Improvement in spirometry was similar between the two groups [ mean change in FEV1 % predicted : IV group 16.4 ( standard deviation 8.5 ) versus TNS group 19.9 ( 11.3 ) , p = 0.26 ] , but there was more suppression of sputum Psa in the TNS group [ mean difference between treatments 0.85 log10 colony-forming units/mL ( CI 0.03 to 1.67 ) , p = 0.05 ] .