4826.0.55.001 - Occasional Paper: Health Risk Factors - a Guide to Time Series Comparability from the National Health Survey, Australia, 2004  
ARCHIVED ISSUE Released at 11:30 AM (CANBERRA TIME) 16/06/2004   
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SUMMARY COMMENTARY


1. INTRODUCTION

This paper is intended as an indicative guide for users undertaking comparisons of selected health risk factors across the National Health Surveys (NHS) of 1989-90, 1995 and 2001. To enable users to check against their own analysis, crude rates are presented from each survey for alcohol consumption, body mass index (BMI), exercise level, and smoking status. In some instances, there has been a change over time in the wording of questions or associated inclusions, exclusions and prompts. To assist in understanding whether these factors may influence the level of response, questions and other notes on the questionnaire are included. A provisional assessment of the reliability of the NHS time series is given for each selected risk factor from both the trend in risk factor prevalence and the questionnaire differences. This information may help inform decisions on the suitability of using data for particular risk factors for analysis over time.


Throughout this paper, comments are made about the changes between surveys and their expected impact on the comparability of data. These are general comments based on ABS experience in survey development, results of testing, and a preliminary examination of results.



2. BACKGROUND

The 2001 NHS collected information about the health status of Australians, their use of health services and facilities, and health-related aspects of their lifestyle. Previous surveys in the series were conducted in 1989-90 and 1995. Surveys conducted by the ABS in 1977-78 and 1983, while not part of the NHS series, also collected information similar to that obtained in the National Health Surveys. The NHS is now expected to be collected every three years.


Changes to the 2001 NHS design were made to better meet the needs of key users, while maximising the reliability and validity of the data within cost and operational constraints.


Health risk factors have been identified as a key area of interest among clients undertaking across time analysis. This publication will provide users with a resource to assist in making NHS inter-survey comparability for health risk factors across the 1989-90, 1995 and 2001 surveys.



3. COMPARISON OF SURVEY DESIGN AND OPERATION FOR THE 1989-90, 1995 AND 2001 NHS

Understanding the comparability of data from the 2001 NHS with data from the previous National Health Surveys is important for the use of those data when interpreting changes in health characteristics over time. While the 2001 NHS is deliberately the same or similar in many ways to the 1995 NHS (and in part to the 1989-90 NHS), there are important differences in survey methodology and content, definitions, classification, etc. These differences will affect the degree to which data are directly comparable between the surveys, and hence the interpretation of apparent changes over the period from 1989-90 to 2001. This paper presents crude rates for selected health risk factors, and describes the methodological approach used in each survey to 'capture' the data. Issues of coding and classification will also be addressed.


The following table shows general characteristics of the three surveys, and where differences have the potential to affect comparability between surveys. It also provides some general comments as to the likely effects of these differences.

TABLE 1: General Survey Characteristics

Collection method
1989/90 NHS
1995 NHS
2001 NHS(G)
Personal interview with adult respondents;
Personal interview with parents consent for children aged 15-17 years (otherwise a proxy interview);
Proxy interview for children less than 15 years
Personal interview with adult respondents;
Personal interview with parents consent for children aged 15-17 years (otherwise a proxy interview);
Proxy interview for children less than 15 years
Personal interview with adult respondents;
Personal interview with parents consent for children aged 15-17 years (otherwise a proxy interview);
Proxy interview for children less than 15 years.
Self-completion women's health questionnaire for adult female respondentsSelf-completion women's health questionnaire for adult female respondentsSelf-completion women's health questionnaire
for adult female respondents
Self-completion general health & well-being questionnaire for adult respondents (SF 36)

Questionnaires
Household form; Main questionnaire; Women's supplementary questionnaireHousehold form; Main questionnaire; Women's supplementary questionnaire;
General health and well-being questionnaire
Household form; Main adult questionnaire; Main child questionnaire; Women's supplementary questionnaire

Sample coverage
Private and special dwellings
Urban and rural areas
All States and Territories; Additional sample in NSW, Vic and Tas.
Private and special dwellings
Urban, rural and sparsely settled areas
All States and Territories; Additional sample in Vic, SA, NT and ACT
Private dwellings only
Urban and rural areas
All States and Territories; Additional sample in ACT. The NT sample was reduced such that it contributes appropriately to national estimates, but is not large enough to support estimates for the NT.

Sample design/size
All personsAll personsAll children aged 0-6 years, one child 7-17 years, one adult per dwelling
Fully responding H'holds = 22,202
Final sample = 54,576 persons
Response rate = 96.1%
Sub-sampling of some topics.
Fully responding H'holds = 21,787
Final sample = 53,828 persons
Response rate = 91.5%
Sub-sampling of some topics.
Fully responding H'holds = 17,918
Final sample = 26,863 persons
Response rate = 92%

Enumeration period
October 1989 to September 1990January 1995 to January 1996 February 2001 to November 2001
The survey was suspended during a six week period from 28 July to 10 September for the Census of Population and Housing enumeration period.

