A geographic analysis of socioeconomic factors associated with spondylodiscitis

Spondylodiscitis is classically believed to reflect intravenous drug use in urban centers, hemodialysis-associated complications, and generalized poor medical care, but these associations may be more complex and reflect underlying systemic societal problems. The authors sought to characterize socioeconomic and demographic elements associated with spondylodiscitis to better understand community factors placing patients at risk of this infection.

All cases of spondylodiscitis at an urban, tertiary-level academic hospital since 2015 were surveyed. The zip code of residence for all patients with spondylodiscitis was captured and a referral map of the authors' urban center was created, demonstrating whether these areas had spondylodiscitis cases as well as the case density. A validated database of public data was used to compare demographic and socioeconomic factors between zip codes with and without cases of spondylodiscitis.

Two-hundred sixty-two cases with complete datasets between September 2015 and July 2021 were identified. Thirty-seven of the 56 zip codes within the authors' urban center had discitis cases, ranging from 1 to 4 (median 2) per zip code. Zip codes with spondylodiscitis cases had a higher median housing density (2.4 vs 1.8, p = 0.004), higher percentage of minority residents (59.0% vs 31.9%, p = 0.011), greater proportion of residents younger than 20 years (26.8% vs 16.2%, p = 0.001), higher rates of residents below the poverty level (17.4% vs 8.8%, p = 0.007), lower median annual income ($52,193 vs $103,173, p < 0.001), lower median rent and home value (p < 0.001 and p = 0.021, respectively), and lower rates of high school graduation and higher education (both p < 0.001).

This is the first time that the incidence of spondylodiscitis has been demonstrated to be strongly associated with regions of poverty and worse socioeconomic indicators, independent of healthcare referral patterns. Long-term interventions may depend on improving general living conditions for this at-risk population.