, International HTA Database, KSR Evidence, Ovid MEDLINE, PROSPERO and PsycINFO); the references of included studies were also screened. We included studies of any design that compared case-identification with a relevant screening tool to the outcome of a diagnostic interview based on the Diagnostic and Statistical Manual of Mental Disorders, fourth or fifth edition (DSM-IV or DSM-5), or the International Statistical Classification of Diseases and Related Health Problems, 10th revision (ICD-10). Diagnoses of interest were major depressive disorder and anxiety disorders. Two authors independently screened abstracts and full-texts for relevance and evaluated the risk of bias using QUADAS-2. Data extraction was performed by one person and checked by another team member for accuracy. For synthesis, a bivariate model was used. The certainty of evidence was assessed using Grading of Recommendations Assessment, Development and Evaluation (GRADE).

REGISTRATION

PROSPERO CRD42021236333.

RESULTS

We screened 8276 records for eligibility and included 16 original articles reporting on diagnostic test accuracy: 12 for the EPDS, one article each for the GAD-2, MGMQ, PHQ-9, PHQ-2, and Whooley questions, and no articles for the EPDS-3A or GAD-7. Most of the studies had moderate to high risk of bias. Ten of the EPDS articles provided data for synthesis at cutoffs ≥10 to ≥14 for diagnosing major depressive disorder. Cutoff ≥10 gave the optimal combined sensitivity (0.84, 95% confidence interval [CI]: 0.75-0.90) and specificity (0.87, 95% CI: 0.79-0.92).

CONCLUSIONS

Findings from the meta-analysis suggest that the EPDS alone is not perfectly suitable for detection of major depressive disorder during pregnancy. Few studies have evaluated the other instruments, therefore, their usefulness for identification of women with depression and anxiety during pregnancy remains very uncertain. At present, case-identification with any tool may best serve as a complement to a broader dialogue between healthcare professionals and their patients.

Rapid reviews methods series: Guidance on assessing the certainty of evidence

This paper is part of a series of methodological guidance from the Cochrane Rapid Reviews Methods Group. Rapid reviews (RRs) use modified systematic review methods to accelerate the review process while maintaining systematic, transparent and reproducible methods. This paper addresses considerations for rating the certainty of evidence (COE) in RRs. We recommend the full implementation of GRADE (Grading of Recommendations, Assessment, Development and Evaluation) for Cochrane RRs if time and resources allow.If time or other resources do not permit the full implementation of GRADE, the following recommendations can be considered: (1) limit rating COE to the main intervention and comparator and limit the number of outcomes to critical benefits and harms; (2) if a literature review or a Delphi approach to rate the importance of outcomes is not feasible, rely on informal judgements of knowledge users, topic experts or team members; (3) replace independent rating of the COE by two reviewers with single-reviewer rating and verification by a second reviewer and (4) if effect estimates of a well-conducted systematic review are incorporated into an RR, use existing COE grades from such a review. We advise against changing the definition of COE or the domains considered part of the GRADE approach for RRs.

Comparative Efficacy of Endogenous Stem Cells Recruiting Hydrogels and Stem Cell-loaded Hydrogels in Knee Cartilage Regeneration: A Meta- analysis

BACKGROUND

Cartilage defects remain a challenge in diseases such as osteoarthritis (OA) and fractures. Scientists have explored the use of hydrogels in conjunction with stem cell technology as a tissue engineering method to treat cartilage defects in joints. In recent years, research into hydrogels containing stem cell technology for cartilage repair has mainly focused on two categories: stem cell-loaded hydrogels and endogenous stem cell recruiting hydrogels. The latter, utilizing cell-free products, represents a novel concept with several advantages, including easier dose standardization, wider sources, and simpler storage. This meta-analysis aims to assess and compare the therapeutic effects of endogenous stem cell recruiting hydrogels and stem cell-loaded hydrogels in promoting articular cartilage regeneration in animal models, with the goal of exploring endogenous stem cell recruiting hydrogels as a promising replacement therapy for knee cartilage regeneration in preclinical animal studies.

METHODS

We systematically searched PubMed, Web of Science, Cochrane Library, and Embase until January 2023 using key words related to stem cells, cartilage regeneration and hydrogel. A random-effects meta-analysis was performed to evaluate the therapeutic effect on newborn cartilage formation. Stratified analyses were also carried out by independently classifying trials according to similar characteristics. The level of evidence was determined using the GRADE method.

RESULTS

Twenty-eight studies satisfied the inclusion criteria. Comprehensive analyses revealed that the use of endogenous stem cell recruiting hydrogels significantly promoted the formation of new cartilage in the knee joint, as evidenced by the histological score (3.77, 95% CI 2.40, 5.15; p < 0.0001) and the International Cartilage Repair Society (ICRS) macroscopic score (3.00, 95% CI 1.83, 4.18; p = 0.04), compared with the control group. The stem cell-loaded hydrogels also increased cartilage regeneration in the knee with the histological score (3.13, 95% CI 2.22, 4.04; p = 0.02) and the ICRS macroscopic score (2.49, 95% CI 1.16, 3.82; p = 0.03) in comparison to the control. Significant heterogeneity between studies was observed, and further stratified and sensitivity analyses identified the transplant site and modelling method as the sources of heterogeneity.

CONCLUSION

The current study indicates that both endogenous stem cell recruiting hydrogels and stem cell loaded hydrogels can effectively promote knee joint cartilage regeneration in animal trials.

Significance of carcinoembryonic antigen detection in the early diagnosis of colorectal cancer: A systematic review and meta-analysis

BACKGROUND

Colorectal cancer (CRC) is a prevalent malignant tumor involving adenomas that develop into malignant lesions. Carcinoembryonic antigen (CEA) is a non-specific serum biomarker upregulated in CRC. The concentration of CEA is modulated by tumor stage and grade, tumor site in the colon, ploidy status, and patient smoking status. This study aimed to evaluate current evidence regarding the diagnostic power of CEA levels in the early detection of CRC recurrence in adults.

AIM

To evaluate current evidence regarding the diagnostic power of CEA levels in the early detection of CRC recurrence in adults.

METHODS

A systematic search was performed using four databases: MEDLINE, Cochrane Trials, EMBASE, and the Web of Science. The inclusion criteria were as follows: Adult patients aged ≥ 18 years who had completed CRC curative treatment and were followed up postoperatively; reporting the number of CRC recurrences as an outcome; and randomized, clinical, cohort, and case-control study designs. Studies that were not published in English and animal studies were excluded. The following data were extracted by three independent reviewers: Study design, index tests, follow-up, patient characteristics, and primary outcomes. All statistical analyses were performed using the RevMan 5.4.1.

RESULTS

A total of 3232 studies were identified, with 73 remaining following the elimination of duplicates. After screening on predetermined criteria, 12 studies were included in the final analysis. At a reference standard of 5 mg/L, CEA detected only approximately half of recurrent CRCs, with a pooled sensitivity of 59% (range, 33%-83%) and sensitivity of 89% (range, 58%-97%).

CONCLUSION

CEA is a significant marker for CRC diagnosis. However, it has insufficient sensitivity and specificity to be used as a single biomarker of early CRC recurrence, with an essential proportion of false negatives.

Patient-targeted interventions for opioid deprescribing: An overview of systematic reviews

BACKGROUND

Deprescribing (reduction or cessation) of prescribed opioids can be challenging for both patients and healthcare professionals.

OBJECTIVE

To synthesize and evaluate evidence from systematic reviews examining the effectiveness and outcomes of patient-targeted opioid deprescribing interventions for all types of pain.

METHODS

Systematic searches were conducted in five databases with results screened against predetermined inclusion/exclusion criteria. Primary outcomes were (i) reduction in opioid dose, reported as change in oral Morphine Equivalent Daily Dose (oMEDD) and (ii) success of opioid deprescribing, reported as the proportion of the sample for which opioid use declined. Secondary outcomes included pain severity, physical function, quality of life and adverse events. The certainty of evidence was assessed using Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology.

FINDINGS

Twelve reviews were eligible for inclusion. Interventions were heterogeneous in nature and included pharmacological (n = 4), physical (n = 3), procedural (n = 3), psychological or behavioural (n = 3) and mixed (n = 5) interventions. Multidisciplinary care programmes appeared to be the most effective intervention for opioid deprescribing; however, the certainty of evidence was low, with significant variability in opioid reduction across interventions.

CONCLUSIONS

Evidence is too uncertain to draw firm conclusions about specific populations who may derive the greatest benefit from opioid deprescribing, warranting further investigation.

Intermittent fasting for adults with overweight or obesity

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

To assess the effects of intermittent fasting for adults with overweight or obesity.

Serenoa repens for the treatment of lower urinary tract symptoms due to benign prostatic enlargement

BACKGROUND

Benign prostatic hyperplasia (BPH) is a non-malignant enlargement of the prostate, which can lead to obstructive and irritative lower urinary tract symptoms (LUTS). The pharmacologic use of plants and herbs (phytotherapy) for the treatment of LUTS associated with BPH is common. The extract of the berry of the American saw palmetto or dwarf palm plant, Serenoa repens (SR), which is also known by its botanical name of Sabal serrulatum, is one of several phytotherapeutic agents available for the treatment of BPH.

