Understanding the differential effect of local socioeconomic conditions on the relation between prescription opioid supply and drug overdose deaths in US counties

Poverty rate, income inequality, and HDI scores were found to modify the effect of prescription opioid supply on heroin overdose deaths. The plot of the interactions showed that when disadvantage is high, increasing prescription opioid supply does not increase heroin-related deaths. The less disadvantage there is, indicated by lower poverty rates, higher HDI scores, and lower income inequality, the greater the effect of increasing prescription opioid supply relative to population size on heroin-related deaths in US counties.