Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Multicenter Study
. 2020 Oct 20;21(6):249-256.
doi: 10.5811/westjem.2020.7.46385.

Characterization of Regional Poison Center Utilization Through Geospatial Mapping

Travis D Olives  1   2   3 , Bjorn Westgard  2   3   4 , Lila W Steinberg  1   2   3 , Jon B Cole  1   2   3
Affiliations
Multicenter Study

Characterization of Regional Poison Center Utilization Through Geospatial Mapping

Travis D Olives et al. West J Emerg Med. .

Abstract

Introduction: Penetrance is the annual rate of human exposure calls per 1000 persons, a measure that historically describes poison center (PC) utilization. Penetrance varies by sociodemographic characteristics and by geography. Our goal in this study was to characterize the geospatial distribution of PC calls and describe the contribution of geospatial mapping to the understanding of PC utilization.

Methods: This was a single-center, retrospective study of closed, human, non-healthcare facility exposure calls to a regional PC over a five-year period. Exposure substance, gender, age, and zone improvement plan (ZIP) Code were geocoded to 2010 US Census data (household income, educational attainment, age, primary language) and spatially apportioned to US census tracts, and then analyzed with linear regression. Penetrance was geospatially mapped and qualitatively analyzed.

Results: From a total of 304,458 exposure calls during the study period, we identified 168,630 non-healthcare exposure calls. Of those records, 159,794 included ZIP Codes. After exclusions, we analyzed 156,805 records. Penetrance ranged from 0.081 - 38.47 calls/1000 population/year (median 5.74 calls/1000 persons/year). Regression revealed positive associations between >eighth-grade educational attainment (β = 5.05, p = 0.008), non-Hispanic Black (β = 1.18, p = 0.032) and American Indian (β = 3.10, p = 0.000) populations, suggesting that regions with higher proportions of these groups would display greater PC penetrance. Variability explained by regression modelling was low (R2 = 0.054), as anticipated. Geospatial mapping identified previously undocumented penetrance variability that was not evident in regression modeling.

Conclusion: PC calls vary substantially across sociodemographic strata. Higher proportions of non-Hispanic Black or American Indian residents and >eighth-grade educational attainment were associated with higher PC call penetrance. Geospatial mapping identified novel variations in penetrance that were not identified by regression modelling. Coupled with sociodemographic correlates, geospatial mapping may reveal disparities in PC access, identifying communities at which PC resources may be appropriately directed. Although the use of penetrance to describe PC utilization has fallen away, it may yet provide an important measure of disparity in healthcare access when coupled with geospatial mapping.

PubMed Disclaimer

Conflict of interest statement

Conflicts of Interest: By the WestJEM article submission agreement, all authors are required to disclose all affiliations, funding sources and financial or management relationships that could be perceived as potential sources of bias. No author has professional or financial relationships with any companies that are relevant to this study. There are no conflicts of interest or sources of funding to declare.

Figures

Figure 1
Figure 1
Study flow diagram of phone calls made to Minnesota Poison Control System, using geospatial analysis to pinpoint origin.
Figure 2
Figure 2
A) 2012 distribution of poison center penetrance (calls per 1000 population) prior to geospatial mapping of all calls. Legend reports penetrance as calls per 1000 residents per year. B) 2010 – 2014 census tract geospatial mapping of poison control call penetrance. Legend reports penetrance as calls per 1000 residents per year over the study period.
Figure 2
Figure 2
A) 2012 distribution of poison center penetrance (calls per 1000 population) prior to geospatial mapping of all calls. Legend reports penetrance as calls per 1000 residents per year. B) 2010 – 2014 census tract geospatial mapping of poison control call penetrance. Legend reports penetrance as calls per 1000 residents per year over the study period.
Figure 3
Figure 3
Case examples. A) High penetrace region at the confluence of three rural counties and overlying Leech Lake Reservation. B) Low penetrance region in far southeastern Minnesota. C) Low penetrance region correlating with the Cedar-Riverside neighborhood of Minneapolis.
See this image and copyright information in PMC

Similar articles

See all similar articles

References

    1. Gummin DD, Mowry JB, Spyker DA, et al. 2016 Annual Report of the American Association of Poison Control Centers’ National Poison Data System (NPDS): 34th Annual Report. Clin Toxicol (Phila) 2017;55(10):1072–252. - PubMed
    1. Miller TR, Lestina DC. Costs of poisoning in the United States and savings from poison control centers: a benefit-cost analysis. Ann Emerg Med. 1997;29(2):239–45. - PubMed
    1. Friedman LS, Krajewski A, Vannoy E, et al. The association between U.S. poison center assistance and length of stay and hospital charges. Clin Toxicol. 2014;42(3):198–206. - PubMed
    1. Offerman SR. The clinical management of acetaminophen poisoning in a community hospital system: factors associated with hospital length of stay. J Med Toxicol. 2011;7:4–11. - PMC - PubMed
    1. Litovitz T, Benson BE, Youniss J, et al. Determinants of U.S. poison center utilization. Clin Toxicol. 2010;48(5):449–57. - PubMed

Publication types