OBJECTIVES

To assess the effects of Serenoa repens in the treatment of men with LUTS consistent with BPH.

SEARCH METHODS

We performed a comprehensive search of multiple databases (the Cochrane Library, MEDLINE, Embase, Scopus, Web of Science, and LILACS), trials registries, other sources of grey literature, and conference proceedings published up to 16 September 2022, with no restrictions on language or publication status.

SELECTION CRITERIA

We included randomized controlled trials of participants with BPH who were treated with Serenoa repens or placebo/no treatment.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion at each stage and undertook data extraction and risk of bias assessment and GRADE assessment of the certainty of the evidence. We considered review outcomes measured up to 12 months after randomization as short term, and beyond 12 months as long term. Our main outcomes included urologic symptom scores, quality of life, and adverse events.

MAIN RESULTS

For this update, we narrowed the review question to only comparisons with placebo. We included 27 studies (of which 9 were new) involving a total of 4656 participants, 19 studies comparing Serenoa repens with placebo, and 8 studies comparing Serenoa repens in combination with other phytotherapeutic agents versus placebo. Most studies included men aged > 50 (mean age range 52 to 68) with moderate urologic symptoms (International Prostate Symptom Score [IPSS] range 8 to 19). Ten studies were funded by the pharmaceutical industry; two studies were funded by government agencies; and the remaining studies did not specify funding sources. Serenoa repens versus placebo or no intervention Results for this comparison are based on predefined sensitivity analyses limited to studies at low risk of bias. Serenoa repens results in little to no difference in urologic symptoms at short-term follow-up (3 to 6 months; IPSS score range 0 to 35, higher scores indicate worse symptoms; mean difference (MD) -0.90, 95% confidence interval (CI) -1.74 to -0.07; I2 = 68%; 9 studies, 1681 participants; high-certainty evidence). Serenoa repens results in little to no difference in the quality of life at short-term follow-up (3 to 6 months; IPSS quality of life domain range 0 to 6, higher scores indicate worse quality of life; MD -0.20, 95% CI -0.40 to -0.00; I2 = 39%; 5 studies, 1001 participants; high-certainty evidence). Serenoa repens probably results in little to no difference in adverse events (1 to 17 months; risk ratio (RR) 1.01, 95% CI 0.77 to 1.31; I2 = 18%; 12 studies, 2399 participants; moderate-certainty evidence). Based on 164 cases per 1000 men in the placebo group, this corresponds to 2 more (38 fewer to 51 more) per 1000 men in the Serenoa repens group. Serenoa repens results in little to no difference in urologic symptoms at long-term follow-up (12 to 17 months, IPSS score, MD 0.07, 95% CI -0.75 to 0.88; I2 = 34%; 3 studies, 898 participants; high-certainty evidence). Serenoa repens results in little to no difference in quality of life at long-term follow-up (12 to 17 months, IPSS quality of life, MD -0.11, 95% CI -0.41 to 0.19; I2 = 65%; 3 studies, 882 participants; high-certainty evidence). There were no data on long-term adverse events for this comparison. Serenoa repens in combination with other phytotherapy versus placebo or no intervention Different phytotherapeutic agents that include Serenoa repens may result in little to no difference in urologic symptoms compared to placebo at short-term follow-up (12 to 24 weeks, IPSS score, MD -2.41, 95% CI -4.54 to -0.29; I2 = 67%; 4 studies, 460 participants; low-certainty evidence). We are very uncertain about the effects of these agents on quality of life (very low-certainty evidence). These agents may result in little to no difference in the occurrence of adverse events; however, the CIs included substantial benefits and harms (12 to 48 weeks, RR 0.91, 95% CI 0.58 to 1.41; I2 = 0%; 4 studies, 481 participants; low-certainty evidence). Based on 132 cases per 1000 men in the placebo group, this corresponds to 12 fewer (55 fewer to 54 more) per 1000 men in the combined phytotherapeutic agents with Serenoa repens group.

AUTHORS' CONCLUSIONS

Serenoa repens alone provides little to no benefits for men with lower urinary tract symptoms due to benign prostatic enlargement. There is more uncertainty about the role of Serenoa repens in combination with other phytotherapeutic agents.

Evaluation of the use of GRADE in dentistry systematic reviews and its impact on conclusions: a protocol for a methodological study

BACKGROUND

There is a growing body of evidence of systematic reviews (SRs) with varying degrees of methodological quality. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach allows SR authors to assess the certainty of the evidence they found and transparently relay their conclusions. As there appears to be infrequent utilization of GRADE in the field of dentistry, to identify the impact of GRADE, the aim of this study is to evaluate the use of GRADE in the dental literature and determine whether SRs that use GRADE differ from those that do not with respect to their conclusions.

METHODS/DESIGN

We will search Ovid MEDLINE for SRs published from 2016 to the present. We will conduct both screening and data extraction independently and in duplicate and use pre-piloted, standardized forms for data extraction. We will determine the frequency of the use of GRADE and the varying levels of certainty in the current literature and evaluate whether GRADE is being used appropriately. We will also evaluate whether SRs not using GRADE differ from those that use GRADE with regard to methodological quality. We will also determine whether the conclusions of SRs that do not use GRADE would change had GRADE been utilized. Additionally, we will evaluate whether SRs using GRADE are more likely to formulate appropriate conclusions compared to SRs that do not use it.

DISCUSSION

This study will investigate the frequency of GRADE assessments in dentistry SRs and the impact of GRADE assessments on the conclusions of a SR. It has important implications for both SR authors and users of this type of literature.

Parathyroidectomy for adults with primary hyperparathyroidism

BACKGROUND

Primary hyperparathyroidism (PHPT), a disorder in which the parathyroid glands produce excessive amounts of parathyroid hormone, is most common in older adults and postmenopausal women. While most people with PHPT are asymptomatic at diagnosis, symptomatic disease can lead to hypercalcaemia, osteoporosis, renal stones, cardiovascular abnormalities and reduced quality of life. Surgical removal of abnormal parathyroid tissue (parathyroidectomy) is the only established treatment for adults with symptomatic PHPT to prevent exacerbation of symptoms and to be cured of PHPT. However, the benefits and risks of parathyroidectomy compared to simple observation or medical therapy for asymptomatic and mild PHPT are not well established.

OBJECTIVES

To evaluate the benefits and harms of parathyroidectomy in adults with PHPT compared to simple observation or medical therapy.

SEARCH METHODS

We searched CENTRAL, MEDLINE, LILACS, ClinicalTrials.gov and WHO ICTRP from their date of inception until 26 November 2021. We applied no language restrictions.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing parathyroidectomy with simple observation or medical therapy for the treatment of adults with PHPT.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were 1. cure of PHPT, 2. morbidity related to PHPT and 3. serious adverse events. Our secondary outcomes were 1. all-cause mortality, 2. health-related quality of life and 3. hospitalisation for hypercalcaemia, acute renal impairment or pancreatitis. We used GRADE to assess the certainty of the evidence for each outcome.

MAIN RESULTS

We identified eight eligible RCTs that included 447 adults with (mostly asymptomatic) PHPT; 223 participants were randomised to parathyroidectomy. Follow-up duration varied from six months to 24 months. Of the 223 participants (37 men) randomised to surgery, 164 were included in the analyses, of whom 163 were cured at six to 24 months (overall cure rate 99%). Parathyroidectomy compared to observation probably results in a large increase in cure rate at six to 24 months follow-up: 163/164 participants (99.4%) in the parathyroidectomy group and 0/169 participants in the observation or medical therapy group were cured of their PHPT (8 studies, 333 participants; moderate certainty).  No studies explicitly reported intervention effects on morbidities related to PHPT, such as osteoporosis, osteopenia, kidney dysfunction, urolithiasis, cognitive dysfunction or cardiovascular disease, although some studies reported surrogate outcomes for osteoporosis and cardiovascular disease. A post-hoc analysis revealed that parathyroidectomy, compared to observation or medical therapy, may have little or no effect after one to two years on bone mineral density (BMD) at the lumbar spine (mean difference (MD) 0.03 g/cm2,95% CI -0.05 to 0.12; 5 studies, 287 participants; very low certainty). Similarly, compared to observation, parathyroidectomy may have little or no effect on femoral neck BMD after one to two years (MD -0.01 g/cm2, 95% CI -0.13 to 0.11; 3 studies, 216 participants; very low certainty). However, the evidence is very uncertain for both BMD outcomes. Furthermore, the evidence is very uncertain about the effect of parathyroidectomy on improving left ventricular ejection fraction (MD -2.38%, 95% CI -4.77 to 0.01; 3 studies, 121 participants; very low certainty). Four studies reported serious adverse events. Three of these reported zero events in both the intervention and control groups; consequently, we were unable to include data from these three studies in the pooled analysis. The evidence suggests that parathyroidectomy compared to observation may have little or no effect on serious adverse events (RR 3.35, 95% CI 0.14 to 78.60; 4 studies, 168 participants; low certainty).  Only two studies reported all-cause mortality. One study could not be included in the pooled analysis as zero events were observed in both the intervention and control groups. Parathyroidectomy compared to observation may have little or no effect on all-cause mortality, but the evidence is very uncertain (RR 2.11, 95% CI 0.20 to 22.60; 2 studies, 133 participants; very low certainty). Three studies measured health-related quality of life using the 36-Item Short Form Health Survey (SF-36) and reported inconsistent differences in scores for different domains of the questionnaire between parathyroidectomy and observation. Six studies reported hospitalisations for the correction of hypercalcaemia. Two studies reported zero events in both the intervention and control groups and could not be included in the pooled analysis. Parathyroidectomy, compared to observation, may have little or no effect on hospitalisation for hypercalcaemia (RR 0.91, 95% CI 0.20 to 4.25; 6 studies, 287 participants; low certainty). There were no reported hospitalisations for renal impairment or pancreatitis.

