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Impact of a Social Influence Intervention on Condom Use and Sexually Transmitted Infections Among Establishment-Based Female Sex Workers in the Philippines: A Multilevel Analysis
Global Health Sciences Literature Digest
Published November 16, 2006
Journal Article

Morisky DE, Stein JA, Chiao C, Ksobiech K, Malow R. Impact of a Social Influence Intervention on Condom Use and Sexually Transmitted Infections Among Establishment-Based Female Sex Workers in the Philippines: A Multilevel Analysis. Health Psychol. 2006 Sep;25(5):595-603.


To assess the relative impact of peer educator and management interventions on reducing sexually transmitted infections (STIs) and HIV risk behavior among female sex workers (FSWs) in the Philippines.

Study Design

A multi-stage cluster-randomized design was used to assign four different sites (within five cities), comprising 103 establishments with female sex workers to one of four study arms (three interventions and one control). Women completed baseline and follow-up interviews.


Four sites in cities with populations over 200,000, located approximately 250 miles south of Manila, Philippines.


Eight hundred ninety-seven women from 103 establishments participated in the study. Establishments included nightclubs, disco bars, beer gardens, and karaoke bars. The number of women in each cluster ranged from 2-47 (mean 8.7); mean age was 22.5 years, and 10% were married. Although managers were not surveyed, they were included in two of the study arms.


The four participating sites were randomly assigned to one of the following interventions: peer counseling, manager training, manager training plus peer counseling, or control. In all arms, women were required by their establishments to attend social hygiene clinics either weekly or bimonthly, presumably for STI testing and treatment, although this was not specified.

For the peer counseling intervention, two FSWs from each establishment attended a five-day training about STIs and HIV, modes of transmission, interpersonal relationships with peers and clients, sexual negotiation, role-playing, and modeling; peers also had monthly meetings with the project staff to discuss issues around sexual negotiations.

The manager training intervention involved training managers in the same topics as the peer counseling intervention, with additional emphasis on how to promote condom use among employees and customers (such as providing educational materials and condoms to both FSW and customers, having a 100% condom-use policy, meeting regularly with employees, and monitoring attendance at the hygiene clinics). Information on length of the intervention or the interval between pre- and post-intervention surveys was not provided. It was not clear if the control group received anything.

Primary Outcomes

The outcomes were based on pre-post intervention surveys completed by FSWs, and included scaled measures of perceived risk; AIDS knowledge; establishment practices (whether a co-worker had tried to convince the FSW to use a condom; whether there was a condom-use policy; whether condoms were available; whether the manager ever talked about condoms); attitudes about condoms; self-reported condom use during the last sexual episode; and self-reported STIs.


At follow up, there were significant changes in the control arm compared to baseline; women reported improved knowledge, but poorer establishment practices, worse condom attitudes, and less condom use than at baseline (all p<0.01). Women in the peer intervention group reported more knowledge, poorer establishment practices, and better condom attitudes at follow up (all p<0.01). Women in the manager-training arm demonstrated improved knowledge, reported poorer establishment practices, and increased condom use (all p<0.001). Women in the combination intervention had improved knowledge, reported better establishment practices and better condom attitudes, and were more likely to have used a condom (all p<0.05). Post-intervention, self-reported STIs were significantly reduced among women in the manager-training arm (p<0.05) and in the combined intervention arm (p<0.001). In a multilevel analysis between groups, there was a significant effect of establishment practices on condom use during the last sexual encounter (regression coefficient=0.90).


The authors concluded that this study made use of a more encompassing macro-level approach to risk-reduction by including establishment managers, FSW peer groups, and public health officials. The combined manager-peer education approach demonstrated the greatest impact in facilitating desirable outcomes than did any of the other intervention groups.

Quality Rating

Using the Jadad grading system, this study was of adequate quality. Differences between the study arm sites and between participants in each study arm were not presented. There were considerable omissions in the description of the intervention and methodology, including a lack of information about the total duration of the intervention; the participation rates of managers and during the monthly follow up with project staff; the time period between baseline interviews and follow-up interviews; and the number of hygiene clinics attended by women. The use of self-reported STIs is not very accurate, making it difficult to determine the validity of the data, especially given that there was no correlation made with STI diagnosis from the hygiene clinics. No description of STI treatment protocols was provided. Even though managers were directly involved in two of the four study arms, they were not surveyed and process measures were not collected. The number of sexual encounters each woman had was not determined; other measures of condom use (such as the number of unprotected episodes of sex), rather than condom use at last encounter, would have been useful. Validation of 100% condom policies and availability of condoms at establishments was not performed.

In Context

This study shows that involving managers of establishments with commercial sex workers is important to improving condom use. Although this study purports to assess structural factors and social influences, it actually evaluates the extent to which managers are needed to help enforce condom use when women have little economic power to do so. This has been most ably demonstrated by the Thailand 100% condom-use policy. Many studies from other countries, such as Thailand, Dominican Republic, India, and Madagascar, have shown the success of including a supportive environment in individually focused interventions among FSWs.(1,2,3,4,5) Means of targeting the clients, apart from reinforcement by managers, also need to be considered.

Programmatic Implications

This is another study that points to the need to educate and involve managers, as well as peer educators, in encouraging safe sexual behaviors among FSWs. Interestingly, improved condom-use policies were not reported by women in the manager-only intervention, even though this was a focus of the training for managers in this arm. Improved condom-use policy only occurred when both FSWs and managers were targeted, suggesting that managers might not be inclined to support condom use unless there is additional pressure from FSWs to do so. In resource-limited settings, it is critical to engage establishment owners and managers, as well as peer educators, in order to support FSWs in being able to insist on condom use.


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