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Evaluation of a prevention intervention to reduce HIV risk among Angolan soldiers
Global Health Sciences Literature Digest
Published July 10, 2008
Journal Article

Bing EG, Cheng KG, Ortiz DJ, Ovalle-Bahamon E, Francisco E, Weiss RE, et al. Evaluation of a prevention intervention to reduce HIV risk among Angolan soldiers. AIDS Behav 2008;12:384-95.

In Context

Male soldiers are often at high risk of acquiring and transmitting HIV infection. High rates of HIV in the military poses a threat to a country's stability.(1,2) Prevention interventions designed for the military in resource-limited countries have not been evaluated, despite the high prevalence of HIV and risk behaviors in these settings.


To assess the effect over time of an HIV prevention intervention compared with a non-HIV-focused health promotion intervention on HIV knowledge, motivations, and behaviors.


Angolan military bases; eight in the capital, Luanda or within 80 km of that city, two in Huila (southern province), and two in Malanje (northern province).

Study Design

Randomized, controlled intervention.


Male soldiers stationed at one of 12 military bases.


Changes in HIV knowledge, perceived vulnerability to HIV, condom use, proportion of unprotected sex acts, and alcohol consumption before sex.


Military bases were matched by region and geographically separated to minimize study contamination. Within each matched pair of bases one was randomly assigned to receive the HIV prevention intervention and the other to receive the control intervention (the non-HIV-focused health intervention). The prevention intervention was based on the Information, Motivation, and Behavioral Skills (IMB) model.(3) Key components of the intervention were avoiding sex while under the influence of alcohol, negotiating condom use, and proper use of condoms. The intervention was delivered in four-hour sessions over five consecutive days. The last hour of the course consisted of a one-hour presentation on malaria prevention. The control intervention focused on malaria prevention and was delivered in four-hour sessions over five consecutive days. The last hour of the intervention addressed HIV prevention. Optional booster sessions were available for five months following the intervention. Because civilians are not permitted access to lists of soldiers, participants were randomly selected by military personnel who were trained by study personnel.


Of the 568 soldiers enrolled, 280 were randomized to receive the HIV prevention intervention and 288 to receive the control (malaria prevention) intervention. Intervention and control groups were similar except that a higher proportion of control participants were officers and older than 26 years of age with more years in the military (P<0.05). At baseline 85.9% of participants reported vaginal sex in the past three months; condom use was infrequent. Retention was 87.3% at three months and 86.4% at six months for both groups.

Within-group analysis revealed that over time, participants in the HIV prevention group significantly increased their HIV knowledge; perception of vulnerability to HIV among themselves, persons like themselves (soldiers), and others; and condom use. They also decreased the number of unprotected vaginal sex acts with steady partners, occasional partners, and commercial sex workers. Within the control group there was increased HIV knowledge; perceived vulnerability to HIV among others and soldiers, but not themselves; condom use at six months but not at three months follow-up; and decreased unprotected vaginal sex with occasional partners.

Between-group analyses revealed that the HIV prevention group had a greater increase in HIV knowledge and perceived vulnerability to HIV occurring among others and soldiers, and greater change in frequency of condom use than the control group. The groups did not differ in the proportion of unprotected sex acts.

Alcohol consumption before sex did not change within or between groups.


Military-focused HIV prevention interventions using the IMB model can significantly increase HIV knowledge and decrease sexual risk behaviors in male soldiers.

Quality Rating

This study was of very good quality in that the bases were truly allocated randomly; soldiers were sampled randomly, although verification of this was not possible given the sensitivity of military information; the outcomes were measured without bias; loss-to-follow-up was accounted for and minimal; and an intention-to-treat analysis was performed.

Programmatic Implications

Soldiers frequently engage in high risk behaviors, and HIV within the military can impair the security and stability of countries. The intervention developed and tested in this study demonstrated effectiveness as measured by self-report. The intervention required a minimum of 20 hours within a single week, which may not be practical in all military settings. This intervention appears to have had some efficacy. There likely would be benefit in developing and testing additional interventions for soldiers.


  1. Altman D. AIDS and security. Int Rel 2003;17:417-27.
  2. Yeager RD, Kingman SJ. HIV/AIDS: destabilizing national security and the multi-national response. Revue Internationale des Services de Sante des Forces Armees 2001;74:3-12.
  3. Fisher JD, Fisher WA. Changing AIDS risk behavior. Psych Bull 1992;111:455-74.