Work-exacerbated asthma and occupational asthma: do they really differ?
BACKGROUND
Although work-exacerbated asthma (WEA) is a prevalent condition likely to have an important societal burden, there are limited data on this condition.


OBJECTIVE
The aims of this study were (1) to compare the clinical, functional, and inflammatory characteristics of workers with WEA and occupational asthma (OA) and (2) compare health care use and related costs between workers with WEA and OA, as well as between workers with work-related asthma (WRA; ie, WEA plus OA) and those with non-work-related asthma (NWRA) in a prospective study.


METHODS
We performed a prospective observational study of workers with and without WRA with a 2-year follow-up. The diagnosis of OA and WEA was based on the positivity and negativity of results on specific inhalation challenges, respectively.


RESULTS
One hundred fifty-four subjects were enrolled: 53 with WEA, 68 with OA, and 33 control asthmatic subjects (NWRA). WEA was associated with more frequent prescriptions of inhaled corticosteroids (odds ratio [OR], 4.4; 95% CI, 1.4-13.6; P = .009), a noneosinophilic phenotype (OR, 0.3; 95% CI, 0.1-0.9; P = .04), a trend toward a lower FEV1 (OR, 0.9; 95% CI, 0.9-1.0; P = .06), and a higher proportion of smokers (OR, 2.5; 95% CI, 0.96-9.7; P = .06) than the diagnosis of OA. The health care use of WRA and related costs were 10-fold higher than those of NWRA.


CONCLUSIONS
Workers with WEA appeared to have features of greater asthma severity than workers with OA. In contrast with OA, WEA was associated with a noneosinophilic phenotype. Both OA and WEA were associated with greater health care use and 10-fold higher direct costs than NWRA.
Hôpital du Sacré-Cœur de Montréal (Québec) Canada, Université de Montréal, Montreal, Quebec, Canada. catherine.lemiere@umontreal.ca
Catherine
C
Lemière
Louis-Phillippe
LP
Boulet
Simone
S
Chaboillez
Amélie
A
Forget
Samah
S
Chiry
Hélène
H
Villeneuve
Philippe
P
Prince
Karim
K
Maghni
Wendy A
WA
Kennedy
Lucie
L
Blais
D000328:Adult; D001249:Asthma / Q000175:diagnosis* / Q000191:economics / Q000503:physiopathology; D005260:Female; D005102:Health Expenditures; D006801:Humans; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000175:diagnosis* / Q000191:economics / Q000503:physiopathology; D011792:Quebec; D055815:Young Adult