A systematic review of tools used to assess the quality of observational studies that examine incidence or prevalence and risk factors for diseases

The Methodological Quality of Observational Studies Examining the Risk of Pregnancy Drug Use on Congenital Malformations Needs Substantial Improvement: A Cross-Sectional Survey

BACKGROUND AND OBJECTIVE

An increasing number of observational studies have investigated the risk of using drugs during pregnancy on congenital malformations. However, the credibility of the causal relationships drawn from these studies remains uncertain. This study aims to evaluate the potential methodological issues in existing observational studies.

METHODS

We used a stepwise approach to investigate this issue. First, we identified observational studies published in 2020 that examined the risk of congenital malformations associated with medication use during pregnancy. We assessed the methodological characteristics for establishing causality, including study design, confounding control, and sensitivity analysis, and compared them between "core clinical journals" and "general journals." For studies reporting an increased risk of congenital malformations in core clinical journals, we searched for subsequent studies addressing the same research question published between January 2021 and May 2023 to assess the consistency of the literature.

RESULTS

A total of 40 eligible studies were published in 2020, primarily focused on the safety of vitamin B12 and folic acid (n = 4), antidepressants (n = 4), and others (n = 32). Our findings suggest that only two (5.00%) studies used causal models to guide the identification of confounding, and only eight (20.00%) studies assessed the potential dose-response relationship. In all, 15 (37.50%) studies used propensity score analysis strategy to achieve "mimic-randomization." In addition, 22 studies (55.00%) performed sensitivity analyses, while 10 (45.45%) showed inconsistency with the primary outcome. Furthermore, 5 studies reported positive outcomes, whereas only 1 out of 11 studies demonstrated a positive correlation between drug usage during pregnancy and major malformations in subsequent studies.

CONCLUSION

A significant portion of the studies has failed to sufficiently consider the essential methodological characteristics required to improve the credibility of causal inferences. The increased risk of congenital malformations documented in core clinical journal was not adequately replicated in subsequent studies.

Review of the Literature on the Current State of Periosteum-Mediated Craniofacial Bone Regeneration

Study Design

This is an article review on the current state of periosteum-mediated bone regeneration (PMBR). It is a known mandibular reconstruction option in children, and though poorly understood and unpredictable, the concerns of developmental changes to donor and recipient tissues shared by other treatment options are nonexistent. The definitive role of periosteum during bone regeneration remains largely unknown.

Objective

The objective is to review the literature on the clinical and molecular mechanism evidence of this event.

Methods

Our search methodology was modeled after the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) guidelines. Search strategies were categorized into search 1 for clinical evidence of mandibular regeneration and search 2 for gene expression review for craniofacial regeneration. The quality assessment of each publication was undertaken, and inclusion criteria comprise mandibular continuity defect for search 1 and use of gene expression assay propriety kit for search 2.

Results

33 studies were selected for search 1 while four studies with non-human subjects were selected for search 2. Monitoring of PMBR onset was advised at 2 weeks post-operative, and the gene expression results showed an upregulation of genes responsible for angiogenesis, cytokine activities, and immune-inflammatory response in week 1 and skeletal development and signaling pathways in week 2.

Conclusions

The results suggest that young periosteum has a higher probability of PMBR than adult periosteum, and skeletal morphogenesis regulated by skeletal developmental genes and pathways may characterize the gene expression patterns of PMBR.

A scoping review shows that no single existing risk of bias assessment tool considers all sources of bias for cross-sectional studies

OBJECTIVES

Different tools to assess the potential risk of bias (RoB) for cross-sectional studies have been developed, but it is unclear whether all pertinent bias concepts are addressed. We aimed to identify RoB concepts applicable to cross-sectional research validity and to explore coverage for each in existing appraisal tools.

STUDY DESIGN AND SETTING

This scoping review followed the Joanna Briggs Institute methodology. We included records of any study design describing or reporting methods, concepts or tools used to consider RoB in health research reported to be descriptive/prevalence survey or analytic/association (cross-sectional) study designs. Synthesis included quantitative and qualitative analysis.

RESULTS

Of the 4556 records screened, 90 were selected for inclusion; 67 (74%) described the development of, or validation process for, appraisal tools, 15 (17%) described methodological content or theory relevant to RoB for cross-sectional studies and 8 (9%) records of methodological systematic reviews. Review of methodological reports identified important RoB concepts for both descriptive/prevalence and analytic/association studies. Tools identified (n = 64 unique tools) were either intended to appraise quality or assess RoB in multiple study designs including cross-sectional studies (n = 21; 33%) or cross-sectional designs alone (n = 43; 67%). Several existing tools were modified (n = 17; 27%) for application to cross-sectional studies. The RoB items most frequently addressed in the RoB tools were validity and reliability of the exposure (53%) or outcome (65%) measurement and representativeness of the study population (59%). Most tools did not consider nonresponse or missingness appropriately or at all.

CONCLUSION

Assessing cross-sectional studies involve unique RoB considerations. We identified RoB tools designed for broad applicability across various study designs as well as those specifically tailored for cross-sectional studies. However, none of the identified tools comprehensively address all potential biases pertinent to cross-sectional studies. Our findings indicate a need for continued improvement of RoB tools and suggest that the development of context-specific or more precise tools for this study design may be necessary.

Estimating the Global and Regional Burden of Streptococcus pneumoniae Meningitis in Children: Protocol for a Systematic Review and Meta-Analysis

BACKGROUND

Streptococcus pneumoniae (Spn) has been a leading cause of bacterial meningitis in children. The most recent estimation of the global burden of Spn meningitis indicates a positive trajectory in eliminating Spn through the implementation of pneumococcal conjugate vaccines. However, continuous monitoring and assessment of the disease burden are necessary due to the evidence of serotype replacement, antibiotic resistance, and the impact of the recent COVID-19 pandemic.

OBJECTIVE

The aim of this systematic review is to provide an updated and focused assessment of the global and regional burden of Spn meningitis in children, which can guide policies and strategies to reduce the disease burden.

METHODS

Population-based studies published from January 1, 2000, to January 1, 2022, were preliminarily searched from the electronic databases PubMed, Embase, Global Health (CABI), and CINAHL Plus without any language restrictions. Studies were included if they reported the incidence, prevalence, mortality, or case-fatality ratio (CFR) for Spn meningitis in children aged 0-4 years; meningitis was confirmed by cerebrospinal fluid culture; the study period was a minimum of 1 year; the number of reported cases was at least 10; and the study had no methodological ambiguities. The article screening process follows the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines. Characteristics including study period, setting, World Health Organization region, income level, vaccination information, and participant data (age, number of cases, deaths, sequelae, and risk factors) will be extracted from the included studies. Search results will be updated and incorporated into our review prior to finalizing the extraction of data. Generalized linear mixed models meta-analysis will be performed to estimate the pooled incidence and CFR. We will further assess the risk of bias and heterogeneity, and will perform subgroup and sensitivity analyses to provide a meaningful interpretation of the current burden and literature for pneumococcal meningitis.

RESULTS

Our preliminary search in December 2021 yielded 9295 articles. Out of 275 studies that were assessed with our eligibility criteria, 117 articles were included. Data extraction and analysis are expected to be complete by January 2025. We plan to publish the results from the full study, including an updated search in 2024, by March 2025.

CONCLUSIONS

Given that the major burden of Spn meningitis affects children under the age of 5 years, this systematic review will provide a thorough understanding of the global burden of Spn meningitis in this vulnerable population over a span of 2 decades. Insights into incidence trends, geospatial distribution, risk factors, and sequelae will be valuable for stakeholders, policy makers, and the academic community. This information will aid in the ongoing monitoring of the disease and in enhancing targeted vaccine programs to further mitigate the impact of the disease on children worldwide.

TRIAL REGISTRATION

PROSPERO CRD42021293110; https://tinyurl.com/kc3j5k4m.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/50678.

Scientific Committee guidance on appraising and integrating evidence from epidemiological studies for use in EFSA's scientific assessments

EFSA requested its Scientific Committee to prepare a guidance document on appraising and integrating evidence from epidemiological studies for use in EFSA's scientific assessments. The guidance document provides an introduction to epidemiological studies and illustrates the typical biases, which may be present in different epidemiological study designs. It then describes key epidemiological concepts relevant for evidence appraisal. This includes brief explanations for measures of association, exposure assessment, statistical inference, systematic error and effect modification. The guidance then describes the concept of external validity and the principles of appraising epidemiological studies. The customisation of the study appraisal process is explained including tailoring of tools for assessing the risk of bias (RoB). Several examples of appraising experimental and observational studies using a RoB tool are annexed to the document to illustrate the application of the approach. The latter part of this guidance focuses on different steps of evidence integration, first within and then across different streams of evidence. With respect to risk characterisation, the guidance considers how evidence from human epidemiological studies can be used in dose-response modelling with several different options being presented. Finally, the guidance addresses the application of uncertainty factors in risk characterisation when using evidence from human epidemiological studies.

Quality Appraisal in Systematic Literature Reviews of Studies Eliciting Health State Utility Values: Conceptual Considerations

BACKGROUND

The increasing number of studies that generate health state utility values (HSUVs) and the impact of HSUVs on cost-utility analyses make a robust tailored quality appraisal (QA) tool for systematic reviews of these studies necessary.

