Table 1

Baseline characteristics of participants

All participants (n=502 647)Participants completed cognitive test
 Verbal–numerical reasoning (n=165 493)Memory (n=482 766)Reaction time (n=496 813)
Cognitive test score5.98±2.16 (max. correct of 13)4.25±3.36 (no. of errors)559±118 (ms)
Age (years)57.03±8.0957.20±8.1456.96±8.0857.02±8.09
Gender (female) (%)55.054.554.554.4
Education
 A levels and above (%)43.645.744.043.4
 Other educational qualifications (%)33.233.933.433.0
 Professional qualifications only (%)5.25.25.25.1
 None of the above (%)17.214.316.416.7
 Prefer not to answer (%)2.02.02.01.7
Household income (GBP/year)
 <18 000 (%)19.618.819.219.2
 18 000–30 999 (%)21.822.021.922.2
 31 000–51 999 (%)22.322.622.622.2
 52 000–100 000 (%)17.417.917.717.4
 >100 000 (%)4.65.14.74.6
 Do not know (%)4.33.94.04.1
 Prefer not to answer (%)10.09.49.79.9
  • The table shows summary statistics of all UK Biobank participants (first column) and the participants who completed each cognitive test during their baseline visit (second to fourth columns). Values indicate mean±SD for cognitive test score and age, or percentages for gender, education and household income.