1.011; P < .001 for general practitioner visits; OR, 1.015;
P < .001 for emergency department visits; and OR,
1.023, P ¼ .005 for hospitalization for respiratory illness)
(Table 8).
After adjusting for age, sex, and BMI, dyspnea was
associated with a reduced likelihood of current
employment (OR, 0.993;P < .001), increased
absenteeism (coefﬁcient, 0.066; P < .001), increased
presenteeism (coefﬁcient, 0.349; P < .001), higher work
productivity loss (coefﬁcient, 0.383; P < .001), and
greater activity impairment (coefﬁcient, 0.501;P < .001),
as measured by the Work Productivity and Activity
Impairment questionnaire21 (Table 9).
Discussion
Our study explored dyspnea in community-based adults
with undiagnosed respiratory symptoms identiﬁed via
case ﬁnding. Surprisingly, we found that the dyspnea
experienced by those with PRISm had a greater impact
on their activities and health status than those with
newly diagnosed COPD or asthma.
The prevalence of individuals who were obese and
morbidly obese in the PRISm group partially explains
the between-group difference in dyspnea. The excess
dyspnea seen in the PRISm group when compared with
the normal spirometry group is partly explained by
patient-speciﬁc risk factors, including BMI, which
shrink the mean dyspnea differential between the groups
from 11.2 to 5.5 points (Tables 3-6). The remaining 5.5-
point difference indicates that PRISm patients have
excess dyspnea relative to symptomatic individuals with
normal spirometry for additional reasons other than
obesity.
TABLE 4] Sequential Regression Analyses of Risk Factors Contributing to Variability in Dyspnea: Dyspnea
Regressed on Patient-Speciﬁc Risk Factors (20.6% of Variability Explained)
Risk Factor Regression Coef ﬁcient P Value
Age /C0 0.0909 .005
Female 8.217 < .001
BMI 0.899 < .001
Household income< CAD $30,000 1.420 .40
Household income$ CAD $30,000 /C0 2.149 .07
Smoking history, pack-y 0.144 < .001
Smoking exposure 5.123 < .001
Occupational exposure 0.00975 < .001
Congestive heart failure 10.119 .004
Coronary artery disease 4.813 .001
Depression/anxiety 6.892 < .001
Diabetes mellitus 1.627 .22
Hypertension 3.433 < .001
Anemia 1.738 .15
Cancer 0.952 .49
GERD 4.663 < .001
Liver disease 1.081 .61
Renal disease 2.073 .32
Stroke 8.463 < .001
Boldface indicates statitistical signiﬁcance. GERD¼ gastroesophageal reﬂux disease.
TABLE 5] Dyspnea Regressed on Spirometry Disease
Group
Disease Group Regression Coef ﬁcient P Value
Control /C0 31.2 < .001
Normal spirometrya NA NA
Asthma 4.6 .001
COPD 3.8 .003
PRISm 5.5 .001
Constant 51.9 NA
Dyspnea regressed on spirometry disease group, after removing contri-
butions from subject-speci ﬁc factors in Table 4 (12.4% of variability
explained). Boldface indicates statitistical signiﬁcance. NA ¼ not appli-
cable; PRISm ¼ preserved ratio impaired spirometry.
aNormal spirometry group is the reference category.
1304 Original Research [ 166#6 CHEST DECEMBER 2024 ]