Collection methodology
Pen and paper questionnaire
Optical Mark Reader and key data entry
Manual coding
Pen and paper questionnaire
Optical Mark Reader and key data entry
Manual coding
Pen and paper questionnaire
Optical Mark Reader and key data entry
Manual coding, supported by Computer Assisted Coding systems.

Main output units
Person
Household, family, income unit
Person
Household, family, income unit
Person
Income unit and some household characteristics (eg: household structure)

Sample design/size

The sample design and size was similar in the 1989/90 and 1995 surveys and any differences in estimates between these two surveys is unlikely to be due to these factors. While the overall sample of households was about 18% lower in 2001 than 1995, the enumeration of selected persons only within households means that the 2001 sample of persons is about half that of the 1995 survey. The 2001 approach enabled a greater spreading of the sample and reduced the effects of clustering of characteristics within households on the final estimates. However the smaller sample in 2001 has the effect of more than doubling the standard errors on estimates as shown below:

TABLE 2: Relative standard errors (%)

Size of estimate: Australia
1995 NHS
2001 NHS(G)

10,000
13.2
30.6
100,000
4.4
9.7
1,000,000
1.3
2.4


As shown in table 2, the lower reliability of similar sized estimates from the 2001 survey should be considered in interpreting apparent changes between the two surveys. It is recommended that apparent changes are tested for 95% confidence intervals to ensure that any changes are not the product of different sample size and design. (For an example of how to calculate 95% confidence intervials, see Appendix A.)


As a result of the sample design, and through the weighting process, survey estimates at the State and part of State level by sex and by broad age group will be the same or very similar to the benchmark populations. Because the characteristics of the sample are not identical to those of the benchmark population (see table 3), some records will receive higher or lower weights than others. As a result, the Relative Standard Error (RSE) on estimates for groups which are affected by this may also be slightly higher or lower than the average RSE shown in the table above. As this will vary between surveys, it is a factor to consider in comparing the 1989/90, 1995 and 2001 data, but its impact on comparability is expected to be small.

TABLE 3: Comparison of weighted estimates to benchmark populations

1989/90 NHS
1995 NHS
2001 NHS
Sex / age (yrs)
% of adults in sample
% of adults in pop'n
% of adults in sample
% of adults in pop'n
% of adults in sample
% of adults in pop'n(a)

Males
48.8
49.4
48.4
49.2
45.6
48.9
Females
51.2
50.6
51.6
50.8
54.4
51.1
18-24
14.3
15.6
13.9
14.2
9.1
12.5
25-34
23.4
22.5
21.9
21.2
19.4
19.8
35-44
21.1
20.6
21.8
20.5
22.7
20.6
45-54
14.3
14.4
17.0
16.7
17.9
18.4
55-64
11.9
11.7
11.0
11.3
12.6
12.7
65-74
9.7
9.7
9.3
10.1
10.1
9.1
75 and over
5.2
5.5
5.1
6.0
8.2
6.9
Persons
100.0
100.0
100.0
100.0
100.0
100.0

(a) Benchmark population as at 30 June 2001.

Partial enumeration of households

In the 1989/90 and 1995 NHS all persons in sampled dwellings were included in the survey, and only records from fully responding households were retained on the data file. This meant that results could be compiled at household, family and income unit level in addition to person level. Because the 2001 survey sub-sampled persons in households (one adult, one child 7-17 years, all children 0-6 years) complete enumeration only occurred in a minority of households, and by definition, only in single adult households. The table below shows the degree of enumeration within households, by household composition.

TABLE 4: Number of Households by Composition and Coverage: 2001 NHS(G)

Household
type
All household members enumerated
All children enumerated (a) but one or more adults not enumerated
All adults enumerated but one or more children not enumerated
One or more adults and one or more children not enumerated
Total

Single person
4 326
na
na
na
4 326
Couple only
6 (b)
4 561
na
na
4 567
Single adult with child(ren)
651
592
378
26
1 647
Couple with child(ren)
683 (b)
3 198
421
1 421
5 723
Other
65
1 455
19
116
1 655
Total - number
5 731
9 806
818
1 563
17 918
Total - per cent
32.0
54.7
4.6
8.7
100.0

(a) Includes households with no children.
(b) Includes households where a spouse was less than 18 years old.


Enumeration period

The 2001 NHS was enumerated over about a ten month period, compared with a 12 month period for the 1995 survey; the 2001 survey was not enumerated in December or January, nor during a 6 week period mid-winter (coinciding with the conduct of the 2001 Census of Population and Housing and the Post Enumeration Survey) (ABS 2003a).

4. OTHER ISSUES AFFECTING COMPARABILITY

In addition to survey design and operation, other factors may influence the way respondents answer questions and therefore, the comparability of surveys over time. Two such factors include context effects and social desirability.

