A Cox proportional-hazards model analysis was used with time-to-first-exacerbation as the outcome variable and MBL group (ie, below versus above specified limits) as the primary variable of interest. Bootstrap methods were used to compute confidence intervals for median survival times. Rates of AECOPDs were determined by dividing the number of AECOPDs by person-years of follow-up and were analyzed as a function of MBL concentration using a negative binomial model. MBL concentrations are presented as medians and interquartile ranges. P , 0.05 was considered to be statistically significant. The study (ClinicalTrials.gov number NCT00325897) was approved by the institutional review boards at all participating centers. submit your manuscript | www.dovepress.com