AUTHORS' CONCLUSIONS

In accordance with the literature, our review findings suggest that parathyroidectomy, compared to simple observation or medical (etidronate) therapy, probably results in a large increase in cure rates of PHPT (with normalisation of serum calcium and parathyroid hormone levels to laboratory reference values). Parathyroidectomy, compared with observation, may have little or no effect on serious adverse events or hospitalisation for hypercalcaemia, and the evidence is very uncertain about the effect of parathyroidectomy on other short-term outcomes, such as BMD, all-cause mortality and quality of life. The high uncertainty of evidence limits the applicability of our findings to clinical practice; indeed, this systematic review provides no new insights with regard to treatment decisions for people with (asymptomatic) PHPT. In addition, the methodological limitations of the included studies, and the characteristics of the study populations (mainly comprising white women with asymptomatic PHPT), warrant caution when extrapolating the results to other populations with PHPT. Large-scale multi-national, multi-ethnic and long-term RCTs are needed to explore the potential short- and long-term benefits of parathyroidectomy compared to non-surgical treatment options with regard to osteoporosis or osteopenia, urolithiasis, hospitalisation for acute kidney injury, cardiovascular disease and quality of life.

One-Third of Systematic Reviews in Rehabilitation Applied the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) System to Evaluate Certainty of Evidence: A Meta-Research Study

OBJECTIVE

To determine how many systematic reviews (SRs) of the literature in rehabilitation assess the certainty of evidence (CoE) and how many apply the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system to do this.

DATA SOURCES

For this meta-research study, we searched PubMed and Cochrane Database of Systematic Reviews databases for SRs on rehabilitation published in 2020.

STUDY SELECTION AND DATA EXTRACTION

Two reviewers independently selected the SRs and extracted the data. Reporting characteristics and appropriate use of the GRADE system were assessed.

DATA SYNTHESIS

The search retrieved 827 records: 29% (239/827) SRs evaluated CoE, 68% (163/239) of which applied the GRADE system. GRADE was used by SRs of randomized controlled trials (RCTs, 88%; 144/163), non-randomized intervention studies (NRIS, 2%; 3/163), and both RCT and NRIS (10%; 16/163). In the latter case, a separate GRADE assessment according to the study design was not provided in 75% (12/16). The reasons for GRADE judgment were reported in 82% (134/163) of SRs.

CONCLUSIONS

One-third of SRs in rehabilitation assessed CoE with the GRADE system. GRADE assessment was presented transparently by most SRs. Journal editors and funders should encourage the uptake of the GRADE system when considering SRs in rehabilitation for publication. The authors should pre-define GRADE assessment in a registered and/or published protocol.

Nordic dietary patterns and cardiometabolic outcomes: a systematic review and meta-analysis of prospective cohort studies and randomised controlled trials

AIMS/HYPOTHESIS

Nordic dietary patterns that are high in healthy traditional Nordic foods may have a role in the prevention and management of diabetes. To inform the update of the EASD clinical practice guidelines for nutrition therapy, we conducted a systematic review and meta-analysis of Nordic dietary patterns and cardiometabolic outcomes.

METHODS

We searched MEDLINE, EMBASE and The Cochrane Library from inception to 9 March 2021. We included prospective cohort studies and RCTs with a follow-up of ≥1 year and ≥3 weeks, respectively. Two independent reviewers extracted relevant data and assessed the risk of bias (Newcastle-Ottawa Scale and Cochrane risk of bias tool). The primary outcome was total CVD incidence in the prospective cohort studies and LDL-cholesterol in the RCTs. Secondary outcomes in the prospective cohort studies were CVD mortality, CHD incidence and mortality, stroke incidence and mortality, and type 2 diabetes incidence; in the RCTs, secondary outcomes were other established lipid targets (non-HDL-cholesterol, apolipoprotein B, HDL-cholesterol, triglycerides), markers of glycaemic control (HbA_1c, fasting glucose, fasting insulin), adiposity (body weight, BMI, waist circumference) and inflammation (C-reactive protein), and blood pressure (systolic and diastolic blood pressure). The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach was used to assess the certainty of the evidence.

RESULTS

We included 15 unique prospective cohort studies (n=1,057,176, with 41,708 cardiovascular events and 13,121 diabetes cases) of people with diabetes for the assessment of cardiovascular outcomes or people without diabetes for the assessment of diabetes incidence, and six RCTs (n=717) in people with one or more risk factor for diabetes. In the prospective cohort studies, higher adherence to Nordic dietary patterns was associated with 'small important' reductions in the primary outcome, total CVD incidence (RR for highest vs lowest adherence: 0.93 [95% CI 0.88, 0.99], p=0.01; substantial heterogeneity: I²=88%, p_Q<0.001), and similar or greater reductions in the secondary outcomes of CVD mortality and incidence of CHD, stroke and type 2 diabetes (p<0.05). Inverse dose-response gradients were seen for total CVD incidence, CVD mortality and incidence of CHD, stroke and type 2 diabetes (p<0.05). No studies assessed CHD or stroke mortality. In the RCTs, there were small important reductions in LDL-cholesterol (mean difference [MD] -0.26 mmol/l [95% CI -0.52, -0.00], p_MD=0.05; substantial heterogeneity: I²=89%, p_Q<0.01), and 'small important' or greater reductions in the secondary outcomes of non-HDL-cholesterol, apolipoprotein B, insulin, body weight, BMI and systolic blood pressure (p<0.05). For the other outcomes there were 'trivial' reductions or no effect. The certainty of the evidence was low for total CVD incidence and LDL-cholesterol; moderate to high for CVD mortality, established lipid targets, adiposity markers, glycaemic control, blood pressure and inflammation; and low for all other outcomes, with evidence being downgraded mainly because of imprecision and inconsistency.

CONCLUSIONS/INTERPRETATION

Adherence to Nordic dietary patterns is associated with generally small important reductions in the risk of major CVD outcomes and diabetes, which are supported by similar reductions in LDL-cholesterol and other intermediate cardiometabolic risk factors. The available evidence provides a generally good indication of the likely benefits of Nordic dietary patterns in people with or at risk for diabetes.

REGISTRATION

ClinicalTrials.gov NCT04094194.

FUNDING

Diabetes and Nutrition Study Group of the EASD Clinical Practice.

Surgery for the treatment of obesity in children and adolescents

BACKGROUND

Child and adolescent overweight and obesity have increased globally and are associated with significant short- and long-term health consequences.

OBJECTIVES

To assess the effects of surgery for treating obesity in childhood and adolescence.

SEARCH METHODS

For this update, we searched Cochrane Central Register of Controlled Trials, MEDLINE, Latin American and Caribbean Health Science Information database (LILACS), World Health Organization International Clinical Trials Registry Platform (ICTRP)and ClinicalTrials.gov on 20 August 2021 (date of the last search for all databases). We did not apply language restrictions. We checked references of identified studies and systematic reviews.

SELECTION CRITERIA

We selected randomised controlled trials (RCTs) of surgical interventions for treating obesity in children and adolescents (age < 18 years) with a minimum of six months of follow-up. We excluded interventions that specifically dealt with the treatment of eating disorders or type 2 diabetes, or which included participants with a secondary or syndromic cause of obesity, or who were pregnant.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Two review authors independently extracted data and assessed the risk of bias using the Cochrane Risk of Bias 2.0 tool. Where necessary, we contacted authors for additional information.

MAIN RESULTS

With this update, we did not find any new RCTs. Therefore, this updated review still includes a single RCT (a total of 50 participants, 25 in both the intervention and comparator groups). The intervention focused on laparoscopic adjustable gastric banding surgery, which was compared to a control group receiving a multi-component lifestyle programme. The participating population consisted of Australian adolescents (a higher proportion of girls than boys) aged 14 to 18 years, with a mean age of 16.5 and 16.6 years in the gastric banding and lifestyle groups, respectively. The trial was conducted in a private hospital, receiving funding from the gastric banding manufacturer. For most of the outcomes, we identified a high risk of bias, mainly due to bias due to missing outcome data. Laparoscopic gastric banding surgery may reduce BMI by a mean difference (MD) of -11.40 kg/m2 (95% CI -13.22 to -9.58) and weight by -31.60 kg (95% CI -36.66 to -26.54) compared to a multi-component lifestyle programme at two years follow-up. The evidence is very uncertain due to serious imprecision and a high risk of bias. Adverse events were reported in 12/25 (48%) participants in the intervention group compared to 11/25 (44%) in the control group. A total of 28% of the adolescents undergoing gastric banding required revisional surgery. The evidence is very uncertain due to serious imprecision and a high risk of bias. At two years of follow-up, laparoscopic gastric banding surgery may increase health-related quality of life in the physical functioning scores by an MD of 16.30 (95% CI 4.90 to 27.70) and change in health scores by an MD of 0.82 (95% CI 0.18 to 1.46) compared to the lifestyle group. The evidence is very uncertain due to serious imprecision and a high risk of bias. No data were reported for all-cause mortality, behaviour change, participants' views of the intervention and socioeconomic effects. Finally, we have identified three ongoing RCTs that are evaluating the efficacy and safety of metabolic and bariatric surgery in children and adolescents.

