Table 1.
Baseline characteristics of participants by recruitment sites based on participants with available information
|
Total cohort |
Active surveillance cohort |
|||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Scotland | England | Spain | Finland | Netherlands | All | Scotland | England | Spain | Finland | Netherlands | All | |||
| Total number of participants | 2130 | 1972 | 1080 | 2093 | 1879 | 9154 | 203 | 198 | 205 | 200 | 187 | 993 | ||
| Follow-up time (infant-months) | 25 498 | 23 458 | 12 949 | 25 119 | 22 484 | 109 507 | 2408 | 2288 | 2404 | 2384 | 2245 | 11 729 | ||
| Pregnancy | ||||||||||||||
| Vaccination* | 1815/2127 (85%) | 1766/1947 (91%) | 632/1037 (61%) | 933/2072 (45%) | 626/1827 (34%) | 5772/9010 (64%) | 188/203 (93%) | 183/196 (93%) | 118/200 (59%) | 129/198 (65%) | 57/186 (31%) | 675/983 (69%) | ||
| Influenza | 1444/2127 (68%) | 1417/1947 (73%) | 294/1037 (28%) | 931/2072 (45%) | 25/1827 (1%) | 4111/9010 (46%) | 154/203 (76%) | 142/196 (72%) | 37/200 (19%) | 128/198 (65%) | 5/186 (3%) | 466/983 (47%) | ||
| Pertussis | 1742/2127 (82%) | 1672/1947 (86%) | 597/1037 (58%) | 3/2072 (<1%) | 617/1827 (34%) | 4631/9010 (51%) | 181/203 (89%) | 179/196 (91%) | 113/200 (57%) | 1/198 (1%) | 55/186 (30%) | 529/983 (54%) | ||
| Smoking during pregnancy | 153/2129 (7%) | 102/1954 (5%) | 109/1049 (10%) | 112/2086 (5%) | 65/1827 (4%) | 541/9045 (6%) | 9/203 (4%) | 10/198 (5%) | 18/204 (9%) | 13/198 (7%) | 4/186 (2%) | 54/989 (5%) | ||
| Birth | ||||||||||||||
| Month of birth* | ||||||||||||||
| Oct–Dec | 509/2130 (24%) | 437/1972 (22%) | 285/1080 (26%) | 435/2093 (21%) | 518/1879 (28%) | 2184/9154 (24%) | 30/203 (15%) | 26/198 (13%) | 69/205 (34%) | 38/200 (19%) | 62/187 (33%) | 225/993 (23%) | ||
| Jan–March | 658/2130 (31%) | 565/1972 (29%) | 254/1080 (24%) | 324/2093 (15%) | 612/1879 (33%) | 2413/9154 (26%) | 32/203 (16%) | 28/198 (14%) | 33/205 (16%) | 58/200 (29%) | 63/187 (34%) | 214/993 (22%) | ||
| April–June | 468/2130 (22%) | 543/1972 (28%) | 157/1080 (15%) | 615/2093 (29%) | 310/1879 (16%) | 2093/9154 (23%) | 70/203 (34%) | 60/198 (30%) | 29/205 (14%) | 68/200 (34%) | 29/187 (16%) | 256/993 (26%) | ||
| July–Sept | 495/2130 (23%) | 427/1972 (22%) | 384/1080 (36%) | 719/2093 (34%) | 439/1879 (23%) | 2464/9154 (27%) | 71/203 (35%) | 84/198 (42%) | 74/205 (36%) | 36/200 (18%) | 33/187 (18%) | 298/993 (30%) | ||
| Male sex | 1108/2130 (52%) | 1036/1944 (53%) | 555/1080 (51%) | 1093/2093 (52%) | 933/1869 (50%) | 4725/9116 (52%) | 106/203 (52%) | 108/197 (55%) | 107/205 (52%) | 106/200 (53%) | 85/187 (45%) | 512/992 (52%) | ||
| Female sex | 1022/2130 (48%) | 908/1944 (47%) | 525/1080 (49%) | 1000/2093 (48%) | 936/1869 (50%) | 4391/9116 (48%) | 97/203 (48%) | 89/197 (45%) | 98/205 (48%) | 94/200 (47%) | 102/187 (55%) | 480/992 (48%) | ||
| Multiple birth* | 52/2120 (2%) | 65/1940 (3%) | 36/1080 (3%) | 17/2093 (1%) | 27/1872 (1%) | 197/9105 (2%) | 18/203 (9%) | 5/195 (3%) | 7/205 (3%) | 2/200 (1%) | 6/187 (3%) | 38/990 (4%) | ||
| Caesarean delivery* | 927/2126 (44%) | 742/1941 (38%) | 238/1080 (22%) | 293/2091 (14%) | 409/1872 (22%) | 2607/9110 (29%) | 83/203 (41%) | 76/197 (39%) | 65/205 (32%) | 28/200 (14%) | 44/187 (24%) | 296/992 (30%) | ||
