A cluster randomized-controlled trial to determine the effectiveness of Stepping Stones in preventing HIV infections and promoting safer sexual behaviour amongst youth in the rural Eastern Cape, South Africa: trial design, methods and baseline findings R. Jewkes 1 , M. Nduna 2 , J. Levin 3 , N. Jama 1 , K. Dunkle 4 , N. Khuzwayo 1 , M. Koss 5 , A. Puren 6 , K. Wood 7 and N. Duvvury 8 1 Gender and Health Research Unit, Medical Research Council, Pretoria, South Africa 2 Population Council, Johannesburg, South Africa 3 Bio-statistics Unit, Medical Research Council, Pretoria, South Africa 4 Behavioral Sciences and Health Education, Emory University, Atlanta, GA, USA 5 College of Public Health, University of Arizona, Tucson, AZ, USA 6 National Institute for Communicable Disease, Sandringham, South Africa 7 Thomas Coram Research Unit, Institute of Education, London, UK 8 International Center for Research on Women, Washington, DC, USA Summary objective To describe the study design, methods and baseline findings of a behavioural intervention trial aimed at reducing HIV incidence. method A cluster randomized-controlled trial (RCT) conducted in 70 villages in rural South Africa. A behavioural intervention, Stepping Stones, was implemented in 35 communities in two workshops of 20 men and 20 women in each community who met for 17 sessions (50 h) over a period of 3–12 weeks. Individuals in the control arm communities attended a single session of about 3 h on HIV and safer sex. Impact assessment was conducted through two questionnaire and serological surveys at 12-month intervals. The primary outcome was HIV incidence and secondary measures included changes in knowledge, attitude and sexual behaviours. Qualitative research was also undertaken with 10 men and 10 women from two sites receiving the intervention (one rural and one urban) and five men and five women from one village in the control arm. They were interviewed individually three times prior to the workshops and then 9–12 months later. results A total of 2776 participants (1409 intervention and 1367 control) were enrolled at baseline and had an interview, and HIV sero-status was established. HIV baseline prevalence rates in women were 9.8% in the intervention arm and 12.8% in the control arm. In men the prevalence was 1.7% in the intervention arm and 2.1% in the control arm. Demographic and behavioural characteristics were similar in the two arms. In the intervention groups 59.9% of participants attended more than 75% of the sessions. In the control group 66.3% attended the control session. conclusion This is the third RCT to be conducted in sub-Saharan Africa evaluating a behavioural intervention using HIV incidence as a primary outcome. It is of particular interest as the intervention in question is used in many developing countries. There is good baseline comparability between the study arms and the process data on the workshops suggested that the interventions were feasible and ade- quately implemented. keywords cluster randomized-controlled trial, South Africa, human immunodeficiency virus prevention, behavioural intervention evaluation Introduction Ten years after South Africa achieved democracy, HIV is arguably the most important problem facing the country and threatens to undermine many recent social achieve- ments. Considerable efforts have been directed at harnes- sing the preventive potential of biotechnology in combating the epidemic, yet best estimates are that there Tropical Medicine and International Health doi:10.1111/j.1365-3156.2005.01530.x volume 11 no 1 pp 3–16 january 2006 ª 2006 Blackwell Publishing Ltd 3