This is a prospective, multi-center cohort study. 150 subjects with COPD and in stable stage will be included. Wearable device's physiological parameters will be continually collected, the investigators aim to explore whether consumer wearable devices are useful for early warning deterioration of COPD.

This is a prospective cohort study. 150 subjects aged 35～80y with stable COPD will be recruited. After enrollment, subjects wear consumer wearable devices and install APP on their mobile phones. The first 7 days of wearing are to evaluate the stability of data collection and the subject compliance, and to correct the wrong wearing. The subjects are required to fill in the COPD symptom diary every day, and conducted online or offline follow-up at the 4th, 8th, 12th, 16th, 20th, and 24th weeks after enrollment. The physiological parameters of wearable devices, including pulse rate, blood oxygen saturation, physical activity, electrocardiogram, and sleep, will be continuously collected during the study. The Department of Respiratory and Critical Care of Peking University First Hospital is responsible for this research. Primary outcome is the moderate or more severe COPD acute exacerbation events. The purpose of this study is to use consumer wearable devices to monitor the changes of COPD, and to establish a physiological parameters model of wearable device that can predict the acute exacerbation of COPD.

The study protocol has been approved by the Peking University First Hospital Institutional Review Board (IRB) (2021-397). Any protocol modifications will be submitted for the IRB review and approval.

Inclusion Criteria:

• Patients diagnosed with stable COPD (refer to 2021 GOLD guidelines);
• Age between 35 and 80 years (both 35 and 80), either gender;
• A post-bronchodilator forced expiratory volume in 1 second percentage (FEV1%) predicted between 25%~80%;
• Having mobile phone which can install APP of wearable device;
• Able to engage in daily activities;

Exclusion Criteria:

• History of asthma, lung cancer, active pulmonary tuberculosis, bronchiectasis, diffuse lung disease (interstitial pneumonia, pulmonary sarcoidosis, occupational lung disease, sarcoidosis et al) and pleural disease;
• History of lobectomy and/or lung transplantation;
• Predicted life expectancy less than 3 years;
• History of serious underlying diseases (including severe psychiatric illnesses, mental disorders, neurological disorders, malignant tumors, chronic liver disease, heart failure, autoimmune diseases, chronic kidney disease);
• Alcoholism, drug or toxic solvents abuse;
• Moderate to severe anemia;
• Smoking or quitting smoking for less than 6 weeks;
• Skin pigmentation, deformity, arterial stenosis or occlusion of both upper limbs;
• Skin allergy to metal/plastic;
• Those who are participating in other clinical trials, cannot be followed up for a long time or have poor compliance.

Outpatients and inpatients from Peking University First Hospital