Table 1.

Spatial clusters of nonmedical vaccine exemptions for kindergarteners during the 2011–2012/2012–2103 academic years

Exemption clusterStateCounty/Health districtObserved exemptionsExpected exemptionsRelative riskP value
1OregonLane, Linn, Marion, Polk, Coos, Deschutes, Yamhill, Jackson, Clackamas, Josephine, Benton, Lincoln, Tillamook, Multnomah, Douglas, Washington, Curry, Jefferson, and Klamath5,2712,5032.50<0.0001
2ArizonaMaricopa, Pinal, and Yavapai5,1493,6891.55<0.0001
3UtahCentral Utah, Utah County, Southwest, and Southeastern1,2138481.46<0.0001
4WashingtonSan Juan, Island, Whatcom, Clallam, Skagit, and Jefferson2401511.59<0.0001
5WashingtonPend Oreille, Stevens, Ferry, Spokane, Lincoln, Okanogan, and Whitman2781851.51<0.0001
6OregonBaker, Union, Grant, and Wallowa75381.99<0.0001
7UtahSummit and Wasatch93541.720.0003
8ArizonaNavajo, Apache, and Coconino2902261.290.0068