# Office for National Statistics (ONS) Longitudinal Study

```Office for National Statistics (ONS) Longitudinal Study
(aggregated data)
Unit of observation (before aggregation): LS sample member
Number of observations (before aggregation): 314,493
Sample selection criteria: The dataset includes all LS members who:

were enumerated at both of the most recent Censuses (1991 and 2001), and:

reported that they were without a limiting long term illness in 1991, and:

gave a valid response on whether they had a limiting long term illness in 2001, and:

were aged 20 years or more in 2001.
To analyse this aggregated dataset using STATA:
[fweight=cascount]
to every analytical command. For example:
bys agegrp0: ta gender [fweight=cascount], nolab
The results will be exactly the same as they would if you were using a non-aggregated dataset.
To analyse this aggregated dataset using SPSS:
Before performing any analyses, run the command:
Weight by cascount.
The results will be exactly the same as they would if you were using a non-aggregated dataset.
List of variables and values:
GENDER
Value label
1
2
Male
Female
AGEGRP0
Age group in 2001
Value label
1
2
3
4
20-34 years
35-49 years
50-64 years
65 years or over
Frequency
(before
aggregation)
148, 830
165, 663
Frequency
(before
aggregation)
80, 638
94, 880
79, 670
59, 305
PARTNER9
Whether has partner in 1991
Value label
0
1
No partner 1991 or not known
Has partner 1991
PARTNER0
Whether has partner in 2001
Value label
0
1
No partner 2001 or not known
Has partner 2001
ECONACT9
Economic activity 1991
Value label
1
2
3
Working
Retired, disabled, aged 65+
Not working or not known
ECONACT0
Economic activity 2001
Value label
Frequency
(before
aggregation)
126, 285
188, 208
Frequency
(before
aggregation)
119, 995
194, 498
Frequency
(before
aggregation)
189, 160
33, 144
92, 189
Frequency
(before
aggregation)
179, 986
78, 913
55, 594
1
2
3
Working
Retired, disabled, aged 65+
Not working or not known
LLTI0
Whether has limiting long term illness 2001
Value label
Frequency
(before
aggregation)
No LLTI
259, 717
Has LLTI
54, 776
0
1
CASCOUNT
Number of cases in a category (variable used for analysis, frequency not shown)
Cleared by Office for National Statistics: clearance numbers LS30041P, LS30041S &amp; LS30041U
```