Table 2.
Year (no. of localities inside the cluster)* | Expected average disease frequency API (×1,000) | Observed average disease frequency† API (×1,000) | Relative risk† | Log-likelihood ratio |
---|---|---|---|---|
2001 (7) | 44.3 | 118.5 | 2.7 | 65.5‡ |
2002 (11) | 159.8 | 315.5 | 1.9 | 773.1‡ |
2003 (7) | 43.7 | 111.4 | 2.5 | 194.1‡ |
2004 (10) | 31.1 | 63.1 | 2.0 | 167.9‡ |
2005 (10) | 31.1 | 58.8 | 1.9 | 175.2‡ |
2006 (10) | 18.4 | 38.1 | 2.1 | 133.6‡ |
2007 (10) | 9.4 | 19.3 | 2.0 | 64.7‡ |
Maximum spatial population radius analyzed (50% of total population).
Observed incidence in cluster/expected incidence outside the cluster.
P < 0.01 (P values based on 999 simulations under the constant risk hypothesis).