Christine, Lohse M

Background: We recently developed an index of socioeconomic status (SES) termed HOUSES ( HOU sing-based index of S ocio E conomic S tatus) to overcome the absence of SES measures in common data sources. HOUSES has been associated with various childhood health outcomes to a similar extent as other measures of SES. Whether it is associated with outcomes in adults is unknown. To address this question, we assessed whether HOUSES was associated with mortality after MI. Methods: We conducted a population-based cohort study among all Olmsted County, MN residents with MI who were prospectively identified using predetermined criteria from November 1, 2002 to May 31, 2006. HOUSES was formulated based on a z-score for housing value, actual square footage, and numbers of bedrooms and bathrooms and categorized into quartiles. The 1-year mortality rate post MI was compared among subjects with different SES by HOUSES based on a log-rank test. Results: Among 696 patients with MI; 623 (90%) were successfully geo-coded to address and real property data. Of these 623 subjects, 594 (95%) were white and 263 (42%) female; the mean age was 68±15 years. Spearman correlation coefficient between HOUSES and education level was 0.23 (p<0.001). Mortality rates at 1 year following MI were 20% (95%CI: 13 - 26), 18% (11 - 24), 14% (8 - 19), and 16% (10 - 21) for patients in the first (lowest SES), second, third, and fourth quartiles (highest SES) of the HOUSES index, respectively (p=0.032). This association between HOUSES and mortality after MI was primarily explained by age and comorbid conditions which were associated with HOUSES. Cardioprotective drugs such as aspirin, beta-blocker, and statins were not associated with HOUSES nor accounted for the association between HOUSES and mortality after MI. Conclusions: Despite the lack of a strong correlation with other SES measure (i.e. no redundancy), HOUSES may be useful for overcoming the paucity of conventional SES measures in commonly used datasets in epidemiological research concerning cardiovascular disease among adults.