Context effects are the influences on response by accompanying or associated questions. For example, in the 2001 NHS, before the questions on alcohol, respondents were asked certain questions about their nutrition, whereas for 1995 this was not the case. While the affect of this difference is expected to be limited, this may have provided an opportunity for respondents to think about consumption of food and drink, thus resulting in a higher alcohol consumption rate in 2001 when compared to 1995.

A further factor which may affect comparability is social desirability. The reported prevalence of risk factors is complex and dynamic, and directly a function of respondent knowledge and attitudes. This in turn may be influenced by the availability of health services and health information such as public education and awareness. Social desirability has been found to affect how respondents answer questions on some health risk factors. For example, for self-reported data, estimates of height are generally found to be overestimates and for weight, underestimates (ABS 1998). In addition, due to the implementation of promotional campaigns, drinking heavily and smoking may be increasingly less socially desirable and respondents may be under-reporting these activities. Similarly, campaigns to encourage people to exercise more have been introduced in recent years and this may influence respondents to over-report their exercise level. As there is currently no objective way to measure these differences, it is not possible to determine the degree to which social desirability has affected responses to alcohol consumption, smoking status or exercise level.

5. SELECTED HEALTH RISK FACTORS

The criteria used to determine the usefulness of a particular comparison over time are based on both the conceptual consistency between surveys and the plausibility of the trend produced. These assessments should be considered provisional as it is not possible to quantify the effect of changing the questionnaire, independently from the actual change in prevalence of risk factors among respondents over time. Each user is encouraged to take into consideration their own data needs and the purpose for which comparisons are being made before assessing whether the comparisons over time would be legitimate. For each selected risk factor, assessments are made for three inter survey comparisons (1989-90 to 1995, 1995 to 2001 and 1989-90 to 2001) and categorised with the following notations:

  • Acceptable: No significant changes between surveys;
  • Acceptable with limitations: Difficult to quantify the impact of questionnaire changes. Use with caution;
  • Not acceptable: Significant inter survey differences or unexplainable major change in prevalence preclude the reliable use of data for comparison across time.

In addition to the assessments for each health risk factor, notes on the questionnaire design that may have influenced the level of response for the various health risk factors are also provided. Crude rates are provided for users to check against their own analysis to ensure their method of comparability is correct. Where relevant, comments (including information from other sources) are provided to assist in making assessments on the reliability of the comparison over time.

Alcohol

Comparability:
1989/90 and 1995: Acceptable with limitations
1995 and 2001: Acceptable with limitations
1989-90 to 2001: Acceptable with limitations



Questions

1989/90
1995
2001
Q 428
The next few questions are about alcoholic drinks.

In the last seven days have you had any drinks at all that contain alcohol, including home made wine and beer?
Q 219
The next few questions are about alcoholic drinks.

How long ago did you last have an alcoholic drink?
  • 1 week or less
  • More than 1 week to less that 2 weeks
  • 2 weeks to less than a month
  • 1 month to less than 3 months
  • 3 months to less than 12 months
  • 12 months or more
  • Never
  • Don't remember
Q 311
The next few questions are about alcoholic drinks.

Some people may drink more or less than others, depending on their lifestyle and individual choices.

How long ago did you last have an alcoholic drink?
  • 1 week or less
  • More than 1 week to less that 2 weeks
  • 2 weeks to less than 1 month
  • 1 month to less than 3 months
  • 3 months to less than 12 months
  • 12 months or more
  • Never
  • Don't remember
Q 429
How long ago did you last have an alcoholic drink?
  • More than one week to less than 1 month ago
  • 1 month to less than 3 months ago
  • 3 months to less than 12 months ago
  • 12 months or more ago
  • Never
Q 222
On which days in the last seven did you have drinks that contained alcohol?
Q 312
On which days in the last 7, did you have drinks that contained alcohol?
Q 432
Did you have any drinks that contained alcohol on (specify each day of week starting from yesterday)?
Q 224
What did you have to drink on (specify day) (up to the last 3 days alcohol was consumed)?
(Interviewer: prompt for quantity if not given)
Q 314B
What did you have to drink on (specify day)?
(Interviewer: prompt for quantity and brand type if not given)
Q 433
Interviewer: for each day on which respondent drank, ask both questions below.

What kind of drinks did you have on (specify day)?
How much (specify drink) did you have on (specify day)?
Q 225
Is the amount you drank last week more, less or about the same compared to most weeks? (more/less/about the same)
Q 318
Is the amount you drank last week more, about the same, or less, compared to most weeks? (more/about the same/less)
Q 459
Is the amount you drank last week more, less or about the same as you would drink most weeks? (more/less/about the same)

Population


1989/90
1995
2001
18 + yearsPersons aged 18 years or more who were not selected in the sub-sample to complete the General Health and Wellbeing Questionnaire. It should be noted that the weight for the non-General Health and Wellbeing sample should be used for obtaining estimates. Refer to the 1995 National Health Survey User's Guide for more information.18 + years

Description

1989/90
1995
2001
Collected detailed consumption information for 7 days prior to interview.Collected detailed consumption data for the 3 most recent drinking days in the past 7 days prior to interview and extrapolated to 7 days based on number of drinking days.Collected detailed consumption data for the 3 most recent drinking days in the past 7 days prior to interview and extrapolated to 7 days based on number of drinking days.

