scholarly journals 1483A meta-analysis of the serial interval and generation time of COVID-19 transmission

2021 ◽  
Vol 50 (Supplement_1) ◽  
Author(s):  
Sanjay Rampal ◽  
Vivek Jason Jayaraj ◽  
Diane Woei Quan Chong ◽  
Chiu-Wan Ng
Keyword(s):  
Generation Time ◽  
Data Extraction ◽  
Meta Analysis ◽  
Model Misspecification ◽  
Geographical Region ◽  
Time Intervals ◽  
Interval Estimates ◽  
Generation Times ◽  
Serial Interval ◽  
Transmission Models

Abstract Background Variation of the estimated serial interval and generation time introduces heterogeneity in COVID-19 transmission models. We conducted a systematic review and meta-analysis to estimate more precise serial intervals and generation times of COVID-19. Methods A literature search was conducted using the WHO Global COVID-19 Literature database from 1 January 2020 to 30 April 2021. A single reviewer performed the data extraction. A random-effects model was used to pool the estimates. Subgroup analysis was performed to check the estimates for heterogeneity by geographical region and the presence of lockdown measures. Results A total of 222 articles were retrieved of which 73 articles were included based on the selection criteria. Serial intervals were reported in 65 articles that provided 75 unique estimates from 16,805 transmission pairs. Generation intervals were reported in 9 articles that provided 9 unique estimates from 1,150 transmission pairs. The pooled serial interval was 5.00 days (95% CI: 4.68, 5.33). The pooled generation time was 4.37 days (95% CI: 3.58, 5.16). The serial interval estimates did not vary by either geographical region (P > 0.05) or the presence of lockdown measures (P > 0.05). Conclusions This analysis provides more precise pooled serial and generation intervals that may decrease misspecifications of future transmission models. Key messages Epidemiological parameters are crucial components in estimating the dynamics of COVID-19 transmission. Periodically updating serial and generation time intervals are important to reduce model misspecification for a new disease such as COVID-19.

scholarly journals On the relationship between serial interval, infectiousness profile and generation time

2021 ◽  
Vol 18 (174) ◽  
pp. 20200756
Author(s):  
Sonja Lehtinen ◽  
Peter Ashcroft ◽  
Sebastian Bonhoeffer
Keyword(s):  
Symptom Onset ◽  
Generation Time ◽  
Time Distribution ◽  
Contact Tracing ◽  
Time Interval ◽  
Single Individual ◽  
Generation Times ◽  
Serial Interval ◽  
The Impact ◽  
The Relationship

The timing of transmission plays a key role in the dynamics and controllability of an epidemic. However, observing generation times—the time interval between the infection of an infector and an infectee in a transmission pair—requires data on infection times, which are generally unknown. The timing of symptom onset is more easily observed; generation times are therefore often estimated based on serial intervals—the time interval between symptom onset of an infector and an infectee. This estimation follows one of two approaches: (i) approximating the generation time distribution by the serial interval distribution or (ii) deriving the generation time distribution from the serial interval and incubation period—the time interval between infection and symptom onset in a single individual—distributions. These two approaches make different—and not always explicitly stated—assumptions about the relationship between infectiousness and symptoms, resulting in different generation time distributions with the same mean but unequal variances. Here, we clarify the assumptions that each approach makes and show that neither set of assumptions is plausible for most pathogens. However, the variances of the generation time distribution derived under each assumption can reasonably be considered as upper (approximation with serial interval) and lower (derivation from serial interval) bounds. Thus, we suggest a pragmatic solution is to use both approaches and treat these as edge cases in downstream analysis. We discuss the impact of the variance of the generation time distribution on the controllability of an epidemic through strategies based on contact tracing, and we show that underestimating this variance is likely to overestimate controllability.

scholarly journals Presymptomatic transmission of SARS-CoV-2 infection: a secondary analysis using published data

