Depression and anxiety among children and adolescents during the COVID-19 pandemic in Europe: A systematic review protocol

doi:10.21203/rs.3.rs-1638547/v2

Background: A growing number of studies point to a high mental health burden among children and adolescents during the COVID-19 pandemic, particularly concerning depression and anxiety. However, the study quality and effect direction are heterogeneous in the existing studies with a lacking overview for the European continent. Therefore, research gaps exist particular regarding (1) the impact of the COVID-19 pandemic on depression and anxiety among children and adolescents in European countries with (2) a methodologically high-quality summarizing review of studies. Therefore, the planned systematic review aims to close these gaps.

Methods: The systematic review was registered in the Prospective Register of Systematic Reviews (PROSPERO) and the protocol was prepared in accordance to the Preferred Reporting Items for Systematic review and Meta-Analysis Protocols (PRISMA-P) statement. Search strategy was peer reviewed according to the evidence-based checklist Peer Review of Electronic Search Strategies (PRESS). Systematic search was conducted in six databases (MEDLINE, EMBASE, PsycINFO, Cochrane Central Register of Controlled Trials, Web of Science and WHO COVID-19 database). Literature screening will be conducted independent by two authors, disagreement will be solved by a third author. Risk of bias (RoB) will be assessed using the RoB instrument for non-randomized studies of exposures. Certainty of evidence will be evaluated by using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach adapted to the use of non-randomized studies. Also, subgroup analysis, sensitivity analysis, and publication bias will be performed.

Discussion: This systematic review will summarize the actual overall prevalence of depression and anxiety among children and adolescents in European countries compared to a pre-pandemic baseline with an expert opinion on the clinical relevance and extrapolation of depression and anxiety in children and adolescents in the next years. In addition, it aims identifying geographic and pandemic-policy differences and designate particularly vulnerable risk groups within European children and adolescents.

depression

anxiety

COVID-19

children

adolescents

Europe

systematic review

systematic review protocol

The COVID-19 pandemic affects many public health (PH) fields. Besides disease rates, persistent symptoms (Long-COVID) and death, impacts on mental health aspects are essential with regard to short-term and long-term well-being [1,2]. To keep incidence rates as low as possible, governments used various combinations of social isolation strategies [3–5]. However, compared to adults, children and adolescents (CA) represent a particularly vulnerable group and tend to be affected differently by the pandemic and social distancing policies. The short-term health effects of COVID-19 infections on CA without comorbidities seemed to generally be mild, e.g. clinically mild disease or asymptomatically infection [6–8]. However, a growing number of studies point to a high mental health burden among the youth during the pandemic, particularly regarding depression and anxiety (DA) [6,9–11].

In studies of earlier pandemics and disease-related quarantine, associations between loneliness and isolation with mental health problems such as DA are already well described in CA [12,13]. Many of the exposed children began using mental health services and were particularly affected by depressive symptoms [14,15]. Hence, CA seemed to be particularly vulnerable to isolation or loneliness which could lead to an increase in mental health impacts through COVID-19 containment measures [16]. According to UNICEF pre-pandemic estimates, the prevalence of mental disorders for boys and girls aged 10–19 in Europe was 16.3% in 2019; thus, DA were the most common mental health disorders and accounted for 55% within CA mental disorders [13].

Within the ongoing COVID-19 pandemic, the number of primary studies on the effects of the pandemic on DA among CA is rapidly increasing. However, the existing studies provide partially contradictory findings [17,18], have different results regarding the magnitude of DA [9] and used heterogeneous diagnostic instruments [9]. Up to now existing systematic reviews primarily focus on the general population [19], the global prevalence of DA among CA [9] or the situation in China [20].

So far, two research gaps exist: (1) Analysis of the impact of the COVID-19 pandemic on DA among CA in European countries (taking pandemic-specific national context variables into account) with (2) a high-quality methodological approach (e.g. considering a pre-pandemic baseline). Thereby, it remains unclear which vulnerable groups exist among CA in the European context, which clinical relevance a changed DA prevalence may have, and which influence certain determinants could have on the DA in CA.