AUTHORS' CONCLUSIONS

Laparoscopic gastric banding led to greater body weight loss compared to a multi-component lifestyle program in one small study with 50 participants. These results have very limited application, primarily due to more recent recommendations derived from observation studies to avoid the use of banding in youth due to long-term reoperation rates. This systematic review update still highlights the lack of RCTs in this field. The authors are concerned that there may be ethical barriers to RTCs in this field, despite the lack of other effective therapies for severe obesity in children and adolescents and the significant morbidity and premature mortality caused by childhood obesity. Nevertheless, future studies, whether pre-registered and planned non-randomised or pragmatic randomised trials, should assess the impact of the surgical procedure and post-operative care to minimise adverse events, including the need for post-operative adjustments and revisional surgery. Long-term follow-up is also critical to comprehensively assess the impact of surgery as participants enter adulthood.

Effectiveness of aromatherapy for prevention or treatment of disease, medical or preclinical conditions, and injury: protocol for a systematic review and meta-analysis

BACKGROUND

Aromatherapy - the therapeutic use of essential oils from plants (flowers, herbs or trees) to treat ill health and promote physical, emotional and spiritual well-being - is one of the most widely used natural therapies reported by consumers in Western countries. The Australian Government Department of Health (via the National Health and Medical Research Council) has commissioned a suite of independent evidence evaluations to inform the 2019-20 Review of the Australian Government Rebate on Private Health Insurance for Natural Therapies. This protocol is for one of the evaluations: a systematic review that aims to examine the effectiveness of aromatherapy in preventing and/or treating injury, disease, medical conditions or preclinical conditions.

METHODS

Eligibility criteria: randomised trials comparing (1) aromatherapy (delivered by any mode) to no aromatherapy (inactive controls), (2) aromatherapy (delivered by massage) to massage alone or (3) aromatherapy to 'gold standard' treatments.

POPULATIONS

any condition, pre-condition, injury or risk factor (excluding healthy participants without clearly identified risk factors).

OUTCOMES

any for which aromatherapy is indicated. Searches: Cochrane Central Register of Controlled Trials (CENTRAL), with a supplementary search of PubMed (covering a 6-month lag period for processing records in CENTRAL and records not indexed in MEDLINE), AMED and Emcare. No date, language or geographic limitations will be applied.

DATA AND ANALYSIS

screening by two authors, independently (records indexed by Aromatherapy or Oils volatile or aromatherapy in title; all full text) or one author (remaining records) with second author until 80% agreement. Data extraction and risk of bias assessment (ROB 2.0) will be piloted by three authors, then completed by a single author and checked by a second. Comparisons will be based on broad outcome categories (e.g. pain, emotional functioning, sleep disruption) stratified by population subgroups (e.g. chronic pain conditions, cancer, dementia) as defined in the analytic framework for the review. Meta-analysis or other synthesis methods will be used to combine results across studies. GRADE methods will be used to assess certainty of evidence and summarise findings.

DISCUSSION

Results of the systematic review will provide a comprehensive and up-to-date synthesis of evidence about the effectiveness of aromatherapy.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42021268244.

Reliability of the straight leg raise test for suspected lumbar radicular pain: A systematic review with meta-analysis

BACKGROUND

The passive straight leg raise (SLR) and crossed SLR are recommended tests for lumbar radicular pain. There are no recent reviews of test reliability.

OBJECTIVES

To summarize SLR and crossed SLR reliability in patients with suspected lumbar radicular pain.

DESIGN

Systematic review with meta-analysis.

METHOD

MEDLINE and CINAHL were searched for studies published before April 2021 that reported SLR or crossed SLR reliability in patients with low back-related leg pain. Supplemental analyses also included patients with low back pain only. Study selection, risk of bias assessment (QAREL), and data extraction were performed in duplicate. Kappa, intraclass correlation coefficients, and smallest detectable difference (SDD₉₅) quantified reliability. Meta-analysis was performed when appropriate. Confidence in the evidence was determined by applying GRADE principles.

RESULTS/FINDINGS

Fifteen studies met selection criteria. One-hundred-eighty-nine participants had low back-related leg pain. Four-hundred-thirty-nine were included in supplemental analyses. Meta-analyses showed at least fair inter-rater reliability when a positive SLR required provocation of lower extremity symptoms or pain. SLR reliability was at least moderate when testing included structural differentiation (e.g., ankle dorsiflexion). A low prevalence of positive crossed SLR tests led to wide-ranging reliability estimates. Confidence in the evidence for identifying a positive SLR or crossed SLR was moderate to very low. SDD₉₅ values for different raters measuring SLR range of motion ranged from 13 to 20°.

CONCLUSIONS

Reliability data support testing SLR with structural differentiation manoeuvres. Crossed SLR reliability data are inconclusive. Measurement error likely prohibits using SLR range of motion for clinical decision-making.

Strengthening women's empowerment and gender equality in fragile contexts towards peaceful and inclusive societies: A systematic review and meta-analysis

BACKGROUND

Across the globe, gender disparities still exist with regard to equitable access to resources, participation in decision-making processes, and gender and sexual-based violence. This is particularly true in fragile and conflict-affected settings, where women and girls are affected by both fragility and conflict in unique ways. While women have been acknowledged as key actors in peace processes and post-conflict reconstruction (e.g., through the United Nations Security Council Resolution 1325 and the Women, Peace and Security Agenda) evidence on the effectiveness of gender-specific and gender-transformative interventions to improve women's empowerment in fragile and conflict-affected states and situations (FCAS) remains understudied.

OBJECTIVES

The purpose of this review was to synthesize the body of evidence around gender-specific and gender-transformative interventions aimed at improving women's empowerment in fragile and conflict-affected settings with high levels of gender inequality. We also aimed to identify barriers and facilitators that could affect the effectiveness of these interventions and to provide implications for policy, practice and research designs within the field of transitional aid.

METHODS

We searched for and screened over 100,000 experimental and quasi-experimental studies focused on FCAS at the individual and community levels. We used standard methodological procedures outlined by the Campbell Collaboration for the data collection and analysis, including quantitative and qualitative analyses, and completed the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) methodology to assess the certainty around each body of evidence.

RESULTS

We identified 104 impact evaluations (75% randomised controlled trials) assessing the effects of 14 different types of interventions in FCAS. About 28% of included studies were assessed as having a high risk of bias (45% among quasi-experimental designs). Interventions supporting women's empowerment and gender equality in FCAS produced positive effects on the outcomes related to the primary focus of the intervention. There are no significant negative effects of any included interventions. However, we observe smaller effects on behavioural outcomes further along the causal chain of empowerment. Qualitative syntheses indicated that gender norms and practices are potential barriers to intervention effectiveness, while working with local powers and institutions can facilitate the uptake and legitimacy of interventions.

CONCLUSIONS

We observe gaps of rigorous evidence in certain regions (notably MENA and Latin America) and in interventions specifically targeting women as actors of peacebuilding. Gender norms and practices are important elements to consider in programme design and implementation to maximise potential benefits: focusing on empowerment only might not be enough in the absence of targeting the restrictive gender norms and practices that may undermine intervention effectiveness. Lastly, programme designers and implementation should consider explicitly targeting specific empowerment outcomes, promoting social capital and exchange, and tailoring the intervention components to the desired empowerment-related outcomes.

The effect of long-term radiofrequency exposure on cognition in human observational studies: A protocol for a systematic review

BACKGROUND

The long term effects of exposure to radiofrequency (RF) electromagnetic fields (EMF) for frequencies from 100 kHz to 300 GHz on cognitive performance are best assessed using observational studies. In recent years, the use of mobile (cell) phones has been the main source of RF EMF exposure to the brain, although other sources of exposure may be significant. Cognitive function includes various mental and psychological abilities, which can be measured in a range of domains, such as learning, memory, reasoning, problem solving, decision making and attention. Although effects on cognitive function may be most evident later in life, in the experimental setting acute and immediate effects can only be studied. Observational studies are needed when effects are observed after months or years following short or long-term exposure. The importance of the effects of exposure on children has also been recently identified.

OBJECTIVES

To assess the long-term effects of RF EMF local and whole-body exposure compared to no or a lower level of exposure on indicators of cognition, including complex attention, executive function, learning and memory, perceptual motor ability and social cognition, but excluding cognitive effects caused by neurodegenerative diseases or neurodevelopmental disorders, and to assess if there is evidence of a dose response relationship.

STUDY ELIGIBILITY AND CRITERIA

We will include observational studies that have evaluated cognitive effects of RF energy including a comparator group with a different level of exposure. Studies must report at least one validated measure of cognitive function, including global or domain specific measures, or cognitive impairment, with a minimum follow-up of 6 months. Cohort or case-control studies published in the peer review literature in any language are eligible. We will exclude cross-sectional studies and any that only report brain structure or biomarkers.

