Systematic Review

A systematic review answers one focused question by finding, appraising, and synthesizing all relevant studies with a transparent, reproducible method. The costly failure it prevents is post-hoc bias: deciding what counts as evidence after seeing the results. Every eligibility decision is therefore locked in a protocol before the first search runs, and every excluded study leaves a logged reason. Follow PRISMA 2020 throughout.

Operating procedure

Order is mandatory: the protocol must exist before the search, and the search before screening, or the review is not systematic - it is a literature review wearing a lab coat (route that job to literature-review).

Step 1: Gather inputs and frame the PICO question

Collect from the user before starting:

• The research question, decomposed into Population, Intervention/Exposure, Comparison, Outcome. If it has no clear PICO, refuse and help them write one - a question like "is telehealth good?" cannot be reviewed.
• Intended study designs (RCTs only? observational too?).
• Databases available to them (default: PubMed/MEDLINE, Embase, plus one field-specific database - a minimum of 3).
• Team size: two independent screeners are required; if the user is solo, flag this as a methodological limitation up front, not in the discussion section.
• Timeline and whether meta-analysis is intended.

Label any assumed input as a guess and confirm before Step 3.