BMJ Open ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. e041240
Author(s):  
Miriam Casey-Bryars ◽  
John Griffin ◽  
Conor McAloon ◽  
Andrew Byrne ◽  
Jamie Madden ◽  
...  
Keyword(s):  
Incubation Period ◽  
Symptom Onset ◽  
Generation Time ◽  
Meta Analysis ◽  
Secondary Analysis ◽  
Transmission Time ◽  
Contact Tracing ◽  
Rapid Review ◽  
Published Data ◽  
Serial Interval

ObjectiveTo estimate the proportion of presymptomatic transmission of SARS-CoV-2 infection that can occur, and the timing of transmission relative to symptom onset.Setting/designSecondary analysis of international published data.Data sourcesMeta-analysis of COVID-19 incubation period and a rapid review of serial interval and generation time, which are published separately.ParticipantsData from China, the Islamic Republic of Iran, Italy, Republic of Korea, Singapore and Vietnam from December 2019 to May 2020.MethodsSimulations were generated of incubation period and of serial interval or generation time. From these, transmission times relative to symptom onset, and the proportion of presymptomatic transmission, were estimated.Outcome measuresTransmission time of SARS-CoV-2 relative to symptom onset and proportion of presymptomatic transmission.ResultsBased on 18 serial interval/generation time estimates from 15 papers, mean transmission time relative to symptom onset ranged from −2.6 (95% CI −3.0 to –2.1) days before infector symptom onset to 1.4 (95% CI 1.0 to 1.8) days after symptom onset. The proportion of presymptomatic transmission ranged from 45.9% (95% CI 42.9% to 49.0%) to 69.1% (95% CI 66.2% to 71.9%).ConclusionsThere is substantial potential for presymptomatic transmission of SARS-CoV-2 across a range of different contexts. This highlights the need for rapid case detection, contact tracing and quarantine. The transmission patterns that we report reflect the combination of biological infectiousness and transmission opportunities which vary according to context.

A Systematic Review and Meta-Analysis about the Effect of Bisphosphonates on the Risk of Skeletal-Related Event in Men with Prostate Cancer

2020 ◽  
Vol 20 (13) ◽  
pp. 1604-1612
Author(s):  
Congcong Wu ◽  
Hua Jiang ◽  
Jianghua Chen
Keyword(s):  
Prostate Cancer ◽  
Fixed Effects ◽  
Data Extraction ◽  
Controlled Trial ◽  
Meta Analysis ◽  
Control Group ◽  
Fixed Effects Model ◽  
Related Event ◽  
Mineral Density ◽  
Skeletal Related Event

Background: Although the adjuvant therapy of bisphosphonates in prostate cancer is effective in improving bone mineral density, it is still uncertain whether bisphosphonates could decrease the risk of Skeletal- Related Event (SRE) in patients with prostate cancer. We reviewed and analyzed the effect of different types of bisphosphonates on the risk of SRE, defined as pathological fracture, spinal cord compression, radiation therapy to the bone, surgery to bone, hypercalcemia, bone pain, or death as a result of prostate cancer. Methods: A systemic literature search was conducted on PubMed and related bibliographies. The emphasis during data extraction was laid on the Hazard Ratio (HR) and the corresponding 95% Confidence Interval (CI) from every eligible Randomized Controlled Trial (RCT). HR was pooled with the fixed effects model, and preplanned subgroup analyses were performed. Results: 5 RCTs (n = 4651) were included and analyzed finally after screening 51 articles. The meta-analysis of all participants showed no significant decrease in the risk of SRE when adding bisphosphonates to control group (HR = 0.968, 95% CI = 0.874 - 1.072, p = 0.536) with low heterogeneity (I2 = 0.0% (d.f. = 4) p = 0.679). There was no significant improvement on SRE neither in the subgroups with Metastases (M1) or Castration-Sensitive Prostate Cancer (CSPC) (respectively HR = 0.968, 95% CI = 0.874 - 1.072, p = 0.536, I2 = 0.0% (d.f. = 4) p = 0.679; HR = 0.954, 95% CI = 0.837 - 1.088, p = 0.484, I2 = 0.0% (d.f. = 3) p = 0.534). Conclusion: Our study demonstrated that bisphosphonates could not statistically significantly reduce the risk of SRE in patients with prostate cancer, neither in the subgroups with M1 or CSPC.