Collection Method

1989/90
1995
2001
Self reports. Adult respondents were asked the questions above.Self reports. Adult respondents were asked the questions above.Self reports. Adult respondents were asked the questions above.
Reported quantities of drinks were converted during office processing to millilitres of alcohol present in those drinks. For this purpose, a computer assisted coding system was developed. Coders could access the system via brand name or drink type and by entering the quantity and size of drinks, the system would calculate the quantity of alcohol consumed. This system covered common drinks (including common mixed drinks and cocktails) and common quantity measures.

Where precise brand information was not recorded, the coding system used default alcohol content values based on drink type. These values are shown below and the amount (in mls) of beverage consumed was multiplied by the values below to obtain pure alcohol consumption (in mls).



Calculations

1989/90
1995
2001
special/extra light beer 0.009
low alcohol beer 0.022
full-strength beer 0.048
stout 0.079
wine coolers 0.040-0.060
low alcohol wines 0.010
reduced/light alcohol wine 0.050
fortified wines 0.185
other wines 0.115
spirits 0.385
pre mixed spirits 0.057
alcoholic cider 0.050
cocktails (various as per listing)
other alcoholic 0.115
special/extra light beer 0.009
low alcohol beer 0.027
full-strength beer 0.049
stout 0.058
coolers 0.035-0.055
low alcohol wines 0.061
reduced/light alcohol wine 0.065
fortified wines 0.179
white wine 0.124
red wine 0.127
sparkling/champagne 0.119
spirits 0.385
liqueurs 0.200
pre mixed drinks 0.060
alcoholic cider 0.047
extra strong cider 0.083
cocktails (various as per listing)
other alcoholic 0.127
light beer 0.027
mid-strength beer 0.035
full-strength beer 0.049
stout 0.058
wine coolers 0.035
low alcohol wines 0.090
fortified wines 0.179
white wine 0.124
red wine 0.133
sparkling/champagne 0.119
spirits 0.385
liqueurs 0.200
pre mixed drinks 0.050
alcoholic cider 0.047
extra strong cider 0.075
cocktails (various as per listing)
other alcoholic 0.274

Context effects

1989/90
1995
2001
Alcohol topic is preceded by smoking status topicAlcohol topic is preceded by smoking status topicAlcohol topic is preceded by nutrition topic
The different contexts of the preceding topics is expected to cause minimal effect.

Alcohol risk level ranges
The following output categories were used at the time of each survey.

1989/90
1995
2001
Relative risk
Consumption per day
Relative risk
Consumption per day
Relative risk
Consumption per day
Male
Female
Male
Female
Male
Female
Did not consume
0ml
0ml
Did not consume
0ml
0ml
Did not consume
0ml
0ml
Low
<50ml
<25ml
Low
<50ml
<25ml
Low risk
<50ml
<25ml
Medium
50-75ml
25-50ml
Medium
50-75ml
25-50ml
Risky
>50-75ml
>25-50ml
High
>75ml
>50ml
High
>75ml
>50ml
High risk
>75ml
>50ml



Crude rate percentages for alcohol risk level based on 2001 alcohol risk level ranges (see above), persons aged 18 years and over


1989/90
1995
2001



Males
Did not consume%
26.5
    Males
    Did not consume %

34.2
    Males
    Did not consume %
28.6
Low risk %
58.8
    Low risk %
55.3
    Low risk %
58.1
Risky %
7.7
    Risky %
5.5
    Risky %
6.9
High risk %
7.1
    High risk %
5.0
    High risk %
6.4
Total %
100.0
    Total %
100.0
    Total %
100.0
Females
Did not consume%
48.2
    Females
    Did not consume%
54.6
    Females
    Did not consume%
47.7
Low risk %
44.4
    Low risk %
39.3
    Low risk %
43.9
Risky %
5.8
    Risky %
4.8
    Risky %
6.6
High risk %
1.6
    High risk %
1.3
    High risk %
1.9
Total %
100.0
    Total %
100.0
    Total %
100.0



Comparability
1989/90
1995
2001
Comparisons with 2001 appear acceptable. However, changes in methodolody have produced some minor differences. Analysis has shown that the three day method results in a less than 1% increase in the risky and high risk categories when compared to the 7 day method.While the methodology for 1995 and 2001 is very similar, percentage estimates for 1995 are quite different from those of 2001. For 1995, there appears to be relatively more persons in the 'did not consume alcohol' category and less persons in the 'risky' and 'high risk' categories when compared to those for 2001. This pattern is consistent across age groups in 1995 estimates, but is not present in 1989/90 data. This change may be due to the addition of the introductory statement in 2001, "Some people may drink more or less than others depending on their lifestyle and individual choices". This statement was originally designed to decrease the effect of social desirability and hence, an increase in risky/high risk drinking in 2001 would be expected.Comparisons with 1989–90 appear acceptable (see comments for more details).

