Mortality and Disease Progression in WA Seniors with Obstructive Airways Disease

1. Mortality and Disease Progression in WA Seniors with Obstructive Airways Disease A whole-population linked data study (XJSC 403928) Dr Kristjana Einarsdottir, Dr David B Preen, Prof Jon Emery, Prof D’Arcy Holman Centre for Health Services Research, UWA School of Population Health

2. Background • Asthma prevalence 10-12% in Australian adults • COPD prevalence 9-12% in Australian adults >45 • Similar manifestations in older people despite different causes • > Obstructive Airways Disease • Limited work done on risk factors for all-cause mortality in older asthma/COPD patients • Particularly by severity level

3. Aims • Describe the effect of • gender, ethnicity, socio-economic status, and residential remoteness • GP visit regularity • on disease progression and mortality by disease severity among older asthma/COPD patients in WA

4. Data Sources • WA used linked data for WA Seniors ≥65 years between 1st Jan 1992 - 31st Dec 2006 • HMDS • Death Registry • Electoral Roll • MBS • PBS • Linkages created by Cross-Jurisdictional Linkage Facility of the WA Data Linkage System (WADLS) maintained by the WA Department of Health

5. Identification of Study Population • HMDS • Individuals with asthma or COPD diagnoses • Death Registry • Individuals who had died from asthma or COPD • MBS • Individuals who had used ‘asthma cycle of care’ services • PBS • Individuals who had been prescribed asthma or COPD medication

6. Study Population • 108,455 obstructive airway disease patients (asthma or COPD) • Disease severity level classification • Medication use • Hospital admissions • Statistics • Cox Proportional Hazards Model

7. Results – Disease Severity Survival * Adjusted for gender, ethnicity, age, socio-economic status, residential remoteness, Charlson Index, admission type and length of hospital stay

8. Results – Mortality Characteristics of patients with obstructive airways disease and risk of death, overall and by disease severity * Adjusted forgender, ethnicity, age, socio-economic status, residential remoteness, Charlson Index, admission type and length of hospital stay

9. Results – Disease Progression Characteristics of patients with obstructive airways disease and risk of progression to a higher level of disease severity * Adjusted for gender, ethnicity, age, socio-economic status, residential remoteness, Charlson Index, admission type and length of hospital stay

10. Results – GP Visit Regularity - Mortality Association between GP visit regularity of patients with obstructive airway disease and risk of death * Adjusted for number of GP visits, gender, ethnicity, age, socio-economic status, residential remoteness, Charlson Index, admission type and length of hospital stay

11. Results – GP Visit Regularity - Disease Progression GP visit regularity of patients with obstructive airway disease and risk of disease progression * Adjusted for number of GP visits, gender, ethnicity, age, socio-economic status, residential remoteness, Charlson Index, admission type and length of hospital stay

12. Conclusions • Mild disease group had 2nd worst survival after severe group • Effect of male gender and low SES on mortality was pronounced in patients with severe disease • Effect of indigenous status and low SES on disease progression was stronger if disease was already moderately severe • Visiting a GP regularly was protective against all-cause mortality and disease progression (if disease already moderate)

13. Acknowledgements • Dr David Preen • Prof Jon Emery • Prof D’Arcy Holman • Dr Frank Sanfilippo • Department of Health WA, Data Linkage team • Commonwealth Department of Health and Ageing • Medicare Australia