This study aims to identify the effects of patient and clinical therapy factors on the length of hospital stay (LOS) for admission due to chronic obstructive pulmonary disease (COPD) in Macao. Patients and Methods: Health record of patients with COPD admitted to Kiang Wu Hospital from January 2017 to December 2019 was retrospectively analyzed. Demographic information, blood test results, clinical therapies, and LOS were described and analyzed by multivariable regression. Results: A total of 1116 admissions were included with the average LOS being 12.28 (±9.23) days. Among them, 735 (66.6%) were male with mean age 79.42 (±10.35) years old, 697 were current or previous smokers (62.5%), and 360 (32.2%) had 3 or more comorbidities. During hospitalization, the most common treatments received were oxygen therapy (n=991,88.8%), antibiotics (n=828,74.2%), and systemic steroids (n=596,53.4%); only 120 (10.8%) had pulmonary rehabilitation (PR) and 128 (11.5%) received noninvasive ventilation (NIV). Inhaled medications were used during nearly 95% of hospitalization cases, while 2 and 3 types of inhaled medications were used during 230 (20.6%) and 582 (52.2%) hospitalization cases, respectively. Patient factors including age (B=0.

Chronic Obstructive Pulmonary Disease (COPD) is the third most common chronic disease in China with frequent exacerbations, resulting in increased hospitalization and readmission rate. COPD readmission within 30 days after discharge is an important indicator of care transitions, patient’s quality of life and disease management. Identifying risk factors and improving 30-day readmission prediction help inform appropriate interventions, reducing readmissions and financial burden. This study aimed to develop a 30-day readmission prediction model using decision tree by learning from the data extracted from the electronic health record of COPD patients in Macao. Health records data of COPD inpatients from Kiang Wu Hospital, Macao, from January 1, 2018, to December 31, 2019 were reviewed and analyzed. A total of 782 hospitalizations for AECOPD were enrolled, where the 30-day readmission rate was 26.5% (207). A balanced dataset was randomly generated, where male accounted for 69.1% and mean age was 80.73 years old. Age, length of stay, history of tobacco smoking, hemoglobin, systemic steroids use, antibiotics use and number of hospital admission due to COPD in last 12 months were found to be significant risk factors for 30-day readmission of CODP patients (P < 0.01). A data-driven decision tree-based modelling approach with Bayesian hyperparameter optimization was developed. The mean precision-recall and AUC value for the classifier were 73.85, 73.7 and 0.7506, showing a satisfying prediction performance. The number of hospital admission due to AECOPD in last 12 months, smoke status and patients’ age were the top factors for 30-day readmission in Macao population.