Area-level socio-economic status and health status among adults with asthma and rhinitis

Abstract

Socio-economic status (SES) may affect health status in airway disease at the individual and area level. In a cohort of adults with asthma, rhinitis or both conditions, questionnaire-derived individual-level SES and principal components analysis (PCA) of census data for area-level SES factors were used. Regression analysis was utilised to study the associations among individual- and area-level SES for the following four health status measures: severity of asthma scores and the Short Form-12 Physical Component Scale (SF-12 PCS) (n = 404); asthma-specific quality of life (QoL) scores (n = 340); and forced expiratory volume in one second (FEV1) per cent predicted (n = 218). PCA yielded a two-factor solution for area-level SES. Factor 1 (lower area-level SES) was significantly associated with poorer SF-12 PCS and worse asthma QoL. These associations remained significant after adding individual-level SES. Factor 1 was also significantly associated with severity of asthma scores, but not after addition of the individual-level SES. Factor 2 (suburban area-level SES) was associated with lower FEV1 per cent predicted in combined area-level and individual SES models. In conclusion, area-level socio-economic status is linked to some, but not all, of the studied health status measures after taking into account individual-level socio-economic status.