Table 1.
Baseline characteristics of respondents, by vaccination and case status, using variables from the original study data (NIMS and SGSS)
| Characteristics according to NIMS and SGSS | Respondents not vaccinated at symptom onset, N = 1907 | Respondents vaccinated at symptom onset, N = 6741 | Difference in absolute percentage (vaccinated – non-vaccinated) | p-value | Respondents who were negative controls, N = 6541 | Respondents who were cases, N = 2107 | Difference in absolute percentage (cases – negative controls) | p-value |
|---|---|---|---|---|---|---|---|---|
| Vaccine status at symptom onset, n (%) | <0.001 | |||||||
| Not vaccinated | 1351 (20.7%) | 556 (26.4%) | 5.70% | |||||
| Vaccinated | 5190 (79.3%) | 1551 (73.6%) | −5.70% | |||||
| Test result | <0.001 | |||||||
| Negative | 1351 (70.8%) | 5190 (77.0%) | 6.2% | |||||
| Positive | 556 (29.2%) | 1551 (23.0%) | −6.2% | |||||
| Age group in years, n (%) | <0.001 | 0.626 | ||||||
| 70–74 | 1492 (78.2%) | 2931 (43.5%) | −34.7% | 3348 (51.2%) | 1075 (51.0%) | −0.20% | ||
| 75–79 | 279 (14.6%) | 2056 (30.5%) | 15.9% | 1778 (27.2%) | 557 (26.4%) | −0.80% | ||
| 80–84 | 57 (3.0%) | 1031 (15.3%) | 12.3% | 826 (12.6%) | 262 (12.4%) | −0.20% | ||
| 85–89 | 43 (2.3%) | 473 (7.0%) | 4.7% | 381 (5.8%) | 135 (6.4%) | 0.60% | ||
| =>90 | 36 (1.9%) | 250 (3.7%) | 1.8% | 208 (3.2%) | 78 (3.7%) | 0.50% | ||
| Gender, n (%) | 0.421 | 0.115 | ||||||
| Female | 1081 (56.7%) | 3749 (55.6%) | −1.1% | 3685 (56.3%) | 1145 (54.3%) | −2.00% | ||
| Male | 826 (43.3%) | 2992 (44.4%) | 1.1% | 2856 (43.7%) | 962 (45.7%) | 2.00% | ||
| Ethnicity, n (%) | 0.075 | <0.001 | ||||||
| White | 1756 (92.1%) | 6266 (93.0%) | 0.9% | 6114 (93.5%) | 1908 (90.6%) | −2.90% | ||
| Non-white | 84 (4.4%) | 224 (3.3%) | −1.1% | 185 (2.8%) | 123 (5.8%) | 3.00% | ||
| Prefer not to say | 67 (3.5%) | 251 (3.7%) | 0.2% | 242 (3.7%) | 76 (3.6%) | −0.10% | ||
| Geographical region, n (%) | <0.001 | <0.001 | ||||||
| East of England | 246 (12.9%) | 814 (12.1%) | −0.8% | 834 (12.8%) | 226 (10.7%) | −2.10% | ||
| London | 104 (5.5%) | 614 (9.1%) | 3.6% | 530 (8.1%) | 188 (8.9%) | 0.80% | ||
| Midlands | 360 (18.9%) | 1415 (21.0%) | 2.1% | 1265 (19.3%) | 510 (24.2%) | 4.90% | ||
| Northeast and Yorkshire | 317 (16.6%) | 1043 (15.5%) | −1.1% | 948 (14.5%) | 412 (19.6%) | 5.10% | ||
| Northwest | 232 (12.2%) | 994 (14.7%) | 2.5% | 922 (14.1%) | 304 (14.4%) | 0.30% | ||
| Southeast | 394 (20.7%) | 1116 (16.6%) | −4.1% | 1202 (18.4%) | 308 (14.6%) | −3.80% | ||
| Southwest | 254 (13.3%) | 745 (11.1%) | −2.2% | 840 (12.8%) | 159 (7.5%) | −5.30% | ||
| IMD quintile, n (%) | 0.085 | <0.001 | ||||||
