This protocol was prepared in accordance with the usual structured methodology for systematic reviews (PRISMA-P 2015) [21, 22]. The protocol is registered on an appropriate website, the International Prospective Register of Systematic Reviews (PROSPERO) database under the number CRD42023413973.
Research question
What is the prevalence of unprotected sex and multiple sexual partners among adolescents and young adults in West Africa?
Eligibility criteria
Studies will be selected according to the following criteria: participants, outcome(s) of interest, study design, and context [23, 24].
Participants (Population)
The review will include studies involving adolescents and young adults living in West Africa aged 15–24 (regardless of gender).
Outcomes of interest
Two primary outcomes are expected. The prevalence of unprotected sex and the prevalence of multiple sexual partnerships. The prevalence of unprotected sex indicate the number of people that has the condition divided by the population number at a given point in time.
The prevalence of unprotected sex indicates the number of young adults not using condoms divided by the number of young adults at a given point in time. Similarly, the prevalence of multiple sexual partnerships indicates the number of young adults with multiple sexual partners divided by the number of young adults at a given point in time. This is often presented as a (prevalence) proportion. Secondary outcomes will be the prevalence of other sexual behaviors at risk. Potential sexual behaviors at risk may include the following: early sexual activity and alcohol and drug use before sexual intercourse.
Study design
Studies reporting the prevalence of unprotected sex or multiple sexual partnerships will be eligible. These studies must be observational studies (cohort, cross-sectional, or health surveys) reporting prevalence data using either validated or non-validated tools and conducted in West Africa. Cross-sectional studies are the most appropriate for assessing the prevalence of risky sexual behaviors, so only data from the initial cross-sectional phase of cohort studies will be considered. Randomized trials, quasi-experimental studies, case studies, case series, qualitative studies, systematic reviews, protocols, commentaries, and editorial studies will be excluded.
Context/settings
We will include studies conducted in West African countries. Unpublished studies, such as conference proceedings and abstracts, will be eligible for inclusion. We will only include studies published in English (or with an English translation available) from January 2013 onwards that have been conducted between January 1st, 2013, and December 30th, 2023. We have chosen to include studies carried out within the last ten years to have more recent data that will serve as leverage for the implementation of strategies to combat STIs.
Information sources and search strategy
We will conduct systematic searches of the following electronic databases: PubMed/MEDLINE, Embase, African Index Medicus. In addition, we will systematically search electronic academic databases, health organization websites, electronic grey literature, and internet search engines (Google Scholar). The search strategy will combine the following key concepts and their synonyms: “Sexual risk behavior”, “multiple sexual partners”, “unprotected sex”, “adolescent”, “young adult”, “West Africa”.
Selection of studies
First, the results of the systematic search will be downloaded into Zotero to identify duplicate references for deletion. Then, the references will be uploaded into Rayyan ( http://rayyan.qcri.org ), a free web-based tool for independent study selection [25] .
In a second step, two reviewers will independently review (i) the titles and abstracts according to the eligibility criteria to identify studies for inclusion and (ii) the full texts of the previously selected articles. Disagreements will be resolved by discussion or by involving a third reviewer.
All studies excluded on the basis of the full text will be listed in a table with their reasons for exclusion. The final list of included studies will be checked by both reviewers.
The results of the study selection process will be reported in the review and in a flow chart [26] .
Data extraction
Data will be extracted independently by both examiners using a standardized Excel extraction form. To ensure consistency between the reviewers, benchmarking exercises will be carried out before the extractions begin. Discrepancies will be resolved by consensus or by arbitration by a third reviewer if necessary.
The extracted information will include the following information:
-
General information: study background (study authors and year of publication, study country, published or unpublished data, level of study implementation).
-
Study characteristics: type of study, study period, funding, ethical approval.
-
Population characteristics: type of population, age/age group, total number of participants, percentage of males and females, percentage of children under 19 years, number of pupils.
