| Counties | Counties included | E [c|H0] | E [c|H A ] | Relative risk |
---|---|---|---|---|---|
Rural clusters | 1 | Grand Isle, VT | 0.05 | 10 | 192.89 |
 | 2 | above + Franklin, VT | 0.46 | 12 | 27.03 |
 | 4 | above + Clinton, NY, Chittenden, VT | 2.69 | 18 | 7.05 |
 | 8 | above + Lamoille, VT, Washington, VT, Essex, NY, Addison, VT | 4.16 | 22 | 5.35 |
 | 16 | above + Orleans, VT, Franklin, NY, Caledonia, VT, Orange, VT, Essex, VT, Rutland, VT, Warren, NY, Windsor, VT | 7.32 | 28 | 3.90 |
Mixed clusters | 1 | Allegheny, PA | 14.43 | 39 | 2.85 |
 | 2 | above + Washington, PA | 16.41 | 42 | 2.70 |
 | 4 | above + Beaver, PA, Westmoreland, PA | 22.52 | 51 | 2.40 |
 | 8 | above + Butler, PA, Armstrong, PA, Lawrence, PA, Fayette, PA | 27.47 | 58 | 2.24 |
 | 16 | above + Greene, PA, Indiana, PA, Clarion, PA, Mercer, PA, Somerset, PA, Venango, PA, Cambria, PA, Jefferson, PA | 34.22 | 67 | 2.10 |
Urban clusters | 1 | New York, NY | 15.97 | 42 | 2.73 |
 | 2 | above + Hudson, NJ | 21.78 | 50 | 2.43 |
 | 4 | above + Bronx, NY, Kings, NY | 59.99 | 100 | 1.81 |
 | 8 | above + Queens, NY, Bergen, NJ, Essex, NJ, Richmond, NY | 101.96 | 150 | 1.63 |
 | 16 | above + Union, NJ. Nassau, NY, Passaic, NJ, Rockland, NY, Westchester, NY, Morris, NJ, Middlesex, NJ, Monmouth, NJ | 154.94 | 209 | 1.53 |