Characteristics of included studies
| Study (first author, year) | Additional sources | Country | Year started | Design | Aim | Population | N (FSWs) at baseline | Age (median)† | Current contraceptive use‡ (%) | Consistent condom use§ | Number of sex partners/frequency of sex¶ | Gender-based violence (GBV)/alcohol/other risk factor | HIV/STI prevalence |
| Outcome 1: unintended pregnancy | |||||||||||||
| Behets,39 2005 | Madagascar | 2004 | Prospective cohort (with intervention). | Assess acceptability and feasibility of diaphragm use. | FSWs who use condoms inconsistently. | 91 | 28 | Any: 47% LARC or permanent: <1%. | 0% with clients in last month (inconsistent use was an inclusion criterion). | Five partners. Six sex acts. | N/A. | Vaginitis/Pelvic inflammatory disease (PID): 8%. TP (RPR): 27%. | |
| Behets,40 2008 | Author†† Khan et al 4 Penman-Aguilar et al 72 | Madagascar | 2005 | RCT (pilot). | Assess acceptability and feasibility of diaphragm and microbicide use for STI prevention. | Women with high-risk sex behaviours (sex work self-reported: 81% current, 100% ever). | 192 | 29 | Any (excl. condoms): 24%. | 0% in last 2 weeks (inconsistent use was an inclusion criterion). | Six casual partners. 10 sex acts. | Ever violence from casual partner for suggesting condom: 21%. Ever received more money for no condom: 38%. | N/A. |
| Braunstein,32 2011 | Braunstein et al 73 | Rwanda | 2006 | Prospective cohort. | Measure HIV incidence (secondary aim: measure pregnancy incidence). | HIV-uninfected women at high risk of HIV exposure (94% reported current sex work). | 397 | 24 | Any: 91%. LARC or permanent: 0%. | 21% with clients 18% with non-paying partners. | 90 partners in past 3 months. 10 clients per week. 40 vaginal sex acts in last month. | Forced sex ever: 19%. Alcohol before sex: 52%. | CT: 5%. GN: 12%. TV: 17%. TP (RPR+TPHA pos): 7%. HSV2: 54%. |
| Chersich,34 2014 | Author†† Luchters et al 5 | Kenya (Mombasa). | 2006 | Prospective cohort. | Assess HIV incidence and microbicide trial feasibility. This substudy: investigate links between alcohol use, and unsafe sex and incident HIV infection. | HIV-uninfected FSWs. | 386 | Mean 25.1 | Any (incl. consistent condom use): 57.1%. LARC: 3.0%. Permanent: 0%. | 21.3% in last 3 months. | N/A. | Hazardous or harmful drinking: 26.8%. Ever had abortion: 21%. | N/A. |
| Deschamps,33 2016 | Deschamps et al 74 | Haiti, Puerto Rico and Dominican Republic | 2009 | Prospective cohort. | Assess feasibility of establishing a high-risk cohort for HIV vaccine trials. This substudy: assess retention, HIV and pregnancy incidence and risk behaviours. | HIV-uninfected FSWs. | 634 | 24‡‡ | Permanent: 10.0% (excluded from pregnancy analysis). Others not reported. | 0.5% in last 6 months. | 447 partners in last 6 months‡‡. | Forced sex by client in last 6 months: 37.1%. Heavy drinker: 38.8%. Drug use: 14.0%. | N/A. |
| Gaffoor,42 2013 | Author†† Skoler-Karpoff et al 75 | South Africa (one site of a multisite trial) | 2004 | RCT (phase 3, double blind, placebo-controlled). | Test safety and efficacy of the microbicide. Carraguard for HIV prevention. This substudy: describe prevalence and associations of forced sex. | HIV-uninfected sexuallyactive women (3% FSWs). | 41 | §§ | §§ | N/A. | §§ | N/A. | §§ |
