Lung clearance index is a repeatable and sensitive indicator of radiological changes in bronchiectasis

Am J Respir Crit Care Med. 2014 Mar 1;189(5):586-92. doi: 10.1164/rccm.201310-1747OC.


Rationale: In bronchiectasis there is a need for improved markers of lung function to determine disease severity and response to therapy.

Objectives: To assess whether the lung clearance index is a repeatable and more sensitive indicator of computed tomography (CT) scan abnormalities than spirometry in bronchiectasis.

Methods: Thirty patients with stable bronchiectasis were recruited and lung clearance index, spirometry, and health-related quality of life measures were assessed on two occasions, 2 weeks apart when stable (study 1). A separate group of 60 patients with stable bronchiectasis was studied on a single visit with the same measurements and a CT scan (study 2).

Measurements and main results: In study 1, the intervisit intraclass correlation coefficient for the lung clearance index was 0.94 (95% confidence interval, 0.89 to 0.97; P < 0.001). In study 2, the mean age was 62 (10) years, FEV1 76.5% predicted (18.9), lung clearance index 9.1 (2.0), and total CT score 14.1 (10.2)%. The lung clearance index was abnormal in 53 of 60 patients (88%) and FEV1 was abnormal in 37 of 60 patients (62%). FEV1 negatively correlated with the lung clearance index (r = -0.51, P < 0.0001). Across CT scores, there was a relationship with the lung clearance index, with little evidence of an effect of FEV1. There were no significant associations between the lung clearance index or FEV1 and health-related quality of life.

Conclusions: The lung clearance index is repeatable and a more sensitive measure than FEV1 in the detection of abnormalities demonstrated on CT scan. The lung clearance index has the potential to be a useful clinical and research tool in patients with bronchiectasis.

Publication types

  • Clinical Trial
  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Breath Tests
  • Bronchiectasis / diagnosis*
  • Bronchiectasis / diagnostic imaging
  • Bronchiectasis / physiopathology
  • Feasibility Studies
  • Female
  • Forced Expiratory Volume
  • Humans
  • Lung / diagnostic imaging
  • Lung / physiopathology*
  • Male
  • Middle Aged
  • Models, Statistical
  • Quality of Life
  • ROC Curve
  • Regression Analysis
  • Respiratory Function Tests
  • Sensitivity and Specificity
  • Severity of Illness Index
  • Spirometry
  • Surveys and Questionnaires
  • Tomography, X-Ray Computed* / methods
  • Young Adult