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Evidence of population mixing based on the geographical distribution of childhood leukemia in Ohio
Author(s) -
Clark Brenda R.,
Ferketich Amy K.,
Fisher James L.,
Ruymann Frederick B.,
Harris Randall E.,
Wilkins John R.
Publication year - 2007
Publication title -
pediatric blood and cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.116
H-Index - 105
eISSN - 1545-5017
pISSN - 1545-5009
DOI - 10.1002/pbc.21181
Subject(s) - medicine , demography , incidence (geometry) , population , leukemia , epidemiology , poisson regression , standardized rate , pediatrics , environmental health , physics , sociology , optics
Background This ecologic study examined the geographic distribution of childhood leukemias in Ohio, 1996–2000, among children aged 0–19 for evidence that population mixing may be a factor. Procedure (1) State incidence rates were compared to Surveillance, Epidemiology and End Results (SEER) rates for each year and for the 5‐year period, 1996–2000; (2) incidence rates for each of Ohio's 88 counties were compared to statewide rates; and (3) county incidence rates were compared based on population density, population growth, and rural/urban locale. SEER*Stat version 5.0 was used to derive age‐specific and 0–19 age‐adjusted rates. Expected values, standardized incidence ratios (SIRs), and Poisson P ‐values were calculated with Excel using the indirect method of standardization. Results Of the 585 cases, 73.3% were acute lymphocytic leukemia (ALL), 16.6% acute myelogenous leukemia (AML), 3.2% acute monocytic leukemia (AMoL), and 2.6% chronic myelogenous leukemia (CML). Rates for total leukemia burden were significantly below national levels for all races ( P = 0.00001), likely due to poor ascertainment of cases. Yearly incidence rates for 1996–2000 were stable for ALL and AML; CML rates declined over the period. Based on 2000 Census and intercensal population estimates for 1996–2000, statistically higher rates for ALL were noted for counties experiencing >10% population change 1990–2000 ( P < 0.05), especially for ages 1–4 ( P < 0.03) in counties with 10–20% growth. Counties 67.9–99.2% urban experienced fewer than expected cases of AML + AMoL ( P < 0.06). Conclusion Data support Kinlen's theory of population mixing and warrant further studies in Ohio, the US and other countries. Pediatr Blood Cancer 2007;49:797–802. © 2007 Wiley‐Liss, Inc.