| Lara,41 2009 | Author†† | Dominican Republic | 2006 | Prospective cohort (with intervention). | Assess acceptability of the female condom and diaphragm, determinants of use, and impact on unprotected sex. | FSWs. | 243 | 58.8% aged 20–29 years | Any (excl. condoms): 22.2%. Permanent: 0%. | 66% in last month. | N/A. | Ever had abortion: 70%. | HIV: 1%. CT: 13%. GN: 2%. TP (VDRL): 8%. |
| McClelland,45 2008 | Author†† Martin et al 76 McClelland et al 77 McClelland et al 78 | Kenya (Mombasa) | 2003 | RCT (placebo-controlled, nested in an open cohort study). | Test efficacy of monthly periodic presumptive antibiotic treatment at reducing incidence of vaginal infections and promoting vaginal Lactobacillus colonisation. | HIV-uninfected FSWs. | 310 | 32 | Any (excl. condoms): 35.5%. LARC: 3.6%. Permanent: 2.9%. | Median 100% coverage of sex acts in past week.‡‡ | One partner. One sex act.‡‡ | N/A. | GN: 0.3%. TV: 1%. Cervicitis (microscopy): 0.6%. HSV2: 74%. BV: 34.5%. |
| Peterson,46 2007 | Author†† Macqueen et al 66 | Ghana, Cameroon and Nigeria | 2004 | RCT (phase 2, double blind, placebo controlled). | Investigate safety and preliminary effectiveness of tenofovir disoproxil fumarate in preventing HIV infection. | HIV-uninfected women who work in hotels, bars, markets in high HIV transmission areas (areas known for sex work). | 936 | Mean 23.6‡‡ | Any (excl. condoms): 7.22%. LARC: <2%. Permanent: <2%. | N/A. | Mean 21 partners in 30 days. Mean 12 coital acts per week. | N/A. | Any STI in last 6 months (self-reported): 41.2%. |
| Watson-Jones,44 2008 | Author†† Odutola et al 79 | Tanzania | 2004 | RCT (double blind, placebo controlled). | Determine whether HSV2 suppressive therapy reduces the risk of HIV acquisition and genital shedding of HIV. | Female workers at food and recreational facilities at risk of HIV (38% FSWs). | 499 | §§ | §§ | §§ | §§ | §§ | §§ |
| Outcome 2: pregnancy (intention undefined) | |||||||||||||
| Bazzi,54 2015 | Author†† Syvertsen et al 80 | Mexico | 2010 | Prospective cohort. | Identify time varying risk factors for STI acquisition within FSWs’ intimate partnerships. | FSWs with drug use history and their steady male partners. | 212 | 33 | Any (excl. condoms): 53.3%. LARC: 12.3%. Permanent: 25.5%. | Often or always: 56%. | N/A. | In last year: physical assault by partner: 41%. Sexual coercion in relationship: 9%. In last 6 months: hazardous drinking: 23%. Intravenous drug use: 62%. | HIV: 2.6%. CT: 5.9%. GN: 1.2%. TP (active): 1.4%. Any STI: 8%. |
| Page,38 2013 | Author†† Duff et al 55 Couture et al 81 | Cambodia | 2009 | Prospective cohort. | Estimate HIV and STI prevalence, incidence and associated factors. This substudy: describe contraceptive utilisation and correlates of incident pregnancy. | Young women who practice SW and/or have multiple partners (all those recruited had practiced SW). | 220 | 60.3% aged 25–29 years | Any hormonal (not LARC): 10.8%. LARC: <1.0%. | N/A. | Four partners in last month. | In last year: physical or sexual violence by client: 26.0%. Intimate partner: 20.1%. In last 3 months: stimulant drug use: 27.0%. Abortion: 11.3%. | HIV: 16.2%. |
| Feldblum,35 2007 | Feldblum et al
