Repeated dyspnea score and percent FEV1 are modest predictors of
hospitalization/relapse in patients with acute asthma exacerbation.
Author(s): Schneider JE(1), Lewis LM(2), Ferguson I(3), House SL(3), Liu J(4), Matsuda K(5),
Johnson K(5).
Affiliation(s): Author information:
(1)University of Missouri School of Medicine, Columbia, MO, USA. (2)Emergency
Medicine Division, Washington University in St. Louis, USA. Electronic address:
Lewisl@wusm.wustl.edu. (3)Emergency Medicine Division, Washington University in
St. Louis, USA. (4)Division of Biostatistics, Washington University in St. Louis,
USA. (5)MediciNova Inc., La Jolla, CA, USA.
Publication date & source: 2014, Respir Med. , 108(9):1284-91
OBJECTIVES: (1) Compare ideal cut-off points for DS and %FEV1 at 1 and 3 h to
predict hospitalization/relapse in subjects with moderate to severe asthma
exacerbation (2) Develop a multivariate regression model using DS, %FEV1,
demographic, and clinical variables to predict hospitalization/relapse.
METHODS: Subjects with acute exacerbation of asthma (FEV1 <50% predicted
following 30 min of standardized treatment: 5 mg nebulized albuterol; 0.5-1.5 mg
nebulized ipratropium; and 50 mg oral prednisone) were eligible. All subjects had
%FEV1 and DS obtained at baseline and hourly for 3 h. Using
hospitalization/relapse as the outcome of interest; we compared the area under
the receiveroperator curves (AUC) between the 1 and 3 h DS and %FEV1
measurements, and the AUC for the change in DS and %FEV1 between baseline and
hour-3. We determined ideal cut-points for %FEV1 and DS to maximize sensitivity
and specificity. Sensitivity, specificity, positive and negative predictive
values, and positive and negative likelihood ratios (LR) were compared between
%FEV1 and DS. We developed a multivariate regression model examining the
association of specific demographic and clinical variables to
hospitalization/relapse.
RESULTS: 142 patients were included for analysis. The AUC was greatest for the
3-h DS (0.721), followed by the 3-h %FEV1 (0.669). Optimum cut-off values were a
DS of 2, and an FEV1 of 42%. These were associated with a +LR for the composite
outcome of 3.06 and 2.48 respectively. Logistic regression showed baseline DS,
3-h DS, change in DS, and oxygen use at hour 3 were all associated with the
composite outcome.
CONCLUSIONS: The 3-h score for %FEV1 and DS performed better than scores at any
other time point and better than either parameter over time. The 3-h DS had the
greatest association with the composite outcome. Neither test was a strong enough
predictor to be used solely for this purpose.
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