1. Department of Geriatric MedicineThe Fuling Central Hospital of ChongqingChongqingChina
2. Department of Respiratory medicineThe Second Clinical Hospital of Chongqing Medical UniversityChongqingChina
3. Department of Respiratory MedicineThe First Clinical Hospital of Kunming Medical CollegeKunmingChina
4. Department of Respiratory MedicineThe Second People’s Hospital of Chengdu CityChengduChina