Table 3.
Estimated levels of “alarm thresholds” of the pertussis outbreak in all age groups in different clusters according to the incidence of suspected cases.
| Stratum | Indices | Poisson median (95% coverage) | Poisson median (per 10,000,000) (95% coverage) | EWMA* | EWMA (per 10,000,000) |
|---|---|---|---|---|---|
| Stratum 1 Total population: (7,000,000) |
Overall | 3.55 (2.19–5.46) | 5.07 (3.13–7.80) | 2.68 | 3.83 |
| Spring | 4.09 (2.98–5.84) | 5.84 (4.26–8.34) | 3.39 | 4.84 | |
| Summer | 3.38 (2.52–6.10) | 4.83 (3.60–8.71) | 2.62 | 3.74 | |
| Autumn | 3.28 (2.47–4.02) | 4.69 (3.53–5.74) | 2.54 | 3.63 | |
| Winter | 3.56 (2.00–4.77) | 5.09 (2.86–6.81) | 2.56 | 3.66 | |
| Stratum 2 Total population: (43,000,000) |
Overall | 5.45 (3.50–7.62) | 1.27 (0.81–1.77) | 5.01 | 1.17 |
| Spring | 6.58 (4.94–8.40) | 1.53 (1.15–1.95) | 5.86 | 1.36 | |
| Summer | 4.65 (3.40–7.14) | 1.08 (1.08–1.66) | 4.26 | 0.99 | |
| Autumn | 4.32 (3.22–6.36) | 1.00 (0.75–1.48) | 4.35 | 1.01 | |
| Winter | 6.09 (4.02–7.70) | 1.42 (0.93–1.79) | 5.33 | 1.24 | |
| Stratum 3 Total population: (30,000,000) |
Overall | 2.01 (1.15–3.11) | 0.67 (0.38–1.04) | 1.08 | 0.36 |
| Spring | 2.51 (1.54–3.52) | 0.84 (0.51–1.17) | 1.67 | 0.56 | |
| Summer | 2.03 (1.18–2.93) | 0.68 (0.39–0.98) | 1.04 | 0.35 | |
| Autumn | 1.77 (1.31–2.31) | 0.59 (0.44–0.77) | 0.99 | 0.33 | |
| Winter | 1.98 (1.05–2.63) | 0.66 (0.35–0.88) | 1.02 | 0.34 |
*
Exponentially weighted moving average.