If you think in terms of QALYs, that could be one reason to prefer interventions targeted at children. Your average child has more life to live than your average adult, so if you permanently improve their quality of life from 0.8 QALYs per year to 0.95 QALYs per year, that would result in a larger QALY change than the same intervention on the adult.
This argument has numerous flaws. One which comes to mind immediately are that many interventions are not so long lasting, so both adults and children would presumably gain the same. It also is tied to particular forms of utilitarianism one might not subscribe to.
If you think in terms of QALYs, that could be one reason to prefer interventions targeted at children. Your average child has more life to live than your average adult, so if you permanently improve their quality of life from 0.8 QALYs per year to 0.95 QALYs per year, that would result in a larger QALY change than the same intervention on the adult.
This argument has numerous flaws. One which comes to mind immediately are that many interventions are not so long lasting, so both adults and children would presumably gain the same. It also is tied to particular forms of utilitarianism one might not subscribe to.