Table 1

Population demographics

Routine group (n=56 234)Catch-up group (n=56 217)Non-linked women (n=428 526)
% (n)% (n)% (n)
Mother's year of birth
 1944–19480.26 (144)0.36 (203)10.12 (43 366)
 1949–19530.70 (395)1.26 (707)10.46 (44 805)
 1954–19584.10 (2304)6.73 (3785)11.35 (48 640)
 1959–196316.58 (9325)21.94 (12 334)12.62 (54 089)
 1964–196831.73 (17 842)33.92 (19 067)12.85 (55 057)
 1969–197328.28 (15 902)24.79 (13 938)13.21 (56 588)
 1974–197815.62 (8783)10.09 (5673)12.69 (54 386)
 1979–19842.74 (1539)0.91 (510)16.71 (71 595)
IMD ranks
 1 (Most deprived)20.01 (11 253)21.22 (11 928)19.59 (83 964)
 219.99 (11 242)20.33 (11 427)19.92 (85 372)
 320.00 (11 246)18.71 (10 517)20.32 (87 083)
 420.01 (11 253)19.39 (10 900)20.26 (86 839)
 5 (Least deprived)19.99 (11 240)20.36 (11 445)19.89 (85 225)
Ethnicity*
 White93.3293.6893.72
 Mixed0.990.971.01
 Αsian4.374.093.86
 Βlack0.730.680.74
 Other0.590.590.67
  • *Ethnicity is calculated by totalling the Census 2001 ethnicity data and calculating a total proportion for the cohort.

  • IMD, Index of Multiple Deprivation.