| 1. |
The following conventions
have been used in tables: |
| |
- |
No observations
(zero value) |
| |
0 |
Non-zero values
of less than 0.5% and thus rounded to zero |
| |
[ ] |
Normally used to warn of small sample bases, if the
unweighted base is less than 50. |
|
|
(If a group's unweighted base is less than 30, data
are normally not shown for that
group.) |
| 2. |
Because of rounding,
row or column percentages may not add exactly to 100%. |
| 3. |
A percentage may be quoted in the text for a single category
that aggregates two or more of the percentages shown in a table.
The percentage for the single category may, because of rounding,
differ by one percentage point from the sum of the percentages in
the table. |
| 4. |
Values for means, medians, percentiles and standard errors
are shown to an appropriate number of decimal places. Standard Error
may sometimes be abbreviated to SE for space reasons, and Standard
Deviation to SD. |
| 5. |
'Missing values' occur for several reasons, including refusal
or inability to answer a particular question; refusal to co-operate
in an entire section of the survey (such as the nurse visit or a
self-completion questionnaire); and cases where the question is
not applicable to the informant. In general, missing values have
been omitted from all tables and analyses. |
| 6. |
The population sub-group to whom each table refers is stated
at the upper left corner of the table. |
| 7. |
Where appropriate, data from the 2002 Health Survey has
been combined with 2001 to increase the base size for comparisons.
Similarly, when comparing trends over time, data from previous years
in the series have sometimes been amalgamated to improve precision.
|
| 8. |
The child sample is weighted to compensate for limiting
the number of children interviewed in a household to two. Data in
all tables that include children have therefore been weighted. The
weighted bases for the child sample have been scaled to the achieved
sample size. |
| 9. |
Both weighted and unweighted sample bases are shown
at the foot of each table. The weighted numbers reflect the relative
size of each group in the population, not numbers of interviews
made, which are shown by the unweighted bases. |
| 10. |
The samples of young adults aged 16-24 in 2001 and 2002
were unweighted. However, in some tables where results for young
adults aged 16-24 are shown alongside results for children, a weighted
base may be shown for young adults as well as for children. Weighted
bases for young adults are purely notional, being identical to the
unweighted bases |
| 11. |
The term 'significant' refers to statistical significance
(at the 95% level) and is not intended to imply substantive importance.
|
