Study Types & Quality Guidelines

Learn which study design fits your question, and how to assess trustworthiness.

Think of It Like Hiring

Each step builds on the last:

1REPORTING

"Is the resume complete?"

Can't judge what's not there

2APPRAISAL

"Are they actually qualified?"

Reference check their claims

3INTERPRETATION

"Should we hire for THIS role?"

Right fit for your needs?

Complete resume ≠ good candidate ≠ right hire. Each step answers a different question.

Two Types of Research

Primary Studies

"Doing the experiment"

✓ Report → ✓ Appraise → ⟳ Feeds into GRADE

Contribute to systematic reviews where GRADE applies

Evidence Synthesis

"Combining experiments"

✓ Report → ✓ Appraise → ✓ GRADE

Bodies of evidence get interpreted

How GRADE works: When a systematic review synthesizes studies, GRADE rates the body of evidence. RCTs start HIGH, observational starts LOW, diagnostic starts HIGH but often downgrades (accuracy ≠ patient outcomes).

Primary Studies

(→ feed into GRADE)

Evidence Synthesis

(+GRADE)
See It In Action →

Walk through a real systematic review using PRISMA, NOS, and GRADE