OBJECTIVE

This study aimed to address conceptual issues regarding QA in systematic reviews of studies eliciting HSUVs by establishing a consensus on the definitions, dimensions and scope of a QA tool specific to this context.

METHODS

A modified Delphi method was used in this study. An international multidisciplinary panel of seven experts was purposively assembled. The experts engaged in two anonymous online survey rounds. After each round, the experts received structured and controlled feedback on the previous phase. Controlled feedback allowed the experts to re-evaluate and adjust their positions based on collective insights. Following these surveys, a virtual face-to-face meeting was held to resolve outstanding issues. Consensus was defined a priori at all stages of the modified Delphi process.

RESULTS

The response rates to the first-round and second-round questionnaires and the virtual consensus meeting were 100%, 86% and 71%, respectively. The entire process culminated in a consensus on the definitions of scientific quality, QA, the three QA dimensions-reporting, relevance and  methodological quality-and the scope of a QA tool specific to studies that elicit HSUVs.

CONCLUSIONS

Achieving this consensus marks a pivotal step towards developing a QA tool specific to systematic reviews of studies eliciting HSUVs. Future research will build on this foundation, identify QA items, signalling questions and response options, and develop a QA tool specific to studies eliciting HSUVs.

Psychometric Evaluation of the Bahasa Malaysia Version of the Lymphedema Functioning, Disability, and Health Questionnaire for Upper Limb Lymphedema in Patients with Breast Cancer-Related Lymphedema

Background: Breast cancer-related lymphedema (BCRL) is the most prevalent comorbidity that occurs following breast cancer treatments and has negative impact on the patients' quality of life (QoL). The Lymphedema Functioning, Disability, and Health Questionnaire for Upper Limb Lymphedema (Lymph-ICF-UL) is a valid and reliable instrument in assessing the QoL of patients with BCRL. However, the Bahasa Malaysia (BM) version is not available yet. This study aimed to translate the Lymph-ICF-UL into BM and to evaluate its validity and reliability. Methods and Results: A forward-backward translation was performed based on Sousa's guideline, and then, the face, content, construct validity, internal consistency, and test-retest reliability were tested. Face validity was assessed by five patients, and content validity was evaluated by six experts. Then, construct validity and internal validity were assessed in 107 patients. Finally, test-retest reliability was analyzed in 21 patients. Two items were eliminated following suggestions from the patients and experts. All patients found the scoring system and items clear and relevant. The results showed sufficient content validity index and modified kappa statistics value. Confirmatory factor analysis showed acceptable fit indices. Cronbach's alpha values ranged from 0.67 to 0.95, intraclass correlation coefficient ranged from 0.88 to 0.99, standard error measurement was 2.29-6.15, and the Bland-Altman plot showed an agreement between two test occasions. Conclusion: These results suggested that the Lymph-ICF-UL BM has good validity and reliability in evaluating the QoL of patients with BCRL in Malaysia.

Risk of bias in cross-sectional studies: Protocol for a scoping review of concepts and tools

Cross-sectional studies are commonly used to study human health and disease, but are especially susceptible to bias. This scoping review aims to identify and describe available tools to assess the risk of bias (RoB) in cross-sectional studies and to compile the key bias concepts relevant to cross-sectional studies into an item bank. Using the JBI scoping review methodology, the strategy to locate relevant RoB concepts and tools is a combination of database searches, prospective review of PROSPERO registry records; and consultation with knowledge users and content experts. English language records will be included if they describe tools, checklists, or instruments which describe or permit assessment of RoB for cross-sectional studies. Systematic reviews will be included if they consider eligible RoB tools or use RoB tools for RoB of cross-sectional studies. All records will be independently screened, selected, and extracted by one researcher and checked by a second. An analytic framework will be used to structure the extraction of data. Results for the scoping review are pending. Results from this scoping review will be used to inform future selection of RoB tools and to consider whether development of a new RoB tool for cross-sectional studies is needed.

Inter-rater reliability of risk of bias tools for non-randomized studies

PURPOSE

There is limited knowledge on the reliability of risk of bias (ROB) tools for assessing internal validity in systematic reviews of exposure and frequency studies. We aimed to identify and then compare the inter-rater reliability (IRR) of six commonly used tools for frequency (Loney scale, Gyorkos checklist, American Academy of Neurology [AAN] tool) and exposure (Newcastle-Ottawa scale, SIGN50 checklist, AAN tool) studies.

METHODS

Six raters independently assessed the ROB of 30 frequency and 30 exposure studies using the three respective ROB tools. Articles were rated as low, intermediate, or high ROB. We calculated an intraclass correlation coefficient (ICC) for each tool and category of ROB tool. We compared the IRR between ROB tools and tool type by inspection of overlapping ICC 95% CIs and by comparing their coefficients after transformation to Fisher's Z values. We assessed the criterion validity of the AAN ROB tools by calculating an ICC for each rater in comparison with the original ratings from the AAN.

RESULTS

All individual ROB tools had an IRR in the substantial range or higher (ICC point estimates between 0.61 and 0.80). The IRR was almost perfect (ICC point estimate > 0.80) for the AAN frequency tool and the SIGN50 checklist. All tools were comparable in IRR, except for the AAN frequency tool which had a significantly higher ICC than the Gyorkos checklist (p = 0.021) and trended towards a higher ICC when compared to the Loney scale (p = 0.085). When examined by category of ROB tool, scales, and checklists had a substantial IRR, whereas the AAN tools had an almost perfect IRR. For the criterion validity of the AAN ROB tools, the average agreement between our raters and the original AAN ratings was moderate.

CONCLUSION

All tools had substantial IRRs except for the AAN frequency tool and the SIGN50 checklist, which both had an almost perfect IRR. The AAN ROB tools were the only category of ROB tools to demonstrate an almost perfect IRR. This category of ROB tools had fewer and simpler criteria. Overall, parsimonious tools with clear instructions, such as those from the AAN, may provide more reliable ROB assessments.

Endocrine-disrupting chemicals and breast cancer: a meta-analysis

Background

Globally, the burden of breast cancer has increased significantly in recent decades. Emerging evidence suggested that endocrine-disrupting chemicals (EDCs), which have the potential to interfere with the function of normal hormones, may play a crucial role in this trend. However, the potential relationships were inconsistent in various studies.

Objective and search methods

In our study, we sought to fully evaluate the currently available epidemiological evidence to ascertain whether certain EDC congeners and their metabolites are related to breast cancer risk. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we conducted a comprehensive literature search of original peer-reviewed publications in three electronic databases: PubMed, Web of Science, and Embase. Publications that covered xenobiotic EDC exposures and breast cancer-confirmed histological results or antecedent medical records or reporting to health registers were taken into consideration.

Outcomes

The final result of the literature search was 6,498 references, out which we found 67 publications that matched the requirements for meta-analysis and eight publications for qualitative trend synthesis. In this meta-analysis, statistically significant associations revealed that (i) 1-chloro-4-[2,2,2-trichloro-1-(4-chlorophenyl)ethyl]benzene (p,p'-DDT) and its major metabolite 2,2-bis(4-chlorophenyl)-1,1-dichloroethylene (p,p'-DDE) were somewhat related to a greater risk of breast cancer. However, this relationship only existed in blood serum but not in adipose tissue. (ii) Breast cancer risk was increased by exposure to chlordane and hexachlorocyclohexane. (iii) Five polychlorinated biphenyls (PCB 99, PCB 105, PCB 118, PCB 138, and PCB 183) can increase the risk of breast cancer. (iv) One phthalate congener (BBP) and one per- and polyfluoroalkyl substance congener (PFDoDA) were negatively associated with breast cancer risk. Unfortunately, heterogeneity was not well explained in our review, and a limited number of available prospective studies investigating the associations between EDC exposure and breast cancer were included in our meta-analysis. To elucidate the overall associations, future large, longitudinal epidemiological investigations are needed.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD 42023420927.

Recommendations for Designing, Conducting and Reporting Clinical Observational Studies in Homeopathic Veterinary Medicine

BACKGROUND

Clinical observational studies are an important methodological approach in human and veterinary research, examining and describing treatment experience with good external validity. There are currently few observational studies in the field of homeopathic veterinary medicine.

AIM

The aim of the study was to develop recommendations for designing, conducting and reporting observational studies in homeopathic veterinary medicine.

MATERIALS AND METHODS

A literature review was performed using various search strategies for identifying guidelines and checklist tools relevant for observational studies, veterinary research and homeopathy. Useful guidelines were selected. Prior recommendations for designing and conducting observational studies in human homeopathic medicine were supplemented with recommendations for homeopathic veterinary medicine that were evaluated by an expert panel.

RESULTS

The veterinary extension of the Strengthening the Reporting of Observational Studies in Epidemiology - Veterinary (STROBE-Vet) statement was identified as a useful tool to improve the reporting quality of observational studies, and it has been supplemented here with additional recommendations that are applicable to homeopathy. STROBE-Vet is complemented in the literature by several reports, checklists and guidelines on veterinary medicine in general, such as the Checklist for One Health Epidemiological Reporting of Evidence (COHERE) and the Animal Health Surveillance Reporting Guidelines (AHSURED). Identified items that related to laboratory animal research were excluded as non-relevant to our study.

