Abbreviations: GOLD, Global Initiative for Chronic Obstructive Lung Disease; MMRC, Modified Medical Research Council; SGRQ, St George’s Respiratory Questionnaire.
Multivariate logistic or linear regression models, adjusted for sex, age, age 2, weight, smoking status, and pack-years smoked. Referral category for all comparisons includes participants with no history of high exposure to biological
dust, mineral dust, or gases/fumes (n = 110; see Table 2).
* As compared to MMRC dyspnea scale 0, 1 or 2.
{As compared to GOLD Stage.
doi:10.1371/journal.pone.0088426.t003