Trial emulation with observational data in cystic fibrosis.

Competing Interests: GD reports institutional fees for clinical trial leadership and advisory board roles from Vertex Pharmaceuticals and speaker honoraria from Vertex Pharmaceuticals and Chiesi outside of the submitted work. GD is a member of the UK Cystic Fibrosis Registry steering committee. RHK reports speaker honoraria from Vertex Pharmaceuticals outside of the submitted work. Both authors are funded by UK Research and Innovation (RHK: Future Leaders Fellowship MR/S017968/1; GD: Future Leaders Fellowship MR/T041285/1). Both authors are co-leads of the Cystic Fibrosis Trial Emulation Network.