CONCLUSION

Clinical observational studies are an important methodological approach, having currently unrealized potential in the field of homeopathic veterinary medicine. With relatively minor adjustments, the practical guidelines and checklists available to researchers in designing, conducting and reporting observational studies in human homeopathic medicine have been adapted for homeopathic veterinary medicine, for which high quality can be assured by implementing recommendations such as those in STROBE-Vet. With the emergence of the One Health concept, the COHERE checklist can be viewed with growing significance.

Published registry-based pharmacoepidemiologic associations show limited concordance with agnostic medication-wide analyses

OBJECTIVES

To assess how the results of published national registry-based pharmacoepidemiology studies (where select associations are of interest) compare with an agnostic medication-wide approach (where all possible drug associations are tested).

STUDY DESIGN AND SETTING

We systematically searched for publications that reported drug associations with any, breast, colon/colorectal, or prostate cancer in the Swedish Prescribed Drug Registry. Results were compared against a previously performed agnostic medication-wide study on the same registry.

PROTOCOL

https://osf.io/kqj8n.

RESULTS

Most published studies (25/32) investigated previously reported associations. 421/913 (46%) associations had statistically significant results. 134 of the 162 unique drug-cancer associations could be paired with 70 associations in the agnostic study (corresponding drug categories and cancer types). Published studies reported smaller effect sizes and absolute effect sizes than the agnostic study, and generally used more adjustments. Agnostic analyses were less likely to report statistically significant protective associations (based on a multiplicity-corrected threshold) than their paired associations in published studies (McNemar odds ratio 0.13, P = 0.0022). Among 162 published associations, 36 (22%) showed increased risk signal and 25 (15%) protective signal at P < 0.05, while for agnostic associations, 237 (11%) showed increased risk signal and 108 (5%) protective signal at a multiplicity-corrected threshold. Associations belonging to drug categories targeted by individual published studies vs. nontargeted had smaller average effect sizes; smaller P values; and more frequent risk signals.

CONCLUSION

Published pharmacoepidemiology studies using a national registry addressed mostly previously proposed associations, were mostly "negative", and showed only modest concordance with their respective agnostic analyses in the same registry.

Maternal Exposure to Cigarette Smoke during Pregnancy and Testicular Cancer in Offspring: A Systematic Review and Meta-Analysis

Background: Maternal exposure to cigarette smoke in pregnancy may play a role in the development of testicular cancer in offspring. An updated and comprehensive systematic review of the available evidence is needed. Objective: To identify and evaluate current evidence on maternal exposure to cigarette smoke during pregnancy and testicular cancer in offspring. Methods: A systematic search of English peer-reviewed original literature in PubMed through a block search approach. Publications were considered if assessing maternal exposure to cigarette smoke and the risk of testicular cancer in offspring. Results: Among the 636 identified records, 14 publications were eligible for review and 10 for meta-analysis. Quality assessment of the publications was conducted. Most included publications were case-control studies (n = 11, 79%), while the remaining were ecological studies (n = 3, 21%). Completeness of reporting was high, but more than half were considered subject to potential bias. The trend synthesis showed that half (n = 7) of the included publications demonstrated a higher risk of testicular cancer in the sons of mothers exposed to cigarette smoke during pregnancy. The meta-analysis generated an overall summary risk estimate of 1.00 (95% CI: 0.88; 1.15) (n = 10 publications), with a lower risk for seminoma (0.79, 95% CI: 0.59; 1.04) and nonseminoma (0.96, 95% CI: 0.74; 1.26) (n = 4 publications). Conclusions: This systematic review did not provide evidence of an association between maternal exposure to cigarette smoke and risk of testicular cancer in offspring. An overall positive trend was suggested, but it had low statistical precision. The methodological limitations across publications encourage further research based on valid exposure data.

Increased social identification is linked with lower depressive and anxiety symptoms among ethnic minorities and migrants: A systematic review and meta-analysis

Evidence suggests that social identities, which provide purpose and a sense of belonging to the social world, promote resilience against psychological strain and protect well-being. This is especially important in ethnic minorities, who experience exclusion and discrimination from the majority group, and in migrant populations where adverse experiences, such as prejudice, disconnection from previous identities and issues of integration into the host country, negatively impact well-being. Drawing from the social identity theory, a meta-analysis was conducted examining the influence of group memberships and sense of belonging on ethnic minority and migrant mental health (depression and anxiety). The final search on three databases (i.e., PubMed, PsycINFO, Web of Science) was conducted on August 9th, 2022, identifying 3236 citations before removing any duplicates within and between databases. Across the 74 studies that met the inclusion criteria for the meta-analysis, increased social identification (ethnic, national and other types of identification) was associated with low psychological symptoms. We found that social identification is protective against common psychological disorders but with small effect sizes for depression (r = - 0.09, CI = [- 0.12; - 0.06]) and anxiety (r = - 0.08, CI [- 0.12; - 0.03]). Results are discussed with regard to the role that social context plays on ethnic minority and migrant mental health and the importance of facilitating migrant integration with the host society after displacement.

Holistic Assessment of Factors Associated with Exhaustion, the Main Symptom of Burnout: A Meta-Analysis of Longitudinal Studies

BACKGROUND

This meta-analysis summarized longitudinal findings pertaining to exhaustion's predictors. In so doing, our aim was ultimately to identify target factors for the prevention of burnout.

METHODS

We searched for studies that (a) examined predictors of exhaustion longitudinally and (b) reported correlation coefficients as an effect estimate. We conducted our literature search in three databases: MEDLINE, PsycINFO, and Embase. We focused on studies published between January 1990 and November 2020. Predictors were grouped into families, subfamilies, and subgroups. A meta-analysis of z-transformed correlation coefficients (rho) was performed. The results were scrutinized in relation to studies' follow-up length.

RESULTS

We included 65 studies assessing 242 predictors of different types captured across different occupations. Our findings highlighted mostly weak associations (rho < 0.30). For six predictors-Job control, Job resources, Interactions at work, Communication and leadership, Job attitudes, and Work-family interface-longer length of follow-up involved weaker associations with exhaustion. The quality of the evidence available was generally low.

CONCLUSIONS

The evidence available does not point to clear target factors for preventing burnout. The decrease in associations as the follow-up length increases may suggest a relatively short latency period, followed by recovery. Higher-quality cohorts should be conducted to better understand the etiology and course of burnout.

Estimating the global and regional burden of meningitis in children caused by Haemophilus influenzae type b: A systematic review and meta-analysis

Background

Haemophilus influenzae Type B (Hib) meningitis caused significant public health concern for children. Recent assessment in 2015 suggests vaccination has virtually eliminated invasive Hib diseases. However, many countries launched their programs after 2010, and few are yet to establish routine Hib immunisations. We therefore aimed to update the most recent global burden of Hib meningitis before the impact of COVID-19 pandemic, from 2010 to 2020, in order to aid future public health policies on disease management and prevention.

Methods

Epidemiological data regarding Hib meningitis in children <5 years old were systematically searched and evaluated from PubMed and Scopus in August, 2020. We included studies published between 2010 and 2019 that reported incidence, prevalence, mortality, or case-fatality-ratio (CFR), and confirmation of meningitis by cerebrospinal fluid culture, with a minimum one year study period and ten cases. Each data was stratified by one study-year. Median study-year was used if information was not available. Quality of all studies were assessed using our adapted assessment criteria from Grading of Recommendations Assessment, Development and Evaluation (GRADE) and Study Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies from National Heart, Lung and Blood Institute (NHLBI). We constructed and visually inspected a funnel plot of standard error by the incidence rate and performed an Egger’s regression test to statistically assess publication bias. To ascertain incidence and CFR, we performed generalised linear mixed models on crude individual study estimates. Heterogeneity was assessed using I-squared statistics whilst further exploring heterogeneity by performing subgroup analysis.

Results

33 studies were identified. Pooled incidence of global Hib meningitis in children was 1.13 per 100 000-child-years (95% confidence interval (CI) = 0.80-1.59). Southeast Asian Region (SEAR) of World Health Organisation (WHO) region reported the highest incidence, and European Region (EUR) the lowest. Considering regions with three or more data, Western Pacific Region (WPR) had the highest incidence rate of 5.22 (95% CI = 3.12-8.72). Post-vaccination incidence (0.67 cases per 100 000-child-years, 95% CI = 0.48-0.94) was dramatically lower than Pre-vaccination incidence (4.84 cases per 100 000-child-years, 95% CI = 2.95-7.96). Pooled CFR in our meta-analysis was 11.21% (95% CI = 7.01-17.45). Eastern Mediterranean Region (EMR) had the highest CFR (26.92, 95% CI = 13.41-46.71) while EUR had the lowest (4.13, 95% CI = 1.73-9.54). However, considering regions with three or more data, African Region (AFR) had the highest CFR at 21.79% (95% CI = 13.65-32.92). Before the coronavirus disease 2019 (COVID-19) impact, the estimation for global Hib meningitis cases in 2020 is 7645 and 857 deaths.

Conclusions

Global burden of Hib meningitis has markedly decreased, and most regions have implemented vaccination programs. Extrapolating population-at-risk from studies has possibly led to an underestimation. Continuous surveillance is necessary to monitor vaccination impact, resurgence, vaccine failures, strain variance, COVID-19 impact, and to track improvement of regional and global Hib meningitis mortality.