As mental health is an essential predictor for health over the life course of CA [1,2], a comprehensive, systematic and differentiated analysis of the COVID-19 impact on DA among CA in Europe is of particular PH interest.

Therefore, the planned systematic review (SR) aims to

Estimate the change in overall prevalence of DA among CA in Europe before versus during the COVID-19 pandemic.
Conduct an effect pooling within particular European countries and comparison with other European countries (a quasi-experimental design), if possible.
Outline the clinical relevance of the available results and extrapolation of DA in CA in the next years, if possible.
Perform stratified analyses regarding relevant factors: demographic (e.g. age, sex), social status (e.g. education) and methodological (e.g. pandemic time point, study quality) determinants, if possible.

In this protocol of the planned SR, the used methods will be described.

The SR was registered on the International Prospective Register of SR (PROSPERO) (CRD42022303714) (Appendix 1). This protocol is prepared in accordance with the Preferred Reporting Items for Systematic review and Meta-Analysis Protocols (PRISMA-P) statement [21] (Appendix 2); the PROSPERO record will be updated regularly.

The final SR will be conducted according to updated PRISMA statement [22] and will follow the guidelines of the actual Cochrane Handbook for SR, as far as possible [23].

Eligibility criteria and information sources

In accordance with general recommendations the Population-Intervention-Comparison-Outcome (PICO) scheme was used [23]. Based on the examination of an environmental exposure, namely the COVID-19 pandemic, the research question was formulated within a Population-Exposure-Comparison-Outcome (PECO) scheme [24]:

Population: General population ≤19 years in Europe
Exposure: COVID-19 pandemic
Comparison: Pre-pandemic baseline
Outcome: Depression or anxiety

The eligibility criteria were conducted in accordance to the PECO scheme and are presented in Table 1. Also, further categories were defined, e.g. effect measure, study design, language, time frame and publication status.

The search plan includes the following databases: MEDLINE (Pubmed), EMBASE, PsycINFO, Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science and WHO COVID-19 database (also including pre-prints). Also, study registries (e.g. PROSPERO), relevant grey literature (e.g. government reports), related articles, reference lists of included articles and previous published reviews will be screened. Translating the research question into a search string was performed in accordance with the guideline for Peer Review of Electronic Search Strategies (PRESS) [25]. Development of the database specified search strings occurred using validated or recommended search filters where possible (e.g. for identifying pediatric studies in PubMed [26], search strings for COVID-19 records in PubMed [27,28], search filters offered by the InterTASC Information Specialists’ Subgroup Search Filter Resource [29]; in parts adapted). Both free-text and subject headings (e.g. Medical Subject Headings [MeSH], Emtree) will be used in combination with the adequate use of the Boolean operators “AND” and “OR”. The search strategy was peer reviewed before the searches were run by an expert in conducting SR in health sciences according to the evidence-based checklist PRESS Evidence-Based Checklist [25] to ensure a high-quality search strategy (search submission and peer review assessment are attached in Appendix 3 and 4). The draft search strategy for Pubmed is presented in Appendix 5.

Study selection will be conducted in three steps: (1) duplicates removal; (2) screening at title and abstract level; and (3) screening the full text. Several publications with the equal or similar study population will be considered once; duplicates with e.g. smaller sample sizes will be excluded. Two independent reviewers will screen the studies in step (2) and (3); any discrepancies will be discussed and, if necessary, resolved by a third author. The reasons for study exclusion in step 3 will be reported in the Appendix of the final study. All screening procedures will be presented using the PRISMA flow diagram [22]. It is also intended to use the recommended EPPI-Reviewer Web software in all screening steps [30].

Data extraction

Data extraction will be conducted by two authors using specially developed tabular data collection forms [23]. These forms will be pilot tested with about one third of the included studies by both authors transferring the data independently from the studies to the forms and discussing possible discrepancies. Remaining data extraction will be then completed by one reviewer and verified by the other. Any discrepancies between the two reviewers will be discussed extensively and, if necessary, resolved by a third author.