57 Hoke et al 82 | Madagascar | 2001 | RCT. | Assess impact of two condom promotion interventions. This substudy: estimate pregnancy incidence rate and predictive factors. | FSWs. | 935 | Mean 28.3 | Any highly effective (excl. condoms): 16.3%. | No unprotected sex with any partners: 13.2%. | Mean 5–6 partners. | N/A. | CT: 14.6%. GN: 21.7%. TV: 11.7%. Any STI: 36.1%. ‡‡ |
| Kaewkungwal,36 2013 | Rerks-Ngarm et al 83 | Thailand (two provinces) | 2003 | RCT (multisite double blind placebo controlled). | Assess the efficacy of two vaccines to prevent HIV. This substudy: determine the qualities and outcomes of women’s participation. | HIV-uninfected women (5% FSWs). | 318 | N/A | N/A. | §§ | N/A. | §§ | N/A. |
| Kaul,47 2004 | Yadav et al
84 Fonck et al 85 | Kenya (Nairobi) | 1998 | RCT (double blind placebo controlled). | Assess impact of monthly PPT on HIV and STI incidence. | HIV-uninfected FSWs. | 430 | 28.6‡‡ | Any hormonal (not LARCs): 39.1%. | 17.2% with casual partner.‡‡ | 15.4 partners.‡‡ | Daily alcohol: 47.6%. Ever intravenous drug use: 4.1%. | CT: 9.9%. GN: 10.3%. TV: 12.2%. TP: 4.4%. HSV2: 73.9%. BV: 51.1%. |
| Liu,53 2015 | Author†† | China | 2009 | Cluster RCT. | Assess the impact of a preventive intervention for FSWs on condom use with clients and partners. | FSWs. | 750 | Mean 27.8‡‡ | LARC: 29.9%. | 43.6% in past month. | Mean 8.3 clients.‡‡ | N/A. | CT: 14.0%. GN: 3.3%. TP: 1.3%. Any STI: 16.9%. |
| McClelland,37 2011 | Author†† Martin et al 76 McClelland et al 86 | Kenya (Mombasa) | 1993 | Open cohort. | Assess HIV-1 incidence and relationships between hormonal contraception, STIs and HIV. This substudy: examine relationship between risk behaviour and biologic outcomes (STI, pregnancy, seminal fluid deposition) among HIV-positive FSWs. | HIV-infected FSWs. | 898 | 31 | Any (excl. condoms): 43.0%. LARC: 2.34%. Permanent: 2.67%. | 55% in past week. | One partner. Two sex acts. | N/A. | N/A. |
| Price,49 2012 | Author†† | Kenya (Nairobi, Kilifi) | 2005 | Prospective cohort. | Describe populations at risk of HIV, including HIV incidence, in preparation for HIV trials. | HIV-uninfected women and men at risk of HIV (75% of women were FSWs). | 515 | §§ | N/A. | N/A. | N/A. | §§ | Any non-ulcerative STI: 9.1%. Genital ulcers: 1.5%. TP: 0.6%. Any STI: 10.6%. |
| Priddy,56 2011 | Kenya (Nairobi) | 2008 | Prospective cohort. | Assess HIV risk behaviour and incidence, STI prevalence, vaginal practices and retention. | HIV-uninfected FSWs. | 200 | Mean 28 | Any non-barrier method: 52.0%. LARC: 3.0%. Permanent: 1.0%. | N/A (only reported sometimes/always use). | Mean per day: 2.4 regular clients. 1.9 casual clients. | Sexual/physical violence related to Sex work (SW) in last month: 19.5%. Sometimes/always paid more for no condom: 29.0%. Sometimes/always has sex while intoxicated: 31.5%. | CT: 5.5%. GN: 6.0%. TV: 9.0%. TP: 2.5%. HSV2 (antibody): 72.0%. BV: 38.0%. | |
| Robb,51 2016 | Author†† Rono et al 87 | Kenya, Tanzania and Uganda | 2009 | Prospective cohort. | Describe the trajectory of acute HIV infection. | HIV-uninfected women and men at high risk for HIV (64% FSWs). | 1463 | N/A | Any hormonal (incl. implant): 36.5%. IUD: 0.5%. Permanent: 0.5%. | 32.6% with clients. 20.3% with non-paying partners. | N/A. | Abortion in last 3 months: 0.43%. | N/A. |