Caesarean section and obesity in young adult offspring: Update of a systematic review with meta-analysis

As compared with vaginal delivery (VD), caesarean section (CS) birth could be associated with increased risk of obesity in young adult offspring. We aimed to evaluate this association by updating data from a systematic review with meta-analysis of observational studies. From 3774 records identified in PubMed and Embase, we retained six studies and added five studies from the last systematic review, for a total of 11 studies. Crude estimates of the association were retrieved from nine cohort studies (n = 143,869), and maximally adjusted estimates were retrieved from eight cohort studies. Young adults born by CS had higher risk of obesity (body mass index [BMI] ≥ 30 kg/m² ) than young adults born by VD, corresponding to a crude pooled risk ratio (RR) of 1.30 [95% confidence interval (CI) 1.13 to 1.50] and a maximally adjusted pooled RR of 1.22 [95% CI 1.02 to 1.46]. In a sensitivity analysis pooling, five studies that included maternal prepregnancy BMI, a major potential confounding factor, in the set of controlled covariates, the RR was 1.08 [95% CI 0.92 to 1.27]. We concluded that the association between CS and obesity in young adulthood was mostly explained by confounding from maternal prepregnancy BMI.

OUP accepted manuscript

BACKGROUND

Globally, the ages at pubertal onset for girls and boys have been decreasing during recent decades, partly attributed to excess body fat accumulation. However, a growing body of literature has recognized that endocrine disrupting chemicals (EDCs) may play an important role in this global trend, but the association has not yet been fully established.

OBJECTIVE AND RATIONALE

EDCs can interfere with normal hormone function and metabolism and play a role in pubertal onset. We aimed to systematically identify and evaluate the current evidence on the timing of pubertal onset in girls and boys following prenatal or postnatal exposures to xenobiotic EDCs.

SEARCH METHODS

Following PRISMA guidelines, we performed a systematic literature search of original peer-reviewed publications in the PubMed database through a block search approach using a combination of index MeSH and free text search terms. Publications were considered if they covered biomarkers of prenatal or postnatal exposures to xenobiotic EDCs (European Commission's list of category 1 EDCs) measured in maternal or child biospecimen and pubertal onset defined by the progression of the following milestones (and assessed in terms of the following measures): menarche (age), thelarche (Tanner staging) and pubarche (Tanner staging), in girls, and genital stage (Tanner staging), testicular volume (ml) and pubarche (Tanner staging), in boys.

OUTCOMES

The literature search resulted in 703 references, of which we identified 52 publications fulfilling the eligibility criteria for the qualitative trend synthesis and 23 publications for the meta-analysis. The qualitative trend synthesis provided data on 103 combinations of associations between prenatal or postnatal exposure to EDC compounds groups and puberty outcomes and the meta-analysis enabled 18 summary risk estimates of meta-associations.

WIDER IMPLICATIONS

Statistically significant associations in the qualitative trend synthesis suggested that postnatal exposure to phthalates may be associated with earlier thelarche and later pubarche. However, we did not find consistent evidence in the meta-analysis for associations between timing of pubertal onset in girls and boys and exposures to any of the studied xenobiotic EDCs. We were not able to identify specific pre- or postnatal windows of exposure as particularly critical and susceptible for effects of EDCs. Current evidence is subject to several methodological challenges and inconsistencies and evidence on specific exposure-outcome associations remains too scarce to firmly confirm EDC exposure as a risk factor for changes in age of pubertal onset in the general child population. To create a more uniform foundation for future comparison of evidence and to strengthen pooled studies, we recommend the use of more standardized approaches in the choice of statistical analyses, with exposure transformations, and in the definitions and assessments of puberty outcomes. The impact of mixtures of EDC exposures on the association also remains unestablished and would be valuable to elucidate for prenatal and postnatal windows of exposure. Future large, longitudinal epidemiological studies are needed to clarify the overall association.

Safety of Complementary and Alternative Medicine (CAM) treatment among children and young adults who suffer from adverse effects of conventional cancer treatment: A systematic review

BACKGROUND

Complementary and Alternative Medicine (CAM) is widely used around the world to treat adverse effects derived from cancer treatment among children and young adults. Parents often seek CAM to restore and maintain the child's physical and emotional condition during and after cancer treatment.

OBJECTIVES

The objectives of this review were (i) to identify literature that investigates CAM use for treating adverse effects of conventional cancer treatment, (ii) to investigate the safety of the included CAM modalities, and (iii) to evaluate the quality of included studies.

METHODS

Five scientific research databases were used to identify observational, quasi-experimental, and qualitative studies from January 1990 to May 2021. Included studies investigated the use of CAM to treat adverse effects of cancer treatment in childhood cancer.

RESULTS

Fifteen studies were included in this review. Ten quasi-experimental, 3 observational studies (longitudinal/prospective), 2 qualitative studies, and 1 study with a quasi-experimental and qualitative arm were identified. Less than half (n = 6; 40%) of the studies included reported adverse effects for the CAM modality being studied. Among the studies that reported adverse effects, they were mostly considered as direct risk, as 13% reported mainly bleeding and bruising upon acupuncture treatment, and dizziness with yoga treatment. All adverse effects were assessed as minor and transient. CAM modalities identified for treating adverse effects of cancer treatment were alternative medical systems, manipulative and body-based therapies, biologically-based therapies, and mind-body therapies. CAM modalities were used to alleviate anxiety, pain, toxicity, prevent trauma, and improve health-related quality of life, functional mobility, and physical activity levels. All studies assessed scored 70% or above according to the Joanna Briggs Institute critical appraisal for study quality checklists.

CONCLUSION

Most of the studies (58.3%) included in this review did not report adverse effects from CAM modalities used to treat adverse effects of cancer treatment in children and young adults. This lack of safety information is of concern because parents need to know whether the modality represents an extra burden or harm to the child. To improve awareness about safety in the field, a universal and uniform reporting system for adverse effects in CAM research is needed.

Occupational pesticide exposure, cancer and chronic neurological disorders: A systematic review of epidemiological studies in greenspace workers

CONTEXT

The greenspace sector includes a broad range of occupations: gardeners, landscapers, municipal workers, maintenance operators of public facilities, golf-course employees and other sports facilities, horticulturists, plant and tree nursery workers etc. The health impact of occupational pesticide exposure has mainly been studied among farmers. Other professionals such as greenspace workers are also extremely exposed, presenting specific exposure features (practices, types of pesticide used). The aim of this review was to summarize epidemiological literature that examine the relationship between pesticide exposure and the risk of cancer and long-term health effects in greenspace workers.

METHOD

Six main groups of greenspace workers were identified and examined through a systematic literature review based on PubMed and Scopus. The studies were then grouped according to their design, health outcomes and the type of population studied.

RESULTS

Forty-four articles were selected among the 1679 identified. Fifteen studies were conducted exclusively among greenspace workers, while ten also studied these workers with other pesticide applicators. Six were cohorts from the general population in which greenspace workers were identified. Elevated risks were found in several studies for leukaemia, soft-tissue sarcoma, multiple myeloma, non-Hodgkin lymphoma and Parkinson's disease.

DISCUSSION

The majority of studies used rough parameters for defining exposure such as job titles which could lead to the misclassification of exposure, with the risk of false or positive negative conclusions. Health outcomes were mainly collected through registries or death certificates, and information regarding potential confounders was often missing.

CONCLUSION

The review identified only 15 studies conducted exclusively among greenspace workers. Elevated risk was found for several sites of cancer and Parkinson's diseases. Further epidemiological research is needed, conducted specifically on these workers, to better characterize this population, its exposure to pesticides and the related health effects.

Assessments of risk of bias in systematic reviews of observational nutritional epidemiologic studies are often not appropriate or comprehensive: a methodological study

BACKGROUND

An essential component of systematic reviews is the assessment of risk of bias. To date, there has been no investigation of how reviews of non-randomised studies of nutritional exposures (called 'nutritional epidemiologic studies') assess risk of bias.

OBJECTIVE

To describe methods for the assessment of risk of bias in reviews of nutritional epidemiologic studies.

METHODS

We searched MEDLINE, EMBASE and the Cochrane Database of Systematic Reviews (Jan 2018-Aug 2019) and sampled 150 systematic reviews of nutritional epidemiologic studies.

RESULTS

Most reviews (n=131/150; 87.3%) attempted to assess risk of bias. Commonly used tools neglected to address all important sources of bias, such as selective reporting (n=25/28; 89.3%), and frequently included constructs unrelated to risk of bias, such as reporting (n=14/28; 50.0%). Most reviews (n=66/101; 65.3%) did not incorporate risk of bias in the synthesis. While more than half of reviews considered biases due to confounding and misclassification of the exposure in their interpretation of findings, other biases, such as selective reporting, were rarely considered (n=1/150; 0.7%).

CONCLUSION

Reviews of nutritional epidemiologic studies have important limitations in their assessment of risk of bias.

