A Systematic Literature Review (SLR) is a rigorous, transparent, and reproducible methodology for identifying, evaluating, and synthesizing all relevant research evidence to answer a specific, focused research question.
Unlike traditional literature reviews, an SLR follows a predefined protocol with explicit steps designed to minimize bias and provide a reliable summary of the current state of knowledge. This process typically involves:
- Protocol Development: Defining a clear question (often using the PICO framework: Population, Intervention, Comparator, Outcome).
- Comprehensive Search: Executing an exhaustive search across multiple electronic databases (like PubMed, Embase) using explicit keywords and strategies to capture all published evidence.
- Screening and Selection: Applying predefined inclusion and exclusion criteria to filter studies, typically in a two-stage process (title/abstract screening followed by full-text review).
- Data Extraction and Quality Appraisal: Critically assessing the methodological quality and risk of bias of the included studies, and extracting relevant data.
- Synthesis: Analyzing and synthesizing the findings, which may include a Meta-Analysis (a statistical pooling of results).
SLRs are considered the gold standard for evidence-based decision-making in healthcare. They are essential in Health Economics and Outcomes Research (HEOR) for informing clinical guidelines, developing Health Technology Assessments (HTAs), and justifying the clinical and economic value of new interventions to payers and regulatory bodies.
