The role of contact efficacy in evaluating sexual health promotion - evidence-based outreach work within a public sex environment

Background: This paper explores the role of contact efficacy in evidence-based health promotion by evaluating a public sex environment (PSE) based sexual health outreach program. The service operated in situ from a dedicated mobile unit to promote sexual health among PSE users. Methods: A cross-sectional survey (response rate 56%) measured socio-demographics, sexual health behaviours and outreach-service use among men sampled within the PSE (n ≤ 216). Results: Most participants were aware of the service and two-thirds had contacted them. Men who had not completed hepatitis A vaccination (odds ratio (OR) ≤ 2.02), who had ever received money for sex (OR ≤ 2.07) or who reported a diagnosed mental health disorder(s) (OR ≤ 2.38) were significantly more likely to have contacted the service. Although 89% of service users perceived the intervention positively, only 26% felt it had contributed to sexual behaviour changes. Conclusions: The 'mobile-unit' outreach model contacted a large proportion of PSE users, specifically men who had greater health needs. We advocate the adoption of this outreach model over traditional PSE-based outreach approaches. Contact efficacy evaluation is useful to assess ongoing health interventions. However, caution must be exerted when interpreting certain contact efficacy results. Since causality may not always be inferred, triangulation with other evaluative methodologies is recommended.