As Binka et al say “The original trials ran for only 1-2 years each. At the end of these periods, the efficacy of the intervention was considered proven and the control groups were provided with nets or curtains, thus these trials could not be used to demonstrate the effects of long-term transmission control.”.
The evidence is quite strong. You can most likely get more detail than you ever wanted from the GiveWell review.
Thanks.
It seems like there are 4 studies with extended follow up—Binka et al https://doi.org/10.1016/S0035-9203(02)90321-4 , Diallo et al https://pmc.ncbi.nlm.nih.gov/articles/PMC2585912/ , Lindblade et al https://doi.org/10.1001/jama.291.21.2571 , Louis et al https://doi.org/10.1111/j.1365-3156.2012.02990.x—but not of the type that would be directly informative.
As Binka et al say “The original trials ran for only 1-2 years each. At the end of these periods, the efficacy of the intervention was considered proven and the control groups were provided with nets or curtains, thus these trials could not be used to demonstrate the effects of long-term transmission control.”.