Table 2 Estimated power, sensitivity and positive predictive value (PPV) when the normal scan statistic is used to detect different types of clusters, as described in the text.
From: A scan statistic for continuous data based on the normal probability model
Cluster number | Cluster size (%) | Sample size | Cluster mean | Cluster STD | Power (%) | Sensitivity | PPV |
|---|---|---|---|---|---|---|---|
Different Cluster Locations | |||||||
1 | 10 | 600 | -10% | 600 | 66 | 0.70 | 0.74 |
2 | 10 | 600 | -10% | 600 | 54 | 0.56 | 0.65 |
3 | 10 | 600 | -10% | 600 | 64 | 0.72 | 0.82 |
4 | 10 | 600 | -10% | 600 | 61 | 0.61 | 0.64 |
Different Cluster Size | |||||||
1 | 5 | 600 | -10% | 600 | 34 | 0.52 | 0.48 |
1 | 10 | 600 | -10% | 600 | 66 | 0.70 | 0.74 |
1 | 20 | 600 | -10% | 600 | 96 | 0.87 | 0.89 |
Different Sample Size | |||||||
1 | 10 | 300 | -10% | 600 | 34 | 0.55 | 0.56 |
1 | 10 | 600 | -10% | 600 | 66 | 0.70 | 0.74 |
1 | 10 | 900 | -10% | 600 | 89 | 0.83 | 0.82 |
1 | 10 | 1200 | -10% | 600 | 98 | 0.85 | 0.85 |
Different Mean Weight Reduction | |||||||
1 | 10 | 600 | -5% | 600 | 14 | 0.30 | 0.38 |
1 | 10 | 600 | -8% | 600 | 42 | 0.56 | 0.61 |
1 | 10 | 600 | -10% | 600 | 66 | 0.70 | 0.74 |
1 | 10 | 600 | -13% | 600 | 92 | 0.84 | 0.84 |
1 | 10 | 600 | -15% | 600 | 98 | 0.88 | 0.88 |
1 | 10 | 600 | -20% | 600 | 100 | 0.93 | 0.93 |
Different Standard Deviation | |||||||
1 | 10 | 600 | -10% | 300 | 100 | 0.93 | 0.93 |
1 | 10 | 600 | -10% | 600 | 66 | 0.70 | 0.74 |
1 | 10 | 600 | -10% | 900 | 28 | 0.45 | 0.51 |