Comments

1989/90
1995
2001
Although the reference period for this survey was for seven days prior to interview as opposed to the 3 most recent drinking days in the past seven days (as was the case for the 2001 survey), conceptually the methods are identical and the changes do not produce a significant bias.The reference period in this survey was the 3 most recent drinking days in the past seven days as opposed to the whole seven days in 1989–90. The reference period in this survey was the 3 most recent drinking days in the past seven days as opposed to the whole seven days in 1989–90.



Body mass index

Comparability:
1989/90 and 1995: Acceptable
1995 and 2001: Acceptable
1989-90 to 2001: Acceptable
Questions

1989/90
1995
2001
Q 390
How tall are you without shoes? (Answered either in centimetres or feet/inches or don't know)
Q 203
How tall are you without shoes? (Answered either in centimetres or feet/inches or don't know)
Q 205
How much do you weigh? (Answered in either kilograms, stone/pounds, pounds or don't know)
Q 391
How much do you weigh without clothes and shoes? (Answered in either kilograms, stone/pounds, pounds or don't know)
Q 204
How much do you weigh? (Answered in either kilograms, stone/pounds, pounds or don't know)
Q 206
How tall are you without shoes? (Answered either in centimetres or feet/inches or don't know)

Population
BMI calculated for respondents who were 15 + years

Collection method

1989/90
1995
2001
Self report of weight and height without shoes. Pregnant women were to report weight prior to pregnancy. Self report of weight and height without shoes. Pregnant women were to report weight prior to pregnancy. Self report of weight and height without shoes. Pregnant women were to report weight prior to pregnancy.

Context Effects

1989/90
1995
2001
BMI topic was preceded by exercise topicBMI topic was preceded by self-assessed health topicBMI topic was preceded by self-assessed health topic
The different contexts of the preceding topics is expected to cause minimal effect.

BMI (kg/ m2) ranges
The following output categories were used at the time of each survey.

1989/90
1995
2001
Underweight<20Underweight<20Underweight< 18.5
Acceptable Weight20-25Acceptable Weight20-25Normal Range18.5 - <20
Overweight26-30Overweight26-3020 - <25
Obese>30Obese>30Overweight25 - <30
Obese>= 30


Crude rate percentages of BMI using 2001 ranges, persons aged 15 years and over
The following are based on ranges at the time of 2001 enumeration.


1989/90
1995
2001



Males
Underweight %
2.6
    Males
    Underweight %
2.0
    Males
    Underweight %
1.8
Normal range (18.5-<20) %
5.4
    Normal range (18.5-<20) %
3.5
    Normal range (18.5-<20) %
2.9
Normal range (20-<25) %
47.6
    Normal range (20-<25) %
41.0
    Normal range (20-<25) %
36.8
Overweight %
33.7
    Overweight %
35.7
    Overweight %
38.1
Obese %
7.8
    Obese %
10.5
    Obese %
14.2
Not Stated %
2.9
    Not Stated %
7.3
    Not Stated %
6.1
Total %
100.0
    Total %
100.0
    Total %
100.0
Females
Underweight %
7.2
    Females
    Underweight %
5.2
    Females
    Underweight %
4.8
Normal range (18.5-<20) %
11.5
    Normal range (18.5-<20) %
9.1
    Normal range (18.5-<20) %
8.6
Normal range (20-<25) %
48.3
    Normal range (20-<25) %
43.0
    Normal range (20-<25) %
39.7
Overweight %
19.7
    Overweight %
20.4
    Overweight %
22.1
Obese %
8.6
    Obese %
10.3
    Obese %
14.6
Not Stated %
4.7
    Not Stated %
12.1
    Not Stated %
10.2
Total %
100.0
    Total %
100.0
    Total %
100.0



Comparability

1989/90
1995
2001
Yes
Yes
Yes

Comments
In interpreting data for this topic, users should be aware that the data are 'self-reported' by respondents and hence may differ from those which might be obtained by measurement. Previous studies have indicated that people tend to under report their weight and overestimate their height. For more information, refer to the ABS publication How Australians Measure Up, ABS Cat. No. 4359.0.

No data is available for remote areas in the 1995 NHS.

Note: There are differences in classification of BMI between 1989/90, 1995 and 2001.

2001 NHS meets both the NHMRC and WHO's classification of BMI.


Exercise level

Comparability:
1989/90 and 1995: Acceptable
1995 and 2001: Acceptable
1989-90 to 2001: Acceptable

Questions
1989-90
1995
2001
Q 380.
I now want to ask you about exercise you may do for sport, recreation or fitness.

