Overall, electronic adherence measures are considered valid, reliable, and accurate, with clear advantages over pharmacy refill records, physician estimates and self-report measures. Currently, only one electronic measure capable of monitoring medications in both pill and liquid form is being manufactured: WisePill and WiseBag. While data are limited regarding its validity and reliability, preliminary data support the use of Wise technology to measure adherence to medication. The current study will determine the Wise device's ability to feasibly measure adherence to liquid and solid form HU medication in a pediatric SCD population.