Data
1,239,546 items of data are available, covering 391,819 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 | 2023.4 |
| Decile 9 | 2009.4 |
| Decile 8 | 2007.5 |
| Decile 7 | 2005.5 |
| Decile 6 | 2002.7 |
| Median | 1999.5 |
| Decile 4 | 1995.5 |
| Decile 3 | 1988.5 |
| Decile 2 | 1978.5 |
| Decile 1 | 1965.4 |
| Minimum | 1912.5 |
|
|
- Mean = 1993.62
- Std.dev = 17.2252
- 1 item below graph minimum of 1921.4
- 238 items have value -3 (Preferred not to answer)
- 44810 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
374,939 participants, 902,062 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 | 1912.5 |
|
|
- Mean = 1994.08
- Std.dev = 15.2015
- 1 item below graph minimum of 1931.2
- 222 items have value -3 (Preferred not to answer)
- 32274 items have value -1 (Date uncertain or unknown)
|
Instance 1 : First repeat assessment visit (2012-13)
17,004 participants, 54,870 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 = 18.1882
- 5 items have value -3 (Preferred not to answer)
- 819 items have value -1 (Date uncertain or unknown)
|
Instance 2 : Imaging visit (2014+)
53,038 participants, 217,897 items
| Maximum | 2023.4 |
| Decile 9 | 2017.5 |
| Decile 8 | 2014.5 |
| Decile 7 | 2010.5 |
| Decile 6 | 2005.8 |
| Median | 1999.4 |
| Decile 4 | 1988.5 |
| Decile 3 | 1974.5 |
| Decile 2 | 1965.5 |
| Decile 1 | 1957.9 |
| Minimum | 1938.8 |
|
|
- Mean = 1992.01
- Std.dev = 23.0552
- 11 items have value -3 (Preferred not to answer)
- 10829 items have value -1 (Date uncertain or unknown)
|
Instance 3 : First repeat imaging visit (2019+)
4,867 participants, 19,669 items
| Maximum | 2023.4 |
| Decile 9 | 2018.5 |
| Decile 8 | 2015.5 |
| Decile 7 | 2010.5 |
| Decile 6 | 2003.5 |
| Median | 1994.5 |
| Decile 4 | 1980.5 |
| Decile 3 | 1970.6 |
| Decile 2 | 1964.2 |
| Decile 1 | 1957.8 |
| Minimum | 1940.1 |
|
|
- Mean = 1990.19
- Std.dev = 23.6575
- 888 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"
