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Am J Respir Crit Care Med. 2017 Apr 15;195(8):993-999. doi: 10.1164/rccm.201601-0076OC.

Fluctuation Analysis of Peak Expiratory Flow and Its Association with Treatment Failure in Asthma.

Author information

1
1 Pulmonary and Critical Care, University of Vermont College of Medicine, Burlington, Vermont.
2
2 Department of Biomedical Informatics and Medical Education, University of Washington School of Medicine, Seattle, Washington.
3
3 Woolcock Institute of Medical Research, Syndey, New South Wales, Australia.
4
4 Pulmonary and Critical Care, Johns Hopkins University, Baltimore, Maryland; and.
5
5 Pulmonary and Critical Care Wake Forest School of Medicine, Winston-Salem, North Carolina.

Abstract

RATIONALE:

Temporal fluctuations have been demonstrated in lung function and asthma control, but the effect of controller therapy on these fluctuations is unknown.

OBJECTIVES:

To determine if fluctuations in peak expiratory flow (PEF) are predictive of subsequent treatment failure and may be modified by controller therapy.

METHODS:

We applied detrended fluctuation analysis to once-daily PEF data from 493 participants in the LOCCS (Leukotriene Modifier Corticosteroid or Corticosteroid-Salmeterol) trial of the American Lung Association Airways Clinical Research Centers. We evaluated the coefficient of variation of PEF (CVpef) and the scaling exponent α, reflecting self-similarity of PEF, in relation to treatment failure from the run-in period of open-label inhaled fluticasone, and the treatment periods for subjects randomized to (1) continued twice daily fluticasone (F), (2) once daily fluticasone plus salmeterol (F + S), or (3) once daily oral montelukast (M).

MEASUREMENTS AND MAIN RESULTS:

The CVpef was higher in those with treatment failure in the F and F + S groups in the run-in phase, and all three groups in the treatment phase. α was similar between those with and without treatment failure in all three groups during the run-in phase but was higher among those with treatment failure in the F and F + S groups during the treatment phase. Participants in all three groups showed variable patterns of change in α leading up to treatment failure.

CONCLUSIONS:

We conclude that increased temporal self-similarity (α) of more variable lung function (CVpef) is associated with treatment failure, but the pattern of change in self-similarity leading up to treatment failure is variable across individuals.

KEYWORDS:

asthma; fluctuation analysis; lung function variability; peak expiratory flow; treatment failure

PMID:
27814453
PMCID:
PMC5803646
DOI:
10.1164/rccm.201601-0076OC
[Indexed for MEDLINE]
Free PMC Article

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