scholarly journals Misuse of medication in adult substance misuse services: a systematic review protocol

BMJ Open ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. e047283
Author(s):  
Rosalind Gittins ◽  
Louise Missen ◽  
Ian Maidment
Keyword(s):  
Systematic Review ◽  
Substance Misuse ◽  
Data Extraction ◽  
Meta Analysis ◽  
Grey Literature ◽  
Opioid Analgesics ◽  
Physical And Mental Health ◽  
Qualitative Synthesis ◽  
Treatment Services ◽  
The Impact

IntroductionThere is a growing concern about the misuse of over the counter (OTC) and prescription only medication (POM) because of the impact on physical and mental health, drug interactions, overdoses and drug-related deaths. These medicines include opioid analgesics, anxiolytics such as pregabalin and diazepam and antidepressants. This protocol outlines how a systematic review will be undertaken (during June 2021), which aims to examine the literature on the pattern of OTC and POM misuse among adults who are accessing substance misuse treatment services. It will include the types of medication being taken, prevalence and demographic characteristics of people who access treatment services.Methods and analysisAn electronic search will be conducted on the Cochrane, OVID Medline, Pubmed, Scopus and Web of Science databases as well as grey literature. Two independent reviewers will conduct the initial title and abstract screenings, using predetermined criteria for inclusion and exclusion. If selected for inclusion, full-text data extraction will be conducted using a pilot-tested data extraction form. A third reviewer will resolve disagreements if consensus cannot be reached. Quality and risk of bias assessment will be conducted for all included studies. A qualitative synthesis and summary of the data will be provided. If possible, a meta-analysis with heterogeneity calculation will be conducted; otherwise, Synthesis Without Meta-analysis will be undertaken for quantitative data. The reporting of this protocol follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses.Ethics and disseminationEthical approval is not required. Findings will be peer reviewed, published and shared verbally, electronically and in print, with interested clinicians and policymakers.PROSPERO registration numberCRD42020135216.

scholarly journals A246 THE GLOBAL INCIDENCE OF ACUTE PANCREATITIS IS INCREASING OVER TIME: A SYSTEMATIC REVIEW AND META-ANALYSIS

2021 ◽  
Vol 4 (Supplement_1) ◽  
pp. 304-306
Author(s):  
J Iannuzzi ◽  
J H Leong ◽  
J Quan ◽  
J A King ◽  
J W Windsor ◽  
...  
Keyword(s):  
Acute Pancreatitis ◽  
Data Extraction ◽  
Meta Analysis ◽  
Temporal Trends ◽  
Western World ◽  
Common Disease ◽  
Biliary Disease ◽  
Comprehensive Overview ◽  
Annual Percent Change ◽  
Over Time

Abstract Background Acute pancreatitis is a common disease with significant associated morbidity and mortality. Historically, acute pancreatitis has been considered a disease with multiple etiologies and risk factors but is driven by alcohol and biliary disease. Multiple studies have shown that the incidence of acute pancreatitis is increasing globally among both adults and children. Aims The purpose of this study was to assess temporal trends in incidence of acute pancreatitis globally. Methods We performed a systematic literature search to identify population-based studies reporting the annual incidence of acute pancreatitis. Abstracts were independently assessed in duplicate to identify applicable papers for full-text review and data extraction. Joinpoint temporal trend analyses were performed to calculate the average annual percent change (AAPC) with 95% confidence intervals (CI). The AAPCs were pooled in a meta-analysis to capture the overall and regional trends in acute pancreatitis incidence over time. Temporal data were summarized in a static map and an interactive, web-based map to illustrate global differences. Results Forty-five studies reported the temporal incidence of acute pancreatitis (static map provided, online interactive map: https://kaplan-acute-pancreatitis-ucalgary.hub.arcgis.com/). The incidence of acute pancreatitis has increased from 1961 to 2016 (AAPC = 2.89%; 95% CI: 2.26, 3.52; n=41). Increasing incidence was observed in North America (AAPC = 2.71%; 95% CI: 1.93, 3.50; n=10) and Europe (AAPC = 2.79%; 95% CI: 1.95, 3.63; n=24). The incidence of acute pancreatitis was stable in Asia (AAPC = −0.28%; 95% CI: −5.03, 4.47; n=2). Conclusions This meta-analysis provides a comprehensive overview of the global incidence of acute pancreatitis over the last five decades and demonstrates a steadily rising incidence over time in most countries of the Western world. More studies are needed to better define the changing incidence of acute pancreatitis in Asia, Africa and Latin America. Funding Agencies None