STUDY APPRAISAL AND SYNTHESIS METHOD

We will conduct searches of PubMed, Embase, PsycINFO and the EMF-Portal. At least two authors will independently screen the titles/abstracts of all records, with any conflicts resolved by a third reviewer. Full-text screening will also be conducted independently by two authors with conflicts resolved by consensus. Data will be extracted from the studies included, such as identifiers and characteristics of the study design, exposure and comparator groups, participants, outcomes assessed and results. Risk of bias will be assessed with the Office of Health Assessment and Translation (OHAT) tool. We will conduct a meta-analysis of similar studies with a random effects model in STATA or similar software, if two or more studies are available for a given exposure-outcome combination. Confidence in the body evidence will be judged using GRADE methods as adapted by OHAT for reviews of environmental exposures.

Gastrointestinal recovery after surgery: protocol for a systematic review

INTRODUCTION

Gastrointestinal recovery after surgery is of worldwide significance. Postoperative gastrointestinal dysfunction is multifaceted and known to represent a major source of postoperative morbidity, however, its significance to postoperative care across all surgical procedures is unknown. The complexity of postoperative gastrointestinal recovery is poorly defined within gastrointestinal surgery, and even less so outside this field. To inform the clinical care of surgical patients worldwide, this systematic review and meta-analysis will aim to characterise the duration of postoperative gastrointestinal recovery that can be expected across all surgical procedures and determine the associations between factors that may affect this.

METHODS AND ANALYSIS

MEDLINE, Embase, Cochrane Library and CINAHL will be searched for studies reporting the time to first postoperative passage of stool after any surgical procedure. We will screen records, extract data and assess risk of bias in duplicate. Forest plots will be constructed for time to postoperative gastrointestinal recovery, as assessed by various outcome measures. Because of potential heterogeneity, a random-effects model will be used throughout the meta-analysis. Funnel plots will be used to test for publication bias. Meta-regressions will be undertaken where the outcome is the mean time to first postoperative passage of stool, with potential predictors and confounders being patient characteristics, postoperative outcomes and surgical factors.

ETHICS AND DISSEMINATION

This study will not involve human or animal subjects and, thus, does not require ethics approval. The outcomes will be disseminated via publication in peer-reviewed scientific journal(s) and presentations at scientific conferences.

PROSPERO REGISTRATION NUMBER

CRD42021256210.

PROTOCOL: Strengthening women's empowerment and gender equality in fragile contexts towards peaceful and inclusive societies: A systematic review and meta-analysis

This review builds on 3ie's (international initiative for impact evaluation) evidence gap map (EGM) of the impact evaluation and systematic review (SR) evidence base of interventions aiming to promote peaceful and inclusive societies in fragile contexts. The EGM identified a cluster of studies evaluating gender equality-focused behaviour change communication programmes and raised interest in investigating the evidence base for understanding the role of women more broadly as agents of change in developing peaceful and inclusive societies. Building on the cluster of evidence identified in the EGM, our review will increase generalisability of findings from single studies and focus on interventions across a broad range of geographical locations, settings and populations, types of implementations and outcomes. We will also address (when possible) the identified gaps in literature regarding metaanalysis in conflict-affected contexts. As such, we propose the following objectives: (1) The primary objective of this review is to identify, assess and synthesise evidence on the effect of gender specific and gender transformative interventions within the context of the four pillars of United Nations Security Council Resolution (UNSCR) 1325 on women's empowerment and gender equality in Fragile and Conflict Affected States/Situations (FCAS). The SR will facilitate the use of evidence in informing policy and practice decisions within the field of transition aid, particularly as it relates to gender focused programming. (2) Our second objective is to assess how these interventions contribute to inclusive and sustainable peace in conflict affected situations. We will compare the effectiveness of these different types of interventions through the lenses of their ecological level, types of impact on women's empowerment, local context of gender inequality and conflict. To achieve these objectives we aim to answer the following questions: (1) What are the impacts of gender transformative and specific interventions on women's empowerment and gender equality in FCAS? (2) What are the effects of these interventions on sustainable peace? (3) To what extent do effects vary by population group, ecological level and types of interventions? (4) What are contextual barriers to and facilitators of intervention effectiveness?

Risk of Intestinal Necrosis With Sodium Polystyrene Sulfonate: A Systematic Review and Meta-analysis

BACKGROUND

Reports of severe gastrointestinal side effects associated with sodium polystyrene sulfonate (SPS), particularly intestinal necrosis, have led some to recommend costlier alternative medications. No prior systematic review has included studies with controls reporting intestinal necrosis rates associated with SPS.

METHODS

A systematic literature search was conducted using Cochrane Library, Embase, Medline, Google Scholar, PubMed, Scopus, and Web of Science Core Collection from database inception through October 4, 2020. We included any clinical trial, cohort, or case-control study reporting an association between SPS and intestinal necrosis or severe gastrointestinal side effects.

RESULTS

Six studies including 26,716 patients treated with SPS with controls met inclusion criteria. The pooled odds ratio (OR) of intestinal necrosis was 1.43 (95% CI, 0.39-5.20). The pooled hazard ratio (HR) for intestinal necrosis from the two studies that performed survival analysis was 2.00 (95% CI, 0.45-8.78). The pooled HR for the composite outcome of severe gastrointestinal adverse events was 1.46 (95% CI, 1.01-2.11).

CONCLUSION

Based on our review of six studies, the risk of intestinal necrosis with SPS is not statistically greater than controls, although there was a statistically significantly increased risk for the composite outcome of severe gastrointestinal side effects based on two studies. Because of the risk of bias from potential confounding and selective reporting, the overall strength of evidence to support an association between SPS and intestinal necrosis or other severe gastrointestinal side effects is low. PROSPERO registration CRD42020213119.

A modeling approach to derive baseline risk estimates for GRADE recommendations:Concepts, development, and results of its application to the American Society of Hematology 2019 guidelines on prevention of venous thromboembolism in surgical hospitalized patients

OBJECTIVE

The goal of this study was to develop an approach that can be used where baseline risk estimates that are directly applicable to prioritized patient-important outcomes are not available from published studies.

STUDY DESIGN

The McMaster University GRADE Centre and the ASH guideline panel for the prevention of VTE in surgical patients developed a modeling approach based on explicit assumptions about the distribution of symptoms, anatomical location, and severity of VTE events.

RESULTS

We applied the approach to derive modeled estimates of baseline risk. These estimates were used to calculated absolute measures of anticipated effects that informed the discussion of the evidence and the formulation of 30 guideline recommendations.

CONCLUSIONS

Our approach can assist guideline developers facing a lack of information about baseline risk estimates that directly apply to outcomes of interest. The use of modeled estimates increases transparency in the process and makes the baseline risk used by guideline experts explicit during their decision-making.

The short- and long-term effects of dietary patterns on cardiometabolic health in adults aged 65 years or older: a systematic review

CONTEXT

Cardiometabolic diseases are leading causes of death and morbidity. Aging increases the risk of disease development. Diet has protective and causal effects on cardiometabolic health.

OBJECTIVE

To consolidate the current evidence on the short- and long-term effects of dietary patterns on cardiometabolic health in adults aged ≥ 65 years.

DATA SOURCES

The Medline, Embase, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, Cumulative Index to Nursing and Allied Health Literature, Web of Science, Scopus, Global Health, and Pre-Medline databases, along with ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform were searched.

DATA EXTRACTION

A total of 40 042 records were identified. Quality assessment involved using the revised Cochrane risk-of-bias tool for randomized trials and Joanna Briggs Institute checklists. The certainty of evidence was assessed using Grading of Recommendations, Assessment, Development, and Evaluation.

RESULTS

Thirteen articles were included (n = 5 cohort studies and n = 3 randomized controlled trials). The low-fat dietary pattern reduced adiposity; however, no effects were evident for hypertension incidence, composite coronary heart disease incidence (including myocardial infarction, coronary heart disease, and coronary revascularization), high-density lipoprotein cholesterol level, and increased blood pressure in the long term. The Mediterranean dietary pattern resulted in reduced triglyceride levels and systolic blood pressure, and had no effects on diastolic blood pressure and glucose in the short term. Other dietary patterns had inconclusive effects.

CONCLUSIONS

The Mediterranean dietary pattern showed the most benefits without harm on cardiometabolic health in older adults. The current body of evidence is small, indicating the need for more research to confirm these findings at a high certainty of evidence, and to include dietary patterns combined with other dietary components, subgroups with cardiometabolic disease or risk factors, longer follow-up, and outcomes that have not yet been investigated. Studies including these factors may help identify the most effective dietary pattern for cardiometabolic health benefits in older adults, to inform future guidelines.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42020141400.

[GRADE guidelines 20: Assessing the certainty of evidence in the importance of outcomes or values and preferences-inconsistency, imprecision, and other domains]

OBJECTIVE

To provide Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) guidance for assessing inconsistency, imprecision, and other domains for the certainty of evidence about the relative importance of outcomes.

STUDY DESIGN AND SETTING

We applied the GRADE domains to rate the certainty of evidence in the importance of outcomes to several systematic reviews, iteratively reviewed draft guidance, and consulted GRADE members and other stakeholders for feedback.

