Factorial design and description of individual cells
| No BI | BI | BI+boosters | |
| Text messaging=no | No intervention | BI only | BI+boosters |
| Text messaging=yes | Text messaging only | BI+text messaging | BI+boosters+text messaging |
N for each cell=64 (total N=384). Allocation to all cells is random, stratified by state and binge frequency.
BI, brief intervention.