Control of exposure to mite allergen and allergen-impermeable bed covers for adults with asthma


Woodcock, Ashley, Forster, Louise, Matthews, Edward, Martin, Jeannett, Letley, Louise, Vickers, Madge, Britton, John, Strachan, David, Howarth, Peter, Altmann, Daniel, Frost, Christopher and Custovic, Adrian Medical Research Council General Practice Research Framework (2003) Control of exposure to mite allergen and allergen-impermeable bed covers for adults with asthma. New England Journal of Medicine, 349, (3), 225-236. (doi:10.1056/NEJMoa023175).

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Original Publication URL: http://dx.doi.org/10.1056/NEJMoa023175

Description/Abstract

BACKGROUND: The effectiveness of avoidance of house-dust-mite allergen (Dermatophagoides pteronyssinus 1 [Der p1]) in the management of asthma is uncertain. METHODS: We conducted a double-blind, randomized, placebo-controlled study of allergen-impermeable bed covers involving 1122 adults with asthma. The primary outcomes were the mean morning peak expiratory flow rate over a four-week period during the run-in phase and at six months and the proportion of patients who discontinued inhaled corticosteroid therapy as part of a phased-reduction program during months 7 through 12. Der p1 was measured in mattress dust in a 10 percent random subsample of homes at entry and at 6 and 12 months. RESULTS: The prevalence of sensitivity to dust-mite allergen was 65.4 percent in the group supplied with allergen-impermeable bed covers (active-intervention group) and 65.1 percent in the control group supplied with non-impermeable bed covers. The concentration of Der p1 in mattress dust was significantly lower in the active-intervention group at 6 months (geometric mean, 0.58 microg per gram vs. 1.71 microg per gram in the control group; P=0.01) but not at 12 months (1.05 microg per gram vs. 1.64 microg per gram; P=0.74). The mean morning peak expiratory flow rate improved significantly in both groups (from 410.7 to 419.1 liters per minute in the active-intervention group, P<0.001 for the change; and from 417.8 to 427.4 liters per minute in the control group, P<0.001 for the change). After adjustment for base-line differences (by analysis of covariance), there was no significant difference between the groups in the peak expiratory flow rate at six months (difference in means, active-intervention group vs. control group, -1.6 liters per minute [95 percent confidence interval, -5.9 to 2.7] among all patients [P=0.46] and -1.5 liters per minute [95 percent confidence interval, -6.9 to 3.9] among mite-sensitive patients [P=0.59]). There was no significant difference between the groups in the proportion in whom complete cessation of inhaled corticosteroid therapy was achieved (17.4 percent in the active-intervention group and 17.1 percent in the control group) or in the mean reduction in steroid dose, either among all patients or among mite-sensitive patients. CONCLUSIONS: Allergen-impermeable covers, as a single intervention for the avoidance of exposure to dust-mite allergen, seem clinically ineffective in adults with asthma.

Item Type: Article
ISSNs: 0028-4793 (print)
Related URLs:
Subjects: R Medicine > RA Public aspects of medicine > RA0421 Public health. Hygiene. Preventive Medicine
Q Science > QR Microbiology
Divisions: University Structure - Pre August 2011 > School of Medicine > Infection, Inflammation and Repair
ePrint ID: 46707
Date Deposited: 13 Jul 2007
Last Modified: 27 Mar 2014 18:30
URI: http://eprints.soton.ac.uk/id/eprint/46707

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