A Nomogram For Predicting Severe Exacerbations In COPD Patients

Objective: To investigate factors associated with severe acute exacerbations of chronic obstructive pulmonary disease(AECOPD)and develop a practicable nomogram aimed at predicting the risk of severe exacerbations at 3-and 5-year.Methods: COPD patients with prospective follow-up data were extracted from Subpopulations and Intermediate Outcome Measures in COPD Study(SPIROMICS)obtained from National Heart,Lung and Blood Institute(NHLBI)Biologic Specimen and Data Repository Information Coordinating Center.We comprehensively considered the demographic characteristics,clinical data and inflammation marker of disease severity.Cox proportional hazard regression was performed to identify the best combination of predictors on the basis of the smallest Akaike Information Criterion.A nomogram was developed and evaluated on discrimination,calibration,and clinical efficacy by the concordance index(C-index),calibration plot and decision curve analysis,respectively.Internal validation of the nomogram was assessed with 1000 Bootstrap resamples.Results: Among 1711 COPD patients,523(30.6%)of them suffered from at least one severe AECOPD during follow-up.After stepwise regression analysis,six variables were determined including BMI,severe exacerbations in the prior year,comorbidity index,postbronchodilator FEV1% predicted,and white blood cells.Nomogram to estimate patients’ likelihood of severe AECOPD at 3-and 5-year was established.The C-index of the nomogram was 0.74(95%CI: 0.71–0.76),outperforming ADO,BODE and DOSE risk score.Besides,the calibration plot of 3-and 5-year showed great agreement between nomogram predicted possibility and actual risk.Decision curve analysis indicated that implementation of the nomogram in clinical practice would be beneficial and better than aforementioned risk scores.Conclusion: Our new nomogram was a useful tool to assess the probability of severe exacerbations at 3-and 5-year for COPD patients and could facilitate clinicians in stratifying patients and providing optimal therapies.