Between-Visit Variability in FEV1 as a Diagnostic Test for Asthma in Adults.
Ann Am Thorac Soc
; 15(9): 1039-1046, 2018 09.
Article
in En
| MEDLINE
| ID: mdl-29877740
ABSTRACT
RATIONALE The reliability of using between-visit variation in forced expiratory volume in 1 second (FEV1) to diagnose asthma is understudied, and hence uncertain. OBJECTIVE:
To determine whether FEV1 variability measured over recurrent visits is significantly associated with a diagnosis of current asthma.METHODS:
Randomly selected adults (N = 964) with a history of physician-diagnosed asthma were studied from 2005 to 2007 and from 2012 to 2016. A diagnosis of current asthma was confirmed in those participants who exhibited bronchial hyperresponsiveness to methacholine and/or acute worsening of asthma symptoms while being weaned off asthma medications. Regression analyses and receiver operating curves were used to evaluate the ability of between-visit FEV1 variability to diagnose asthma.RESULTS:
A current diagnosis of asthma was confirmed in 584 of 964 participants (60%). Between-visit absolute variability in FEV1 was significantly greater in those in whom current asthma was confirmed, compared with those in whom current asthma was ruled out (7.3% vs. 4.8%; mean difference between the two groups, 2.5%; 95% confidence interval, 1.7-3.3%). However, a 12% and 200-ml between-visit variation in FEV1, which is the diagnostic threshold recommended by Global Initiative for Asthma, exhibited a sensitivity of only 0.17 and a specificity of 0.94 for confirming current asthma. A between-visit absolute variability in FEV1 ≥ 12% and 200 ml increased the pretest probability of asthma from 60% to a posttest probability of 81%.CONCLUSIONS:
A 12% and 200-ml between-visit variation in FEV1, if present, has reasonably good specificity for diagnosing asthma, but has poor sensitivity compared with bronchial challenge testing. Between-visit variability in FEV1 is a relatively unhelpful test to establish a diagnosis of asthma.Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Asthma
/
Forced Expiratory Volume
Type of study:
Diagnostic_studies
/
Observational_studies
/
Risk_factors_studies
Limits:
Female
/
Humans
/
Male
/
Middle aged
Language:
En
Journal:
Ann Am Thorac Soc
Year:
2018
Document type:
Article
Affiliation country:
Canada
Publication country:
EEUU
/
ESTADOS UNIDOS
/
ESTADOS UNIDOS DA AMERICA
/
EUA
/
UNITED STATES
/
UNITED STATES OF AMERICA
/
US
/
USA