Table 1. Characteristics of the 240,477 UK Biobank participants included in analyses.
| Trait | N | Mean (SD) | Min—Max |
|---|---|---|---|
| Age (years) | 240,477 | 55.05 (8.1) | 40–70 |
| RDW (%) | 240,477 | 13.35 (0.8) | 10.8–34.2 |
| Mean Cell Volume (fL) | 240,477 | 91.42 (4.1) | 57.4–160.3 |
| Hemoglobin conc. (g/dL) | 240,477 | 144.84 (9.8) | 120–206 |
| Follow-up (years since visit) | |||
| Hospital records * | 240,477 | 7.00 (0.92) | 0.01–9.87 |
| Death registry | 3,888 | 4.43 (1.93) | 0.06–8.72 |
| Sex | N | % | |
| Females | 115,811 | 48.16 | |
| Males | 124,666 | 51.84 | |
| Smoking status | |||
| Never | 136,444 | 56.74 | |
| Former | 76,707 | 31.90 | |
| Current | 27,326 | 11.36 | |
| Education attained | |||
| None | 32,440 | 13.49 | |
| CSEs (up to 16 years) † | 9,442 | 3.93 | |
| GCSEs (up to 16 years) † | 30,648 | 12.74 | |
| A-levels (16 to 18 years) † | 45,647 | 18.98 | |
| Professional qualification | 35,020 | 14.56 | |
| Degree | 87,280 | 36.29 | |
| RDW (%) | |||
| <12.5 | 20,844 | 8.67 | |
| 12.5–12.9 | 56,446 | 23.47 | |
| 13.0–13.4 | 73,496 | 30.56 | |
| 13.5–13.9 | 51,274 | 21.32 | |
| 14.0–14.4 | 23,600 | 9.81 | |
| 14.5–14.9 | 8,767 | 3.65 | |
| ≥15.0 | 6,050 | 2.52 |
* = years from baseline visit to first hospital admission, or 1st March 2016 if no visit, or death.
† = or equivalent qualification; CSEs and GCSEs were lower/higher-level qualifications, respectively