Condom Use of Sex Workers with Non-Commercial Casual Sex Partners: Testing an Extended Information-Motivation-Behavioral Skills Model

Studies reveal that condomless sex is more common among sex workers with casual and steady partners than with commercial partners. There is limited research explaining condom use among sex workers with non-commercial casual partners. Therefore, this study aims to identify predictors of condom use among sex workers with non-commercial casual partners using an extended Information-Motivation-Behavioral Skills (IMB) model.

The research was conducted using a cross-sectional online survey between March and October 2022. Non-commercial casual partners were defined as sexual relationships without long-term commitments, including one-night stands, affairs, anonymous encounters, friends with benefits, and similar arrangements. Eligible participants were aged 16 or older, living in Switzerland, and had received money or gifts for sexual services in the past 12 months. The data were collected via a self-administered online questionnaire, developed in collaboration with partners of Non-Governmental Organizations (NGOs), pretested twice, and available in 11 languages. Recruitment was supported by local NGOs through advertising, social media, and outreach at sex worker drop-in centers, with options for independent completion or computer-assisted interviews. Using validated instruments, the researchers measured condom use frequency during vaginal or anal sex with non-commercial casual partners in the past 12 months and the variables of the extended IMB model. The convenience sample consisted of 386 sex workers (265 cisgender women, 82 cisgender men, 39 transgender) who had vaginal or anal sex with at least one non-commercial casual partner within the 12 months before the survey. Fifty-six percent were heterosexual, 16.3% were homosexual, and 14.8% were bisexual. Approximately 31% were migrants from HIV high-prevalence countries. Structural Equation Modeling (AMOS) was used to analyze predictors of condom use.

Fifty-seven percent of the sex workers always used condoms when having sex with non-commercial casual partners. Higher condom use was associated with stronger intention to use condoms (β = 0.28, p < 0.001), more positive attitudes toward condoms (β = 0.22, p < 0.001), and higher perceived subjective norm supporting condom use (β = 0.12, p < 0.01). Older age (β = 0.11, p < 0.05) was associated with increased condom use frequency, while non-heterosexual orientation (β = −0.11, p < 0.05) and sex-related drug use (β = −0.14, p < 0.01) were associated with decreased condom use frequency. Higher intention to use condoms was associated with older age (β = 0.21, p < 0.001). Intention to use condoms was lower in sex workers with non-heterosexual orientation (β = −0.10, p < 0.05). A more positive attitude towards condoms was observed among cisgender females (β = 0.13, p < 0.05) and among sex workers with a higher level of education (β = 0.14, p < 0.01). Attitude was more negative in non-heterosexual sex workers (β = −0.20, p < 0.001). Greater experiences of sex worker-related discrimination were associated with more negative attitudes (β = −0.13, p < 0.01). Sex workers in committed relationships had a more positive subjective norm for condom use (β = 0.11, p < 0.05). Experiences of sex-work-related discrimination (β = 0.13, p < 0.01) and a suicide attempt in the last 12 months (β = 0.14, p < 0.01) were associated with more frequent sex-related drug use and a higher likelihood of having attempted suicide more often. The explained variance for condom use was 30%.

Psychosocial factors, particularly intention, attitude, and subjective norm, emerged as crucial to condom use among sex workers, whereas information and behavioral skills had no effect. Lower condom use was observed among non-heterosexual and younger sex workers who engaged in sex-related drug use. The latter was more prevalent among younger, well-educated, cisgender male and transgender sex workers and was positively associated with discrimination experiences and suicide attempts. These findings underscore the intersecting vulnerabilities related to gender identity, sexual orientation, discrimination, and mental health. Nevertheless, the findings must be interpreted with caution, given the cross-sectional design, self-reported data, and limited generalizability due to convenience sampling. The unexplained variance suggests the presence of additional influences such as condom negotiation and power dynamics with non-commercial casual partners, which require further investigation through qualitative research.

The extended IMB model offers significant insights into condom use behavior among sex workers who have sex with non-commercial casual partners. Interventions should aim to strengthen intention and positive attitudes toward condoms, challenge prevailing discrimination, and address co-occurring issues such as sex-related drug use and mental health, with a focus on tailoring these interventions to diverse genders.