Factors affecting treatment outcome in patients with idiopathic nonspecific interstitial pneumonia: a nationwide cohort study

Table 1 Characteristics of the study population

	Total patients (n = 261)	Patients followed up more than 1 year (n = 95)
Age (year)	57.1 ± 10.7	56.2 ± 10.3
F: M	170 (65.1): 91 (34.9)	64 (67.4): 31 (32.6)
^*Follow-up duration (month)	21.6 ± 16.6	32.1 ± 13.9
Pulmonary function test
FVC (%)	71.8 ± 18.4	72.5 ± 19.3
FEV₁ (%)	79.8 ± 20.9	81.1 ± 21.2
DLco (%)	64.9 ± 21.3	64.7 ± 22.5
^*Resting PaO₂ mm Hg	81.6 ± 17.3	86.7 ± 14.8
Smoking status
Never smoker	169/241 (70.1)	68/92 (73.9)
Ex-smoker	38/241 (15.8)	16/92 (17.4)
current smoker	34/241 (14.1)	8/92 (8.7)
^*Smoking amount (Pys)	29.3 ± 16.8	29.0 ± 15.2
Initial symptom
Dyspnea of exertion	179/230 (77.8)	64/80 (80.0)
Cough	159/219 (72.6)	55/81 (67.9)
Sputum	69/186 (37.1)	28/71 (39.4)
^*Duration of symptom (month)	6.2 ± 10.2	7.1 ± 12.0
^*CRP (mg/dL)	2.52 ± 6.21	1.56 ± 3.68
ANA (positive)	58/185 (31.4)	18/59 (30.5)
RF (positive)	28/173 (16.2)	11/59 (18.6)
Outcome
Alive	157/261 (60.2)	73/95 (76.8)
Death	26/261 (10.0)	3/95 (3.2)
Follow-up loss	78/261 (29.9)	19/95 (20.0)

Note: Values in parentheses are percentages
F:M female:male, FVC, forced vital capacity, % pred percentage of the predicted value, FEV ₁ forced expiratory volume, DL _CO diffusing capacity of the lung for carbon monoxide, PaO ₂ arterial oxygen tension, CRP C-reactive protein, ANA antinuclear antibody, RF rheumatoid factor
^*Follow-up duration, smoking amount, duration of symptoms, and CRP showed a non-normal distribution in all patients
^*Resting PaO₂ mm Hg, duration of symptom, and CRP showed a non-normal distribution in patients followed up for more than 1 year

ISSN: 1465-993X