Table 3. Hazard ratios (95% CI) for prostate cancer in relation to various health status, prostate specific factors prior to recruitment, sexual history, and early life factors at baseline.

Characteristics	Total n	Cases	HR (95% CI) minimally adjusteda	HR (95% CI) multivariable-adjustedb	P-valuec
Health status
Vasectomy					0.662
No or unknown	207 969	4343	1 ref	1 ref
Yes	11 366	232	1.05 (0.92–1.20)	1.03 (0.90–1.18)
Hypertension					0.965
No or unknown	104 608	1866	1 ref	1 ref
Yes	114 193	2700	0.99 (0.93–1.05)	1.00 (0.94–1.06)
Diabetes					<0.001
No	202 785	4283	1 ref	1 ref
Yes	15 191	270	0.65 (0.57–0.73)	0.70 (0.62–0.80)
Prostate-specific factors prior to recruitment
PSA test					<0.001
No	154 265	2283	1 ref	1 ref
Yes	58 497	2009	1.43 (1.35–1.52)	1.31 (1.23–1.40)
Enlarged prostate					<0.001
No or unknown	212 242	4216	1 ref	1 ref
Yes	7093	359	1.57 (1.41–1.76)	1.54 (1.38–1.71)
Any first-degree family history of prostate cancer					<0.001
No	103 961	1745	1 ref	1 ref
Yes	16 449	599	1.96 (1.78–2.15)	1.94 (1.77–2.13)
Family history of prostate cancer
No	103 961	1745	1 ref	1 ref	<0.001
Father or brother	16 098	569	1.91 (1.74–2.10)	1.90 (1.72–2.09)
Father and brother	351	30	3.51 (2.45–5.04)	3.35 (2.33–4.81)
Sexual history
Ever had children					0.007
Yes	171 957	3879	1 ref	1 ref
Never	45 375	669	0.87 (0.80–0.94)	0.89 (0.81–0.97)
Number of children					0.001
1	27 488	517	0.94 (0.85–1.03)	0.95 (0.86–1.04)
2	90 098	2131	1 ref	1 ref
⩾3	54 371	1231	0.92 (0.86–0.99)	0.93 (0.86–1.00)
Ever had sexual intercourse					0.007
Yes	191 476	3999	1 ref	1 ref
Never	1916	18	0.51 (0.32–0.81)	0.53 (0.33–0.84)
Age at first sexual intercourse, years					0.024
<16	88 078	1781	0.93 (0.86–1.01)	0.97 (0.89–1.06)
⩾16–<20	48 186	803	1 ref	1 ref
⩾20–<25	42 717	1125	1.02 (0.94–1.09)	0.98 (0.91–1.06)
⩾25	12 495	290	0.96 (0.84–1.08)	0.91 (0.80–1.03)
Lifetime number of heterosexual partners					0.013
1	41 598	1126	1 ref	1 ref
⩾2–<6	65 701	1392	0.96 (0.89–1.04)	0.99 (0.91–1.07)
⩾6	68 971	1161	0.99 (0.91–1.07)	1.03 (0.95–1.13)
Same-sex intercourse					0.171
No	189 406	3989	1 ref	1 ref
Yes	8576	146	1.07 (0.90–1.26)	1.12 (0.95–1.33)
Lifetime number of same-sex partners					0.964
1	977	18	1 ref	1 ref
⩾2–<6	1340	25	1.05 (0.57–1.92)	1.05 (0.57–1.92)
⩾6	1716	22	0.94 (0.50–1.75)	0.93 (0.50–1.74)
Early life
Relative age of first facial hair					0.454
Younger than average	14 262	243	1.01 (0.89–1.15)	1.03 (0.90–1.17)
About average	167 220	3656	1 ref	1 ref
Older than average	27 009	459	0.97 (0.88–1.06)	0.94 (0.86–1.04)
Relative age voice broke					0.548
Younger than average	8769	143	0.99 (0.84–1.17)	1.00 (0.85–1.18)
About average	178 309	3813	1 ref	1 ref
Older than average	11 861	194	0.95 (0.83–1.10)	0.92 (0.80–1.07)
Comparative body size at age 10					0.156
Thinner	75 069	1516	0.94 (0.88–1.00)	0.94 (0.88–1.00)
About average	109 231	2414	1 ref	1 ref
Plumper	29 305	536	0.92 (0.84–1.01)	0.96 (0.88–1.06)
Comparative height size at age 10					0.986
Shorter	42 033	865	1.00 (0.93–1.08)	1.00 (0.92–1.08)
About average	119 071	2510	1 ref	1 ref
Taller	53 953	1115	1.01 (0.94–1.09)	1.00 (0.94–1.08)
Hair colour and pattern
Hair colour (natural, before greying in whites)					0.597
Light brown	79 825	1790	1 ref	1 ref
Red	7726	144	0.88 (0.75–1.05)	0.88 (0.74–1.05)
Blonde	19 935	418	0.95 (0.86–1.06)	0.96 (0.86–1.06)
Dark brown	77 304	1523	0.98 (0.91–1.05)	0.97 (0.91–1.04)
Black	16 718	406	1.02 (0.92–1.14)	1.03 (0.92–1.14)
Other	17 152	287	1.01 (0.89–1.14)	0.99 (0.79–1.23)
Hair/balding patternd					0.595
Pattern 1	69 647	1317	1 ref	1 ref
Pattern 2	49 303	903	0.99 (0.91–1.08)	0.99 (0.91–1.07)
Pattern 3	57 208	1388	1.00 (0.93–1.08)	0.99 (0.92–1.07)
Pattern 4	39 051	882	0.95 (0.87–1.03)	0.95 (0.87–1.03)

Abbreviations: CI=confidence interval; HR, hazard ratio; PSA=prostate-specific antigen; ref, reference.

Missing and/or unknown values of the exposure of interest were not included in the analyses, but missing and/or unknown values were assigned to a separate category when the variable was included as a covariate.

^aMinimally adjusted model: HRs are stratified by region (10 UK cancer registry regions) and age at recruitment (<45, 45–49, 50–54, 55–59, 60–64, and ⩾65 years) and adjusted for age (underlying time variable), use as appropriate.

^bMultivariable-adjusted model: HRs are stratified by region and age at recruitment and adjusted for age (underlying time variable), Townsend deprivation score (fifths, unknown), ethnicity (white, mixed background, Asian, black, other, and unknown), lives with a wife or partner (no and yes), BMI (<25, ⩾25–<30, ⩾30–<35, ⩾35 kg m⁻², and unknown), smoking (never, former, current, and unknown), physical activity (low (0–<10 METs per week), moderate (⩾10–<50 METs per week), high (⩾50 METs per week), and unknown), diabetes (no, yes, and unknown), enlarged prostate (no or unknown, and yes), and family history of prostate cancer (no, yes, and unknown), use as appropriate.

^cP-values from the multivariable-adjusted model were calculated as follows: P-values for likelihood ratio test for variables with more than two categories were obtained comparing the model with and without the variable of interest; P-values for dichotomous variables were obtained comparing the reference category to the other category in the model; P-values for trend were obtained using a pseudo-continuous variable equal to the median value in each category for continuous variables.

^dPattern 1, no balding; pattern 2, balding at the front; pattern 3, balding on the top of head; pattern 4, complete balding.