systematic-review

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.

Step 2: Write and register the protocol

Document eligibility criteria, databases, full search strings, screening process, extraction fields, risk-of-bias tool, and analysis plan. Recommend PROSPERO registration (health topics) or OSF (other fields). Fill this criteria table - every row, every cell, before searching:

INCLUSION / EXCLUSION CRITERIA - [FILL: review title]

Domain         | INCLUDE                              | EXCLUDE (with justification)
---------------|--------------------------------------|------------------------------------------
Population     | [FILL: e.g. adults ≥18 with T2DM]    | [FILL: e.g. type 1, gestational - different pathology]
Intervention   | [FILL: e.g. telehealth coaching ≥8w] | [FILL: e.g. one-off SMS reminders - not coaching]
Comparison     | [FILL: e.g. usual care, waitlist]    | [FILL: e.g. head-to-head telehealth arms]
Outcome        | [FILL: e.g. HbA1c at ≥3 months]      | [FILL: e.g. satisfaction-only studies]
Study design   | [FILL: e.g. RCTs, cluster RCTs]      | [FILL: e.g. case reports, editorials, protocols]
Language       | [FILL - restricting is a limitation] | [FILL]
Setting        | [FILL]                               | [FILL]