The mMRC scale is a self-rating tool to measure the degree of disability that breathlessness poses on day-to-day activities on a scale from 0 to 4: 0, no breathlessness except on strenuous exercise; 1, shortness of breath when hurrying on the level or walking up a slight hill; 2, walks slower than people of same age on the level because of breathlessness or has to stop to catch breath when walking at their own pace on the level; 3, stops for breath after walking ∼100 m or after few minutes on the level; and 4, too breathless to leave the house, or breathless when dressing or undressing.

It will done by patients.

The Charlson Comorbidity Index is a method of categorizing comorbidities of patients based on the International Classification of Diseases (ICD) diagnosis codes found in administrative data, such as hospital abstracts data. Each comorbidity category has an associated weight (from 1 to 6), based on the adjusted risk of mortality or resource use, and the sum of all the weights results in a single comorbidity score for a patient. A score of zero indicates that no comorbidities were found. The higher the score, the more likely the predicted outcome will result in mortality or higher resource use.

The St George's Respiratory Questionnaire (SGRQ) is a validated, commonly used questionnaire for measuring quality of life in patients with chronic obstructive pulmonary disease (COPD). It consists of 76 items in three domains (symptoms, activity, impact of disease on daily life).

A total score of SGRQ is calculated from 0 (no health impairment) to 100 (maximum health impairment). There are also the score of each domain are scored from 0 to 100.

The 11-point numeric scale ranges from '0' (e.g. "nothing known") to '10' (e.g. "maximal knowledge").

It can be administered verbally. Scores range from 0-10 points, with higher scores indicating greater knowledge. It will done by patients and their proxies. They will be asked to rate their level of knowledge about COPD and general health.

The sociodemographic characteristics of the patient and their relatives will be recorded in the registration form.

Socio-demographic information will be asked from people and their relatives by mutual interview method.

Age, gender, marital status, education level, occupation, medical history, duration of COPD, regularly used medications - oxygen support - non-invasive mechanical ventilation (NIMV), smoking status, alcohol consumption, exercise habits, attacks and pulmonary rehabilitation histories will be questioned in this section.