We identified three primary mechanisms of spillovers : reduced disease transmission , social proximity and substitution of re sources within households .
We found the strongest evidence for spillovers through reduced disease transmission , particularly vaccines and mass drug administration .
In general , the proportion of a population receiving an intervention was associated with improved health .
We found evidence of publication bias for certain spillover estimates but not for total or direct effects .
Conclusions We found the strongest evidence for spillovers from vaccines and mass drug administration to control infectious disease .
There was little high quality evidence of spillovers for other interventions
Background Many interventions delivered to improve health may benefit not only direct recipients but also people in close physical or social proximity .
Our objective was to review all published literature about the spillover effects of interventions on health outcomes in low-middle income countries and to identify methods used in estimating these effects .
Effectiveness and spillover of an after-school health promotion program for Hispanic elementary school children.
OBJECTIVES We evaluated the effectiveness and spillover of an after-school health education and physical activity program among Hispanic elementary school children . METHODS In fall 2008 , students in third through fifth grade s in 6 schools in El Paso , Texas ( n = 901 ) , were r and omized to intervention ( n = 292 participants ) or control ( n = 354 ) classrooms ( 4 unknown ) . Intervention classrooms also contained a spillover group ( n = 251 ) that did not join the after-school program but that completed measurements and surveys . The intervention was a 12-week culturally tailored after-school program meeting twice a week . Four-month outcomes were body mass index , aerobic capacity , and dietary intentions and knowledge . We calculated intervention exposure as the proportion of after-school participants per classroom . RESULTS Intervention exposure predicted lower body mass index ( P = .045 ) , higher aerobic capacity ( P = .012 ) , and greater intentions to eat healthy ( P = .046 ) for the classroom at follow-up . Intervention effectiveness increased with increasing proportions of intervention participants in a classroom . Non participants who had classroom contact with program participants experienced health improvements that could reduce their risk of obesity . CONCLUSIONS Spillover of beneficial intervention effects to non participants is a valuable public health benefit and should be part of program impact assessment
We identified three primary mechanisms of spillovers : reduced disease transmission , social proximity and substitution of re sources within households .
We found the strongest evidence for spillovers through reduced disease transmission , particularly vaccines and mass drug administration .
In general , the proportion of a population receiving an intervention was associated with improved health .
We found evidence of publication bias for certain spillover estimates but not for total or direct effects .
Conclusions We found the strongest evidence for spillovers from vaccines and mass drug administration to control infectious disease .
There was little high quality evidence of spillovers for other interventions
Background Many interventions delivered to improve health may benefit not only direct recipients but also people in close physical or social proximity .
Our objective was to review all published literature about the spillover effects of interventions on health outcomes in low-middle income countries and to identify methods used in estimating these effects .