AB024. Influences of socio-economic status on costs of asthma under universal health coverage

Background: Canada provides universal access to health-care, but the extent of inequalities in the direct medical costs of asthma across different socio-economic status (SES) groups and its trends over time remain unclear. To characterize SES-related differences in the direct costs of asthma and the trends in a universal health-care system, and explore the patterns of costs for asthma medication as potential determinants of these SES-related inequalities.

Methods: A total of 29,283 individuals aged 18 to 45 years with newly diagnosed moderate-to-severe asthma were identified from British Columbia’s administrative health data between 1997 and 2013. Each asthmatic was matched to a non-asthmatic based on sex and date of birth. Direct medical costs [in 2013 Canadian dollars, ($)] included all-cause inpatient, outpatient and pharmacy costs. SES was measured at both individual (receiving social assistance) and neighbourhood (neighbourhood income) levels. We assessed the impact of SES on excess direct medical costs of asthma and compared it between the periods 1997–2004 and 2005–2012 using generalized linear models.

Results: Social assistance recipients incurred $706 (95% CI: $302, $1014) higher annual mean excess costs, of which 60% was due to medication costs. Independently, annual mean excess costs was $120 (95% CI: $18, $168) higher in low-SES neighborhoods. Annual SES-gap in excess costs remained constant at the individual level whereas it fell by $30 (95% CI: −$61 to −$6) at the neighborhood level in the period 2005–2012 compared with 1997–2012. Across individual and neighborhood measures, low-SES was consistently associated with lower costs of controller medications and higher costs of reliever medications.

Conclusions: There are substantial socioeconomic disparities in asthma costs even in the context of a publicly funded health care system. Differential utilization of asthma medications may be a potentially preventable source of disparity.

Keywords: Asthma; socio-economic status (SES); costs; universal health-care system