Endocrine Disrupting Chemicals and Risk of Testicular Cancer: A Systematic Review and Meta-analysis

The incidence of many hormone-dependent diseases, including testicular cancer, has sharply increased in all high-income countries during the 20th century. This is not fully explained by established risk factors. Concurrent, increasing exposure to antiandrogenic environmental endocrine disrupting chemicals (EDCs) in fetal life may partially explain this trend. This systematic review assessed available evidence regarding the association between environmental EDC exposure and risk of testicular cancer (seminomas and nonseminomas). Following PRISMA guidelines, a search of English peer-reviewed literature published prior to December 14, 2020 in the databases PubMed and Embase® was performed. Among the 279 identified records, 19 were eligible for quality assessment and 10 for further meta-analysis. The completeness of reporting was high across papers, but over 50% were considered subject to potential risk of bias. Mean age at diagnosis was 31.9 years. None considered effects of EDC multipollutant mixtures. The meta-analyses showed that maternal exposure to combined EDCs was associated with a higher risk of testicular cancer in male offspring [summary risk ratios: 2.16, (95% CI:1.78-2.62), 1.93 (95% CI:1.49-2.48), and 2.78 (95% CI:2.27-3.41) for all, seminoma, and nonseminoma, respectively]. Similarly, high maternal exposures to grouped organochlorines and organohalogens were associated with higher risk of seminoma and nonseminoma in the offspring. Summary estimates related to postnatal adult male EDC exposures were inconsistent. Maternal, but not postnatal adult male, EDC exposures were consistently associated with a higher risk of testicular cancer, particularly risk of nonseminomas. However, the quality of studies was mixed, and considering the fields complexity, more prospective studies of prenatal EDC multipollutant mixture exposures and testicular cancer are needed.

Prevalence of rheumatoid arthritis in South America: a systematic review and meta-analysis

Rheumatoid arthritis (RA) is among the most prevalent chronic autoimmune and inflammatory diseases worldwide. The aim of this study was to establish a pooled estimate of the RA prevalence in South America by means of a meta-analysis of the available epidemiologic studies. Systematic searches in PubMed, Lilacs, SciELO, Scopus, and Web of Science databases (updated May 2019) were done followed by a systematic grey literature search to identify original research articles and reports, published after 2000, providing data of RA prevalence in any South American country. Proportion meta-analysis of weighted pooled was performed, with between-trial heterogeneity assessed by the inconsistency relative index. Sensitivity analyses and sub-group analyses were also done. A total of 25 articles, representing 27 population-based studies were included. Pooled prevalence of RA resulted in 0.48% with 591,981 cases in a population of 114,537,812 individuals (I2=99%). Brazil and Colombia presented the lowest rates of RA prevalence 0.22%, and 0.24%, respectively. RA prevalence in indigenous population was higher 1.45%, and studies using COPCORD method reported also the highest rates 1.07%.

HIV incidence among men who have sex with men in mainland China: a systematic review protocol

BACKGROUND

Men who have sex with men (MSM) are disproportionately affected by HIV in China. Globally, younger MSM are at higher risk for incident HIV infections, but there has been substantial variation in the estimates of age-stratified HIV incidence among MSM in mainland China, potentially due to regional differences in the nature of the epidemic. Given the need for quality epidemiological data to meet the global goal of ending new HIV infections by 2030, this systematic review and meta-analysis aims to determine age-stratified HIV incidence in mainland China, including consideration by geographic region and time.

METHODS

This review will include longitudinal studies, cross-sectional surveys, and surveillance reports among MSM in mainland China that have reported HIV incidence. We will search studies and reports published from January 1, 2003, to April 30, 2020, in both English and Chinese language literature databases. For each study considered, two reviewers will independently screen, determine eligibility, and extract relevant data, with discrepancies resolved by consensus of a third reviewer. The methodological quality of included studies will be assessed by the Quality Assessment Tool for Systematic Reviews of Observational Studies Score (QATSO). We will develop age-stratified estimates of HIV incidence with geographic variations and temporal trends. Heterogeneity will be examined using statistical techniques appropriate to the dataset. For subgroup analyses, we will conduct mixed-effects meta-analysis models.

DISCUSSION

This review will contribute to a better understanding of the HIV epidemic among MSM in mainland China by providing age-stratified estimates of HIV incidence with a portrayal of geographic and temporal variations. Findings will reflect epidemic dynamics, informing local and national intervention programs and policies for HIV prevention, and providing estimation data to inform future research among MSM in China.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO ID 154834.

Artificial intelligence and the conduct of literature reviews

Artificial intelligence (AI) is beginning to transform traditional research practices in many areas. In this context, literature reviews stand out because they operate on large and rapidly growing volumes of documents, that is, partially structured (meta)data, and pervade almost every type of paper published in information systems research or related social science disciplines. To familiarize researchers with some of the recent trends in this area, we outline how AI can expedite individual steps of the literature review process. Considering that the use of AI in this context is in an early stage of development, we propose a comprehensive research agenda for AI-based literature reviews (AILRs) in our field. With this agenda, we would like to encourage design science research and a broader constructive discourse on shaping the future of AILRs in research.

Predictors of Occupational Burnout: A Systematic Review

We aimed to review occupational burnout predictors, considering their type, effect size and role (protective versus harmful), and the overall evidence of their importance. MEDLINE, PsycINFO, and Embase were searched from January 1990 to August 2018 for longitudinal studies examining any predictor of occupational burnout among workers. We arranged predictors in four families and 13 subfamilies of homogenous constructs. The plots of z-scores per predictor type enabled graphical discrimination of the effects. The vote-counting and binomial test enabled discrimination of the effect direction. The size of the effect was estimated using Cohen's formula. The risk of bias and the overall evidence were assessed using the MEVORECH and GRADE methods, respectively. Eighty-five studies examining 261 predictors were included. We found a moderate quality of evidence for the harmful effects of the job demands subfamily (six predictors), and negative job attitudes, with effect sizes from small to medium. We also found a moderate quality of evidence for the protective effect of adaptive coping (small effect sizes) and leisure (small to medium effect sizes). Preventive interventions for occupational burnout might benefit from intervening on the established predictors regarding reducing job demands and negative job attitudes and promoting adaptive coping and leisure.

Meta-analysis of nursing-related organizational and psychosocial predictors of sickness absence

BACKGROUND

Nursing is a stressful occupation with high rates of sickness absence. To date, there are no meta-analyses that statistically determined the correlates of sickness absence in this population.

AIMS

This meta-analysis examined organizational and psychosocial predictors of sickness absence among nursing staff.

METHODS

As a registered systematic review (PROSPERO: CRD42017071040), which followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, five databases (CINAHL, PROQuest Allied, PROQuest database theses, PsycINFO, PubMed) were reviewed to examine predictors of sickness absence in nurses and nursing assistants between 1990 and 2019. The Population/Intervention/Comparison/Outcome tool was used to support our searches. Effect sizes were analysed using random-effects model.

RESULTS

Following critical appraisals using (i) National Institutes of Health's Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies and (ii) Strengthening the Reporting of Observational Studies in Epidemiology, 21 studies were included. Nursing assistants had greater odds of sickness absence than nurses. Working night shifts, in paediatrics or psychiatric units, experiencing poor mental health, and fatigue, also increased the odds of sickness absence. There was no evidence that job satisfaction or job strain influenced sickness absence; however, job demand increased the likelihood. Finally, work support reduced the odds of lost-time.

CONCLUSIONS

We synthesized three decades of research where several factors influenced sickness absence. Due to limited recent research, the results should be interpreted with caution as some practices may have changed overtime or between countries. Nevertheless, these findings could help in applying preventative strategies to mitigate lost-time in a vulnerable working population.

Incidence of rhegmatogenous retinal detachment in myopic phakic eyes

Rhegmatogenous retinal detachment (RRD) is a potentially blinding disease, more common in the myopic population. This systematic review aimed to collect the existing literature on the incidence of RRD in myopic phakic eyes. MEDLINE, Embase, and the Cochrane Library were searched to identify eligible studies published until February 2020. In total 2715 publications were identified, of which only 3 were considered eligible and 2 as eligible with major limitations. Because of substantial differences between the included studies, a pooled analysis was not conducted. Summarizing the results and considering several limitations, an annual RRD incidence per 100 000 of 15 to 34 for mild myopia, 15 to 73 for moderate myopia, 102 to 128 for high myopia, and 287 in very highly myopic eyes was shown. Large well-designed studies are needed, including precise information on the refractive status or axial eye length, lens status, traumatic injuries, and intraocular surgeries during follow-up.

Mothers' utilization and associated factors of preconception care in Africa, a systematic review and meta-analysis

BACKGROUND

As the studies show, in every minute in the world, 380 women become pregnant and 190 face unplanned or unwanted pregnancies; 110 experience pregnancy-related complications, and one woman dies from a pregnancy-related cause. Preconception care is one of the proven strategies for the reduction in mortality and decreases the risk of adverse health effects for the woman, fetus, and neonate by optimizing maternal health services and improves woman's health. Therefore, this study aimed to estimate the pooled prevalence of utilization of preconception of care and associated factors in Africa.

METHODS

Systematic search of published studies done on PubMed, EMBASE, MEDLINE, Cochrane, Scopus, Web of Science CINAHL, and manually on Google Scholar. This meta-analysis follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The quality of studies was assessed by the modified Newcastle-Ottawa Scale (NOS). Meta-analysis was carried out using a random-effects method using the STATA™ Version 14 software.