scholarly journals Prevalence of retinopathy in prediabetes: protocol for a systematic review and meta-analysis

BMJ Open ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. e040997
Author(s):  
Varo Kirthi ◽  
Paul Nderitu ◽  
Uazman Alam ◽  
Jennifer Evans ◽  
Sarah Nevitt ◽  
...  
Keyword(s):  
Systematic Review ◽  
Diabetic Retinopathy ◽  
Data Extraction ◽  
Meta Analysis ◽  
International Diabetes Federation ◽  
Current Data ◽  
Risk Of Bias ◽  
Fundus Photography ◽  
Primary Data ◽  
Cochrane Library

IntroductionThere is growing evidence of a higher than expected prevalence of retinopathy in prediabetes. This paper presents the protocol of a systematic review and meta-analysis of retinopathy in prediabetes. The aim of the review is to estimate the prevalence of retinopathy in prediabetes and to summarise the current data.Methods and analysisThis protocol is developed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA-P) guidelines. A comprehensive electronic bibliographic search will be conducted in MEDLINE, EMBASE, Web of Science, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Google Scholar and the Cochrane Library. Eligible studies will report prevalence data for retinopathy on fundus photography in adults with prediabetes. No time restrictions will be placed on the date of publication. Screening for eligible studies and data extraction will be conducted by two reviewers independently, using predefined inclusion criteria and prepiloted data extraction forms. Disagreements between the reviewers will be resolved by discussion, and if required, a third (senior) reviewer will arbitrate.The primary outcome is the prevalence of any standard features of diabetic retinopathy (DR) on fundus photography, as per International Clinical Diabetic Retinopathy Severity Scale (ICDRSS) classification. Secondary outcomes are the prevalence of (1) any retinal microvascular abnormalities on fundus photography that are not standard features of DR as per ICDRSS classification and (2) any macular microvascular abnormalities on fundus photography, including but not limited to the presence of macular exudates, microaneurysms and haemorrhages. Risk of bias for included studies will be assessed using a validated risk of bias tool for prevalence studies. Pooled estimates for the prespecified outcomes of interest will be calculated using random effects meta-analytic techniques. Heterogeneity will be assessed using the I2 statistic.Ethics and disseminationEthical approval is not required as this is a protocol for a systematic review and no primary data are to be collected. Findings will be disseminated through peer-reviewed publications and presentations at national and international meetings including Diabetes UK, European Association for the Study of Diabetes, American Diabetes Association and International Diabetes Federation conferences.PROSPERO registration numberCRD42020184820.

scholarly journals Effectiveness of Antalgic Therapies in Patients with Vertebral Bone Metastasis: A Protocol for a Systematic Review and Meta-Analysis

2021 ◽  
Vol 18 (8) ◽  
pp. 3991
Author(s):  
Antonio Jose Martin-Perez ◽  
María Fernández-González ◽  
Paula Postigo-Martin ◽  
Marc Sampedro Pilegaard ◽  
Carolina Fernández-Lao ◽  
...  
Keyword(s):  
Systematic Review ◽  
Bone Metastasis ◽  
Data Extraction ◽  
Meta Analysis ◽  
Risk Of Bias ◽  
Cochrane Library ◽  
Pharmacological Intervention ◽  
Vertebral Metastasis ◽  
Randomized Controlled Clinical Trials