| Birth weight <2500 g | 40/2092 (2%) | 54/1938 (3%) | 27/1080 (3%) | 22/2091 (1%) | 26/1831 (1%) | 169/9032 (2%) | 4/201 (2%) | 6/197 (3%) | 9/205 (4%) | 3/200 (2%) | 3/183 (2%) | 25/986 (3%) | ||
| Antibiotics <72 h post-partum | 8/2130 (<1%) | 146/1972 (7%) | 6/1080 (1%) | 6/1080 (5%) | 41/1879 (2%) | 305/9154 (3%) | 0/203 | 14/198 (7%) | 1/205 (<1%) | 8/200 (4%) | 14/198 (1%) | 24/993 (2%) | ||
| Intention to breastfeed* | 1681/2129 (79%) | 1659/1947 (85%) | 739/1051 (70%) | 2025/2082 (97%) | 1368/1826 (75%) | 7472/9035 (83%) | 182/203 (90%) | 182/198 (92%) | 146/205 (71%) | 196/198 (99%) | 154/186 (83%) | 860/990 (87%) | ||
| Family | ||||||||||||||
| Any siblings | 924/2130 (43%) | 979/1959 (50%) | 549/1055 (52%) | 1103/2091 (53%) | 892/1849 (48%) | 4447/9084 (49%) | 104/203 (51%) | 89/198 (45%) | 99/205 (48%) | 95/200 (48%) | 118/186 (63%) | 505/992 (51%) | ||
| Number of siblings* | 1 (1–2) | 1 (1–2) | 1 (1–1) | 1 (1–2) | 1 (1–2) | 1 (1–2) | 1 (1–1) | 1 (1–1) | 1 (1–1) | 1 (1–1) | 1 (1–2) | 1 (1–1) | ||
| Siblings in daycare or primary school | 799/2130 (38%) | 817/1959 (42%) | 474/1055 (45%) | 849/2091 (41%) | 823/1849 (45%) | 3762/9084 (41%) | 92/203 (45%) | 70/198 (35%) | 87/205 (42%) | 70/200 (35%) | 106/186 (57%) | 425/992 (43%) | ||
| Smokers in the family* | 320/2129 (15%) | 274/1947 (14%) | 299/1050 (28%) | 261/2085 (13%) | 301/1826 (16%) | 1455/9037 (16%) | 15/203 (7%) | 20/198 (10%) | 58/204 (28%) | 23/198 (12%) | 21/186 (11%) | 137/989 (14%) | ||
| Mother | 83/2129 (4%) | 47/1947 (2%) | 61/1050 (6%) | 50/2085 (2%) | 59/1826 (3%) | 300/9037 (3%) | 5/203 (2%) | 2/198 (1%) | 8/204 (4%) | 4/198 (2%) | 1/186 (1%) | 20/989 (2%) | ||
| Father | 265/2129 (12%) | 218/1947 (11%) | 254/1050 (24%) | 235/2085 (11%) | 257/1826 (14%) | 1229/9037 (14%) | 12/203 (6%) | 5/198 (8%) | 50/204 (25%) | 21/198 (11%) | 19/186 (10%) | 117/989 (12%) | ||
| Other family member | 21/2129 (1%) | 45/1947 (2%) | 34/1050 (3%) | 0/2085 | 26/1826 (1%) | 126/9037 (1%) | 1/203 (<1%) | 4/198 (2%) | 6/204 (3%) | 0/198 | 1/186 (1%) | 12/989 (1%) | ||
| Smoking in the house | 29/2129 (1%) | 15/1947 (1%) | 41/1050 (4%) | 9/2085 (<1%) | 4/1826 (<1%) | 98/9037 (1%) | 1/203 (<1%) | 4/198 (2%) | 6/204 (3%) | 0/198 | 1/186 (1%) | 12/989 (1%) | ||
| Family history of atopy* | 1568/2129 (74%) | 1409/1951 (72%) | 578/1037 (56%) | 1319/2079 (63%) | 1292/1831 (71%) | 6166/9027 (68%) | 163/203 (80%) | 150/198 (76%) | 121/203 (60%) | 132/198 (67%) | 142/186 (76%) | 708/988 (72%) | ||
| Siblings use or used respiratory medicine | 172/2130 (8%) | 212/1959 (11%) | 112/1055 (11%) | 167/2091 (8%) | 198/1849 (11%) | 861/9084 (9%) | 11/203 (5%) | 15/198 (8%) | 17/205 (8%) | 10/200 (5%) | 28/186 (15%) | 81/992 (8%) | ||
| Ethnic origin of the mother* | ||||||||||||||
| Northwest Europe | 1643/2124 (77%) | 1473/1952 (75%) | 31/1048 (3%) | 2029/2086 (97%) | 1416/1827 (78%) | 6592/9037 (73%) | 146/203 (72%) | 143/198 (72%) | 9/205 (4%) | 195/198 (98%) | 163/186 (88%) | 656/990 (66%) | ||
