Table 2 Characteristics of the study cohort
Variable | North high IP N(%) | North low IP N(%) | Rotterdam high IP N(%) | Rotterdam low IP N(%) | Controls N(%) |
|---|---|---|---|---|---|
6 hospitals | 7 hospitals | 5 hospitals | 5 hospitals | 7 hospitals | |
Mean age at diagnosis | 61.16 | 61.48 | 61.33 | 61.40 | 59.80 |
SD 14.16 | SD 14.20 | SD 14.34 | SD 14.39 | SD 13.67 | |
Period of diagnosis | Â | Â | Â | Â | Â |
1990-1995 | 3260 (23.21) | 2095 (19.42) | 2310 (23.16) | 2249 (23.28) | 4454 (23.38) |
1996-2001 | 4079 (29.05) | 3085 (28.60) | 2717 (27.24) | 2635 (27.28) | 5131 (26.93) |
2002-2007 | 4426 (31.52) | 3558 (32.98) | 3082 (30.90) | 3044 (31.51) | 5995 (31.47) |
2008-2010 | 2278 (16.22) | 2050 (19.00) | 1866 (18.71) | 1732 (17.93) | 3470 (18.22) |
Stage | Â | Â | Â | Â | Â |
IS | 1097 (7.81) | 776 (7.19) | 794 (7.96) | 775 (8.02) | 1577 (8.28) |
1 | 4758 (33.88) | 3660 (33.93) | 3323 (33.31) | 3249 (33.63) | 6595 (34.62) |
2 | 5881 (41.88) | 4575 (42.41) | 4243 (42.54) | 4097 (42.41) | 7898 (41.46) |
3 | 1480 (10.54) | 1123 (10.41) | 1018 (10.21) | 959 (9.93) | 1835 (9.63) |
4 | 718 (5.11) | 547 (5.07) | 513 (5.14) | 487 (5.04) | 877 (4.60) |
X | 109 (0.78) | 107 (0.99) | 84 (0.84) | 93 (0.96) | 268 (1.41) |
Average annual volume of hospital of diagnosis | Â | Â | Â | Â | Â |
<50 | 924 (6.58) | 647 (6.00) | 0 (0.00) | 0 (0.00) | 953 (5.00) |
50-100 | 4226 (30.09) | 10141 (94.00) | 9975 (100) | 9660 (100) | 16.579 (87.03) |
100 or more | 8893 (63.33) | 0 (0.00) | 0 (0.00) | 0 (0.00) | 1518 (7.97) |