Two-Way Relationship Between Helicobacter Pylori Infection and Periodontitis: Results from A Systematic Review and Meta-Analysis

appraisal methods;


A B S T R A C T
Aim: Helicobacter pylori (H. pylori) infection and periodontitis have considerable worldwide prevalence once they both present systemic alterations with a possible association between them. Therefore, we have performed this meta-analysis to assess the possible association between H. pylori infection and periodontitis.

Material and Methods: A systematic search in the literature was performed for studies published before
December 2, 2019 in diverse scientific and educational databases. The data was extracted by two investigators and the statistical analysis was performed by Review Manager statistical program with heterogeneity and Odds Ratio (OR) with 95% of Confidence Intervals (CI) calculations as well as a sensitive analysis to assess the accuracy of the results. The value of P<0.05 was considered as significant. In addition, we performed the analysis of the quality of included studies as well as the evaluation for risk of bias.  Provide an explicit statement of questions being addressed with reference to participants, interventions, comparisons, outcomes, and study design (PICOS).

Protocol and registration 5
Indicate if a review protocol exists, if and where it can be accessed (e.g., Web address), and, if available, provide registration information including registration number.

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Eligibility criteria 6 Specify study characteristics (e.g., PICOS, length of follow-up) and report characteristics (e.g., years considered, language, publication status) used as criteria for eligibility, giving rationale.

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Information sources 7 Describe all information sources (e.g., databases with dates of coverage, contact with study authors to identify additional studies) in the search and date last searched.

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Search 8 Present full electronic search strategy for at least one database, including any limits used, such that it could be repeated.

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Study selection 9 State the process for selecting studies (i.e., screening, eligibility, included in systematic review, and, if applicable, included in the meta-analysis).

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Data collection process 10 Describe method of data extraction from reports (e.g., piloted forms, independently, in duplicate) and any processes for obtaining and confirming data from investigators.

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Data items 11 List and define all variables for which data were sought (e.g., PICOS, funding sources) and any assumptions and simplifications made. -

Risk of bias in individual studies
12 Describe methods used for assessing risk of bias of individual studies (including specification of whether this was done at the study or outcome level), and how this information is to be used in any data synthesis.

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Summary measures 13 State the principal summary measures (e.g., risk ratio, difference in means).

#6 Synthesis of results
14 Describe the methods of handling data and combining results of studies, if done, including measures of consistency (e.g., I 2 ) for each meta-analysis.

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Risk of bias across studies 15 Specify any assessment of risk of bias that may affect the cumulative evidence (e.g., publication bias, selective reporting within studies).

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Additional analyses 16 Describe methods of additional analyses (e.g., sensitivity or subgroup analyses, meta-regression), if done, indicating which were pre-specified.

Study selection 17
Give numbers of studies screened, assessed for eligibility, and included in the review, with reasons for exclusions at each stage, ideally with a flow diagram.

Figure 1
Study characteristics 18 For each study, present characteristics for which data were extracted (e.g., study size, PICOS, followup period) and provide the citations.

Summary of evidence 24
Summarize the main findings including the strength of evidence for each main outcome; consider their relevance to key groups (e.g., healthcare providers, users, and policy makers).

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Limitations 25 Discuss limitations at study and outcome level (e.g., risk of bias), and at review-level (e.g., incomplete retrieval of identified research, reporting bias).

Conclusions 26
Provide a general interpretation of the results in the context of other evidence, and implications for future research.

Funding 27
Describe sources of funding for the systematic review and other support (e.g., supply of data); role of funders for the systematic review. -