RESULTS

We describe the rationale for considering the remaining GRADE domains when rating the certainty in a body of evidence for the relative importance of outcomes. As meta-analyses are not common in this context, inconsistency and imprecision assessments are challenging. Furthermore, confusion exists about inconsistency, imprecision, and true variability in the relative importance of outcomes. To clarify this issue, we suggest that the true variability is neither equivalent to inconsistency nor imprecision. Specifically, inconsistency arises from population, intervention, comparison and outcome and methodological elements that should be explored and, if possible, explained. The width of the confidence interval and sample size inform judgments about imprecision. We also provide suggestions on how to detect publication bias and discuss the domains to rate up the certainty.

CONCLUSION

We provide guidance and examples for rating inconsistency, imprecision, and other domains for a body of evidence describing the relative importance of outcomes.

Severe COVID-19 and coagulopathy: A systematic review and meta-analysis

Introduction: Coronavirus disease 2019 (COVID-19)-induced coagulopathy (CIC) has been widely reported in the literature. However, the spectrum of abnormalities associated with CIC has been highly variable. Methods: We conducted a systematic review of the literature (until 1 June 2020) to assess CIC and disease severity during the early COVID-19 pandemic. Primary outcomes were pooled mean differences in platelet count, D-dimer level, prothrombin time, activated partial thromboplastin time (aPTT) and fibrinogen level between non-severe and severe patients, stratified by degree of hypoxaemia or those who died. The risk factors for CIC were analysed. Random-effects meta-analyses and meta-regression were performed using R version 3.6.1, and certainty of evidence was rated using the Grading of Recommendation, Assessment, Development, and Evaluation approach. Results: Of the included 5,243 adult COVID-19 patients, patients with severe COVID-19 had a significantly lower platelet count, and higher D-dimer level, prothrombin time and fibrinogen level than non-severe patients. Pooled mean differences in platelet count (-19.7×109/L, 95% confidence interval [CI] -31.7 to -7.6), D-dimer level (0.8μg/mL, 95% CI 0.5–1.1), prothrombin time (0.4 second, 95% CI 0.2–0.6) and fibrinogen level (0.6g/L, 95% CI 0.3–0.8) were significant between the groups. Platelet count and D-dimer level were significant predictors of disease severity on meta-regression analysis. Older men had higher risks of severe coagulopathic disease. Conclusion: Significant variability in CIC exists between non-severe and severe patients, with platelet count and D-dimer level correlating with disease severity. Routine monitoring of all coagulation parameters may help to assess CIC and decide on the appropriate management. Keywords: Coagulation parameters, coagulopathy, D-dimer, platelets

Aerosol-generating behaviours in speech pathology clinical practice: A systematic literature review

OBJECTIVE

To evaluate the evidence of aerosol generation across tasks involved in voice and speech assessment and intervention, to inform better management and to reduce transmission risk of such diseases as COVID-19 in healthcare settings and the wider community.

DESIGN

Systematic literature review.

DATA SOURCES AND ELIGIBILITY

Medline, Embase, Scopus, Web of Science, CINAHL, PubMed Central and grey literature through ProQuest, The Centre for Evidence-Based Medicine, COVID-Evidence and speech pathology national bodies were searched up until August 13th, 2020 for articles examining the aerosol-generating activities in clinical voice and speech assessment and intervention within speech pathology.

RESULTS

Of the 8288 results found, 39 studies were included for data extraction and analysis. Included articles were classified into one of three categories: research studies, review articles or clinical guidelines. Data extraction followed appropriate protocols depending on the classification of each article (e.g. PRISMA for review articles). Articles were assessed for risk of bias and certainty of evidence using the GRADE system. Six behaviours were identified as aerosol generating. These were classified into three categories: vegetative acts (coughing, breathing), verbal communication activities of daily living (speaking, loud voicing), and performance-based tasks (singing, sustained phonation). Certainty of evidence ranged from very low to moderate with variation in research design and variables.

CONCLUSIONS

This body of literature helped to both identify and categorise the aerosol-generating behaviours involved in speech pathology clinical practice and confirm the low level of evidence throughout the speech pathology literature pertaining to aerosol generation. As many aerosol-generating behaviours are common human behaviours, these findings can be applied across healthcare and community settings.

SYSTEMATIC REVIEW REGISTRATION

Registration number CRD42020186902 with PROSPERO International Prospective Register for Systematic Reviews.

PRISMA 2020 explanation and elaboration: updated guidance and exemplars for reporting systematic reviews

The methods and results of systematic reviews should be reported in sufficient detail to allow users to assess the trustworthiness and applicability of the review findings. The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement was developed to facilitate transparent and complete reporting of systematic reviews and has been updated (to PRISMA 2020) to reflect recent advances in systematic review methodology and terminology. Here, we present the explanation and elaboration paper for PRISMA 2020, where we explain why reporting of each item is recommended, present bullet points that detail the reporting recommendations, and present examples from published reviews. We hope that changes to the content and structure of PRISMA 2020 will facilitate uptake of the guideline and lead to more transparent, complete, and accurate reporting of systematic reviews.

Registered trials address questions already answered with high-certainty evidence: A sample of current redundant research

OBJECTIVE

To identify clinical trials registered later than 2015, that study the effect of an intervention on a primary outcome whose "Certainty of Evidence" (CoE) has already been rated "high" in a Cochrane SR.

STUDY DESIGN AND SETTING

We searched the Cochrane Library for all SRs from 2015. We analyzed SRs of interventions and excluded withdrawn reviews or those with no Summary of Findings (SoF) table. We retrieved the GRADE CoE ratings of each SR's primary outcomes in the SoF tables and identified those rated "high." We searched the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials to identify records of clinical studies that tackled those outcomes and were registered after the date of publication of the respective 2015 SR.

RESULTS

We selected 602 SRs. Eighty-one contained a "high" CoE rating on at least one primary outcome, totaling 152 primary outcomes rated "high." We found 39 clinical trials registered for primary outcomes with evidence already rated as "high" in a 2015 Cochrane SR.

CONCLUSION

This study shows the existence of clinical trials registered to study primary outcomes whose CoE has already been rated "high" in a Cochrane SR.

Concurrent Use of Renal Replacement Therapy during Extracorporeal Membrane Oxygenation Support: A Systematic Review and Meta-Analysis

Patients supported with extracorporeal membrane oxygenation (ECMO) often receive renal replacement therapy (RRT). We conducted this systematic review and meta-analysis (between January 2000 and September 2020) to assess outcomes in patients who received RRT on ECMO. Random-effects meta-analyses were performed using R 3.6.1 and certainty of evidence was rated using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach. The primary outcome was pooled mortality. The duration of ECMO support and ICU/hospital lengths of stay were also investigated. Meta-regression analyses identified factors associated with mortality. A total of 5896 adult patients (from 24 observational studies and 1 randomised controlled trial) were included in this review. Overall pooled mortality due to concurrent use of RRT while on ECMO from observational studies was 63.0% (95% CI: 56.0–69.6%). In patients receiving RRT, mortality decreased by 20% in the last five years; the mean duration of ECMO support and ICU and hospital lengths of stay were 9.33 days (95% CI: 7.74–10.92), 15.76 days (95% CI: 12.83–18.69) and 28.47 days (95% CI: 22.13–34.81), respectively, with an 81% increased risk of death (RR: 1.81, 95% CI: 1.56–2.08, p < 0.001). RRT on ECMO was associated with higher mortality rates and a longer ICU/hospital stay compared to those without RRT. Future research should focus on minimizing renal dysfunction in ECMO patients and define the optimal timing of RRT initiation.

Exclusive Maternal Milk Compared With Exclusive Formula on Growth and Health Outcomes in Very-Low-Birthweight Preterm Infants: Phase II of the Pre-B Project and an Evidence Analysis Center Systematic Review

As part of the Pre-B Project, a systematic review was conducted to evaluate associations between exclusive maternal milk (≥75%) intake and exclusive formula intake and growth and health outcomes in very-low-birthweight (VLBW) preterm infants. The protocols from the Academy of Nutrition and Dietetics' Evidence Analysis Center and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist were followed. Thirteen observational studies were included; 11 studies reported data that could be synthesized in a pooled analysis. The evidence is very uncertain (very low quality) about the effect of exclusive maternal milk on all outcomes due to observational study designs and risk of selection, performance, detection, and reporting bias in most of the included studies. Very-low-quality evidence suggested that providing VLBW preterm infants with exclusive maternal milk was not associated with mortality, risk of necrotizing enterocolitis, sepsis, or developing bronchopulmonary dysplasia, as compared with exclusive preterm formula, but exclusive maternal milk was associated with a lower risk of retinopathy of prematurity (very low certainty). Results may change when additional studies are conducted. There was no difference in weight, length, and head circumference gain between infants fed fortified exclusive maternal milk and infants receiving exclusive preterm formula; however, weight and length gain were lower in infants fed non-fortified exclusive maternal milk. Given the observational nature of human milk research, cause-and-effect evidence was lacking for VLBW preterm infants.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=86829, PROSPERO ID: CRD42018086829.