The following data categories will be extracted:

Study information
Information on study population
COVID-19 determinants
Pre-pandemic baseline
Outcomes and findings

Risk of bias assessment

The risk of bias (RoB) will be assessed using the RoB instrument for non-randomized studies of exposures [31]. This instrument is an adaption of the Risk Of Bias In Non-Randomized Studies of Interventions (ROBINS-I) tool regarding effects of environmental exposures on health outcomes [31,32], which is recommended by the Cochrane Handbook for Systematic Reviews [33]. This instrument contains seven RoB items: 1) Bias due to confounding, 2) Bias in selection of participants into the study, 3) Bias in classification of exposures, 4) Bias due to departures from intended exposures, 5) Bias due to missing data, 6) Bias in measurements of outcomes, and 7) Bias in selection of reported results. The defined criteria for each category to assess the included studies will be described in the Appendix of the final study. Judgments for each RoB item could be: “Low RoB”, “Moderate RoB”, “Serious RoB”, or “Critical RoB”. Also, an overall judgment about the bias at the study level is either “Low RoB”, “Moderate ROB”, “Serious RoB”, or “Critical RoB”. The visualization of the RoB assessments will be performed as “traffic light” plots of the domain-level judgements for each individual result and weighted bar plots of the distribution of risk-of-bias judgements within each bias domain, using the tool robvis [34].

Decisions in public health should be based on the best available evidence. Therefore the certainty of evidence for each outcome will be evaluated by using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach adapted to the use of non-randomized studies [35]. GRADE assessments of certainty are determined through consideration of five domains: RoB, inconsistency, indirectness, imprecision and publication bias. Also, assessments can be upgraded through consideration of three further domains: large effects, dose response and opposing plausible residual bias and confounding [36]. The use of the RoB instrument for non-randomized studies will allow to start at “high” initial certainty of evidence within GRADE [31]. The certainty of evidence will be report in the results section for each outcome in a “Summary of findings” table, when applicable [36]. The GRADE approach finally specifies four levels of the certainty for a body of evidence for each outcome: “high”, “moderate”, “low” and “very low”.

The ratings for RoB and GRADE will be separately conducted by two reviewers, and disagreement will be resolved by discussion with involvement of a third author where necessary.

Data synthesis

In accordance with the Cochrane Handbook [23] the characteristics of each study will first be summarized in a “Characteristics of included studies” table. Second the data will be checked which studies are similar enough to be grouped within a comparison by comparing the characteristics across studies (e.g. in a matrix) and it will be determined what data are available for synthesis. If appropriate, a statistical synthesis (meta-analysis) will be performed as random-effects meta-analysis developed by DerSimonian and Laird [37] using a statistical software. If a statistical pooling (meta-analysis) appears to be inappropriate, e.g. if data are highly heterogeneous or if study designs differ considerably, a tabular, graphical or narrative synthesis will be provided [38]. Finally, an interpretation description of the results will be performed, including consideration of the direction of effect and size of the effect. Any deviations from the protocol plans will be notated.

Heterogeneity will be measured by using the I² statistics [39]. I² can range from 0 to 100%, with 100% represent considerable heterogeneity [39].

Sensitivity analysis

To determine whether the pooled results are robust, sensitive analysis will be conducted. This includes the repetition of the primary analysis or meta-analysis with different comparison categories [23] e.g. for different study types, different pandemic time points and RoB [31].

Publication bias

The systematic review will also address RoB due to missing results in a synthesis. Graphical and statistical methods will be used to provide information about the extent of missing results. Funnel plots will be generated and visually interpreted for signs of asymmetry, which could indicate that publication bias is present [40,41]. When at least 10 studies of different sample size will be included in meta-analysis, also statistical tests will be used to test for funnel plot asymmetry [42].

