Table 3 HIV testing, sexually transmitted infection and sexual behaviour by sample.

Denominator*	Sample				Crude OR (95% CI)	p Value‡	aOR§ (95% CI)	p Value¶
	Internet (2065)		Natsal (117 135)
	n	%	n†	% (95% CI)
HIV tested, ever	1090	53.5	57	53.3 (42.8 to 63.4)	1.01 (0.66 to 1.55)	0.958	—	—
STI, past year	346	16.9	6	4.8 (2.2 to 10.4)	4.01 (1.74 to 9.25)	0.001	4.14 (1.76 to 9.74)††	0.001
Anal intercourse
3 months v 4 weeks	1587	76.9	60	51.8 (41.8 to 61.6)	3.09 (2.04 to 4.68)	<0.001	3.24 (2.12 to 4.96)‡‡	<0.001
3 months v 3 months (estimate)**	1587	76.9	74	63.3	—	0.001	—	—
3 months v 6 months	1587	76.9	81	69.3 (59.9 to 77.3)	1.47 (0.96 to 2.25)	0.073	1.59 (1.03 to 2.45)§§	0.036
Unprotected anal intercourse
3 months v 4 weeks	922	45	29	24.9 (17.4 to 34.2)	2.47 (1.56 to 3.91)	<0.001	2.67 (1.66 to 4.31)¶¶	<0.001
3 months v 3 months (estimate)**	922	45	42	36.6	—	0.064	—	—
3 months v 12 months	922	45	56	48.3 (38.7 to 58)	0.88 (0.59 to 1.3)	0.513	—	—

STI, sexually transmitted infection.

*Weighted, unweighted denominator for men surveyed for Natsal.

†Weighted numerator for men surveyed in Natsal.

‡p Value associated with crude OR derived from bivariate model and with χ² statistic from comparing proportions for data that are only available at the sample level.

§OR with Natsal 2000 sample as reference group adjusted in final model by †† not working, lives in London, health self‐reported as good, age of first sex with male partner; ‡‡ lives in London, country of birth, age of first sex with male partner; §§ student, lives in London, country of birth, age of first sex with male partner; ¶¶ student, not working, holds degree or equivalent, country of birth, age at first sex with male partner.

¶p Value associated with aOR derived from multivariate model.

**Natsal 3‐month estimate is calculated for the 13 weeks before the interview.