-
Outcomes: (1) prevalence of condom non-use, (2) prevalence of multiple sexual partnerships, (3) prevalence of early sexual intercourse and (4) prevalence of drug use before sexual intercourse (number of patients tested, number of patients with result, percentage of men with result).
-
Data related to number of homosexuals, number of people with sexually transmitted diseases, STI complications, number of drug users, sex workers.
-
Data to assess risk of bias: (1) representativeness of target population, (2) representativeness of sampling frame, (3) assessment of random selection, (4) assessment of non-response bias, (5) method of data collection (direct or indirect), (6) case definition, (7) assessment of the instrument for measuring the parameter of interest, (8) mode of data collection, (9) assessment of results, (10) reporting of the parameter of interest, (11) overall risk of bias of the study.
Assessment of risk of bias in included studies
The risk of bias in included studies will be assessed using tools developed specifically for prevalence studies [27]. This tool is based on ten criteria or items plus an assessment summary. Items 1 to 4 assess the external validity of the study (the domains are selection bias and non-response bias), items 5 to 10 assess the internal validity (items 5 to 9 assess the extent of measurement bias and item 10 assesses analytical bias). The summary of items concerning the overall risk of bias of the study is a subjective judgement made by the reviewers based on the responses to the first 10 items. This is based on the GRADE (Grades of Recommendation, Assessment, Development and Evaluation) and Cochrane approach [28] .
Data synthesis
If possible, each outcome data will be quantitatively synthesized (meta-analysis) using R or STATA software. The pooled prevalence of each sexual risk behavior will be estimated if the studies are sufficiently homogeneous in terms of design and comparator. Statistical heterogeneity between studies will be assessed using the chi-square test (significance level: 0.1) and the I2 statistic (0–40%: may not be significant; 30–60%: may represent moderate heterogeneity; 50–90%: may represent significant heterogeneity; 75–100%: considerable heterogeneity) [29]. In addition, publication bias will be examined using the Egger test with funnel plots. If there is heterogeneity, we will try to explore the source through subgroup or sensitivity analysis. If the heterogeneity is not significant, we will run the fixed effects model using the Mantel-Haenszel method. If statistically significant heterogeneity is observed (I2 > = 50% or p-value < 0.1), we will run the random effects model. Sensitivity analyses will be used to examine the impact of publications on the overall prevalence. If the quantitative synthesis was not feasible, a narrative synthesis and qualitative summary of the results will be carried out providing information in text and table form to summarize and explain the characteristics and results of the included studies.
Subgroup analysis and investigation of heterogeneity
In the event that heterogeneity is observed, subgroup analyses will be conducted to investigate possible sources of heterogeneity, including differences in effect estimates across countries, settings and years of study, or characteristics of adolescents and young adults. Analyses will be conducted where possible according to patient characteristics (e.g. gender, age), adolescents with STIs, high-risk groups (drug users, gay men, sex workers, etc.). In addition, subgroup analyses will be performed for covariates, such as background, year of study and demographic characteristics, where these may affect the pooled estimates. Finally, the following sensitivity analyses could be performed to explore sources of heterogeneity: published versus unpublished data, and risk of bias (excluding studies deemed to be at high risk of bias).
Overall quality of evidence assessment
The quality of evidence will be assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) tool [28]. The outcome will be assessed from the five aspects: limitations, inconsistency, indirectness, imprecision, and publication bias, and grade the risk in one of four categories: 'very low', 'low', 'high' and 'very high'. The strength of the recommendations from these included studies will be assessed according to the quality of the evidence presented.
Patient and public involvement
No patients involved in this study.
Strengths and limitations of this study
-
This study could provide global and specific data on the prevalence of risky sexual behaviors among adolescents and young adults living in West Africa,
-
The reliability of the pooled results will be based on the comprehensiveness and the methodological quality of the studies included in this review.
-
It’s important to mention, including the possible heterogeneity due to the different types of study designs and the wide range of sample sizes.