Association analysis between JRS scoring system and GAP staging system with prognosis in idiopathic pulmonary fibrosis patients

Objective To compare the existing JRS (Japanese respiratory society) scoring system and GAP (gender, age, and physiologic variables) staging criterion regarding to the consistency and the clinical application value of evaluating the severity of idiopathic pulmonary fibrosis(IPF). Methods A total of 155 patients with IPF diagnosed by Shanghai Pulmonary Hospital of Tongji University between January, 2011 and January, 2016 were collected (male 149, female 6, age 40-80, average age 63±7). The patients were staged by the GAP staging criterion and JRS scoring system, respectively. According to the JRS scoring system, patients with stage Ⅰ,Ⅱ,Ⅲ, Ⅳ were 91 (91/155,58.7%),29 (29/155,18.7%),24 (24/155,15.5%), and 11 (11/155,7.1%), respectively. According to the GAP staging criterion, patients with stage Ⅰ,Ⅱ,Ⅲ were 89 (89/155,57.4%), 52 (52/155,33.5%), and 14 (14/155,9.0%), respectively. Then, we evaluated the statistical significance of patients at each stage. All patients were followed up for 2 years in order to record the prognosis and survival. Finally, we compared the advantages and the disadvantages of these two systems and evaluated the clinical application value of the two systems. Results The distribution of age, sex, physical sign, SaO2%, high-sensitivity-C-reactive protein (hs-CRP), the St George′s Respiratory Questionnaire (SGRQ), partial pressure of carbon dioxide (PaCO2), 6-min walk test (6MWT) and the oxygen saturation on pulse oximetry (SpO2%) during a 6MWT by the GAP staging criterion in each stage was not statistically significant (P>0.05). While smoking history (number of patients with stage Ⅰ,Ⅱ,Ⅲ were 68, 37, 9, respectively], respiratory symptoms (number of patients with stage Ⅰ,Ⅱ,Ⅲ were 70, 48, 14, respectively], pulmonary hypertension (number of patients with stage Ⅰ,Ⅱ,Ⅲ were 22, 20, 8, respectively], erythrocyte sedimentation rate [value of stage Ⅰ,Ⅱ,Ⅲ were (24±17),(30±21),(41±22)mm/h, respectively], PaO2 [value of stage Ⅰ,Ⅱ, Ⅲ were (92±24), (81±20), (74±15)mmHg, respectively], FVC [value of stage Ⅰ,Ⅱ,Ⅲ were (2.86±0.59), (2.20±0.5),(1.56±0.27)L,respectively] and FEV1 [value of stage Ⅰ,Ⅱ,Ⅲ were (2.35±0.46),(1.81±0.46),(1.35±0.27)L, respectively] had statistical significance in the GAP staging criterion in each stage (P 0.05). While PaO2 [value of stage Ⅰ,Ⅱ,Ⅲ, Ⅳ were (99±22), (76±3),(66±3),(54±4) mmHg, respectively],PaCO2 [value of stage Ⅰ,Ⅱ,Ⅲ, Ⅳ were (39±3),(40±3),(39±4), (38±5)mmHg, respectively], SaO2% [value of stage Ⅰ,Ⅱ,Ⅲ, Ⅳ were (97.2±1.2)%,(95.2±1.0)%,(93.2±1.3)%, (87.4±4.1)%,respectively], SpO2% [value of stage Ⅰ,Ⅱ,Ⅲ, Ⅳ were (94.1±1.0)%,(93.2±1.2)%,(90.2±1.1)%, (87.4±4.1)%, respectively] during a 6MWT, pulmonary hypertension (number of patients with stage Ⅰ,Ⅱ, Ⅲ, Ⅳ were 21, 13, 11, 5, respectively] and FVC [value of stage Ⅰ,Ⅱ,Ⅲ, Ⅳwere (2.63±0.68), (2.55±0.70), (2.19±0.59), (2.20±0.67)L, respectively] by JRS scoring system in each stage were statistically significant (P<0.05). The results of the two scoring methods were consistent (P<0.05), but the consistency was not strong (Kappa value<0.75). There was no statistical significance in the one-year survival rate of the GAP staging criterion and the one-year and two-year survival rates of JRS scoring system. Conclusions The GAP staging criterion and JRS scoring system had poor accuracy and consistency in assessing the disease severity in IPF patients. The two scoring methods showed insufficient value in assessing the survival rates. Key words: Idiopathic pulmonary fibrosis; The GAP staging criterion; JRS scoring system; Survival rate