This protocol aims to provide a description of the approach and used methods of the SR addressing the real impact of the COVID-19 pandemic on DA among CA in Europe in contrast to the perceived impact of many clinical and epidemiological observations without pre-pandemic baseline. The results of the SR will provide relevant evidence in order to address the gap in the literature with a high-quality methodological approach.

As a strength of the systematic review it can be pointed out that we will rigorously follow the recommendations of the Cochrane Handbook for systematic reviews of interventions [23], if applicable. Only methods and instruments that have already been tested and approved will be used. Although the study design will be not limited, it can be assumed that in particular observational studies will be included in the final systematic review. At present, there is no applied guideline for the preparation of a systematic review for observational studies or other study designs besides RCTs; however, some guidelines are in preparation [43–45]. The Cochrane Handbook for systematic reviews of interventions [23] is widely cited as the gold standard for preparing systematic reviews. However, it offers very few descriptions of how to prepare and conduct a systematic review with observational studies. Considering this, we aspired to use the methods of the Cochrane Handbook [23] as far as possible and where it will be not applicable, we plan to use instruments recommended in the literature, e.g. RoB instrument for non-randomized studies of exposures [31].

CA	children and adolescents
COVID-19	coronavirus disease 2019
DA	depression and anxiety
GRADE	Grading of Recommendations Assessment, Development and Evaluation
PECO	Population-Exposure-Comparison-Outcome
PH	public health
PRESS	Peer Review of Electronic Search Strategies
PRISMA-P	Preferred Reporting Items for Systematic review and Meta-Analysis Protocols
PROSPERO	Prospective Register of Systematic Reviews
RoB	risk of bias
SR	systematic review

Ethics approval and consent to participate

No ethics approval is required for this protocol as it is based on information from the published data.

Consent for publication

No consent is required as this review is based on information obtained from previously published data.

Availability of data and materials

Data sharing is not applicable to this article as no datasets were generated or analyzed during the current study.

Competing interests

All authors declare no conflict of interest.

Funding

All authors declare that no funds, grants, or other support were received during the preparation of this manuscript.

Authors' contributions

MB is the project leader. HLW and MB formulated the research question with clinical feedback from JMF. All authors contributed to the study conception and design. Material preparation, data collection and analysis were/will be performed by HLW, ID and LP. The first draft of the manuscript was written by HLW and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.

Acknowledgements

We would like to thank Sabrina Schlesinger for peer-reviewing our Pubmed search strategy according to the PRESS guidelines.

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Table 1. Inclusion and exclusion criteria of the systematic review according to the PECO scheme

Category	Inclusion criteria	Exclusion criteria
Population	General population ≤19 years of both sexes and of any ethnicity in Europe Europe will be defined as European continent according to the definition of WHO Regional Office for Europe [16]	Studies with population samples with >19 years or mixed population samples of children, adolescents and/or adults Studies with any population group outside of Europe Samples of children with preexisting psychiatric diagnoses Countries that are not included in the WHO overview [16]
Exposure	Data collection within Covid-19 pandemic	Previous pandemics Studies that analyzed depression and anxiety due to the use of alcohol or other drugs
Comparison	Pre-pandemic baseline (numerically recorded)	No comparison Comparisons of two time points within the Covid-19 pandemic
Outcome	Depression or anxiety, based on self-reports or (validated) measurements	Other outcomes
Effect measures	All effect measures	-
Study design	All study designs	-
Language	English, German	Other languages
Time frame	1.11.2019 – 18.3.2022	Other time frames
Publication status	Published studies, grey literature, pre-prints	Other publication status
Species	Human studies	Animals studies

No competing interests reported.

20220518AppendixProtocolCovid19MentalHealthChildAdol.docx

Depression and anxiety among children and adolescents during the COVID-19 pandemic in Europe: A systematic review protocol

Status:

Version 2

Abstract

Background

Methods

Discussion

Abbreviations

Declarations

References

Table

Additional Declarations

Supplementary Files

Status:

Version 2