RESULT

From 249,301 obtained studies, 28 studies from 3 African regions involving 13067 women included in this Meta-analysis. The overall pooled prevalence of utilization of preconception care among pregnant women in Africa was found to be 18.72% (95% CI: 14.44, 23.00). Knowledge of preconception care (P = <0.001), preexisting medical condition (P = 0.045), and pregnancy intention (P = 0.016) were significantly associated with the utilization of preconception care.

CONCLUSION

The results of this meta-analysis indicated, as one of best approaches to improve birth outcomes, the utilization of preconception care is significantly low among mothers in Africa. Therefore, health care organizations should work on strategies to improve preconception care utilization.

The association between vertebral endplate structural defects and back pain: a systematic review and meta-analysis

PURPOSE

To clarify the current state of knowledge on the association of endplate structural defects and back pain.

METHODS

Five databases were searched for studies reporting on the association between endplate structural defects and back pain. Covidence and comprehensive meta-analysis software were used for article screening and selection and pooling of extracted data. Overall quality of evidence was assessed using GRADE.

RESULTS

Twenty-six studies comprised of 11,027 subjects met inclusion criteria. The presence of moderate heterogeneity (I² = 73%; p = 0.001) prevented the pooling of estimates across all studies. However, it was possible to pool studies of specific endplate defect phenotypes, such as erosion (OR: 2.69; 95% CI: 1.35-5.50) and sclerosis (OR: 1.97; 95% CI: 1.50-2.58), which yielded significant associations with back pain. Schmorl's nodes were also associated with most individual back pain phenotypes (OR: 1.53-1326, I² = 0-7.5%) and back pain overall (OR: 1.63, 95% CI: 1.37-1.94, I² = 26%) in general population samples. The pooling of data from all studies of specific back pain phenotypes, such as frequent back pain (OR: 2.83; 95% CI: 1.77-4.52) and back pain incidence (OR: 1.65; 95% CI: 1.30-2.10), each yielded significant association with endplate structural defects and was supported by low heterogeneity (I² =  < 7.5.%).

CONCLUSION

Overall, there is moderate quality evidence of an association between back pain and endplate structural defects, which is most evident for erosion, sclerosis and Schmorl's nodes. Going forward, research on specific endplate defect phenotypes and back pain case definitions using strong study designs will be important in clarifying the extent of associations and underlying mechanisms. The study was prospectively registered in Prospero (CRD42020170835) on 02/24/2020.

Prevalence and correlates of individuals with sexual interest in children: A systematic review

BACKGROUND

Despite debates on what should constitute sexual interest in children in terms of definition and diagnostic criteria and its strong association with individuals who commit sexual offences against children, research in this area has shown that sexual interest in children is also commonly seen in the general population. Studies in this field have investigated its prevalence and its correlates. However, most research on this topic has focused on men and most particularly sex offender populations. When investigating the general population, again the vast majority of studies used male samples and students.

OBJECTIVE

This systematic review aimed to critically evaluate previous research on the prevalence of sexual interest in children across populations and to examine its correlates.

METHODS

A search of relevant databases was conducted as well as a hand search of selected journals to identify eligible papers. Studies meeting the inclusion criteria had their data extracted and were assessed for risk of bias, with a second rater to establish inter-rater reliability.

RESULTS

A total of 30 studies were reviewed and results indicated a mean prevalence rate of sexual interest in children between 2 %-24 %. Findings also indicated correlates such as the presence of mental health problems and adverse childhood experiences. Most studies showed poor external validity, with the majority of them scoring high on risk of bias.

CONCLUSION

Overall, the findings indicate inconsistencies in terms of methodology and definition/diagnostic criteria of sexual interest in children. Further research in this area using recommended methodology to avoid biases is recommended.

Reconciling estimates of global spread and infection fatality rates of COVID-19: An overview of systematic evaluations

BACKGROUND

Estimates of community spread and infection fatality rate (IFR) of COVID-19 have varied across studies. Efforts to synthesize the evidence reach seemingly discrepant conclusions.

METHODS

Systematic evaluations of seroprevalence studies that had no restrictions based on country and which estimated either total number of people infected and/or aggregate IFRs were identified. Information was extracted and compared on eligibility criteria, searches, amount of evidence included, corrections/adjustments of seroprevalence and death counts, quantitative syntheses and handling of heterogeneity, main estimates and global representativeness.

RESULTS

Six systematic evaluations were eligible. Each combined data from 10 to 338 studies (9-50 countries), because of different eligibility criteria. Two evaluations had some overt flaws in data, violations of stated eligibility criteria and biased eligibility criteria (eg excluding studies with few deaths) that consistently inflated IFR estimates. Perusal of quantitative synthesis methods also exhibited several challenges and biases. Global representativeness was low with 78%-100% of the evidence coming from Europe or the Americas; the two most problematic evaluations considered only one study from other continents. Allowing for these caveats, four evaluations largely agreed in their main final estimates for global spread of the pandemic and the other two evaluations would also agree after correcting overt flaws and biases.

CONCLUSIONS

All systematic evaluations of seroprevalence data converge that SARS-CoV-2 infection is widely spread globally. Acknowledging residual uncertainties, the available evidence suggests average global IFR of ~0.15% and ~1.5-2.0 billion infections by February 2021 with substantial differences in IFR and in infection spread across continents, countries and locations.

Prevalence of human respiratory syncytial virus, parainfluenza and adenoviruses in East Africa Community partner states of Kenya, Tanzania, and Uganda: A systematic review and meta-analysis (2007-2020)

Background

Viruses are responsible for a large proportion of acute respiratory tract infections (ARTIs). Human influenza, parainfluenza, respiratory-syncytial-virus, and adenoviruses are among the leading cause of ARTIs. Epidemiological evidence of those respiratory viruses is limited in the East Africa Community (EAC) region. This review sought to identify the prevalence of respiratory syncytial virus, parainfluenza, and adenoviruses among cases of ARTI in the EAC from 2007 to 2020.

Methods

A literature search was conducted in Medline, Global Index Medicus, and the grey literature from public health institutions and programs in the EAC. Two independent reviewers performed data extraction. We used a random effects model to pool the prevalence estimate across studies. We assessed heterogeneity with the I² statistic, and Cochran’s Q test, and further we did subgroup analysis. This review was registered with PROSPERO under registration number CRD42018110186.

Results

A total of 12 studies met the eligibility criteria for the studies documented from 2007 to 2020. The overall pooled prevalence of adenoviruses was 13% (95% confidence interval [CI]: 6–21, N = 28829), respiratory syncytial virus 11% (95% CI: 7–15, N = 22627), and parainfluenza was 9% (95% CI: 7–11, N = 28363). Pooled prevalence of reported ARTIs, all ages, and locality varied in the included studies. Studies among participants with severe acute respiratory disease had a higher pooled prevalence of all the three viruses. Considerable heterogeneity was noted overall and in subgroup analysis.

Conclusion

Our findings indicate that human adenoviruses, respiratory syncytial virus and parainfluenza virus are prevalent in Kenya, Tanzania, and Uganda. These three respiratory viruses contribute substantially to ARTIs in the EAC, particularly among those with severe disease and those aged five and above.

Does antiretroviral therapy cause congenital malformations? A systematic review and meta-analysis

OBJECTIVES

This meta-analysis investigated the risk of congenital anomalies among infants of human immunodeficiency virus-infected pregnant women who were exposed to antiretroviral therapy (ART).

METHODS

Cohort studies, case-control studies, randomized controlled trials, and controlled clinical trials were reviewed by searching MEDLINE/PubMed, Embase, Web of Science, Scopus, AIDSLINE, CINAHL, Cochrane Library, and Google/Google Scholar. Methodological quality was assessed using the GRADE evaluation. A DerSimonian and Laird random-effects model was used. Subgroup analyses and meta-regression were used to investigate heterogeneity.

RESULTS

The electronic searches yielded 765 items. After quality assessment and grading, 30 studies were suitable for metaanalysis. In total, 1,461 congenital anomalies were found among 53,186 births. Children born to women receiving combined antiretroviral therapy (cART) had an approximately 10% higher risk of developing congenital anomalies (relative risk [RR], 1.09; 95% confidence interval [CI], 1.04 to 1.14). A subgroup analysis found no significant difference in the risk of congenital anomalies between cART and efavirenz users. However, zidovudine and protease inhibitor (RR, 1.09; 95% CI, 1.00 to 1.19) users were found to have a 10% increased risk of congenital anomalies, and integrase inhibitor users had a 60% increase in risk (RR, 1.61; 95% CI, 1.60 to 2.43). The subgroup results should be interpreted cautiously because of the moderate heterogeneity (I² =58%).

CONCLUSIONS

The use of protease inhibitors, integrase inhibitors, zidovudine, and newer drugs should be carefully considered in pregnant women. Further studies are needed to address environmental, nutrition, and adherence factors related to ART. Establishing a congenital anomalies surveillance system is recommended.

A Systematic Review of the Incidence, Prevalence, Costs, and Activity and Work Limitations of Amputation, Osteoarthritis, Rheumatoid Arthritis, Back Pain, Multiple Sclerosis, Spinal Cord Injury, Stroke, and Traumatic Brain Injury in the United States: A 2019 Update

OBJECTIVES

To present recent evidence on the prevalence, incidence, costs, activity limitations, and work limitations of common conditions requiring rehabilitation.

