BMC Public Health 2007, 7:352 http://www.biomedcentral.com/1471-2458/7/352 evision. The documentaries cover topics such as how HIV/ AIDS is affecting Zambian youth, how youth can change their behavior, and how teachers and parents can help youth resist the pressure to have sex [30]. "Our Neigh- bourhood" is a 26-week 30-minute radio distance educa- tion program that focuses on health promotion and community mobilization. The program is produced by ZIPH and is broadcast four times each week, in Zambia's five major languages [31]. ZIHP also produces the televi- sion program X-plosion. X-plosion is a four-episode vari- ety show focusing on HIV/AIDS. The show uses national and international musicians to promote HIV/AIDS aware- ness and prevention [32]. "Lifeline Zambia" was created by World Touch Ministries, and uses radio to highlight HIV/AIDS issues through testimonials from real people [33]. The popular South African drama series Soul City is also broadcast in Zambia. Soul City uses both television and radio soap opera series to educate the public about HIV/AIDS [7,34]. The Soul City TV drama comprises 13 episodes of 30 minutes each, while some of the radio series consist of series of either 45 or 60 episodes of 15 minutes each. The series addresses misinformation about HIV/AIDS and tackles complex topics such as the stigma associated with HIV infection. Methods Data This study uses data from the 2001–2002 Zambia Demo- graphic and Health Survey (ZDHS), which contains infor- mation on a nationally representative sample of 7,658 women aged 15–49 and 2,145 men aged 15–59. The sur- vey was implemented by the Central Statistical Office and the Central Board of Health of Zambia. The survey instru- ments collected information on a wide range of topics, including mass media exposure, family planning, fertility, and HIV/AIDS/STI-related knowledge and behavior [2]. In addition to the standard question modules, the ZDHS includes questions on exposure to social marketing and health communication activities about family planning and HIV/AIDS. Specifically, both female and male respondents were asked if they had listened to any of the following four radio programs in the past six months: 1) Your Health Matters, 2) Lifeline, 3) AIDS and the Family, and 4) Our Neighborhood. They were also asked if they had watched any of the following four television programs in the past six months: 1) Your Health Matters, 2) Lifeline, 3) Soul City, and 4) X-plosion. In addition, male respondents were asked if they had ever seen or hear any messages about Maximum brand condoms, and if so, where they had seen or heard such messages. The data were collected using a three-stage sampling design. First, 320 clusters were selected from the 2000 Population Census. Next, a representative sample of approximately 8,000 households was selected from those clusters. All women aged 15–49 in the selected house- holds were eligible for interviewing. In a sub-sample of one-third of households, all men aged 15–59 were eligi- ble for interviewing [2]. For the analyses, we used the non- weighted samples. Only sexually experienced respondents are included in the analyses. Measures The outcome measures, capturing the respondents' repro- ductive health behaviors, for our analyses are dichoto- mous variables indicating whether the respondent had ever used a condom, and had used a condom during the last sexual encounter. These outcome variables were calcu- lated only for the sexually active respondents. Our indicators of exposure to communication programs about family planning and HIV/AIDS include a count of the number of radio programs that the respondent heard in the previous six months, ranging from 0 to 4 (including Your Health Matters, Lifeline, AIDS and the family, Our Neighborhood) and a count of the number of television programs she or he heard, ranging from 0 through 4 (including Your Health Matters, Lifeline, Soul City, X-plo- sion), as well as a count of the total number of programs they had seen or heard (range 0–8). For men, we also include an indicator of the number of sources of informa- tion about Maximum brand condoms. As control variables, we included the respondents' age (in years), place of residence (Lusaka, other urban, or rural), religion (Protestant, Catholic, or Other), highest level of education achieved (none, primary, secondary or higher), number of sexual partners in the past 12 months, and per- ceived personal risk for HIV/AIDS (none, low, moderate, and high). For the analyses, we combined those who reported being HIV-positive and those with high risk. Ownership of radio and television was measure by a set of dichotomous variables. We also included dummy variables indicating whether the respondent desires a child within the next two years, and whether his or her last partner was a casual partner. Statistical methods As most of the variables were categorical χ2-tests were used to compare their distributions for the female and male samples. For the few parametric variables, independ- ent sample t-tests were performed to compare female and male samples. When examining the effect of program exposure on con- dom use, it is possible that the same unobserved exoge- nous factors that affect condom use also affect program exposure, as well as that condom users may seek out these Page 3 of 12 (page number not for citation purposes)