| Strathdee,43 2013 | Author†† Vera et al 88 Gaines et al 89 | Mexico | 2008 | RCT (four-arm factorial). | Determine effectiveness of two behavioural interventions to reduce sexual and injecting risk. | HIV-uninfected FSWs who inject drugs. | 584 | 33 | Any (excl. condoms): 39.3%. LARC: 25.3%. Permanent: 17.8%. | 14.9% with regular clients. 11.7% with casual clients. | 30 clients per month. 51 paid sex acts per month. | N/A. | CT: 12.0%. GN: 2.2%. TV: 33.6%. TP (active): 8.4%. |
| Van Damme,48 2002 | Author†† Vandebosch et al 90 Ramjee et al 91 | Benin, Cote d’Ivoire, South Africa and Thailand | 1996 | RCT (multisite triple blind placebo-controlled; open cohort design). | Determine effectiveness of nonoxynol-9 microbicide in prevention of HIV-1. | HIV-uninfected FSWs. | 892 | 26 | N/A. | N/A (only reported use of condom in ≥50% of sex acts). | Three partners per day. | N/A. | CT: 4.4%. GN: 5.1%. TV: 3.5%. TP: 11.2%. |
| van Loggerenberg,52 2008 | Author†† Naicker et al 92 | South Africa (Durban) | 2004 | Prospective cohort. | Understand HIV-1 subtype C acquisition, pathogenesis and disease progression. This substudy: describe cohort characteristics and HIV-incidence rates, and report challenges in establishing and maintaining the cohort. | HIV-uninfected women who practice SW (79%) and/or have multiple partners. | 193 | Mean 34.3 | N/A. | 53.9% with casual partners. 20.4% with steady partners. | Two partners per week. | N/A. | Any STI (CT, GN, TV, MG, TP, HSV2): 31.3%. |
| Vandepitte,93 2013 | Author†† Vandepitte et al 94 | Uganda (urban slum). | 2008 | Prospective cohort. | Understand dynamics of HIV and STI infections among FSWs. This substudy: investigate patterns of clearance and recurrence of untreated Mycoplasma genitalium infection. | FSWs. | 1027 | Mean 26 | N/A. | 59.8% in last month. | At least daily sex for money: 50.5%. | Problem drinking: 55.7%. | MG: 14%. |
| Vielot,50 2015 | Author†† | Kenya (Nairobi) | 2009 | Prospective cohort. | Compare the duration of high risk HPV infection among FSWs by exposure to STIs, using a highly sensitive biomarker assay. | FSWs. | 350 | 28 | LARC: 15.5%. Permanent: 2.1%. | Most of the time/always: 73.8% with clients. 24.6% with non-paying partners. | 10 partners per week. | N/A. | HIV: 24.0%. CT: 3.8%. GN: 2.3%. TV: 7.3%. MG: 12.8%. |
†Median unless specified.
‡Any=modern contraceptive method including condoms, unless specified; LARC=long-acting reversible contraception (implants or IUDs); Permanent=any method of permanent contraception, for example, tubal ligation or hysterectomy.
§Always uses condoms (unless specified).
¶Median number per week unless specified. Sex partners may be paying, non-paying, regular or casual, unless specified.
††‘Author’ indicates additional data were obtained from the author. Other references listed here reported on the same study and were used for data extraction.
↵‡‡Reported results segregated by sub-group; data presented here are overall estimates.
↵§§Not disaggregated by sex work status.
BV, bacterial vaginosis; CT, Chlamydia trachomatis; FSW, female sex worker; HSV2, herpes simplex virus type 2; MG, Mycoplasma genitalium; N/A, not measured or reported, data not available from author; NG, Neisseria gonorrhoeae; RCT, randomised controlled trial; STI, sexually transmitted infection; TP, Treponema pallidum (syphilis); TV, Trichomonas vaginalis.