Association between social determinants of health and cardiovascular and cancer mortality in cancer survivors: a nationally representative cohort study

Although it is known that social deprivation is associated with higher risks of cardiovascular and cancer mortality in the general population, these associations may not be directly applicable to cancer survivors. Using data from the National Health Interview Survey (NHIS) 2013-2017 with follow-up till the end of 2019, we examined the associations between social determinants of health (SDOH) and the risk of all-cause, cardiovascular, and cancer mortality in cancer survivors, with separate modelling in individuals without cancer for comparison. Two Cox regression models were fitted for each outcome, the first being adjusted for demographics and the second being additionally adjusted for comorbidities and risk factors. Altogether, 37,882 individuals were analysed (representing a weighted population of 57,696,771), including 4179 cancer survivors and 33,703 individuals without cancer. Amongst cancer survivors, worse SDOH was associated with higher all-cause, cardiovascular, and cancer mortality when adjusted for demographics, which were attenuated but remained significant when further adjusted for comorbidities and risk factors. Amongst individuals without cancer, worse SDOH was associated with higher all-cause and cardiovascular mortality only when adjusted for demographics, but not when further adjusted for comorbidities and risk factors. These suggested that in cancer survivors, associations between SDOH and cardiovascular/cancer mortality may be driven by factors beyond comorbidities and risk factors, contrasting individuals without cancer in whom similar associations were probably driven mostly by comorbidities and risk factors.