Study withdrawn since it was rejected by local regulatory authority.

Chronic obstructive pulmonary disease (COPD) is a common, progressive disease characterized by airflow obstruction which is not fully reversible. Acute exacerbations of COPD (AECOPD) are described as worsening of COPD symptoms (breathlessness, cough, and sputum volume and purulence) beyond normal day to day variation. Between 30-50% of patients with COPD experience at least one AECOPD per year (1). Even a single moderate AECOPD increases risk of future multiple AECOPD events, starting a spiral of excessive disease progression and leading to an increased risk of death (2). AECOPDs have also been associated with other clinical outcomes such as accelerated lung function decline.

Studies have shown that AECOPDs are related to future AECOPDs, however, little is known about clinical burden and health care utilization in the COPD population. To date, most of published literature reports a combined category of moderate-severe exacerbations, typically stratifying patients as experiencing frequent (i.e., two or more events per patient-year) vs. infrequent (none or one) exacerbations.

In Egypt, COPD is considered one of the most burdensome chronic diseases, with acute exacerbations being directly associated with its burden on patients 'lives. Although no official epidemiological data is available for COPD, its prevalence in Egypt was estimated to be 3.5% in the international epidemiological survey study BREATHE in 2012, while its prevalence in high-risk Egyptian population -defined as population engaged in construction, exposed to biomass fuel, or with smoking history - is estimated to be 9.6%. Moreover, a study reporting on the burden of COPD indicated that the age standardized prevalence of COPD increased by 62% over 3 decades. Regarding AECOPD, studies have explored its reported etiologies and clinical outcomes in Egypt; however, data specifying its incidence and frequency in Egypt is still limited.

Inclusion Criteria:

1. are over the age of 40 years old;
2. have had an investigator-confirmed diagnosis of COPD of at least 3 years prior to the index date;
3. have COPD-related data recorded in medical records for at least 3 years prior to the index date, including spirometry (at least one FEV1 measurement) and medication data;
4. have signed a written Informed Consent Form

Exclusion Criteria:

1. have a diagnosis of bronchiectasis, sarcoidosis, Interstitial Lung Diseases, or Idiopathic pulmonary fibrosis. This is because differentiating deteriorations in symptoms/exacerbations in these individuals at attributing them to COPD is impossible.

Patients, treated by pulmonologists, with an investigator-confirmed diagnosis of COPD for at least 3 years from the index date (the date that signed Informed Consent was obtained) and who meet all of the inclusion and none of the exclusion criteria detailed below will be included. The intention is to study a broad COPD patient population, so minimal eligibility criteria will be applied.