Gastroesophageal reflux disease predicts 6-month readmission in acute exacerbation of chronic obstructive pulmonary disease: development and validation of a nomogram.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality worldwide, and acute exacerbation of COPD (AECOPD) frequently leads to hospitalisation and early readmission. Gastroesophageal reflux disease (GERD) is a common comorbidity in COPD, but its role in predicting post-discharge readmission remains unclear. This study aimed to investigate the impact of GERD on the risk of 6-month readmission in patients with AECOPD and to develop an individualized predictive nomogram model. METHODS: A total of 683 patients with AECOPD admitted to the Department of Respiratory Medicine, Anhui No. 2 Provincial People's Hospital, between May 2023 and March 2025 were prospectively enrolled. GERD was assessed using the GERD Questionnaire, with a total score of ≥8 used as the diagnostic cutoff. All patients were followed up for 6 months after discharge. Regression analyses were performed to identify predictors and develop a nomogram, followed by internal validation. RESULTS: Among the 683 enrolled patients, the overall 6-month readmission rate was 29.6% (202/683). Multivariate logistic regression analysis showed that acute exacerbation in previous 1 year [odds ratio (OR) =1.629; 95% confidence interval (CI): 1.035-2.563; P=0.03], GERD (OR =2.553; 95% CI: 1.616-4.033; P<0.001), Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage (OR =1.365; 95% CI: 1.097-1.697; P=0.005), and B-type natriuretic peptide (BNP) (OR =1.008; 95% CI: 1.002-1.014; P=0.006) were independent risk factors for readmission within 6 months after discharge for AECOPD patients, while body mass index (BMI) (OR =0.875; 95% CI: 0.814-0.940; P<0.001) was a protective factor. The model demonstrated moderate discriminative ability, with an area under the curve (AUC) of 0.708 (95% CI: 0.653-0.758) in the training group and 0.731 (95% CI: 0.648-0.784) in the validation group. The calibration curve demonstrated good model fit, and decision curve analysis confirmed that the model had clinical utility within the threshold range of 0.2 to 0.6. CONCLUSIONS: A prediction model based on five clinically accessible variables-BMI, acute exacerbation in previous 1 year, GERD, GOLD stage, and BNP-can effectively identify patients at high risk for readmission within 6 months following discharge for AECOPD. This finding suggests that GERD is an important predictor of readmission in AECOPD patients following discharge.