The STOP PEDS RCT is a study to find the best way to treat lung flare-ups in kids with cystic fibrosis (CF), a disease that affects the lungs. There are two main ways to treat these flare-ups: starting antibiotics right away or waiting to see if symptoms get worse before using antibiotics. The study will last one year, and children will be split into two groups to test these approaches. CF patients will increase airway cleaning when symptoms start. The study includes children aged 3 to 18, and they must have a specific medicine called Highly Effective Modulator Therapy (HEMT) for at least three months if eligible. Some kids may join extra studies, like taking throat swabs or tracking health from home.

• Study Length: 12 months
• Eligibility: Children aged 3-18 with CF
• Extra Studies: Throat swabs, home health tracking