DATA SOURCES

Medline (PubMed), SCOPUS, Web of Science, and the gray literature were searched for relevant articles about amputation, osteoarthritis, rheumatoid arthritis, back pain, multiple sclerosis, spinal cord injury, stroke, and traumatic brain injury.

STUDY SELECTION

Relevant articles (N=106) were included.

DATA EXTRACTION

Two investigators independently reviewed articles and selected relevant articles for inclusion. Quality grading was performed using the Methodological Evaluation of Observational Research Checklist and Newcastle-Ottawa Quality Assessment Form.

DATA SYNTHESIS

The prevalence of back pain in the past 3 months was 33.9% among community-dwelling adults, and patients with back pain contribute $365 billion in all-cause medical costs. Osteoarthritis is the next most prevalent condition (approximately 10.4%), and patients with this condition contribute $460 billion in all-cause medical costs. These 2 conditions are the most prevalent and costly (medically) of the illnesses explored in this study. Stroke follows these conditions in both prevalence (2.5%-3.7%) and medical costs ($28 billion). Other conditions may have a lower prevalence but are associated with relatively higher per capita effects.

CONCLUSIONS

Consistent with previous findings, back pain and osteoarthritis are the most prevalent conditions with high aggregate medical costs. By contrast, other conditions have a lower prevalence or cost but relatively higher per capita costs and effects on activity and work. The data are extremely heterogeneous, which makes anything beyond broad comparisons challenging. Additional information is needed to determine the relative impact of each condition.

The development of a new generic risk-of-bias measure for systematic reviews of surveys

It is important to evaluate risk of bias of the primary studies included in systematic reviews and meta-analyses. Since tools pertinent to surveys are scarce, the goal of the current research was to develop a measure to address this need. In Study 1, an initial list of 10 relevant topics was compiled from previous measures. In Study 2, the list was refined into an eight-item risk-of-bias measure via discussion and a pilot study. In Study 3, experienced researchers used the measure to asses 70 studies, demonstrating high interrater agreement (weighted Kappa = .82). Inexperienced raters also utilized the measure to code 26 different studies included in a prior meta-analysis, which resulted in adequate interrater agreement (weighted Kappa = .64) and excellent convergent validity (r = .66). Thus, the new measure, designed to be accessible and flexible, can increase standardization of risk-of-bias evaluations and contribute to the interpretation of systematic reviews and meta-analytic findings.

The incidence of sore throat and group A streptococcal pharyngitis in children at high risk of developing acute rheumatic fever: A systematic review and meta-analysis

BACKGROUND

Group A streptococcal (GAS) pharyngitis has traditionally been considered the sole precursor of acute rheumatic fever (ARF). Evidence from Australia, however, suggests that GAS skin infections may contribute to the pathogenesis of ARF. A missing piece of evidence is the incidence of sore throat and GAS pharyngitis in this setting. We conducted a systematic review and meta-analysis of the incidence of sore throat and GAS pharyngitis in all children at risk of developing ARF.

METHODS

Databases were systematically searched for studies reporting on the incidence of pharyngitis among children from low to upper-middle income countries, and Indigenous children living in high-income countries. Studies were subjected to data extraction by two independent reviewers. Following an assessment of the methodological quality of the studies, we extracted incidence rates (IRs) and conducted a meta-analysis. This systematic review is registered on PROSPERO (CRD42019113019).

RESULTS

From 607 titles identified by the search, 11 articles met the predetermined inclusion criteria; ten studies reported IRs while for the remaining study, the incidence was calculated. The pooled incidence estimated for sore throat was 82.5 per 100 child-years (95% confidence interval [CI], 6.5 to 1044.4 per 100 child-years, I2 = 100%) and GAS pharyngitis was 10.8 per 100 child-years (95% CI, 2.3 to 50.0 per 100 child-years, I2 = 99.9%).

CONCLUSIONS

The pooled IRs for sore throat in children at risk of developing ARF were higher than rates reported in developed nations (32.70-40 per 100 child-years) and similar for GAS pharyngitis (12.8-14 per 100 years). The limited Australian data lend support to the need for further studies to inform the role of GAS pharyngitis in the development of ARF in Australian Indigenous children, so as to inform local primary prevention strategies for ARF and Rheumatic Heart Disease (RHD).

Characterisation of the environmental presence of hepatitis A virus in low-income and middle-income countries: a systematic review and meta-analysis

OBJECTIVE

To characterise the environmental presence of hepatitis A virus (HAV) in low- and middle-income countries (LMICs).

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

EBSCOhost, PubMed, Scopus, ScienceDirect, Clinical Key and Web of Science were searched. Grey literature was sourced by searching the following electronic databases: Open Grey, National Health Research Database and Mednar.

ELIGIBILITY CRITERIA FOR INCLUDING STUDIES

Cross-sectional and ecological studies reporting HAV environmental presence and conducted in LMICs between January 2005 and May 2019, irrespective of language of publication.

DATA EXTRACTION AND DATA SYNTHESIS

Relevant data were extracted from articles meeting the inclusion criteria, and two reviewers independently assessed the studies for risk of bias. High heterogeneity of the extracted data led to the results being reported narratively.

RESULTS

A total of 2092 records were retrieved, of which 33 met the inclusion criteria. 21 studies were conducted in Tunisia, India and South Africa, and the rest were from Philippines, Pakistan, Morocco, Chad, Mozambique, Kenya and Uganda. In Tunisian raw sewage samples, the prevalence of HAV ranged from 12% to 68%, with an estimated average detection rate of 50% (95% CI 25 to 75), whereas HAV detection in treated sewage in Tunisia ranged from 23% to 65%, with an estimated average detection rate of 38% (95% CI 20 to 57). The prevalence of HAV detection in South African treated sewage and surface water samples ranged from 4% to 37% and from 16% to 76%, with an estimated average detection rates of 15% (95% CI 1 to 29) and 51% (95% CI 21 to 80), respectively. Over the review period, the estimated average detection rate of environmental HAV presence appeared to have declined by 10%.

CONCLUSION

The quality of included studies was fair, but sampling issues and paucity of data limited the strength of the review findings.

PROSPERO REGISTRATION NUMBER

CRD42019119592.

Area-level differences in the prices of tobacco and electronic nicotine delivery systems - A systematic review

OBJECTIVE

To examine associations between area-level characteristics (socioeconomic status, racial or ethnic characteristics, age, and any other characteristics that may be associated with vulnerability) and the prices of tobacco products and electronic nicotine delivery systems (ENDS).

DATA SOURCES

We searched MEDLINE, EconLit and Scopus, unpublished and grey literature, hand-searched four specialty journals, examined references of relevant studies, and contacted key informants.

STUDY SELECTION

We considered all studies that quantitatively examined area-level variations in the prices of tobacco products and ENDS. We included all studies that examined any area-level measures regardless of the geographic location, language or time of publication. At least two reviewers independently screened the articles. We identified 20 studies.

DATA EXTRACTION

At least two reviewers independently extracted the characteristics, methods, and main results and assessed the quality of each included study.

DATA SYNTHESIS

Overall, cigarette prices were found to be lower in lower socioeconomic status neighbourhoods, and in neighbourhoods with a higher percentage of youth, and Blacks or African Americans. We identified too few studies that examined price differences for cigarillos, chewing tobacco, roll-your-own, and ENDS to reach any conclusions.

CONCLUSIONS

Our findings are in keeping with tobacco industry documents that detailed how manufacturers used race, class, and geography to target vulnerable populations and suggest that regulations that can limit industry price manipulation such as minimum, maximum, and uniform prices, and high specific excise taxes should be considered. More frequent and systematic monitoring of tobacco prices and ENDS is warranted.

Prevalence of Undiagnosed Diabetes and Prediabetes in the Dental Setting: A Systematic Review and Meta-Analysis

Background

With the close link between diabetes mellitus (DM) and periodontal disease (PD), dentists have an unrealized opportunity to make a chance discovery of a patient's medical condition. Unlike in the medical setting, information on the point of care (PoC) and opportunistic screening for DM in the dental setting is limited. To make a reliable estimate on the prevalence of undiagnosed type 2 diabetes mellitus (T2DM) and prediabetes among dental patients in the dental setting and to assist healthcare planners in making an informed decision, information on the disease frequency and strategies employed to address this issue is of paramount importance.

Objectives

To summarize the data on the prevalence of undiagnosed T2DM and prediabetes amongst dental patients and further explore the effectiveness of the PoC screening and its implication for use in the dental setting.

Methods

A MEDLINE-PubMed, EMBASE, Web of Science, and Cochrane Library search was conducted with no time specification. Information on study characteristics and diagnostic parameters was retrieved for meta-analysis. All the studies were assessed for methodological quality using the QUADAS-2 tool. Proportions were presented in tables and forest plots. All statistical analysis was performed using the MedCalc software.

Results

Nine studies met the inclusion criteria. The proportion of dental patients identified to be at a risk of hyperglycaemia with the PoC screening using random blood glucose (RBG) and HbA1 was 32.47% and 40.10%, whilst the estimated proportion with undiagnosed T2DM and prediabetes was identified as 11.23% and 47.38%.

Conclusion

A significant proportion of dental patients can be identified as undiagnosed T2DM and prediabetes. Targeted opportunistic screening is a feasible approach and can help reduce the prevalence of undiagnosed T2DM and prediabetes.

