Prescription opioid poisoning across urban and rural areas: identifying vulnerable groups and geographic areas

Magdalena Cerdá, Andrew Gaidus, Katherine M. Keyes, William Ponicki, Silvia Martins, Sandro Galea, Paul Gruenewald

Research output: Contribution to journalArticlepeer-review

54 Scopus citations


Aims: To determine (1) whether prescription opioid poisoning (PO) hospital discharges spread across space over time, (2) the locations of ‘hot-spots’ of PO-related hospital discharges, (3) how features of the local environment contribute to the growth in PO-related hospital discharges and (4) where each environmental feature makes the strongest contribution. Design: Hierarchical Bayesian Poisson space–time analysis to relate annual discharges from community hospitals to postal code characteristics over 10 years. Setting: California, USA. Participants: Residents of 18 517 postal codes in California, 2001–11. Measurements: Annual postal code-level counts of hospital discharges due to PO poisoning were related to postal code pharmacy density, measures of medical need for POs (i.e. rates of cancer and arthritis-related hospital discharges), economic stressors (i.e. median household income, percentage of families in poverty and the unemployment rate) and concentration of manual labor industries. Findings: PO-related hospital discharges spread from rural and suburban/exurban ‘hot-spots’ to urban areas. They increased more in postal codes with greater pharmacy density [rate ratio (RR) = 1.03; 95% credible interval (CI) = 1.01, 1.05], more arthritis-related hospital discharges (RR = 1.08; 95% CI = 1.06, 1.11), lower income (RR = 0.85; 95% CI = 0.83, 0.87) and more manual labor industries (RR = 1.15; 95% CI = 1.10, 1.19 for construction; RR = 1.12; 95% CI = 1.04, 1.20 for manufacturing industries). Changes in pharmacy density primarily affected PO-related discharges in urban areas, while changes in income and manual labor industries especially affected PO-related discharges in suburban/exurban and rural areas. Conclusions: Hospital discharge rates for prescription opioid (PO) poisoning spread from rural and suburban/exurban hot-spots to urban areas, suggesting spatial contagion. The distribution of age-related and work-place-related sources of medical need for POs in rural areas and, to a lesser extent, the availability of POs through pharmacies in urban areas, partly explain the growth of PO poisoning across California, USA.

Original languageEnglish (US)
Pages (from-to)103-112
Number of pages10
Issue number1
StatePublished - Jan 1 2017


  • Bayesian space-time models
  • drug overdose
  • geography
  • hospital discharges
  • prescription opioids
  • rural and urban

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Psychiatry and Mental health


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