Study design: This study is a retrospective observational crosssectional study conducted through review of medical records, internal respiratory databases and electronic hospital patient record (OACIS \& HOMER) over 3x12 blocks.
Participants: COPD patients from The Queen Elizabeth Hospital(TQEH) Respiratory Nursing Service who were new patients in 2006, 2011, 2013 and 2015 (Jan 1st to Dec 31st ). Data collection: Demographics, clinical data, hospital service utilisation, and clinical outcomes such as exacerbation frequency and disease progression. All data will be extracted into a standardised data extraction form, which a random subset will be checked by a second researcher.
Demographic data will include comparison of % without comorbidities, impact of comorbid conditions using Charleston Comorbidity index isolating diabetes, heart failure, anxiety and depression. Demographic and descriptive data will be given in means + SD and compared using a two-tailed Student t-test. Categorical variables will be compared using chisquared or Fisher exact tests, and when appropriate the MannWhitney Utest for nonparametric data. Statistical significance will be determined using an alpha of p \<0.05. All analyses will be examined using SPSS software (version x).