There is no systematic review that has identified existing studies evaluating the pharmacological and non-pharmacological intervention for pain management in patients with bone metastasis. To fill this gap in the literature, this systematic review with meta-analysis aims to evaluate the effectiveness of different antalgic therapies (pharmacological and non-pharmacological) in the improvement of pain of these patients. To this end, this protocol has been written according to the Preferred Reporting Items for Systematic review and Meta-Analysis Protocols (PRISMA-P) and registered in PROSPERO (CRD42020135762). A systematic search will be carried out in four international databases: Medline (Via PubMed), Web of Science, Cochrane Library and SCOPUS, to select the randomized controlled clinical trials. The Risk of Bias Tool developed by Cochrane will be used to assess the risk of bias and the quality of the identified studies. A narrative synthesis will be used to describe and compare the studies, and after the data extraction, random effects model and a subgroup analyses will be performed according to the type of intervention, if possible. This protocol aims to generate a systematic review that compiles and synthesizes the best and most recent evidence on the treatment of pain derived from vertebral metastasis.

scholarly journals Effectiveness of trauma care systems at different stages of development in reducing mortality: a systematic review and meta-analysis protocol

BMJ Open ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. e047439
Author(s):  
Rayan Jafnan Alharbi ◽  
Virginia Lewis ◽  
Sumina Shrestha ◽  
Charne Miller
Keyword(s):  
Systematic Review ◽  
Trauma Care ◽  
Data Extraction ◽  
Meta Analysis ◽  
Trauma System ◽  
Secondary Data ◽  
Trauma Centre ◽  
Trauma Patients ◽  
Trauma Systems ◽  
Stages Of Development

IntroductionThe introduction of trauma systems that began in the 1970s resulted in improved trauma care and a decreased rate of morbidity and mortality of trauma patients. Worldwide, little is known about the effectiveness of trauma care system at different stages of development, from establishing a trauma centre, to implementing a trauma system and as trauma systems mature. The objective of this study is to extract and analyse data from research that evaluates mortality rates according to different stages of trauma system development globally.Methods and analysisThe proposed review will comply with the checklist of the ‘Preferred reporting items for systematic review and meta-analysis’. In this review, only peer-reviewed articles written in English, human-related studies and published between January 2000 and December 2020 will be included. Articles will be retrieved from MEDLINE, EMBASE and CINAHL. Additional articles will be identified from other sources such as references of included articles and author lists. Two independent authors will assess the eligibility of studies as well as critically appraise and assess the methodological quality of all included studies using the Cochrane Risk of Bias for Non-randomised Studies of Interventions tool. Two independent authors will extract the data to minimise errors and bias during the process of data extraction using an extraction tool developed by the authors. For analysis calculation, effect sizes will be expressed as risk ratios or ORs for dichotomous data or weighted (or standardised) mean differences and 95% CIs for continuous data in this systematic review.Ethics and disseminationThis systematic review will use secondary data only, therefore, research ethics approval is not required. The results from this study will be submitted to a peer-review journal for publication and we will present our findings at national and international conferences.PROSPERO registration numberCRD42019142842.

scholarly journals Epidemiology of hepatitis E virus infection in animals in Africa: a systematic review and meta-analysis

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Abdou Fatawou Modiyinji ◽  
Jean Joel Bigna ◽  
Sebastien Kenmoe ◽  
Fredy Brice N. Simo ◽  
Marie A. Amougou ◽  
...  
Keyword(s):  
Systematic Review ◽  
Hepatitis E Virus ◽  
Data Extraction ◽  
Meta Analysis ◽  
Hepatitis E ◽  
Epidemiological Studies ◽  
Cross Sectional ◽  
Resource Limited ◽  
Study Selection ◽  
Language Restriction

