Table 3. Association between lifestyle factors and family history and ovarian cancer-specific survival.

	OC deaths/na	HR model 1b	95% CI	P-value	OC deaths/nc	HR model 2d	95% CI	P-value
Lifestyle factors/family history
Smoking, never/ever
Never	274/661	1.00	Ref.	Ref.	159/372	1.00	Ref.	Ref.
Ever	312/640	1.16	0.99, 1.36	0.08	211/393	1.25	1.01, 1.54	0.04
BMI 5 years before diagnosis (kg m−2), continuous (5-unit increases)	584/1294	1.11	1.03, 1.19	0.006	367/758	1.17	1.07, 1.28	0.0007
BMI 5 years before diagnosis (kg m−2)
<18.5	10/20	1.10	0.58, 2.07	0.77	5/9	0.99	0.40, 2.42	0.97
18.5–<25	288/660	1.00	Ref.	Ref.	178/383	1.00	Ref.	Ref.
25–<30	179/388	1.10	0.92, 1.33	0.30	112/229	1.13	0.89, 1.44	0.31
⩾30	107/226	1.22	0.97, 1.52	0.08	72/137	1.34	1.02, 1.76	0.04
BRCA1/2 mutation
No	539/1224	1.00	Ref.	Ref.	341/725	1.00	Ref.	Ref.
Yes	99/170	1.19	0.95, 1.48	0.13	63/108	1.05	0.80, 1.40	0.72
First-degree relative with breast cancer
No	498/1105	1.00	Ref.	Ref.	317/668	1.00	Ref.	Ref.
Yes	123/257	1.05	0.86, 1.28	0.64	78/146	0.99	0.77, 1.28	0.95
First-degree relative with ovarian cancer
No	568/1259	1.00	Ref.	Ref.	362/754	1.00	Ref.	Ref.
Yes	52/102	1.05	0.79, 1.40	0.73	32/59	1.03	0.71, 1.48	0.89

Abbreviations: BMI=body mass index; CI=confidence interval; HR=hazard ratio; OC=ovarian cancer; ref.=reference value.

^aThere were a total of n=1394 in model 1 because 27 participants had missing information on tumour stage.

^bAdjusted for age at diagnosis (continuous), histology (serous, mucinous, endometrioid, clear cell, other), and stage (I, II, III, IV).

^cThere were a total of n=833 in model 2 because 588 participants had missing information on residual disease after debulking surgery.

^dAdjusted for model 1 and residual disease (no residual disease, any residual disease).