Inotropic agents and vasodilator strategies for the treatment of cardiogenic shock or low cardiac output syndrome

BACKGROUND

Cardiogenic shock (CS) and low cardiac output syndrome (LCOS) are potentially life-threatening complications of acute myocardial infarction (AMI), heart failure (HF) or cardiac surgery. While there is solid evidence for the treatment of other cardiovascular diseases of acute onset, treatment strategies in haemodynamic instability due to CS and LCOS remains less robustly supported by the given scientific literature. Therefore, we have analysed the current body of evidence for the treatment of CS or LCOS with inotropic and/or vasodilating agents. This is the second update of a Cochrane review originally published in 2014.

OBJECTIVES

Assessment of efficacy and safety of cardiac care with positive inotropic agents and vasodilator agents in CS or LCOS due to AMI, HF or after cardiac surgery.

SEARCH METHODS

We conducted a search in CENTRAL, MEDLINE, Embase and CPCI-S Web of Science in October 2019. We also searched four registers of ongoing trials and scanned reference lists and contacted experts in the field to obtain further information. No language restrictions were applied.

SELECTION CRITERIA

Randomised controlled trials (RCTs) enrolling patients with AMI, HF or cardiac surgery complicated by CS or LCOS.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures according to Cochrane standards.

MAIN RESULTS

We identified 19 eligible studies including 2385 individuals (mean or median age range 56 to 73 years) and three ongoing studies. We categorised studies into 11 comparisons, all against standard cardiac care and additional other drugs or placebo. These comparisons investigated the efficacy of levosimendan versus dobutamine, enoximone or placebo; enoximone versus dobutamine, piroximone or epinephrine-nitroglycerine; epinephrine versus norepinephrine or norepinephrine-dobutamine; dopexamine versus dopamine; milrinone versus dobutamine and dopamine-milrinone versus dopamine-dobutamine. All trials were published in peer-reviewed journals, and analyses were done by the intention-to-treat (ITT) principle. Eighteen of 19 trials were small with only a few included participants. An acknowledgement of funding by the pharmaceutical industry or missing conflict of interest statements occurred in nine of 19 trials. In general, confidence in the results of analysed studies was reduced due to relevant study limitations (risk of bias), imprecision or indirectness. Domains of concern, which showed a high risk in more than 50% of included studies, encompassed performance bias (blinding of participants and personnel) and bias affecting the quality of evidence on adverse events. All comparisons revealed uncertainty on the effect of inotropic/vasodilating drugs on all-cause mortality with a low to very low quality of evidence. In detail, the findings were: levosimendan versus dobutamine (short-term mortality: RR 0.60, 95% CI 0.36 to 1.03; participants = 1701; low-quality evidence; long-term mortality: RR 0.84, 95% CI 0.63 to 1.13; participants = 1591; low-quality evidence); levosimendan versus placebo (short-term mortality: no data available; long-term mortality: RR 0.55, 95% CI 0.16 to 1.90; participants = 55; very low-quality evidence); levosimendan versus enoximone (short-term mortality: RR 0.50, 0.22 to 1.14; participants = 32; very low-quality evidence; long-term mortality: no data available); epinephrine versus norepinephrine-dobutamine (short-term mortality: RR 1.25; 95% CI 0.41 to 3.77; participants = 30; very low-quality evidence; long-term mortality: no data available); dopexamine versus dopamine (short-term mortality: no deaths in either intervention arm; participants = 70; very low-quality evidence; long-term mortality: no data available); enoximone versus dobutamine (short-term mortality RR 0.21; 95% CI 0.01 to 4.11; participants = 27; very low-quality evidence; long-term mortality: no data available); epinephrine versus norepinephrine (short-term mortality: RR 1.81, 0.89 to 3.68; participants = 57; very low-quality evidence; long-term mortality: no data available); and dopamine-milrinone versus dopamine-dobutamine (short-term mortality: RR 1.0, 95% CI 0.34 to 2.93; participants = 20; very low-quality evidence; long-term mortality: no data available). No information regarding all-cause mortality were available for the comparisons milrinone versus dobutamine, enoximone versus piroximone and enoximone versus epinephrine-nitroglycerine.

AUTHORS' CONCLUSIONS

At present, there are no convincing data supporting any specific inotropic or vasodilating therapy to reduce mortality in haemodynamically unstable patients with CS or LCOS. Considering the limited evidence derived from the present data due to a high risk of bias and imprecision, it should be emphasised that there is an unmet need for large-scale, well-designed randomised trials on this topic to close the gap between daily practice in critical care of cardiovascular patients and the available evidence. In light of the uncertainties in the field, partially due to the underlying methodological flaws in existing studies, future RCTs should be carefully designed to potentially overcome given limitations and ultimately define the role of inotropic agents and vasodilator strategies in CS and LCOS.

Ventilation Techniques and Risk for Transmission of Coronavirus Disease, Including COVID-19: A Living Systematic Review of Multiple Streams of Evidence

BACKGROUND

Mechanical ventilation is used to treat respiratory failure in coronavirus disease 2019 (COVID-19).

PURPOSE

To review multiple streams of evidence regarding the benefits and harms of ventilation techniques for coronavirus infections, including that causing COVID-19.

DATA SOURCES

21 standard, World Health Organization-specific and COVID-19-specific databases, without language restrictions, until 1 May 2020.

STUDY SELECTION

Studies of any design and language comparing different oxygenation approaches in patients with coronavirus infections, including severe acute respiratory syndrome (SARS) or Middle East respiratory syndrome (MERS), or with hypoxemic respiratory failure. Animal, mechanistic, laboratory, and preclinical evidence was gathered regarding aerosol dispersion of coronavirus. Studies evaluating risk for virus transmission to health care workers from aerosol-generating procedures (AGPs) were included.

DATA EXTRACTION

Independent and duplicate screening, data abstraction, and risk-of-bias assessment (GRADE for certainty of evidence and AMSTAR 2 for included systematic reviews).

DATA SYNTHESIS

123 studies were eligible (45 on COVID-19, 70 on SARS, 8 on MERS), but only 5 studies (1 on COVID-19, 3 on SARS, 1 on MERS) adjusted for important confounders. A study in hospitalized patients with COVID-19 reported slightly higher mortality with noninvasive ventilation (NIV) than with invasive mechanical ventilation (IMV), but 2 opposing studies, 1 in patients with MERS and 1 in patients with SARS, suggest a reduction in mortality with NIV (very-low-certainty evidence). Two studies in patients with SARS report a reduction in mortality with NIV compared with no mechanical ventilation (low-certainty evidence). Two systematic reviews suggest a large reduction in mortality with NIV compared with conventional oxygen therapy. Other included studies suggest increased odds of transmission from AGPs.

LIMITATION

Direct studies in COVID-19 are limited and poorly reported.

CONCLUSION

Indirect and low-certainty evidence suggests that use of NIV, similar to IMV, probably reduces mortality but may increase the risk for transmission of COVID-19 to health care workers.

PRIMARY FUNDING SOURCE

World Health Organization. (PROSPERO: CRD42020178187).

Physical distancing, face masks, and eye protection to prevent person-to-person transmission of SARS-CoV-2 and COVID-19: a systematic review and meta-analysis

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes COVID-19 and is spread person-to-person through close contact. We aimed to investigate the effects of physical distance, face masks, and eye protection on virus transmission in health-care and non-health-care (eg, community) settings.

METHODS

We did a systematic review and meta-analysis to investigate the optimum distance for avoiding person-to-person virus transmission and to assess the use of face masks and eye protection to prevent transmission of viruses. We obtained data for SARS-CoV-2 and the betacoronaviruses that cause severe acute respiratory syndrome, and Middle East respiratory syndrome from 21 standard WHO-specific and COVID-19-specific sources. We searched these data sources from database inception to May 3, 2020, with no restriction by language, for comparative studies and for contextual factors of acceptability, feasibility, resource use, and equity. We screened records, extracted data, and assessed risk of bias in duplicate. We did frequentist and Bayesian meta-analyses and random-effects meta-regressions. We rated the certainty of evidence according to Cochrane methods and the GRADE approach. This study is registered with PROSPERO, CRD42020177047.

FINDINGS

Our search identified 172 observational studies across 16 countries and six continents, with no randomised controlled trials and 44 relevant comparative studies in health-care and non-health-care settings (n=25 697 patients). Transmission of viruses was lower with physical distancing of 1 m or more, compared with a distance of less than 1 m (n=10 736, pooled adjusted odds ratio [aOR] 0·18, 95% CI 0·09 to 0·38; risk difference [RD] -10·2%, 95% CI -11·5 to -7·5; moderate certainty); protection was increased as distance was lengthened (change in relative risk [RR] 2·02 per m; pinteraction=0·041; moderate certainty). Face mask use could result in a large reduction in risk of infection (n=2647; aOR 0·15, 95% CI 0·07 to 0·34, RD -14·3%, -15·9 to -10·7; low certainty), with stronger associations with N95 or similar respirators compared with disposable surgical masks or similar (eg, reusable 12-16-layer cotton masks; pinteraction=0·090; posterior probability >95%, low certainty). Eye protection also was associated with less infection (n=3713; aOR 0·22, 95% CI 0·12 to 0·39, RD -10·6%, 95% CI -12·5 to -7·7; low certainty). Unadjusted studies and subgroup and sensitivity analyses showed similar findings.

