Rowan SA1, Bradley JM, Bradbury I, Lawson J, Lynch T, Gustafsson P, Horsley A, O'Neill K, Ennis M, Elborn JS.

Link to publication page: http://www.ncbi.nlm.nih.gov/pubmed/24428575

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

Abstract:

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.