Incorporating community-level risk factors into traumatic stress research: Adopting a public health lens

Infusing community-level risk factors into traumatic stress research can broaden intervention targets. The Neighborhood Deprivation Index (NDI) and the Index of Concentration at the Extremes (ICE) are two common community-level risk factors derived from U.S. census data. We provide R scripts facilitating the computation of these risk factors and demonstrate their relationship with PTSD symptomatology in 74 injury survivors assessed at 2-weeks, 6-weeks, and 3-months post-injury. The NDI and the ICE were computed using the Census Data Application Programming Interface, then matched to participants’ census tracts using their residential addresses. Results indicated that after controlling for person-level characteristics, both risk factors were associated with PTSD symptom severity at follow up time points (Cohen's f² =0.011,.14). This study provides an easy method for computing the NDI and ICE, demonstrates the increased mental health risk that they convey in the aftermath of injury, and highlights their value in intervention efforts.