Table 1.

Cohort Characteristics by Baseline Lung Function Categories

Characteristic	PRISm (n = 185)	PRISm vs GOLD Grade 0 P Value	GOLD Grade 0 (n = 884)	GOLD Grade 0 vs Obstructed P Value	Obstructed (n = 706)	PRISm vs Obstructed P Value
Sex (female)	103 (55.7)	.71	476 (53.8)	.003	327 (46.3)	.03
Race (Black)	72 (38.9)	.08	283 (32.0)	< .001	136 (19.3)	< .001
Age, y	57.0 ± 8	.58	57.4 ± 8.1	< .001	62.0 ± 7.9	< .001
BMI, kg/m2	31.9 ± 7.1	< .001	29 ± 5.6	< .001	28 ± 5.6	< .001
Current smoking	102 (55.1)	.06	416 (47.1)	.001	274 (38.8)	< .001
Pack-years	44.2 ± 24.5	< .001	36.1 ± 19.8	< .001	48.8 ± 24.4	.02
FEV1 % predicted (postbronchodilator)	70.6 ± 7.9	< .001	97.8 ± 11.1	< .001	65.5 ± 21.6	.002
FVC % predicted (postbronchodilator)	72.3 ± 9.2	< .001	96.8 ± 11.4	< .001	88.5 ± 18.9	< .001
Bronchodilator responsive (baseline)	29 (15.8)	< .001	61 (7.0)	< .001	230 (32.9)	< .001
Percent emphysemaa	2.0 ± 3.5	.04	2.5 ± 3.0	< .001	10 ± 10.5	< .001
Percent gas trappingb	9.9 ± 8.1	.42	10.5 ± 8.4	< .001	30.9 ± 17.8	< .001
Pi10c	2.4 ± 0.6	< .001	2 ± 0.4	< .001	2.5 ± 0.6	.19
Total lung volume % predicteda	90.1 ± 14.6	< .001	103.2 ± 15.4	< .001	112.2 ± 16.6	< .001
Pectoralis muscle area, cm2,d	43.9 ± 15.7	.33	42.5 ± 15.9	< .001	39.5 ± 14.0	.001
SGRQ total score	25.9 ± 21.7	< .001	14.4 ± 16.6	< .001	27.5 ± 21.1	.35
6-min walk distance, m	409.2 ± 111.2	< .001	472.5 ± 111.1	< .001	428.6 ± 110.5	.04
Chronic bronchitis	29 (15.7)	.11	99 (11.2)	< .001	142 (20.1)	.21
Coronary artery disease (baseline)	14 (7.6)	.08	37 (4.2)	.02	50 (7.1)	.95
Hypertension (baseline)	80 (43.2)	.047	311 (35.2)	.06	282 (40.0)	.48
Congestive heart failure (baseline)	9 (4.9)	< .001	8 (0.9)	.47	10 (1.4)	.009
Diabetes (baseline)	33 (17.8)	.001	83 (9.4)	>.99	66 (9.3)	.002
Asthma, physician-diagnosed (baseline)	38 (20.5)	.001	100 (11.3)	< .001	154 (21.8)	.78
Oral steroid use (baseline)	3 (1.6)	.30	5 (0.6)	.001	19 (2.7)	.57
Inhaled steroid use (baseline)	31 (16.8)	< .001	49 (5.5)	< .001	236 (33.4)	< .001
Inhaled bronchodilators (baseline)	55 (29.7)	< .001	100 (11.3)	< .001	370 (52.4)	< .001
Any inhaled medication (baseline)	56 (30.3)	< .001	102 (11.5)	< .001	374 (53.0)	< .001
Respiratory exacerbations (year prior to enrollment)	0.3 ± 0.8	< .001	0.1 ± 0.5	< .001	0.5 ± 1	.11
Respiratory hospitalization (yes/no, year prior to enrollment)	24 (13.0%)	< .001	21 (2.4)	< .001	89 (12.6)	.99
Years of follow-up	10 ± 0.4	.003	10.1 ± 0.4	.04	10.1 ± 0.4	.08
Simple transition (ever)	125 (67.6)	< .001	283 (32.0)	< .001	126 (17.8)	< .001
Significant transition (ever)	71 (38.4)	< .001	179 (20.2)	.001	99 (14.0)	< .001

Data are presented as No. (%), mean ± SD, or as otherwise indicated. Lung function categories were defined as follows: PRISm (FEV₁/FVC ≥ 0.7 and FEV₁ < 80%), obstructed (FEV₁/FVC < 0.7), and GOLD grade 0 (FEV₁/FVC ≥ 0.7 and FEV₁ ≥80%). Bronchodilator response was considered positive if ≥ 200 mL and ≥ 12% increase in either FEV₁ or FVC was observed after administration of albuterol. GOLD = Global Initiative for Chronic Obstructive Lung Disease; SGRQ = Saint George's Respiratory Questionnaire; PRISm = preserved ratio impaired spirometry; Significant transition = change in lung function category plus > 10% change in FEV₁ % predicted or FVC % predicted between consecutive study visits (phase 1 to phase 2 or phase 2 to phase 3); Simple transition = change in lung function category between consecutive study visits.

^an = 1,670; Percent emphysema defined as low attenuation areas < −950 Hounsfield units on inspiratory CT scan.

^bDefined as voxels < −856 Hounsfield units on expiratory CT scan (n = 1,489).

^cDefined as the square root of the wall area of a hypothetical airway with an internal perimeter of 10 mm (n = 1,670).

^dMeasured at the level of the aortic arch (n = 1597).