Participants were evaluated beginning 14 days prior to starting a 28-day course of AZLI (Day 0 to Day 28), followed by post-treatment assessments every 14 days through Day 56, for a total of 70 days of participation in the study.

75 mg aztreonam for inhalation solution (AZLI), administered 3 times daily using the PARI Investigational eFlow® Nebulizer System (with a minimum of 4 hours between doses) following administration of a short-acting bronchodilator

Test-retest reliability is a measure of the stability or reproducibility of a measure over a period of time during which status on the underlying construct has not changed, and is measured by the intraclass correlation of scores obtained at 2 time points within that period. Test-retest reliability of respiratory symptoms was calculated for response at Day -14 and Day 0. Reliability of the participants' QOL-B responses was assessed from an Intraclass Correlation Coefficient (ICC). A score of ≥ 0.70 would indicate strong reliability.

The QOL-B respiratory symptoms score was transformed onto a scale of 0-100, with higher scores representing a better quality of life.

Convergent validity was assessed at Day -14 by examining the correlations between relevant QOL-B domains and other indicators of health status: a bronchiectasis severity score based on high-resolution computerised tomography (HRCT) scan results, forced expiratory volume in 1 second (FEV1) percent predicted, 6-minute walk test (6MWT) results, and St. George's Respiratory Questionnaire (SGRQ) symptoms scores. Correlations with absolute values of 0.30 to 0.50 indicated moderate evidence of convergent validity.

The anchor-based method measured the participant's perception of change at Day 28 using the GRCQ, which assesses improving/worsening symptoms. Distribution of ratings was categorized as no change (-1 to 1), minimal change (≥ 1.1 to < 3.1 or ≤ -1.1 to > -3.1), moderate change (≥ 3.1 to < 5.1 or ≤ -3.1 to > -5.1) or large change (≥ 5.1, ≤ -5.1). The GRCQ evaluated change in respiratory symptoms on a visual analog scale from -7 (worsening) to +7 (improvement). The following algorithm was used to obtain the mean change:

If the corresponding GRCQ score was in the "no change" group, then change from baseline QOL-B = Observed QOL-B change from baseline score; if > 1, then change from baseline QOL-B score = Observed QOL-B change from baseline score; if < -1, the change from baseline QOL-B score = (-1) * Observed QOL-B change from baseline score.

Then the mean change from baseline of QOL-B respiratory symptoms score of the minimal change category group is the anchor-based MCID.