| 1 (most deprived) | 238 (12.5%) | 800 / 6736 (11.9%) | −0.6% | 683 / 6536 (10.4%) | 355 (16.8%) | 6.40% | ||
| 2 | 319 (16.7%) | 1018 / 6736 (15.1%) | −1.6% | 963 / 6536 (14.7%) | 374 (17.8%) | 3.10% | ||
| 3 | 399 (20.9%) | 1425 / 6736 (21.2%) | 0.3% | 1379 / 6536 (21.1%) | 445 (21.1%) | 0.00% | ||
| 4 | 477 (25.0%) | 1622 / 6736 (24.1%) | −0.9% | 1645 / 6536 (25.2%) | 454 (21.5%) | −3.70% | ||
| 5 (least deprived) | 474 (24.9%) | 1871 / 6736 (27.8%) | 2.9% | 1866 / 6536 (28.5%) | 479 (22.7%) | −5.80% | ||
| Missing | 0 | 5 | 5 | 0 | ||||
| Week of symptom onset, n (%) | <0.001 | <0.001 | ||||||
| January week 1 | 10 (0.5%) | <5 | 10 (0.2%) | <5 | ||||
| January week 2 | 32 (1.7%) | <5 | 35 (0.5%) | <5 | ||||
| January week 3 | 86 (4.5%) | 61 (0.9%) | −3.6% | 110 (1.7%) | 37 (1.8%) | 0.10% | ||
| January week 4 | 737 (38.6%) | 987 (14.6%) | −24.0% | 1238 (18.9%) | 486 (23.1%) | 4.20% | ||
| February week 1 | 802 (42.1%) | 2202 (32.73%) | −9.4% | 2203 (33.7%) | 801 (38.0%) | 4.30% | ||
| February week 2 | 178 (9.3%) | 2202 (32.7%) | 23.4% | 1839 (28.1%) | 541 (25.7%) | −2.40% | ||
| February week 3 | 62 (3.3%) | 1280 (19.0%) | 15.7% | 1106 (16.9%) | 236 (11.2%) | −5.70% | ||
| Week of COVID-19 test, n (%) | <0.001 | <0.001 | ||||||
| February week 1 | 1385 (72.6%) | 2166 (32.1%) | −40.5% | 2572 (39.3%) | 979 (46.5%) | 7.20% | ||
| February week 2 | 362 (19.0%) | 2038 (30.2%) | 11.2% | 1772 (27.1%) | 628 (29.8%) | 2.70% | ||
| February week 3 | 160 (8.4%) | 2537 (37.6%) | 29.2% | 2197 (33.6%) | 500 (23.7%) | −9.90% | ||
| Care home status, n (%) | 0.059 | <0.001 | ||||||
| Not care home | 1901 (99.7%) | 6691 (99.3%) | −0.4% | 6514 (99.6%) | 2078 (98.6%) | −1.00% | ||
| Care homea | 6 (0.3%) | 50 (0.7%) | 0.4% | 27 (0.4%) | 29 (1.4%) | 1.00% | ||
| CEV, n (%) | <0.001 | 0.006 | ||||||
| Not CEV | 1709 (89.6%) | 5746 (85.2%) | −4.4% | 5601 (85.6%) | 1854 (88.0%) | 2.40% | ||
| CEV | 198 (10.4%) | 995 (14.8%) | 4.4% | 940 (14.4%) | 253 (12.0%) | −2.40% |
Abbreviations: CEV clinically extremely vulnerable, IQR interquartile range, IMD index of multiple deprivations, n numerator N denominator, NIMS National Immunisation Management System, SGSS Second Generation Surveillance System.
aCare home status is likely low in the current study because the study only included those tested in the community (pillar 2), individuals tested in care homes or in hospital are usually tested under pillar 1.
Note: all tests were conducted using two-sided Chi squared test.
Note: cells <5 have been suppressed and secondary suppression has also been conducted in order to protect patient privacy.