INTERPRETATION

The findings of this systematic review and meta-analysis support physical distancing of 1 m or more and provide quantitative estimates for models and contact tracing to inform policy. Optimum use of face masks, respirators, and eye protection in public and health-care settings should be informed by these findings and contextual factors. Robust randomised trials are needed to better inform the evidence for these interventions, but this systematic appraisal of currently best available evidence might inform interim guidance.

FUNDING

World Health Organization.

Development and use of health outcome descriptors: a guideline development case study

BACKGROUND

During healthcare guideline development, panel members often have implicit, different definitions of health outcomes that can lead to misunderstandings about how important these outcomes are and how to balance benefits and harms. McMaster GRADE Centre researchers developed 'health outcome descriptors' for standardizing descriptions of health outcomes and overcoming these problems to support the European Commission Initiative on Breast Cancer (ECIBC) Guideline Development Group (GDG). We aimed to determine which aspects of the development, content, and use of health outcome descriptors were valuable to guideline developers.

METHODS

We developed 24 health outcome descriptors related to breast cancer screening and diagnosis for the European Commission Breast Guideline Development Group (GDG). Eighteen GDG members provided feedback in written format or in interviews. We then evaluated the process and conducted two health utility rating surveys.

RESULTS

Feedback from GDG members revealed that health outcome descriptors are probably useful for developing recommendations and improving transparency of guideline methods. Time commitment, methodology training, and need for multidisciplinary expertise throughout development were considered important determinants of the process. Comparison of the two health utility surveys showed a decrease in standard deviation in the second survey across 21 (88%) of the outcomes.

CONCLUSIONS

Health outcome descriptors are feasible and should be developed prior to the outcome prioritization step in the guideline development process. Guideline developers should involve a subgroup of multidisciplinary experts in all stages of development and ensure all guideline panel members are trained in guideline methodology that includes understanding the importance of defining and understanding the outcomes of interest.

GRADE guidelines 27: how to calculate absolute effects for time-to-event outcomes in summary of findings tables and Evidence Profiles

OBJECTIVES

To provide GRADE guidance on how to prepare Summary of Findings tables and Evidence Profiles for time-to-event outcomes with a focus on the calculation of the corresponding absolute effect estimates.

STUDY DESIGN AND SETTING

This guidance was justified by a research project identifying frequent errors and limitations in the presentation of time-to-event outcomes in the Summary of Findings tables. We developed this guidance through an iterative process that included membership consultation, feedback, presentation, and discussion at meetings of the GRADE Working Group.

RESULTS

Review authors need to carefully consider the definition of the outcome of interest; although often the event is used as label for the outcome of interest (e.g., death or mortality), the event-free survival (e.g., overall survival) is reported throughout individual studies. Review authors should calculate the absolute effect correctly, either for the event or absence of the event. We also provide examples on how to calculate the absolute effects for events and the absence of events for various baseline or control group risks and time points.

CONCLUSIONS

This article aids in the development of Summary of Findings tables and Evidence Profiles, including time-to-event outcomes, and addresses the most common scenarios when calculating absolute effects in order to provide an accurate interpretation.

Evidence Collection and Evaluation for the Development of Dietary Guidelines and Public Policy on Nutrition

Dietary guidelines and recommendations, usually developed by government bodies or large authoritative organizations, have major downstream effects on public policy. A growing body of evidence supports the notion that there are serious deficiencies in the methods used to develop dietary guidelines. Such deficiencies include the failure to access or conduct comprehensive systematic reviews, a lack of systematic or rigorous evaluation of the quality of the evidence, a failure to acknowledge the limitations of the evidence base underlying recommendations, and insufficiently stringent management of conflicts of interest. These issues may be addressed by adhering to international standards for guideline development, including adopting systematic review methodology and using rigorous systems to evaluate the certainty of the evidence and to move from evidence to recommendations, of which the GRADE approach (Grading of Recommendations Assessment,Development and Evaluation) is the most rigorous and fully developed. Improving the methods by which dietary guidelines are produced has considerable potential to substantially improve public policy decision-making.

[GRADE: Using evidence to decision frameworks for adoption, adaptation and de novo generation of trustworthy guideline recommendations - GRADE-ADOLOPMENT]

BACKGROUND

Guideline developers can: (1) adopt existing recommendations from others; (2) adapt existing recommendations to their own context; or (3) create recommendations de novo. Monetary and nonmonetary resources, credibility, maximization of uptake, as well as logical arguments should guide the choice of the approach and processes.

OBJECTIVES

To describe a potentially efficient model for guideline production based on adoption, adaptation, and/or de novo development of recommendations utilizing the Grading of Recommendations Assessment, Development and Evaluation (GRADE) Evidence to Decision (EtD) frameworks.

STUDY DESIGN AND SETTING

We applied the model in a new national guideline program producing 22 practice guidelines. We searched for relevant evidence that informs the direction and strength of a recommendation. We then produced GRADE EtDs for guideline panels to develop recommendations.

RESULTS

In two waves, a total of 80 EtD frameworks was produced approximately 4 months and 146 EtDs in about 6 months. Use of the EtD frameworks allowed panel members to understand judgments of other guideline groups about the criteria that bear on guideline recommendations and then make their own judgments about those criteria in a systematic approach.

CONCLUSION

The "GRADE-ADOLOPMENT" approach to guideline production combines adoption, adaptation, and, as needed, de novo development of recommendations. If guideline developers apply EtD criteria more widely and make their work publically available, this approach should prove even more useful.

Supplemental perioperative intravenous crystalloids for postoperative nausea and vomiting

BACKGROUND

Postoperative nausea and vomiting (PONV) is a common complication following general anaesthesia. It may be associated with patient dissatisfaction, increased costs of treatment, and unintended admission to hospital.Supplemental intravenous crystalloid administration in the perioperative period may be a simple intervention to prevent PONV.

OBJECTIVES

To assess whether supplemental intravenous crystalloid administration prevents PONV in patients undergoing surgical procedures under general anaesthesia.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 7), MEDLINE (1946 to August 2018), Embase (1947 to August 2018), and the Cumulative Index of Nursing and Allied Health Literature (CINAHL; 1971 to August 2018). We searched clinical trials registers for ongoing or unpublished completed studies (August 2018), handsearched three major journals (British Journal of Anaesthesia, European Journal of Anaesthesiology, and Anesthesiology; August 2018), and conducted backward and forward citation searching of relevant articles.

SELECTION CRITERIA

We included randomized controlled trials of participants older than six months undergoing surgical procedures under general anaesthesia and given supplemental perioperative intravenous crystalloids, defined as a volume larger than that received by a comparator group, to prevent PONV.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures described by Cochrane.

MAIN RESULTS

We included 41 studies (4224 participants). Participants underwent ambulatory or short length of stay surgical procedures, and were predominantly American Society of Anesthesiology (ASA) class I or II. There is one study awaiting classification and three ongoing studies. All studies took place in surgical centres, and were conducted in geographically diverse settings. Risk of bias was generally unclear across all domains.Supplemental intravenous crystalloid administration probably reduces the cumulative risk of postoperative nausea (PON) (risk ratio (RR) 0.62, 95% confidence interval (CI) 0.51 to 0.75; 18 studies; 1766 participants; moderate-certainty evidence). When the postoperative period was divided into early (first six hours postoperatively) and late (at the time point closest to or including 24 hours postoperatively) time points, the intervention reduced the risk of early PON (RR 0.67, 95% CI 0.58 to 0.78; 20 studies; 2310 participants; moderate-certainty evidence) and late PON (RR 0.47, 95% CI 0.32 to 0.69; 17 studies; 1682 participants; moderate-certainty evidence).Supplemental intravenous crystalloid administration probably reduces the risk of postoperative vomiting (POV) (RR 0.50, 95% CI 0.40 to 0.63; 20 studies; 1970 participants; moderate-certainty evidence). The intervention specifically reduced both early POV (RR 0.56, 95% CI 0.41 to 0.76; 19 studies; 1998 participants; moderate-certainty evidence) and late POV (RR 0.48, 95% CI 0.29 to 0.79; 15 studies; 1403 participants; moderate-certainty evidence).Supplemental intravenous crystalloid administration probably reduces the need for pharmacologic treatment of PONV (RR 0.62, 95% CI 0.51 to 0.76; 23 studies; 2416 participants; moderate-certainty evidence).The effect of supplemental intravenous crystalloid administration on the risk of unplanned postoperative admission to hospital is unclear (RR 1.05, 95% CI 0.77 to 1.43; 3 studies; 235 participants; low-certainty evidence).No studies reported serious adverse events that may occur following supplemental perioperative intravenous crystalloid administration (i.e. admission to high-dependency unit, postoperative cardiac or respiratory complication, or death).

AUTHORS' CONCLUSIONS

There is moderate-certainty evidence that supplemental perioperative intravenous crystalloid administration reduces PON and POV, in ASA class I to II patients receiving general anaesthesia for ambulatory or short length of stay surgical procedures. The intervention probably also reduces the risk of pharmacologic treatment for PONV. The effect of the intervention on the risk of unintended postoperative admission to hospital is unclear. The risk of serious adverse events resulting from supplemental perioperative intravenous crystalloid administration is unknown as no studies reported this outcome. The one study awaiting classification may alter the conclusions of the review once assessed.