This will be an observational, retrospective cohort study of patients who are or were diagnosed with COPD. Patterns of use, risk of comorbidities associated with COPD-related systemic corticosteroids use, and related cost impact on COPD patients in the CPRD database will be evaluated. Those initiating SCS (SCS arm) will be compared to those not exposed to SCS (non-SCS arm/control arm). This cohort study will be comprised of a minimum 1-year baseline period. The index date for patients in the SCS arm is the date of their first recorded prescription for parenteral or oral COPD-related corticosteroids while the index date for those in the non-SCS arm is the nearest general practice (GP) visit to the matched-case index date. Patients will be followed-up to the end of their individual records which will be defined as either of the following: date of the last data extraction from the GP, date of leaving the GP, date of death, or any study outcome of interest.The study outcome of interest is the incidence of comorbidity outcomes: type 2 diabetes mellitus, hypertension, cardio-/cerebrovascular disease (myocardial infarction, dyslipidaemia, congestive heart failure, cerebrovascular accident), osteoporosis, osteoporotic fracture, weight gain, sleep disorders, sleep apnoea, peptic ulcer, cataracts, glaucoma, depression/anxiety, psychosis, pneumonia, antibiotic treated infections, sudden death, and renal impairment. The worsening or recurrence of morbidity outcomes: type 2 diabetes, new osteoporosis related fractures, and pneumonia. HCRU and associated costs to the healthcare system will be described for different resource components as well as SCS-related all-cause and specified comorbid conditions. Exposure of SCS will be measured from index date to incidence of the outcome or to the end of a patient’s observation. SCS use will be defined as exposure vs. non-exposure, cumulative dose, average total daily dose, duration of long-term use, acute courses and intermittent use