INSTRUCT trial design

INSTRUCT measures the impact of combined behavioural and structural interventions in a cluster randomized controlled trial. In this trial, districts (clusters) receiving added HIV prevention actions are compared with those with just the regular prevention efforts (controls).

The INSTRUCT trial uses a stepped-wedge design. It is difficult to roll out a new prevention approach everywhere in the country at exactly the same time. The stepped-wedge design divides all the districts into groups, and rolls out the new approach one group at a time. Randomising the order of implementation gives all districts the same chance to go first, and the same chance to benefit from experience of other districts that started earlier. As each new group of districts joins in, their baseline study provides a comparison point (control) for the group of districts that went just before them.

The 30 administrative districts in the country will be randomly allocated into six intervention waves, each of five districts, stratified by development status and HIV prevalence (above or below the national average).

The first year of INSTRUCT will work in one district of the first wave, to operationalize the scaling up of the interventions to the whole district. All five first wave districts will receive the intervention package from years 2-4. In year 4 we will conduct a survey to measure impact, in a sample of communities in the five first wave districts and the five second wave districts (controls for the first wave). This process will be repeated for subsequent waves of districts, with fine-tuning of the intervention package as necessary.

Timing for INSTRUCT

The INSTRUCT intervention is a combined prevention package with three components:

  • Beyond victims and villains is an audio-drama offered to discussion groups of all ages and both sexes throughout each intervention district – it attempts to build an enabling environment for change in the community by making people more aware of gender violence, transactional sex and other aspects of HIV risk in Botswana;
  • Concerting of all prevention services (includes churches, health care, education, poverty eradication, and other enterprise support programmes) concentrates them on those at risk of HIV;
  • Focused Workshop uses skills workshops and government structural support programmes to target women aged 15-29 years, especially those not in school or employment.

 

The impact survey for INSTRUCT will include a questionnaire survey of young women and young men in randomly selected communities in intervention and control districts, and finger prick blood sampling to create dried blood spots for HIV testing.

INSTRUCT seeks to reduce new HIV infections, particularly among young women. The primary outcome of the trial is prevalence of HIV infection among women aged 15-29 years, living in intervention districts compared with such women living in control districts. Because some of them could have been infected before the intervention started, INSTRUCT will also use newer tests to detect recent HIV infection, allowing an estimate of annual HIV incidence.

Secondary outcomes of INSTRUCT will be measured among young women and young men aged 15-29 years. They include protective knowledge, attitudes, subjective norms, intention to change, agency, discussion of prevention, and behaviours related to gender violence and HIV risk and prevention.