In the last two weeks did you do any walking for exercise or recreation?
Q 205.
In the last two weeks have you walked for sport, recreation or fitness?
Q 207.
In the last 2 weeks, have you walked for sport, recreation or fitness?
Q 381.
How many times did you walk in the last two weeks?
Q 206.
How many times did you walk in the last two weeks?
Q 208.
How many times did you walk in the last 2 weeks?
382.
What was the total amount of time you spent walking in the last two weeks?
Q 207.
What was the total amount of time you spent walking in the last two weeks?
Q 209.
What was the total amount of time you spent walking in the last 2 weeks?
Q 383.
I will now ask you about moderate exercise and vigorous exercise apart from walking.

In the last two weeks did you do any exercise which caused a moderate increase in your heart rate or breathing?
Q 208.
I will now ask you about moderate and vigorous exercise apart from walking.

In the last two weeks did you do any exercise which caused a moderate increase in your heart rate or breathing?
Q 210.
I will now ask you about moderate and vigorous exercise apart from walking.

In the last 2 weeks, did you do any exercise which caused a moderate increase in your heart rate or breathing, that is, moderate exercise?
Q 384.
How many times did you do any moderate exercise in the last two weeks?
Q 209.
How many times did you do any moderate exercise in the last two weeks?
Q 211.
How many times did you do any moderate exercise in the last 2 weeks?
Q 385.
What was the total amount of time you spent doing moderate exercise in the last two weeks?
Q 210.
What was the total amount of time you spent doing moderate exercise in the last two weeks?
Q 212.
What was the total amount of time you spent doing moderate exercise in the last 2 weeks?
Q 386.
In the last two weeks did you do any exercise which caused a large increase in your heart rate or breathing, that is, vigorous exercise?
Q 211.
In the last two weeks did you do any (other) exercise which caused a large increase in your heart rate or breathing, that is, vigorous exercise?
Q 213.
In the last 2 weeks, did you do any (other) exercise which caused a large increase in your heart rate or breathing, that is, vigorous exercise?
Q 387.
How many times did you do any vigorous exercise in the last two weeks?
Q 212.
How many times did you do any vigorous exercise in the last two weeks?
Q 214.
How many times did you do any vigorous exercise in the last 2 weeks?
Q 388.
What was the total amount of time you spent doing vigorous exercise in the last two weeks?
Q 213.
What was the total amount of time you spent doing vigorous exercise in the last two weeks?
Q 215.
What was the total amount of time you spent doing vigorous exercise in the last 2 weeks?

Population

1989-90
1995
2001
15+ years
15+ years
15+ years

Collection Method
1989-90
1995
2001
Asked about frequency/ duration of walking, moderate & vigorous exercise in last two weeks.
Measured in minutes
Asked about frequency/ duration of walking, moderate & vigorous exercise in last two weeks.
Measured in minutes
Asked about frequency/ duration of walking, moderate & vigorous exercise in last 2 weeks.
Measured in minutes


Calculations - Scores for Exercise Intensity

1989-90
1995
2001
3.2 for walking,
5.7 for moderate exercise, and
8.5 for vigorous exercise.
3.5 for walking,
5.0 for moderate exercise, and
9.0 for vigorous exercise.
3.5 for walking,
5.0 for moderate exercise, and
7.5 for vigorous exercise.


Context effects
The different contexts of the preceding topics is expected to cause minimal effect.
1989-90
1995
2001
Exercise level topic is preceded by nutrition topicExercise level topic is preceded by body mass index topicExercise level topic is preceded by body mass index topic



Scores for Exercise Level
The following output categories were used at the time of each survey. Scores for exercise level are calculated by the following formula:
Number of times activity undertaken in past 2 weeks X Average time per session (in minutes) X Intensity

1989-90
1995
2001
Low level<1500Sedentary<100Sedentary <100 (including no exercise)
Moderate level1500-<=3250 Low level100 <1600low level100 <1600
High level>3250 Moderate level1600 - 3200 or >3200 and <2 hours vigorous exercise.Moderate level1600 - 3200 or >3200 and <2 hours vigorous exercise.
High level>3200 and 2 hours or more of vigorous exerciseHigh level>3200 and 2 hours or more of vigorous exercise

Crude rate percentages for exercise level using 2001 ranges, persons aged 15 years and over


1989-90
1995
2001



Males
Sedentary %
34.6
    Males
    Sedentary %
33.1
    Males
    Sedentary %
30.0
Low %
29.2
    Low %
31.1
    Low %
33.6
Moderate %
25.5
    Moderate %
26.5
    Moderate %
26.4
High %
10.7
    High %
9.3
    High %
10.0
Total %
100.0
    Total %
100.0
    Total %
100.0
Females
Sedentary %
36.0
    Females
    Sedentary %
34.4
    Females
    Sedentary %
32.0
Low %
37.3
    Low %
39.0
    Low %
41.3
Moderate %
22.4
    Moderate %
22.2
    Moderate %
22.5
High %
4.4
    High %
4.4
    High %
4.3
Total %
100.0
    Total %
100.0
    Total %
100.0


Comparability

1989-90
1995
2001
Yes (refer comments)
Yes
Yes

Comments
1989-90
1995
2001
Due to change in scores for exercise intensity and scores for exercise level cut-offs, the categorised levels of exercise between 1989/90 and 1995 are not directly comparable.Scores for exercise intensity changed between 1995 and 2001.

