Reporting of the review findings
This protocol was developed following the Preferred Reporting Items for Systematic Review and Meta-analysis Protocols (PRISMA-P) statement (15). The protocol has been submitted to the International Prospective Register of Systematic Reviews (PROSPERO) database and is awaiting registration. The Preferred Reporting Items for Systematic review and Meta-analyses (PRISMA-2009) statement will be used to report the findings (16).
Eligibility Criteria
This review will include studies based on the following inclusion criteria: 1) the study is an observational study design including prospective and retrospective cohort studies, case-control studies, and cross-sectional studies; 2) published in English; 3) studies report the prevalence of rectovaginal GBS colonization or rate of vertical transmission of GBS or GBS antibiotic resistance pattern among pregnant women; 4) study was conducted in Ethiopia. Studies will be excluded if the full text of the article is neither available nor accessible after three emails to the corresponding authors. Additionally, commentaries, letters to the editor, reviews (narrative, systematic, scoping), study protocols, validation/ methodology studies, meta-analyses, and case reports will also be excluded.
CoCoPop search guide
We will use the Condition, Context and Population (CoCoPop) search guide as follows (17)
Population: We will include studies involving women in the third trimester of pregnancy. The third trimester includes all pregnant women after 28 weeks up to the delivery of the neonate.
Condition: We will include studies reporting on GBS colonization confirmed by rectovaginal swab culture, and/or vertical transmission, and/or antimicrobial resistance
Context: We will include studies conducted in any settings in Ethiopia
Search strategy
A combination of Medical Subject Heading (Mesh), and text words combined using "OR' and "AND" Boolean operators will be used to develop the search strategy for our chosen databases. A systematic search will be done on PubMed (MEDLINE), EMBASE, CINHAL, and Cochrane Library. Our PubMed search string can be found in Additional file 2. Furthermore, we will search the gray literature using Google and Google Scholar. Additionally, reference lists from the included articles will be screened for additional eligible articles. All identified articles will be collated into an EndNote library and duplicates will be removed.
Selection of studies
Identified records will be exported to an excel spreadsheet. Two researchers will independently screen the titles and abstracts from the search results and classify each reference as “Definitely include”, “Unsure”, and “Definitely exclude” based on the inclusion criteria. Disagreements for article inclusion will be resolved through discussion with a third researcher. Articles classified as “definitely include” and “unsure” will be added to a second tab in the excel sheet for the full-text screening. Based on the inclusion criteria, full-text articles will be reviewed and classified as “Definitely include”, and “Definitely exclude”.
Documents will be excluded if they do not meet inclusion criteria. Reasons for full-text exclusion will be documented.
Data extraction
Data will be extracted onto a Microsoft Excel spreadsheet using the JBI systematic review of prevalence studies data extraction tool Data abstraction will include study characteristics summary, population studied, prevalence data with 95% CI if available, vertical transmission, antibiotic resistance, raw data used to calculate prevalence, sample size, outcomes studied. Two of the authors (DB and DGA) will extract the data from the included studies. If there is a discrepancy between data extractors, it will be discussed to reach a consensus. If a consensus cannot be reached, the authors will consult a third reviewer (LBT).
Assessment of methodological quality
A quality assessment of all articles included in the study will be done by three authors (DB, LB, and WG). The Newcastle–Ottawa assessment checklist for observational studies will be used to assess the quality of each study(18). The tool has three sections. The first section will be on methodological assessment and rated out of four stars, and the second section will be on comparability evaluation and will be rated out of two stars. The third section of the quality assessment tool will be on assessing the outcome for each included study and will be rated out of 3 stars. There will be a joint discussion between the authors for uncertainty, and the mean quality score will be used to decide the quality of the included studies in the meta-analysis.
Data synthesis and analysis
Data extracted from each primary (original) study through Microsoft Excel will be exported to Stata Statistical Software: Release 15 (14). A narrative description of the study population, the studies included, the rate of rectovaginal colonization, vertical transmission and antibiotic resistance pattern will be performed. Tables and figures will be used to summarise the selected studies and results. We will determine the pooled prevalence of maternal rectovaginal colonization among pregnant women in Ethiopia.
The magnitude of heterogeneity between the included studies will be quantitatively measured by an index of heterogeneity (I2 statistics)(19). The low, medium, and high heterogeneity will be represented as the I2 values of 25%, 50%, and 75%, respectively. The statistical significance of heterogeneity will be determined by a p-value of I2 statistics. A p-value ≤ of 0.05 will be taken as statistically significant heterogeneity. If the I2 value is greater than 50%, will use the Dersimonian and Liard random effect model to determine the pooled estimates of GBS colonization proportion, rate of vertical transmission, and antibiotics resistance(20). To examine the possible risk of publication bias, we will use funnel plots and Egger’s test(21). A p-value < 0.10 will be considered indicative of statistically significant publication bias. If there is evidence of publication bias, we will use Duval and Tweedie’s trim-and-fill method(22). We will conduct sensitivity analysis, to assess the stability of the pooled estimates to outliers and the impact of individual studies