Per- and polyfluoroalkyl substances and male reproductive health: a systematic review of the epidemiological evidence

Exposure to environmental pollutants may produce impairment of male reproductive health. The epidemiological literature evaluating potential consequences of human exposure to per- and polyfluoroalkyl substances (PFAS) has grown in recent years with concerns for both pre- and postnatal influences. The aim of this systematic review was to assess available evidence on associations between PFAS exposures in different stages of life and semen quality, reproductive hormones, cryptorchidism, hypospadias, and testicular cancer. A systematic search of literature published prior to March 9th, 2020, was performed in the databases PubMed and Embase®. Predefined criteria for eligibility were applied by two authors screening study records independently. Among the 242 study records retrieved in the literature search, 26 studies were eligible for qualitative assessment. While several investigations suggested weak associations for single compounds and specific outcomes, a lack of consistency across studies limited conclusions of overall evidence. The current gap in knowledge is particularly obvious regarding exposures prior to adulthood, exposure to combinations of both PFAS and other types of environmental chemicals, and outcomes such as cryptorchidism, hypospadias, and testicular cancer. Continued efforts to clarify associations between PFAS exposure and male reproductive health through high-quality epidemiological studies are needed.

Draft for internal testing Scientific Committee guidance on appraising and integrating evidence from epidemiological studies for use in EFSA's scientific assessments

EFSA requested its Scientific Committee to prepare a guidance document on appraising and integrating evidence from epidemiological studies for use in EFSA's scientific assessments. The guidance document provides an introduction to epidemiological studies and illustrates the typical biases of the different epidemiological study designs. It describes key epidemiological concepts relevant for evidence appraisal. Regarding study reliability, measures of association, exposure assessment, statistical inferences, systematic error and effect modification are explained. Regarding study relevance, the guidance describes the concept of external validity. The principles of appraising epidemiological studies are illustrated, and an overview of Risk of Bias (RoB) tools is given. A decision tree is developed to assist in the selection of the appropriate Risk of Bias tool, depending on study question, population and design. The customisation of the study appraisal process is explained, detailing the use of RoB tools and assessing the risk of bias in the body of evidence. Several examples of appraising experimental and observational studies using a Risk of Bias tool are annexed to the document to illustrate the application of the approach. This document constitutes a draft that will be applied in EFSA's assessments during a 1-year pilot phase and be revised and complemented as necessary. Before finalisation of the document, a public consultation will be launched.

Quality assessment of prevalence studies: a systematic review

OBJECTIVES

The objective of the study is to identify items and domains applicable for the quality assessment of prevalence studies.

STUDY DESIGN AND SETTING

We searched databases and the gray literature to identify tools or guides about the quality assessment of prevalence studies. After study selection, we abstracted questions applicable for prevalence studies and classified into at least one of the following domains: 'population and setting', 'condition measurement', 'statistics', and 'other'. PROSPERO registration:CRD42018088437.

RESULTS

We included 30 tools: eight (26.7%) specifically designed to appraise prevalence studies and 22 (73.3%) adaptable for this purpose. We identified 12 unique items in the domain "population and setting", 16 in the domain "condition measurement", and 14 in the domain "statistics". Of those, 25 (59.5%) were identified in the eight specific tools. Regarding the domain "other", we identified 77 unique items, mainly related to manuscript writing and reporting (n = 48, 62.3%); of those, 24 (31.2%) were identified in the eight specific tools and 53 (68.8%) in the additional 22 nonspecific tools.

CONCLUSION

We provide a comprehensive set of items classified by domains that can guide the appraisal of prevalence studies, conduction of primary prevalence studies, and update or development of tools to evaluate prevalence studies.

Meat, fruit, and vegetable consumption in sub-Saharan Africa: a systematic review and meta-regression analysis

CONTEXT

The dietary choices people make affect personal health and have consequences for the environment, both of which have serious implications for the 2030 Sustainable Development Agenda. In global reviews, the literature on meat, fruit, and vegetable consumption in sub-Saharan Africa (SSA) is limited.

OBJECTIVE

This systematic review set out to quantify meat, fruit, and vegetable consumption in SSA populations and to answer the following question: How much meat, fruit, and/or vegetables are being consumed daily by which individuals in SSA over the years?

DATA SOURCES

Following the PRISMA guidelines, the authors systematically searched the MEDLINE, EMBASE, ASSIA CINAHL, Web of Science, POPLINE, and Google Scholar databases to identify 47 (out of 5922 search results) studies reporting meat, fruit, and/or vegetable consumption in SSA populations.

DATA EXTRACTION

Three independent investigators extracted data on year of data collection, study country, study population and geographical context, and population intake of meat, fruit, and/or vegetables.

DATA ANALYSIS

Using STATA SE version 15 software, random-effects meta-regression analyses were used to test the effect of year of data collection and method of data collection on population meat, fruit, and vegetable consumption. The analyses also tested any association between age, sex, rural/urban residence, or a country's economic development and population intake of meat, fruits, and/or vegetables. The review was started in 2017 and completed in 2019.

RESULTS

Richer SSA countries were likely to consume more meat (ß = 36.76, P = 0.04) and vegetables (ß =43.49, P  = 0.00) than poorer countries. Vegetable intake has increased dramatically over the last 3 decades from ≈10 g to ≈110 g (ß = 4.43, P  = 0.00). Vegetable (ß= -25.48, P  = 0.00) consumption was higher in rural than in urban residents. Although the trend of meat consumption has risen (≈25 g to ≈75 g), the trend is nonsignificant (ß = 0.63, N.S.). Daily average per capita meat consumption was 98 g - above the 70 g recommendation - while fruit and vegetable intake (268 g) remain below the World Health Organization's recommendation (400 g).

CONCLUSIONS

Given the low intake of plant-based foods, it is likely that SSA populations may be deficient in high-quality protein and micronutrients as suggested by the EAT-Lancet Commission. There is a need to promote both an adequate supply and demand of plant-based protein and micronutrients, including fruit, vegetables, nuts, seeds, and legumes, in SSA countries. While dietary changes in SSA may offer large absolute benefits, consideration of the magnitude of dietary change, particularly increasing or reducing meat consumption, will need to occur in a way that ensures that policy and interventions support the reduction of undernutrition and micronutrient deficiencies without worsening the prevalence and environmental impacts of noncommunicable diseases. There is also the need for preventive action that ensures that SSA populations do not increase their meat consumption as disposable incomes increase and countries' economic development rises, as is seen in most countries undergoing economic transformation.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42018090497.

National and regional prevalence of posttraumatic stress disorder in sub-Saharan Africa: A systematic review and meta-analysis

BACKGROUND

People living in sub-Saharan Africa (SSA) are disproportionately exposed to trauma and may be at increased risk for posttraumatic stress disorder (PTSD). However, a dearth of population-level representative data from SSA is a barrier to assessing PTSD. This manuscript sought to calculate pooled PTSD prevalence estimates from nationally and regionally representative surveys in SSA.

METHODS AND FINDINGS

The search was conducted in PubMed, Embase, PsycINFO, and PTSDpubs and was last run between October 18, 2019, and November 11, 2019. We included studies that were published in peer-reviewed journals; used probabilistic sampling methods and systematic PTSD assessments; and included ≥ 450 participants who were current residents of an SSA country, at least 50% of whom were aged between 15 and 65 years. The primary outcomes were point prevalence estimates of PTSD across all studies, and then within subgroups. The protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO) (registration number CRD42016029441). Out of 2,825 unique articles reviewed, 25 studies including a total of 58,887 eligible participants (54% female) in 10 out of the 48 countries in SSA were identified. Most studies enrolled any adult aged 18 years or older. However, some studies only enrolled specific age brackets or persons as young as 15 years old. Six studies were national surveys, and 19 were regional. There were 4 key findings in the meta-analysis: (1) the overall pooled prevalence of probable PTSD was 22% (95% CI 13%-32%), while the current prevalence-defined as 1 week to 1 month-was 25% (95% CI 16%-36%); (2) prevalence estimates were highly variable, ranging from 0% (95% CI 0%-0%) to 74% (95% CI 72%-76%); (3) conflict-unexposed regions had a pooled prevalence of probable PTSD of 8% (95% CI 3%-15%), while conflict-exposed regions had a pooled prevalence of probable PTSD of 30% (95% CI 21%-40%; p < 0.001); and (4) there was no significant difference in the pooled prevalence of PTSD for men and women. The primary limitations of our methodology are our exclusion of the following study types: those published in languages other than English, French, and Portuguese; smaller studies; those that focused on key populations; those that reported only on continuous measures of PTSD symptoms; and unpublished or non-peer-reviewed studies.

CONCLUSIONS

In this study, PTSD symptoms consistent with a probable diagnosis were found to be common in SSA, especially in regions exposed to armed conflict. However, these studies only represent data from 10 of the 48 SSA countries, and only 6 studies provided national-level data. Given the enormous heterogeneity expected across the continent, and also within countries and regions, this review cannot speak to rates of PTSD in any regions not included in this review. Thus, substantial gaps in our knowledge of PTSD prevalence in SSA remain. More research on population-level prevalence is needed to determine the burden of trauma symptoms and PTSD in SSA and to identify acceptable and feasible approaches to address this burden given limited mental healthcare resources.