| Southern Europe | 94/2124 (4%) | 46/1952 (2%) | 943/1048 (90%) | 10/2086 (<1%) | 29/1827 (2%) | 1122/9037 (12%) | 11/203 (5%) | 6/198 (3%) | 179/205 (87%) | 0/198 | 4/186 (2%) | 200/990 (20%) | ||
| Other | 393/2124 (19%) | 453/1952 (23%) | 106/1048 (10%) | 54/2086 (3%) | 434/1827 (24%) | 1440/9037 (16%) | 46/203 (23%) | 49/198 (25%) | 17/205 (8%) | 5/198 (3%) | 20/186 (11%) | 137/990 (14%) | ||
| Ethnic origin of the father* | ||||||||||||||
| Northwest Europe | 1664/2124 (78%) | 1475/1952 (76%) | 35/1048 (3%) | 1979/2086 (95%) | 1414/1827 (77%) | 6567/9037 (73%) | 155/203 (76%) | 156/198 (79%) | 9/205 (4%) | 192/198 (97%) | 165/186 (89%) | 677/990 (68%) | ||
| Southern Europe | 79/2124 (4%) | 53/1952 (3%) | 946/1048 (90%) | 13/2086 (1%) | 23/1827 (1%) | 1114/9037 (12%) | 7/203 (3%) | 3/198 (2%) | 181/205 (88%) | 0/198 | 2/186 (1%) | 193/990 (19%) | ||
| Other | 387/2124 (18%) | 444/1952 (23%) | 99/1048 (9%) | 101/2086 (5%) | 442/1827 (24%) | 1473/9037 (16%) | 41/203 (20%) | 39/198 (20%) | 15/205 (7%) | 8/198 (4%) | 20/186 (11%) | 123/990 (12%) | ||
| Highest level of education of the mother* | ||||||||||||||
| Secondary or vocational school | 780/2125 (37%) | 743/1954 (38%) | 540/1049 (51%) | 721/2085 (35%) | 580/1826 (32%) | 3364/9039 (37%) | 36/203 (18%) | 40/198 (20%) | 103/205 (50%) | 62/198 (31%) | 46/186 (25%) | 287/990 (29%) | ||
| University of (applied) sciences | 1336/2125 (63%) | 1202/1954 (62%) | 471/1049 (45%) | 1315/2085 (63%) | 1230/1826 (67%) | 5554/9039 (61%) | 167/203 (82%) | 158/198 (80%) | 94/205 (46%) | 133/198 (67%) | 140/186 (75%) | 692/990 (70%) | ||
| Highest level of education of the father* | ||||||||||||||
| Secondary or vocational school | 1000/2102 (48%) | 917/1928 (48%) | 685/1037 (66%) | 982/2059 (48%) | 732/1818 (40%) | 4316/8944 (48%) | 58/202 (29%) | 67/197 (34%) | 138/203 (68%) | 90/197 (46%) | 68/185 (37%) | 421/984 (43%) | ||
| University of (applied) sciences | 1096/2102 (52%) | 1001/1928 (52%) | 253/1037 (24%) | 986/2059 (48%) | 1063/1818 (58%) | 4399/8944 (49%) | 143/202 (71%) | 129/197 (65%) | 54/203 (27%) | 101/197 (51%) | 116/185 (63%) | 543/984 (55%) | ||
| Employment of the mother before birth | ||||||||||||||
| Full-time | 1384/2129 (65%) | 1250/1954 (64%) | 619/1045 (59%) | 1432/2084 (69%) | 763/1827 (42%) | 5448/9039 (60%) | 140/203 (69%) | 142/198 (72%) | 109/205 (53%) | 137/198 (69%) | 83/186 (45%) | 611/990 (62%) | ||
| Part-time | 519/2129 (24%) | 511/1954 (26%) | 168/1045 (16%) | 264/2084 (13%) | 902/1827 (49%) | 2364/9039 (26%) | 51/203 (25%) | 48/198 (24%) | 38/205 (19%) | 29/198 (15%) | 93/186 (50%) | 259/990 (26%) | ||
| Employment of the father before birth | ||||||||||||||
| Full-time | 1933/2129 (91%) | 1843/1954 (94%) | 955/1045 (91%) | 1827/2084 (88%) | 1520/1827 (83%) | 8078/9039 (89%) | 193/203 (95%) | 187/198 (94%) | 187/205 (91%) | 164/198 (83%) | 150/186 (81%) | 881/990 (89%) | ||
| Part-time | 82/2129 (4%) | 48/1954 (2%) | 37/1045 (4%) | 74/2084 (4%) | 244/1827 (13%) | 485/9039 (5%) | 3/203 (1%) | 8/198 (4%) | 7/205 (3%) | 8/198 (4%) | 31/186 (17%) | 57/990 (6%) | ||
Data are n/N (%), and median (IQR).
*
p<0·05 total active surveillance versus total passive (without active) cohort.