Association of smoking, alcohol, and coffee consumption with the risk of ovarian cancer and prognosis: a mendelian randomization study

Table 1 Data sources of instrumental variables

Traits	No. of participants	Ancestry	Unit for each factor	No. of variants included	Number of SNPs available^a	Number of SNPs used^b	PubMed ID
Cigarettes per day	337,334	European	SD increase in the number of cigarettes per day	11,991,601	2,129	25	30,643,251
Smoking initiation	1,232,091	European	Previous smoking compared with never smoking	11,792,288	7,846	88	30,643,251
Smoking cessation	547,219	European	Current smokers Compared with former smokers	12,186,231	223	7	30,643,251
Alcohol consumption	66,450	European	SD increase in log-transformed alcoholic drinks/week	11,976,706	5,196	37	30,643,251
Coffee consumption	375,833	European	50% change	7,875,318	2,996	32	31,046,077
Ovarian cancer	66, 450	European	-	-	-	-	28,346,442

“a” corresponds to the number of SNPs available at the genome-wide significance level (P < 5 × 10^–8). “b” corresponds to the number of SNPs (or linkage disequilibrium proxies) available in ovarian cancer datasets
SNP Single nucleotide polymorphism, SD Standard deviation

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