Clinical findings and outcomes in patients with possible usual interstitial pneumonia.
BACKGROUND
Patients with possible usual interstitial pneumonia (UIP) constitute a substantial group, and their clinical characteristics and outcomes are not well defined. We compared the clinical characteristics and survival between patients with possible UIP and the UIP pattern.


METHODS
We evaluated 62 patients with possible UIP and 544 patients with the UIP pattern. Both groups were diagnosed by clinical characteristics and high-resolution computed tomography (HRCT) findings. Two radiologists performed radiological evaluation based on the new idiopathic pulmonary fibrosis (IPF) guidelines. Two risk-stratification methods were used to compare UIP pattern and possible UIP patients.


RESULTS
The groups had similar demographic and clinical characteristics. Pulmonary function tests revealed no significant differences in lung volumes between the 2 groups. However, DLCO was significantly lower with the UIP pattern than with possible UIP (p = 0.004). Multivariate analysis showed age, sex, and carbon monoxide diffusing capacity (DLCO) as important independent variables for survival. The UIP HRCT pattern did not affect survival (hazard ratio, 0.83; 95% confidence interval, 0.51-1.24; p = 0.32). Possible UIP was not associated with prognosis when independent predictors for survival rate and propensity score were considered. In the case-control study, the 3-year survival rate was 44.6% in the UIP pattern group and 56.8% in the possible UIP group (p = 0.16).


CONCLUSIONS
Clinical characteristics and outcomes were similar in possible UIP and UIP patients, except for differences in DLCO. The UIP pattern itself did not affect survival.
Department of Internal Medicine, Keimyung University School of Medicine, Daegu, Republic of Korea.
Jin Wook
JW
Lee
Department of Internal Medicine, Keimyung University School of Medicine, Daegu, Republic of Korea; Department of Internal Medicine, Regional Hospital of Durres, Albania.
Esmeralda
E
Shehu
Department of Internal Medicine, Keimyung University School of Medicine, Daegu, Republic of Korea; Department of Internal Medicine, Mother Theresa University Hospital, Tirana, Albania.
Juarda
J
Gjonbrataj
Department of Radiology, Keimyung University School of Medicine, Daegu, Republic of Korea.
Young Eun
YE
Bahn
Department of Radiology, Keimyung University School of Medicine, Daegu, Republic of Korea.
Byung Hak
BH
Rho
Preventive Medicine, Keimyung University School of Medicine, Daegu, Republic of Korea.
Mi-Young
MY
Lee
Department of Internal Medicine, Keimyung University School of Medicine, Daegu, Republic of Korea. Electronic address: wichoi@dsmc.or.kr.
Won-Il
WI
Choi
D000368:Aged; D002248:Carbon Monoxide / Q000737:chemistry / Q000378:metabolism; D016022:Case-Control Studies; D003710:Demography; D003937:Diagnosis, Differential; D055459:Facilitated Diffusion; D005260:Female; D006801:Humans; D054990:Idiopathic Pulmonary Fibrosis / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D008168:Lung / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D057216:Propensity Score; D056910:Republic of Korea / Q000453:epidemiology; D012129:Respiratory Function Tests / Q000379:methods / Q000706:statistics & numerical data; D012189:Retrospective Studies; D015996:Survival Rate; D014057:Tomography, X-Ray Computed / Q000379:methods
D002248:Carbon Monoxide
HRCT; Idiopathic pulmonary fibrosis; Prognosis