Relationship between alcohol and primary headaches: a systematic review and meta-analysis.

"Declarations Competing interestsThe authors declare no competing interests. Competing interests The authors declare no competing interests."

"Funding Not applicable."

"The systematic review presented in this paper was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 (PRISMA 2020) guidelines []. The systematic review was registered on PROSPERO (protocols in the International Register of Systematic Reviews) []—CRD42023412926. Methods: This study was based on PubMed, Embase and Web of Science database searches performed on 11 July 2023. This systematic review was registered in PROSPERO (CRD42023412926). Risk of bias for the included studies was assessed using the Joanna Briggs Institute critical appraisal tools. Meta-analyses were performed using Statistica software. The Risk Ratio (RR) was adopted as the measure of the final effect. Analyses were based on a dichotomous division of the respondents into "non-drinkers" and "drinkers" for headache patients and matched non-headache groups."