After adjustment for sex , baseline FVC as a percentage of predicted , and baseline diffusing capacity of the lung for carbon monoxide as a percentage of predicted , patients taking anti-acid treatment at baseline had a smaller decrease in FVC at 30 weeks ( -006 L , 95 % CI -011 to -001 ) than did those not taking anti-acid treatment ( -012 L , -017 to -008 ; difference 007 L , 95 % CI 0-014 ; p = 005 ) .