TABLE 2

Baseline characteristics by longitudinal blood eosinophil group over 12 months for the 99 patients with sufficient data

Rarely eosinophilicIntermittently eosinophilicPredominantly eosinophilicp-value++
Patients261959
Continuous variables
 Age62.7±8.6367.9±6.87 (n=16)68.0±9.05 (n=57)0.034
 Smoking history pack-years46.3±22.864.9±43.2 (n=16)51.0±28.6 (n=57)0.098
 Body mass index kg·m–228.2 (8.15)27.9 (5.69) (n=16)25.9 (4.73) (n=57)0.280
 Fat-free body mass %53.5 (21.5) (n=25)49.3 (18.3) (n=16)48.8 (22.4) (n=56)0.886
 White blood cells count ×109 L–18.30 (3.30) (n=25)7.65 (1.65) (n=16)7.30 (2.00) (n=57)0.060
 Blood eosinophils count ×109 L–10.10 (0.10) (n=25)0.20 (0.10) (n=16)0.30 (0.20) (n=57)NA
 Blood eosinophils %1.35 (1.45) (n=25)2.12 (1.09) (n=16)4.08 (3.05) (n=57)NA
 Blood neutrophils count ×109 L–15.20 (2.55) (n=25)4.80 (0.50) (n=16)4.30 (1.75) (n=57)0.030
 Fibrinogen g·L–14.70 (1.40) (n=23)4.75 (0.97) (n=14)4.80 (0.90) (n=51)0.905
 C-reactive protein mg·L–14.00 (7.50)5.00 (5.75) (n=16)5.00 (7.00) (n=57)0.966
 Sputum eosinophils %#0.43 (2.89) (n=18)0.82 (1.78) (n=7)2.81 (7.40) (n=40)0.070
 Sputum neutrophils %#9.77 (64.0) (n=18)62.3 (63.4) (n=7)38.0 (71.6) (n=40)0.223
 FEV1 %47.7 (25.6)43.9 (22.4) (n=16)47.5 (26.0) (n=57)0.661
 ΔFEV1 % of baseline3.79 (27.3) (n=19)10.8 (23.2) (n=15)5.03 (21.4) (n=45)0.375
 FEV1 reversibility % of pre-bronchodilator FEV1+7.69 (15.0) (n=24)17.9 (16.6) (n=13)12.6 (12.5) (n=46)0.355
KCO %74.2 (31.0) (n=25)68.3 (26.7) (n=16)69.3 (30.3) (n=53)0.526
TLCO %62.0 (41.1) (n=25)57.8 (28.8) (n=16)56.3 (27.7) (n=53)0.407
 CAT score15.5 (10.0)20.5 (13.0) (n=16)16.0 (9.00) (n=57)0.101
 6MWT distance m300 (199) (n=25)323 (172) (n=16)327 (164) (n=56)0.914
 EXACT-PRO score36.0 (14.0) (n=23)36.5 (7.00) (n=14)36.0 (15.0) (n=46)0.607
 Exacerbation rate in year before study2.00 (3.00)2.00 (3.00) (n=16)2.00 (2.00) (n=57)0.941
 Exacerbation rate in first year of study2.47 (3.22)1.02 (2.00) (n=16)2.04 (3.95) (n=57)0.197
 Eosinophilic exacerbation rate in first year of study0.00 (0.99)0.00 (0.99) (n=16)1.38 (2.99) (n=57)<0.001
 Follow-up in first year of study years1.01 (0.02)1.01 (0.01) (n=16)1.01 (0.02) (n=57)0.448
Categorical variables
 Sex
  Male12 (46)9 (56)34 (60)0.547
  Female14 (54)7 (44)23 (40)
 Current smoker§
  Yes15 (58)4 (25)24 (42)0.125
  No11 (42)12 (75)33 (58)
 Use of ICS at enrolmentƒ
  Yes21 (81)15 (94)51 (89)0.468
  No5 (19)1 (6)6 (11)
 Sputum eosinophils >3%#
  Yes2 (11)0 (0)19 (48)0.003
  No16 (89)7 (100)21 (53)
 Blood eosinophils ≥2%
  Yes7 (28)9 (56)55 (96)NA
  No18 (72)7 (44)2 (4)
 Bacteria present##
  Yes12 (55)6 (50)26 (50)0.952
  No10 (45)6 (50)26 (50)
 Virus present¶¶
  Yes4 (19)0 (0)10 (20)0.288
  No17 (81)12 (100)40 (80)

Data are presented as n for patient numbers, mean±sd or median (interquartile range) for continuous variables, or n (%) for categorical variables, unless otherwise stated. FEV1: forced expiratory volume in 1 s; KCO: transfer coefficient of the lung for carbon monoxide; TLCO: transfer factor of the lung for carbon monoxide; CAT: COPD Assessment Test; 6MWT: 6-min walk test; ICS: inhaled corticosteroid; NA: not appropriate. #: sputum eosinophil and neutrophil percentage at baseline is reported (“baseline” is equal to enrolment if good quality data (squamous cell contamination <30%) is present at enrolment or the next (pre-exacerbation) stable visit with quality data within 4 months of enrolment); : calculated as FEV1 at month 12×100/FEV1 at enrolment; +: calculated as (post-bronchodilator FEV1–pre-bronchodilator FEV1)/pre-bronchodilator FEV1×100; §: smoking status report derived from American Thoracic Society Division of Lung Disease questionnaire ATS-DLD-78A; ƒ: ICS use was coded as “Yes” if one of the following medications/inhalers was on the list: Symbicort, Seretide, QVAR, Fostair, beclomethasone, beclomethasone/formoterol, beclomethasone dipropionate, Clenil, fluticasone/salmeterol or budesonide/formoterol; ##: sputum sampling, measured by culture (includes Haemophilus influenzae, Moraxella catarrhalis, Streptococcus pneumoniae, Staphylococcus aureus and Pseudomonas aeruginosa); ¶¶: sputum sampling, measured by PCR (includes adenovirus, enterovirus, influenza, coronavirus, metapneumovirus, bocavirus, parainfluenza, respiratory syncytial virus and rhinovirus); ++: test for differences between the three longitudinal eosinophil groups (Kruskal–Wallis test for continuous variables; Chi-squared test for categorical variables).