HW5: Interaction

Consider the following abstract adapted from a scientific paper:

World War II-related post-traumatic stress disorder and breast cancer risk among Israeli women.  Int Psychogeriatr. 2013 Dec 2:1-10

Background: Several studies have suggested that post-traumatic stress disorder (PTSD) is related to adverse health outcomes. There are limited data on PTSD and cancer, which has a long latency period. We investigated the association between World War II (WWII)-related PTSD and subsequent breast cancer (BC) among Jewish WWII survivors and examined whether this association was modified by exposure to hunger during WWII.

Methods: We compared 65 BC patients diagnosed in 2005 through 2010 to 200 population-based controls who were members of various organizations for Jewish WWII survivors in Israel. All participants were born in Europe, lived at least six months under Nazi rule during WWII, and immigrated to Israel after the war. We estimated PTSD using the PTSD Inventory and applied logistic regression models to estimate the association between WWII-related PTSD and BC, adjusting for potential confounders.

Results: We observed an association between WWII-related PTSD and BC risk (OR = 2.9, 95% CI = 1.1-7.3). The level of hunger exposure during WWII modified this effect significantly (Breslow-day <0.05):  among women who experienced no hunger or mild hunger BC risk was lower (OR = 0.9, 95%CI = 0.1-9.3) than among women who experienced severe hunger (OR = 5.85, 95% CI = 1.5-22.9).

Conclusions: These findings suggest an independent association between WWII-related PTSD and subsequent BC risk in Jewish WWII survivors that is modified by hunger, a novel finding. Future research is needed to further explore these findings.