Objective      To explore the death risk factors of 277 cases of diffuse parenchymal lung disease (DPLD) in the hospital.       Methods      According to the etiology

the patients with interstitial lung disease were divided into 4 groups: connective tissue disease associated DPLD group (CTD-IP group)

idiopathic interstitial pneumonia (IIPS) group and other known cause associated DPLD group. And each group was further divided into non-death subgroup and death subgroup. All cases were analyzed retrospectively with a case-control study method.       Results      In the IIPS group

the average age

basic disease prevalence rate

C-reactive protein (CRP)

alanine aminotransferase (ALT)

and aspartate aminotransferase (AST) in the death subgroup were higher than those in the non-death subgroup. In the CTD-IP group

the CRP

white blood cell (WBC) and AST in the death subgroup were higher than those in the non-death subgroup. In the other known cause associated DPLD group

the CRP

prothrombin time (PT)

activated partial thromboplastin time (APTT)

ALT and AST in the death subgroup were higher than those in the non-death subgroup

and the difference of etiologies between two subgroups was significant. The above indexes with AUC higher than 0.7 in curve analysis were taken as death risk forecast indexes

and the calculated cutoff points were taken as the best diagnostic thresholds. Multiple logistic regression analysis showed that independent risk factors were CRP40 mg/L and age70 years old in the IIPS group

CRP40 mg/L in the CTD-IP group

and CRP50 mg/L in the other known cause associated DPLD group.       Conclusion      Elevated CRP

advanced age and drug-induced DPLD are death risk factors of DPLD patients in the hospital. The elevated CRP is common death risk factor for DPLD patients

and the advanced age and drug-induced DPLD are independent risk factors for the IIPS group and the other known cause-associated DPLD group

respectively. When the factors are used to predict the death risk of the patients with DPLD

the difference of various types of DPLD needs to be considered.