Table 1.
Phases of the Whitehall II cohort study (http://www.ucl.ac.uk/whitehallII/study-phases)
| Phase | Dates | Type | Number of participants | Response Rate |
|---|---|---|---|---|
| 1 |
1985-1988 |
Screening / questionnaire |
10,308 |
73% of those invited |
| 2 |
1989-1990 |
Questionnaire |
8,132 |
79% of Phase 1 responders |
| 3 |
1991-1994 |
Screening / questionnaire |
8,815 |
86% of Phase 1 responders |
| 4 |
1995-1996 |
Questionnaire |
8,628 |
84% of Phase 1 responders |
| 5 |
1997-1999 |
Screening / questionnaire |
7,870 |
76% of Phase 1 responders |
| 6 |
2001 |
Questionnaire |
7,355 |
71% of Phase 1 responders |
| 7 |
2002-2004 |
Screening / questionnaire |
6,967 |
68% of Phase 1 responders |
| 8 |
2006 |
Questionnaire |
7,173 |
70% of Phase 1 responders |
| 9 | 2007-2009 | Screening / questionnaire | 6,761 | 66% of Phase 1 responders |