Table 3

Risk factors associated with having antibodies to HIV, T pallidum, infection with C trachomatis or N gonorrhoea among indoor-working sex workers in London

	STI/HIV infection		Unadjusted model		Adjusted model^†		p Value^‡
	n^*/n	%	OR	95% CI	OR	95% CI	p Value^‡
Demographic indicators
Migrant status
UK-born	6/93	6.5%	1.0		1.0
Eastern Europe	18/141	12.8%	2.1	0.81 to 5.56	2.1	0.61 to 7.01	0.24
Recruitment method
Outside of project^¶	12/163	7.36%	1.0		1.0
Project drop-in/outreach referral^§	12/71	16.9%	3	1.11 to 6.12	1.7	0.59 to 4.98	0.32
Age (years)
17–22	1/50	2.0%	1.0		1.0
23–26	10/57	17.5%	10.4	1.28 to 84.6	12.3	1.44 to 105.1
27–35	8/58	13.8%	7.8	0.94 to 65.1	6.7	0.76 to 58.9
36+	4/60	6.7%	3.5	0.38 to 32.4	4.7	0.46 to 48.5	0.09
Organisation of sex work
Main location of sex work
Flat	11/141	7.7%	1.0		1.0
Escort	5/42	11.9%	1.6	0.53 to 4.96	1.6	0.42 to 5.87
Sauna	1/18	5.6%	0.7	0.08 to 5.81	0.4	0.04 to 3.61
Bar/private/other^**	4/17	23.5%	3.7	1.02 to 13.3	3.1	0.71 to 13.1	0.29
Duration in sex work
2 years or less	8/83	9.6%	1.0		1.0
3–5 years	7/66	10.6%	1.1	0.38 to 3.24	0.9	0.28 to 2.97
6 years or more	5/65	7.7%	0.8	0.24 to 2.51	1.1	0.28 to 4.05	0.97
Sexual risk behaviours
10 or more clients in last 7 days
No	8/81	9.9%	1.0		1.0
Yes	10/86	11.6%	1.2	0.45 to 3.21	1.3	0.42 to 3.78
Don't know/no response	5/61	8.2%	0.8	0.25 to 2.62	1.1	0.32 to 4.14	0.92
Currently has non-paying sex partner?
No	6/96	6.3%	1.0		1.0
Yes	16/128	12.5%	2.1	0.881 to 5.7	3.0	1.03 to 8.73	0.05
Used condom at last oral sex with client
Yes	16/171	9.4%	1.0		1.0
No	6/47	12.8%	1.4	0.52 to 3.85	1.1	0.36 to 3.48	0.85
Used a condom at last vaginal sex with non-paying partner
Yes	5/59	8.5%	1.0		1.0
No	15/139	10.8%	1.3	0.45 to 3.78	1.1	0.32 to 3.63
No vaginal sex with partner in last 12 months	2/21	9.5%	1.1	0.20 to 6.35	0.7	0.06 to 7.01	0.90
No contraceptive used in last 4 weeks
No	18/184	9.8%	1.0		1.0
Yes	23/44	11.4%	1.2	0.41 to 3.38	1.1	0.31 to 3.61	0.92
Use of services
Ever been visited by an outreach worker/nurse at place of work
Yes	6/101	5.9%	1.0		1.0
No	17/118	14.4%	2.7	1.01 to 7.04	3.6	1.14 to 10.5	0.02
HIV test in the last 12 months
Yes	4/48	8.3%	1.0		1.0
No	17/159	10.7%	1.3	0.42 to 4.12	1.7	0.51 to 5.97	0.38
STI screen in the past 6 months
Yes	16/189	8.5%	1.0		1.0
No	8/45	17.8%	2.3	0.93 to 5.87	2.8	0.93 to 8.29	0.07
Registered with a GP
Yes	13/151	8.6%	1.0		1.0
No	10/72	13.9%	1.7	0.71 to 4.12	1.6	0.51 to 5.26	0.41
Adverse health outcomes
Sexual violence^†† from a client in last 12 months
No	19/194	9.8%	1.0		1.0
Yes	4/31	12.9%	1	0.43 to 4.32	2.1	0.56 to 7.80	0.28
Sexual violence from a non-paying partner in last 12 months
No	21/211	10.0%	1.0		1.0
Yes	2/14	14.3%	1.5	0.32 to 7.20	1.5	0.27 to 8.21	0.64
Alcohol audit score^‡‡
Scores <3	9/90	10.0%	1.0		1.0
Scores 3+	13/121	10.7%	1.1	0.44 to 2.65	1.1	0.38 to 3.12	0.86
Used drugs during or before sex work in last 4 weeks
No	17/181	9.4%	1.0		1.0
Yes	5/39	12.8%	1.4	0.49 to 4.11	1.9	0.29 to 3.14	0.93
Ever been arrested or imprisoned
No	18/183	9.8%	1.0		1.0
Yes	6/48	12.5%	1.3	0.49 to 3.5	2.0	0.58 to 7.18	0.27

↵* This refers to single infections or in combination.
↵† Final model adjusted for age, contact with an outreach service, currently have a non-paying sex partner, recruitment location and migration status.
↵‡ p Values derived from Wald tests.
↵§ 10 people were recruited via outreach referrals.
↵¶ This includes cold calling, field workers' personal contacts or acquaintance or social network referrals and one recruit of unknown origin.
↵** 1=regulars, 1=‘variety’ (3=street omitted from risk factor analysis).
↵†† Sexual violence is defined as reporting one or more of the following incidences: forced to have vaginal or anal sex or oral sex, gang raped, attempted anal or vaginal sex, or touched against will.
↵‡‡ Calculated on the basis of answers to first three questions of AUDIT questionnaire: How often do you have a drink containing alcohol? On a typical day when you are drinking, how many drinks containing alcohol do you have? How often do you have six or more alcoholic drinks on one occasion? A score of three or more suggests hazardous drinking or an active alcohol disorder.
GP, general practitioner; STI, sexually transmitted infection.