Neighborhood disadvantage and immune-related illnesses among residents living in the US Gulf States.

ABSTRACT

PURPOSE: Neighborhood disadvantage has been associated with increased risk for pneumonia and influenza-associated hospitalizations. Few studies, however, have investigated how neighborhood disadvantage may influence immune-related illnesses. The aim of this study was to examine the association between neighborhooddisadvantage and immune-related illnesses. METHODS: We used data from the Gulf Long-term Follow-up (GuLF) Study (n = 32,608). Our analytic sample included home visit participants (n = 11,193) who had complete information on exposure and covariates (n = 10,543). Neighborhood disadvantage was assessed using the 2013 Area Deprivation Index (ADI), which assigns a ranking of 1 to 100 for lowest to highest disadvantage. We linked ADI to participants' geocoded enrollment addresses at the census block group level. ADI was categorized into quartiles based on the national distribution with the first quartile as the referent. Immune-related illnesses self-reported at the home visit (May 2011-May 2013) included occurrence of shingles, pneumonia, cold sores, flu, and colds since the Deepwater Horizon oil spill (April 2010). Frequent colds and frequent flu were defined as ≥4 colds and ≥2 episodes of flu since the spill. An aggregated outcome, based on occurrence of any pneumonia, cold sores, flu, and ≥4 colds since the spill, was also examined. We assessed the association of each outcome with ADI using multivariable log-binomial regression adjusting for individual-level demographics, behavioral factors, kids at home, and season of interview completion. RESULTS: We found elevated prevalence ratios (PR) and 95% confidence intervals (CI) for pneumonia associated with ADI in the third (PR 2.04, 95% CI 1.04, 4.02) and fourth (PR 2.00; 95% CI 1.00, 3.98) quartiles. PRs for frequent colds were also elevated for increasing ADI quartiles, but with confidence intervals including the null value. CONCLUSIONS: The observed associations of frequent colds and pneumonia with increasing neighborhood disadvantage may warrant further research on this topic.