TUBERCULOSIS AND RACE ETHNICITY IN THE UNITED-STATES - IMPACT OF SOCIOECONOMIC-STATUS/

Despite the long-standing observation that tuberculosis (TB) case rate s are higher among racial and ethnic minorities than whites in the Uni ted States (U.S.), the proportion of this increased risk attributable to socioeconomic status (SES) has not been determined. Values for six SES indicators (crowding, income, poverty, public assistance, unemploy ment, and education) were assigned to U.S. TB cases reported from 1987 -1993 by ZIP code-and demographic-specific matching to 1990 U.S. Censu s data. TB risk between racial/ethnic groups was then evaluated by qua rtile for each SES indicator utilizing univariate and Poisson multivar iate analyses. Relative risk (RR) of TB increased with lower SES quart ile for all six SES indicators on univariate analysis (RRs 2.6-5.6 in the lowest versus highest quartiles). The same trend was observed in m ultivariate models containing individual SES indicators (RRs 1.8-2.5) and for three SES indicators (crowding, poverty, and education) in the model containing all six indicators. Tuberculosis risk increased unif ormly between SES quartile for each indicator except crowding, where r isk was concentrated in the lowest quartile. Adjusting for SES account ed for approximately half of the increased risk of TB associated with race/ethnicity among U.S.-born blacks, Hispanics, and Native Americans . Even more of this increased risk was accounted for in the final mode l, which also adjusted for interaction between crowding and race/ethni city. SES impacts TB incidence via both a strong direct effect of crow ding, manifested predominantly in overcrowded settings, and a TB-SES h ealth gradient, manifested at all SES levels. SES accounts for much of the increased risk of TB previously associated with race/ethnicity.