This section forms a structured abstract of the main features of the systematic review. It must be no longer than 500 words and should contain no abbreviations or references. The abstract must accurately reflect and summarize the systematic review with the main focus on the results of the review.
The abstract should report the essential elements of the review using the following sub-headings in this order:
- Objective: State an overarching review objective structured using the key components of the inclusion criteria (approximately one to two sentences).
- Background: Briefly describe what is already known on the topic and what this review will add to the evidence-base (approximately two to three sentences).
- Inclusion criteria: Summarize the inclusion criteria as it relates to the type of review being conducted. Present the information in one or two sentences – NOT under individual subheadings.
- Methods: List the key information sources searched (those that provided the majority of included studies), any limits placed on the scope of the search (e.g. language), and the date range, or the date of the last search. If the recommended JBI approach to critical appraisal, study selection, data extraction and data synthesis was used, simply state it as such (without naming the actual tool). Otherwise, briefly describe any notable deviations to the methodological approach taken (e.g. criteria used to exclude studies on the basis of methodological quality etc.).
- Results: The bulk of the abstract should be reserved to convey the main results of the review.
- As a general rule, report the number and type of included studies and participants, as well as any pertinent study characteristics. Summarize the overall quality of the included studies and notable aspects of risk of bias.
- Report the results for all main outcomes (not only those that were statistically significant or clinically important). If meta-analyses were conducted report the summary measures (estimated effect) and confidence intervals and ensure statistics are presented in a standard way. If a meta-analysis was proposed but not conducted, report the reason (e.g. clinical or methodological heterogeneity). Where possible, indicate the number of studies and participants for each main outcome. Describe the direction of the effect (e.g. lower, fewer, greater, more, etc.) in a way that is understandable to patients and health care professionals (i.e. which group was favored and the size of the effect) and indicate the measurement scale used, where applicable.
- Conclusions: Provide a conclusion based on a general interpretation of the results considering, for example, the methodological quality of the included studies and any limitations of the review. Briefly convey key implications for practice and/or research.