Table 1. Potthoff–Whittinghill test for the existence of a spatial heterogeneity in the incidence of childhood acute leukaemia in France 1990–2000. (a) Spatial heterogeneity over the whole territory (36 343 communes) and (b) Spatial heterogeneity in isolated communes in relation to population density.
|
Whole period 1990–2000
|
1990–1994
|
1995–2000
|
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|---|---|---|---|---|---|---|---|
| Age (years) | No. cases | β̂a (P-valueb) | No. cases | β̂ (P-value) | No. cases | β̂ (P-value) | |
| (a) Spatial heterogeneity over the whole territory (36 343 communes) | |||||||
| All AL | 0–14 | 4897 | 0.5% (0.23) | 2236 | 1.2% (0.06) | 2261 | 0.2% (0.38) |
| 0–4 | 2471 | 0.1% (0.40) | 1141 | 0% (0.40) | 1330 | −0.25% (0.60) | |
| 5–9 | 1435 | −0.5% (0.75) | 666 | −0.25% (0.62) | 769 | −0.2% (0.49) | |
| 10–14 | 991 | −0.4% (0.69) | 429 | −0.2% (0.45) | 562 | −0.2% (0.56) | |
| ALL | 0–14 | 3993 | 0.35% (0.32) | 1831 | 1.2% (0.07) | 2162 | −0.1% (0.52) |
| 0–4 | 2045 | 0.05% (0.40) | 851 | 0.3% (0.28) | 1094 | −0.2% (0.54) | |
| 5–9 | 1208 | −0.5% (0.73) | 559 | −0.4% (0.77) | 649 | 0.03% (0.34) | |
| 10–14 | 740 | −0.4% (0.67) | 321 | −0.6% (0.95) | 419 | −0.3% (0.62) | |
| AML | 0–14 | 837 | −0.5% (0.74) | 374 | 0.3% (0.18) | 463 | −0.4% (0.70) |
| 0–4 | 395 | 0.01% (0.32) | 179 | 0.6% (0.07) | 216 | −0.2% (0.48) | |
| 5–9 | 205 | −0.3% (0.63) | 94 | −0.1% (0.47) | 111 | −0.2% (0.74) | |
| 10–14 | 237 | −0.2% (0.47) | 101 | 0.1% (0.13) | 136 | −0.15% (0.45) | |
|
1990–2000
|
1990–1994
|
1995–2000
|
|||||
|---|---|---|---|---|---|---|---|
| No. cases | β̂a (P-valueb) | No. cases | β̂ (P-value) | No. cases | β̂ (P-value) | ||
| (b) Spatial heterogeneity in isolated communes in relation to population density | |||||||
| 0–14 | |||||||
| Isolated communes | 1469 | 0.1% (0.29) | 700 | 1.6% (0.04) | 769 | −0.2% (0.41) | |
| ⩽50 inhab/km2 | 554 | 0.0% (0.28) | 239 | 0.1% (0.27) | 315 | 0.5% (0.14) | |
| >50 inhab/km2 | 915 | 0.5% (0.39) | 461 | 5.5% (0.01) | 454 | −2.3% (0.92) | |
| 0–4 | |||||||
| Isolated communes | 733 | 0.2 (0.34) | 355 | 0.3% (0.29) | 378 | −0.3% (0.53) | |
| ⩽50 inhab/km2 | 292 | 0.1% (0.34) | 125 | −0.5% (0.50) | 167 | −0.1% (0.34) | |
| >50 inhab/km2 | 441 | 0.5% (0.35) | 230 | 2.5% (0.10) | 211 | −0.9% (0.64) | |
| 5–9 | |||||||
| Isolated communes | 423 | −0.8% (0.86) | 196 | −4.3% (0.66) | 227 | −0.5% (0.63) | |
| ⩽50 inhab/km2 | 151 | −0.7% (0.64) | 64 | −0.3% (0.17) | 87 | −0.4% (0.28) | |
| >50 inhab/km2 | 272 | −1.3% (0.77) | 132 | −0.8% (0.64) | 140 | −0.6% (0.57) | |
| 10–4 | |||||||
| Isolated communes | 313 | −0.2% (0.55) | 149 | 0.0% (0.34) | 164 | −0.3% (0.48) | |
| ⩽50 inhab/km2 | 111 | −0.3% (0.43) | 50 | −0.2% (0.11) | 61 | −0.3% (0.15) | |
| >50 inhab/km2 | 202 | −0.1% (0.49) | 99 | 0.5% (0.32) | 103 | −0.2% (0.40) | |
Isolated communes: non attractive communes, in terms of employment, that are included in a unit with less than 5000 inhabitants (Rudant et al, 2005).
a
Following (Alexander and Boyle, 1996), the ratio of the variance to the mean of the number of cases in any area was equal to 1+β.
b
The Statistical significance level was based on the one-sided tail probability of the null distribution (1000 Monte Carlo simulations).
cThe Statistical significance level was based on the one-sided tail probability of the null distribution (999 Monte Carlo simulations).