Abstract Background Hepatitis E virus (HEV) is a major cause of acute hepatitis in humans worldwide and have high burden in the resource-limited countries. Better knowledge of the epidemiology of hepatitis in animals in Africa can help to understand the epidemiology among humans. The objective of this study was to summarize the prevalence of HEV infection and distribution of HEV genotypes among animals in Africa. Methods In this systematic review and meta-analysis, we comprehensively searched PubMed, EMBASE, African Journals Online, and Africa Index Medicus from January 1st, 2000 to March 22th, 2020 without any language restriction. We considered cross-sectional studies of HEV infection in animals in Africa. Study selection, data extraction, and methodological quality of included studies were done independently by two investigators. Prevalence data were pooled using the random-effects meta-analysis. This review was registered in PROSPERO, CRD42018087684. Results Twenty-five studies (13 species and 6983 animals) were included. The prevalence (antibodies or ribonucleic acid [RNA]) of HEV infection in animals varied widely depending on biological markers of HEV infection measured: 23.4% (95% confidence interval; 12.0–37.2) for anti-HEV immunoglobulins G, 13.1% (3.1–28.3) for anti-HEV immunoglobulins M, and 1.8% (0.2–4.3) for RNA; with substantial heterogeneity. In subgroup analysis, the immunoglobulins G seroprevalence was higher among pigs 37.8% (13.9–65.4). The following HEV genotypes were reported in animals: Rat-HEV genotype 1 (rats and horses), HEV-3 (pigs), HEV-7 (dromedaries), and Bat hepeviruses (bats). Conclusions We found a high prevalence of HEV infection in animals in Africa and HEV genotypes close to that of humans. Some animals in Africa could be the reservoir of HEV, highlighting the need of molecular epidemiological studies for investigating zoonotic transmission.

scholarly journals Overweight and Obesity Among Adult HIV Infected Peoples Receiving ART in Ethiopia: A Systematic Review and Meta-Analysis

2021 ◽  
Vol 12 ◽  
pp. 215013272199364
Author(s):  
Robel Hussen Kabthymer ◽  
Solomon Nega Techane ◽  
Temesgen Muche ◽  
Helen Ali Ewune ◽  
Semagn Mekonnen Abate ◽  
...  
Keyword(s):  
Publication Bias ◽  
Addis Ababa ◽  
Data Extraction ◽  
Meta Analysis ◽  
Overweight And Obesity ◽  
Obesity And Overweight ◽  
Pooled Prevalence ◽  
Nutrition And Diet ◽  
Prevalence Of Obesity ◽  
Trim And Fill

Background: Over-nutrition and diet-linked non-communicable morbidities are showing increasing trend overtime. Even if there are different factors that affect the change in BMI other than ART, several authors have reported increases in BMI among PLHIV on treatment that are equal to or surpass the general population. This study is aimed to estimate the prevalence of obesity and overweight among adult HIV infected peoples taking ART in Ethiopia. Method: PubMed, CINAHL, Web of science, global health and Google scholar electronic databases were used to perform a systematic literature search. Two authors independently extracted all the necessary data using a structured data extraction format. Data analysis was done using STATA Version 14. The heterogeneity of the studies was assessed by using I2 test. A random-effects model was used to estimate the pooled prevalence. Publication bias was checked using Funnel plot and Egger’s test. Result: Two thousand seven hundred and fifty-one studies were reviewed and 13 studies fulfilling the inclusion criteria were included in the meta-analysis. The meta-analysis of 13 studies, comprising 4994 participants resulted in pooled prevalence of overweight to be 17.85% (95% CI: 12.22-23.47). Whereas, the pooled prevalence of overweight was found to be 3.90 (95% CI: 2.31-5.49) but after adjusting for publication bias using trim and fill analysis it has become 3.58 (95% CI: 2.04-5.13). Magnitude of both overweight and obesity was higher in studies conducted in Addis Ababa, studies done after 2016 and studies having sample size of less than 400, in subgroup analysis. Conclusion: The magnitude of overweight and obesity among HIV infected peoples taking ART in Ethiopia is high. There is a need to have a routine screening to PLWHA on the risk of over-nutrition in order to facilitate early detection.

Sign in / Sign up

Export Citation Format

Share Document