Review protocol development
We will use the Preferred Reporting Items for Systematic review and Meta-analyses (PRISMA) to develop the review protocol [28] and PRISMA-P 2015 checklist to report the review findings [29] (Additional file 1).
PECO search guide
Population: Young people (10–24 years old) [30].
Exposure: exposures are determinants that increase or decrease the likelihood of preventive practice toward sexually transmitted infections.
Comparison: The reference group for each determinant in each study will be the comparison variable. It may include good knowledge versus poor, positive attitude versus negative, education versus no education, access to information versus no accesses, consistent use of condoms versus not, etc.
Outcome: The outcome variable will be preventive practices of sexually transmitted infection (STIs). We will consider studies with the primary objective to determine the prevalence of preventive practices of sexually transmitted infections (STIs) and its determinants among young people in Ethiopia.
Data source and searching strategies
We will use online databases such as PubMed, CINAH, Google, and Google Scholar to search published and unpublished studies. The two authors (EW and SB) will retrieve the studies. In addition, we will use a cross-reference search to add other related studies from the final included studies that may miss in the databases search. The search term or keywords will be (Sexually Transmitted infections OR Sexually Transmitted Diseases OR STIs OR Gonorrhea OR Infection OR HIV Infections OR HIV/AIDS OR Human papillomavirus OR Prevalence OR behaviors OR prevention & control OR control OR Practice OR Sexual Behavior OR Sexual Partners OR Unsafe Sex OR utilization OR Sexual Abstinence OR Unsafe Sex OR Condoms OR Condoms use OR preventive practices) AND (Humans OR Adolescence OR Adolescent OR Female OR Male OR Young Adult OR young people OR youths OR unmarried youths) AND (Factors Or predictors OR determinants OR Health Knowledge OR knowledge OR Attitudes OR Attitude to Health OR risk perception OR female sex workers OR commercial sex OR oral sex Or anal sex OR Family Characteristics OR Parents OR education OR alcohol-related sex OR drug-related sex OR Multiple Sexual Partners OR Premarital Sex OR Unprotected Sex OR Unsafe Sexual Practice OR risky sexual behavior OR Risky OR Sexuality) AND (Ethiopia OR Rural OR urban OR community survey OR institution survey OR Sub-Saharan Africa OR low income country OR Developing country) (Additional file 2). The search string will be adapted based on the specific requirement of the database to identify relevant studies. We will export retrieve studies to Endnote version 8 reference manager software [31].
Eligibility criteria
We will include all observational studies (cross-sectional, case-control, and cohort) in the systematic review and meta-analysis. We will include studies that reported the prevalence of preventive practices of sexually transmitted infection (STIs) and its determinants among young people in Ethiopia. Moreover, we will also consider studies that reported only the prevalence of preventive practices of sexually transmitted infections (STIs) or at least measured association between determinants variables with the preventive practice of sexually transmitted infections (STIs). We will include both institutional and community-based studies. We will exclude studies that only address the qualitative approach. However, studies that examine both quantitative and qualitative study findings will only consider the quantitative results. We will not make restrictions to the date of publication. We will exclude studies published other than the English language, expert opinions, conferences, national surveys, and case reports.
Selection of studies
The two authors (EW and SB) will independently screen the studies based on the titles and abstract. We will remove or exclude duplicates, irrelevant titles, and abstracts studies from the citation manager. We will further evaluate the studies of the full text for quality. We will exclude Full-text studies that will not be eligible and include eligible studies in systematic review and meta-analysis. We will discuss with the third author (MA) to solve any disagreement among reviewers during the review process. We will present the selection process flow diagram using the PRISMA chart (Additional file 3).
Quality assessment
To assess the quality and validity of the studies, we will use the Joanna Briggs Institute Meta-Analysis of Statistics Assessment and Review Instrument (JBI-MAStARI) [32]. The quality assessment will focus on clear inclusion criteria, study subjects and setting, standard measurement criteria, exposure and outcomes measurement, and appropriate statistical analysis (Additional 4). The quality of the studies will be assessed independently by the two authors (EW and SB). We will include studies 50% and above of the quality scale and considered them for final systematic review and meta-analysis. We will solve any disagreement among reviewers during the quality review of the studies by the third author (MA).
Data extraction
We will construct a data extraction template form on Microsoft Excel (2016). Before the beginning of the actual data extraction, we will pilot the Microsoft Excel data extraction form. We will include the first author's name, publication year, the study area, study design, sample size, associated factors, odds ratio, and prevalence of the studies on the data extraction template. In addition, we will calculate the logarithm and standard error (SE) of the prevalence and odds ratio. The two authors (EW and SB) will extract the data independently. We will discuss any difference with a third author (MA) to reach on consensus. We will contact the corresponding author of the studies in case of missing data or incomplete reports.
Data synthesis and statistical analysis
We will present the narrative synthesis of data for the included studies. We will prepare a summary table and graph to describe the characteristics of the included studies. We will use a random-effects model [33] to estimate the overall pooled prevalence of preventive practices of sexually transmitted infections (STIs) and identify its determinants among youths in Ethiopia. We will use 95% CI to declare the statistical significance. We will check statistical heterogeneity using the Cochran Q test [34] and I2 statistics [35]. I2 values represent 25% low, 50% moderate, and 75% substantial heterogeneity. We will perform subgroup analyses and meta-regression to identify the sources of heterogeneity. We will do sensitivity analysis to assess the effect of studies on the overall estimation. We will also check the presence of publication bias using funnel plot [36], Egger’s, and Beggar’s test [37].