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Communications to the Editor |

Predictive Parameters of Dropout During Inhaled Corticosteroid Tapering FREE TO VIEW

Daniel K. C. Lee, MRCP; Graeme P. Currie, MRCP; Brian J. Lipworth, MD
Author and Funding Information

Asthma and Allergy Research Group Ninewells Hospital and Medical School Dundee, Scotland

Correspondence to: Brian J. Lipworth, MD, Asthma and Allergy Research Group, Department of Clinical Pharmacology and Therapeutics, Ninewells Hospital and Medical School, University of Dundee, Dundee DD1 9SY, Scotland, UK; e-mail: b.j.lipworth@dundee.ac.uk



Chest. 2002;121(5):1726-1727. doi:10.1378/chest.121.5.1726-a
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Published online

To the Editor:

We have retrospectively analyzed data from four clinical trials whereby treatment with inhaled corticosteroids (ICS) was either tapered down or stopped during a preliminary run-in period. The purpose of the analysis was to evaluate whether parameters at initial screening might be predictive of subsequent patient dropout due to asthma exacerbation.

The doses of ICS were reduced by 50% until the beclomethasone dipropionate (BDP) equivalent dose was ≤ 400 μg/d. BDP equivalent dose of ICS was calculated on the basis of fluticasone propionate (FP) being twice as potent as budesonide or BDP, so that the equivalent FP dose was multiplied twofold. We analyzed data on FEV1, forced expiratory flow, midexpiratory phase (FEF25–75), and ICS (BDP equivalent dose).

Patients were examined in two groups: those who dropped out (group A) during run-in (n = 23) due to exacerbation of their asthma and a matched control group (group B) who did not drop out during this period (n = 23). All patients had stable asthma of mild-to-moderate severity, with an unchanged ICS dose for 3 months prior to run-in. Any second-line nonsteroidal therapy, such as long-acting β2-agonist, leukotriene receptor antagonist, and theophylline, was stopped for 1 week prior to ICS tapering (Table 1 ).

Measurements were made at initial screening, at dropout (for patients who had an exacerbation requiring withdrawal from run-in), and after completion of the run-in period (for patients who did not drop out). Analysis of variance was used for comparisons within and between the two groups of patients, at screening, and at dropout/end of run-in.

There were no significant differences between group A and group B at screening prior to run-in. Patients who dropped out (group A) had a mean fall of FEV1 of 21.3% predicted (confidence interval [CI], 13.7 to 28.9% predicted), FEF25–75 of 15.4% predicted (CI, 8.4 to 22.4% predicted), and BDP equivalent dose reduction of 421.7 μg (CI, 70.3 to 773.2 μg). All of these changes were significant (p < 0.05). %At the end of the run-in period, parameters on patients who did not drop out (group B) had a mean fall of FEV1 of 2.4% predicted (CI, − 7.8 to 12.6% predicted), FEF25–75 of 2.9% predicted (CI, − 7.8 to 13.6% predicted), and BDP equivalent dose reduction of 513.0 μg (CI, 216.0 to 810.1 μg). Only reduction in ICS dose was significant (p < 0.05).

Comparisons between groups A and B at dropout/end of run-in showed a mean difference of FEV1 of 20.7% predicted (CI, 10.6 to 30.9% predicted), FEF25–75 of 19.8% predicted (CI, 10.7 to 28.9% predicted), and BDP equivalent dose difference of 226.1 μg (CI, − 78.0 to 530.1 μg). Differences in FEV1 and FEF25–75 were significant (p < 0.05).

As can be seen from our analysis, the parameters of FEV1, FEF25–75, and ICS dose at screening did not predict whether a patient was likely to drop out due to asthma exacerbation during initial ICS tapering. It is therefore imperative that patients with stable asthma are monitored closely while their ICS regimens are tapered irregardless of initial parameters.

Table Graphic Jump Location
Table 1. Data From Four Trials*
* 

Values are expressed as mean ± SEM unless otherwise indicated.

 

Denotes p < 0.05 for comparison within group A (screening vs dropout) or within group B (screening vs end of run-in).

 

Denotes p < 0.05 for comparison between group A (dropout) vs group B (end of run-in).


Figures

Tables

Table Graphic Jump Location
Table 1. Data From Four Trials*
* 

Values are expressed as mean ± SEM unless otherwise indicated.

 

Denotes p < 0.05 for comparison within group A (screening vs dropout) or within group B (screening vs end of run-in).

 

Denotes p < 0.05 for comparison between group A (dropout) vs group B (end of run-in).

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