Increased overdose mortality during the first week of the month: Revisiting the "check effect" through a spatial lens.

BACKGROUND: The timing of social service benefit issuance is thought to be associated with increased drug overdose fatalities. However, the extent to which this excess mortality is concentrated in communities with higher levels of benefit receipt has not been studied. We sought to examine if benefit receipt at the neighborhood level was associated with spatiotemporal patterns of overdose fatalities.

METHODS: We conducted a retrospective review of all accidental overdose deaths recorded in Rhode Island from 2014 to 2016 (n = 838). Overdose incident locations were geocoded to the census block group level. Clusters of census block groups with excess overdose mortality at the beginning of a month were identified using spatial scan methods. Logistic regression models were fit to identify characteristics associated with the inclusion of a census block group within a cluster.

RESULTS: Increased rates of overdose fatalities at the beginning of a month were observed relative to the end of a preceding month (Ratio: 1.17; 95% CI: 1.04, 1.38). The proportions of residents receiving cash public assistance or Supplemental Security Income were not associated with excess mortality at the beginning of a month; however, the proportion of residents living in unaffordable housing was (OR: 1.42; 95% CI: 1.05, 1.91).

CONCLUSION: Despite previous research on benefit check issuance and overdose, welfare receipt was not associated with excess overdose mortality at the beginning of a month at the neighborhood level. Future research on housing cost burden and its influence on overdose death risk at the individual level is needed.