General Comments
While the derived item cut-offs and the continuous scale scores for exercise level changed between 1989/90, 1995 and 2001, the ability to rederive new data items based on the new cut-offs remains. Therefore it is possible to derive a new data item based on the new score cut-offs for 1989/90 (thus enabling comparability across all three surveys).



Smoking status

Comparability:
1989/90 and 1995: Acceptable
1995 and 2001: Acceptable
1989-90 to 2001: Acceptable

Questions used in Survey

1989/90
1995
2001
Q 401.
I would now like to ask you some questions about smoking.
Do you currently smoke?
Q 215.
I would now like to ask you some questions about smoking.
Do you currently smoke?
Q 220.
I would now like to ask you some questions about smoking.
Do you currently smoke?
Q 402.
Do you smoke -
  • cigarettes?
  • cigars?
  • or a pipe?
Q 216.
Do you smoke regularly, that is, at least once a day?
Q 221.
Do you smoke regularly, that is, at least once a day?
Q 403.
How old were you when you started smoking regularly?
Q 217.
Have you ever smoked regularly (that is, at least once a day)?
Q 222.
Have you ever smoked regularly (that is, at least once a day)?
Q 405.
Do you usually smoke packet cigarettes or roll-your-own cigarettes?
Q 224.
Does anyone else in this household smoke regularly, that is at least once a day?
Q 406.
How many cigarettes do you usually smoke a day?
Q 225.
How many other people in this household smoke regularly?
Q 407.
Have you ever tried to give up smoking cigarettes?
Q 408.
What is the tar content of your cigarettes?
Q 409.
What is the nicotine content of your cigarettes?
Q 413.
Have you ever smoked regularly?
Q 414.
Did you smoke -
  • cigarettes?
  • cigars?
  • a pipe?
Q 415.
How old were you when you started smoking regularly?
Q 417.
Have you ever smoked cigarettes regularly?
Q 418.
Did you usually smoke packet cigarettes or roll your own cigarettes?
Q 419.
How many cigarettes did you usually smoke a day?
Q 420.
How old were you when you last gave up smoking cigarettes?
Q 421.
Why did you give up smoking cigarettes?
  • advice of family/friend/doctor (Why did ____ advise you to give up?
  • Health (Interviewer ask: what particular aspect of health do you mean?)
  • smoking harmful to health /cancer /lung disease/heart disease
  • cough/sore throat
  • reduces fitness/restricts activity
  • other health reasons eg. operations, pregnancy
  • Offensive to others
  • Expense
  • Lost interest/didn't feel like it anymore
  • Other reasons
Q 423.
Which was the main reason for giving up smoking cigarettes (Enter code from 421)
Population

1989/90
1995
2001
18 + years
18 + years
18 + years


Collection method

1989/90
1995
2001
Respondents were asked questions about smoking whether current or ex-smoker. Any cigarette which is lit was counted as smoked, even if only one puff was taken.Respondents were asked questions about smoking. Respondents were asked questions about smoking. In addition, respondents were asked whether anyone else in the household smoked regularly, and if so, the number of people.


Context effects
The different contexts of the preceding topics is expected to cause minimal effect.
1989/90
1995
2001
Smoking status topic was preceded by rubella topicSmoking status topic was preceded by exercise topicSmoking status topic was preceded by exercise topic


Crude rate percentages smoking status, persons aged 18 years and over


1989/90
1995
2001



Males
Smoker %
32.1
    Males
    Smoker %
29.2
    Males
    Smoker %
27.6
Ex-smoker %
28.8
    Ex-smoker %
31.1
    Ex-smoker %
30.3
Never smoked %
39.1
    Never smoked %
39.6
    Never smoked %
42.0
Total %
100.0
    Total %
100.0
    Total %
100.0
Females
Smoker %
24.7
    Females
    Smoker %
22.0
    Females
    Smoker %
21.1
Ex-smoker %
17.8
    Ex-smoker %
21.5
    Ex-smoker %
22.4
Never smoked %
57.4
    Never smoked %
56.5
    Never smoked %
56.4
Total %
100.0
    Total %
100.0
    Total %
100.0



Comparability

1989/90
1995
2001
Yes
Yes
Yes

Comments

1989/90
1995
2001
Data collected in 1995 were not as detailed as data collected in 1989/90 and 2001.Collection method different to 1995 NHS and may include persons aged less than 18 years old due to the question "How many other people in the household smoke regularly?"


General Comments
Data not available for remote areas in 1995 NHS.

Data on smoking status are generally considered directly comparable so long as the same items are being compared.


6. REFERENCES

ABS 2003a, National Health Survey, Australia, 2001 Users' Guide, cat. no. 4816.0.55.001 last viewed 14 May 2004.


