Objectives: To compare performance of weight-for-length and body mass index as estimators of undernutrition in children with cystic fibrosis (CF).
Study Design: We analyzed pediatric anthropometric data from the Cystic Fibrosis Foundation Patient Registry. Undernutrition was defined by weight-for-length z score (WFLZ) or body mass index z score (BMIZ) ≤-1 (15th-percentile).