Quality assessment of case-control studies.

Quality assessment of case-control studies.</p

Flow chart of study selection for inclusion in the systematic review and meta-analysis.

Flow chart of study selection for inclusion in the systematic review and meta-analysis.</p

Search strategy of PubMed/Medline, Embase and Scopus.

(DOCX)</p

Interventions and exposures characteristics.

Interventions and exposures characteristics.</p

Data extraction form.

(XLSX)</p

Study characteristics.

Study characteristics.</p

PRISMA 2020 checklist.

(DOCX)</p

The funnel plot of analysis.

The funnel plot of analysis.</p

Pooled RR for clinical trials.

Pooled RR for clinical trials.</p

Quality assessment of cohort studies.

Quality assessment of cohort studies.</p