Data
1,132,005 items of data are available, covering 386,093 participants.
Some values have special meanings defined by Data-Coding
13.
Defined-instances run from 0 to 3, labelled using Instancing
2.
Array indices run from 0 to 33.
Units of measurement are years.
| Maximum | 2021.5 |
| Decile 9 | 2008.5 |
| Decile 8 | 2007 |
| Decile 7 | 2005.3 |
| Decile 6 | 2002.7 |
| Median | 1999.7 |
| Decile 4 | 1996 |
| Decile 3 | 1989.8 |
| Decile 2 | 1980.5 |
| Decile 1 | 1967.5 |
| Minimum | 1937.9 |
|
|
- Mean = 1994.06
- Std.dev = 16.292
- 236 items have value -3 (Preferred not to answer)
- 37897 items have value -1 (Date uncertain or unknown)
|
4 Instances
Instance 0 : Initial assessment visit (2006-2010) at which participants were recruited and consent given
375,004 participants, 902,202 items
| Maximum | 2010.7 |
| Decile 9 | 2007.8 |
| Decile 8 | 2006.5 |
| Decile 7 | 2004.5 |
| Decile 6 | 2002.5 |
| Median | 1999.5 |
| Decile 4 | 1996.3 |
| Decile 3 | 1990.5 |
| Decile 2 | 1982.4 |
| Decile 1 | 1969.5 |
| Minimum | 1937.9 |
|
|
- Mean = 1994.08
- Std.dev = 15.2011
- 222 items have value -3 (Preferred not to answer)
- 32278 items have value -1 (Date uncertain or unknown)
|
Instance 1 : First repeat assessment visit (2012-13)
17,005 participants, 54,872 items
| Maximum | 2013.4 |
| Decile 9 | 2011.5 |
| Decile 8 | 2009.5 |
| Decile 7 | 2007.5 |
| Decile 6 | 2004.4 |
| Median | 2000.8 |
| Decile 4 | 1995.5 |
| Decile 3 | 1987.5 |
| Decile 2 | 1976.5 |
| Decile 1 | 1963.5 |
| Minimum | 1938.5 |
|
|
- Mean = 1993.79
- Std.dev = 18.188
- 5 items have value -3 (Preferred not to answer)
- 819 items have value -1 (Date uncertain or unknown)
|
Instance 2 : Imaging visit (2014+)
34,763 participants, 123,256 items
| Maximum | 2020.2 |
| Decile 9 | 2016.5 |
| Decile 8 | 2013.8 |
| Decile 7 | 2010.5 |
| Decile 6 | 2007.5 |
| Median | 2002.5 |
| Decile 4 | 1995.5 |
| Decile 3 | 1983.6 |
| Decile 2 | 1970 |
| Decile 1 | 1959.6 |
| Minimum | 1938.8 |
|
|
- Mean = 1994.36
- Std.dev = 21.4115
- 9 items have value -3 (Preferred not to answer)
- 4367 items have value -1 (Date uncertain or unknown)
|
Instance 3 : First repeat imaging visit (2019+)
3,651 participants, 13,542 items
| Maximum | 2021.5 |
| Decile 9 | 2018.5 |
| Decile 8 | 2015.5 |
| Decile 7 | 2010.5 |
| Decile 6 | 2005.5 |
| Median | 1997.6 |
| Decile 4 | 1985.5 |
| Decile 3 | 1973.2 |
| Decile 2 | 1966 |
| Decile 1 | 1959 |
| Minimum | 1940.1 |
|
|
- Mean = 1991.65
- Std.dev = 22.9288
- 433 items have value -1 (Date uncertain or unknown)
|
Notes
This is the interpolated time when the participant indicated the corresponding condition was first diagnosed by a doctor, measured in years.
- If the participant gave a calendar year, then the best-fit time is half-way through that year. For example if the year was given as 1970, then the value presented is 1970.5
- If the participant gave their age then the value presented is the fractional year corresponding to the mid-point of that age. For example, if the participant said they were 30 years old then the value is the date at which they were 30years+6months.
- Interpolated values before the date of birth were truncated forwards to that time.
- Interpolated values after the time of data acquisition were truncated back to that time.
Coding 13 defines 2 special values:
- -1 represents "Date uncertain or unknown"
- -3 represents "Preferred not to answer"
