Natural product extracts for ischemic stroke: a methodological evaluation and meta-epidemiological analysis

Area of Science:

• Neurology
• Pharmacology
• Evidence-Based Medicine

Background:

• Numerous systematic reviews (SRs) and meta-analyses (MAs) exist for natural product extracts (NPEs) in ischemic stroke.
• However, their methodological quality and redundancy remain unquantified, and the impact of PRISMA is unclear.

Purpose of the Study:

• Evaluate the methodological quality of SRs/MAs on NPEs for ischemic stroke.
• Assess the impact of the PRISMA statement on methodological quality.
• Quantify the frequency of redundant publications in this field.

Main Methods:

• Systematic search for SRs/MAs of NPEs for ischemic stroke.
• Methodological quality assessed using AMSTAR-2.
• Redundancy classified using PIC frameworks (population, intervention, comparison).

Main Results:

• 86.1% of SRs/MAs were rated "critically low" in quality, mainly due to unregistered protocols and missing excluded study lists.
• Publications following PRISMA 2020 showed significant improvements in protocol registration, risk of bias assessment, and statistical combination methods.
• Among GBEs and PNEs focused SRs/MAs, 85.5% were redundant, including conceptual and excessive replications.

Conclusions:

• SRs/MAs on NPEs for ischemic stroke exhibit suboptimal methodological quality and high redundancy.
• The PRISMA statement has positively impacted methodological quality.
• Prospective protocol registration and transparent search processes are essential for enhancing evidence synthesis.