Variable Controls SCD p-value N 74 154   Age 30.7 (10.3) 33.8 (12.0) 0.053 Height, m 1.71 (0.093) 1.69 (0.09) 0.064 FEV1 (L) 3.13 (0.62) 2.34 (0.66) <0.001 FEV1% 94.9 (11.6) 74.5 (13.3) <0.001 FVC (L) 3.83 (0.79) 3.13 (0.93) <0.001 FVC% 97.6 (12.1) 83.6 (16.3) <0.001 FEV1/FVC% 82.0 (5.6) 75.5 (11.0) <0.001 Abbreviations: SCD: Sickle Cell Disease; ACS: Acute Chest Syndrome; N: Number; M: Male; BMI: Body Mass Index

Table 1: Baseline data/confounding variables for 74 controls and 154 sickle cell disease patients. Data are shown as mean (SD) or IQR (25th centile, 75th centile) or number (%). There were N = 36 (48.6%) males amongst the controls and 67 (43.5%) sickle cell disease patients. BMI for sickle cell disease patients was 21.0 (4.2) kg per square metre.