| Characteristic | Variable | Non-responders, n (%) | Responders, n (%) | % of records available for the non-responders | P value |
|---|---|---|---|---|---|
| Sex | Male | 867 (46.0) | 194 (47.9) | 96.2 | 0.26a |
| Female | 1017 (54.0) | 211 (52.1) | |||
| Deprivation index | More deprived (IMD 1–5) | 814 (43.2) | 198 (43.9) | 96.2 | 0.79a |
| Less deprived (IMD 6–10) | 1070 (56.8) | 253 (56.1) | |||
| Age, years | <39 | 82 (7.1) | 14 (3.5) | 59.0 | 0.003b |
| 40–64 | 572 (49.5) | 187 (46.5) | |||
| >64 | 501 (43.4) | 201 (50.0) |
aχ2 test, two-sided P value. b t-test. IMD = Index of Multiple Deprivation.