ABS 2003b. Occasional paper: long-term health conditions: a guide to time series comparability from the National Health Survey, Australia, cat. no. 4816.0.55.001 last viewed 14 May 2004.


ABS 1998. How Australian's Measure Up, cat. no. 4359.0.


ABS 1996, National Health Survey, Australia, 1995 Users' Guide, cat. no. 4363.0


ABS 1992, National Health Survey, Australia, 1989-90 Users' Guide, cat. no. 4363.0



7. ATTACHMENT A

RELIABILITY OF ESTIMATES

Measuring sample variability

Since the estimates produced from data from the National Health Surveys are based on information obtained from a sub-sample of usual residents of a sample of dwellings, they are subject to sampling variability. That is, they may differ from those that would have been produced if all usual residents of all dwellings had been included in the survey. One measure of the likely difference is given by the standard error (SE), which indicates the extent to which an estimate might have varied by chance because only a sample of dwellings was included. There are about two chances in three that a sample estimate will differ by less than one SE from the number that would have been obtained if all dwellings had been included, and about 19 chances in 20 that the difference will be less than two SEs. Another measure of the likely difference is the relative standard error (RSE), which is obtained by expressing the SE as a percentage of the estimate.


CALCULATION OF STANDARD ERRORS

Tables of SEs and RSEs for estimates of numbers of persons appears at the end of this appendix. These figures will not give a precise measure of the SE for a particular estimate but will provide an indication of its magnitude.


An example of the calculation and the use of SEs in relation to estimates of persons is as follows. Consider the estimate for Australia in the 2001 National Health Survey of women aged 18 years and over who reported being current smokers (1,530,200). Since this estimate (1,530,200) is between 1,000,000 and 2,000,000 in the SE table for 2001, the SE will be between 24,000 and 30,000 and can be approximated by linear interpolation (see below) as 27,200 (rounded to the nearest 100). Therefore, there are about two chances in three that the value that would have been produced if all dwellings had been included in the survey will fall in the range 1,503,000 to 1,557,400 and about 19 chances in 20 that the value will fall within the range 1,475,800 to 1,584,600.


As can be seen from the SE tables at the end of this appendix, the smaller the estimate the higher the RSE. Very small estimates are thus subject to such high RSEs as to detract seriously from their value for most reasonable uses. Only estimates with RSEs of less than 25% are considered sufficiently reliable for most purposes. Estimates with larger RSEs should be used with caution and estimates with RSEs greater than 50% are considered too unreliable for general use.


How to interpolate between the estimates for SE tables


To interpolate between the estimates for SE tables the following formula is used:

    Equation: Interpolation of RSE


Example: To find the RSE% for the estimate of female current smokers aged 18 or more in 1995 (1,496,300), linear interpolation was used between the two adjacent estimates.


The estimate 1,496,300 lies between:

      ESTIMATE
RSE%
      1,000,000
1.3
      2,000,000
0.9

The RSE% for an estimate is:

      Equation: SE of estimate

where

      x = estimate corresponding to lower RSE%
      y = actual estimate
      z = estimate corresponding to upper RSE%

RSE% for an estimate of 1,496,300 is:

      = 0.9 + (1,496,300 - 2,000,000) / (1,000,000 - 2,000,000) x (1.3 - 0.9)
      = 0.9 + (503,700 / 1,000,000) x 0.4
      = 1.1

PROPORTIONS AND PERCENTAGES

Proportions and percentages formed from the ratio of two estimates are also subject to sampling errors. The size of the error depends on the accuracy of both the numerator and denominator. A formula to approximate the RSE of a proportion is given below:

      Equation: RSE of proportion

Using this formula, the RSE of the estimated proportion will be lower than the RSE estimate of the numerator. Therefore an approximation for RSEs of proportions may be derived by neglecting the RSE of the denominator - i.e. obtaining the RSE of the number of persons corresponding to the numerator of the proportion and then applying this figure to the estimated proportion.


This formula can also be used to determine whether the confidence intervals of two proportions from two different National Health Surveys overlap. A confidence interval is a statement to the effect that the true value for a population lies within a given range of values at a specified level of confidence.


For example, in order to determine whether the crude smoking rate for women in 2001 was likely to be different from that in 1995, the following calculations can be made.


First, determine an approximation of RSEs for the two proportions. This will be done by neglecting the RSE of the denominator as suggested above.


Crude smoking rate in 2001 is:

      1,530,300 / 7,238,300 x 100 = 21.1%.

      RSE of 1,530,300 = 1.8%


Crude smoking rate for women in 1995 is

      1,496,300/6,799,200 x 100 = 22.0%
      RSE of 1,496,300 = 1.1

Now the 95% confidence interval is determined using the following formula:

      Equation: 95% confidence interval
      (where p1 = the proportion)

For the crude smoking rate of women in 2001...


lower 95% confidence limit = 21.1 - (21.1 x 0.018 x 1.96)

      = 21.1 - 0.7
      = 20.4%

upper 95% confidence limit = 21.1 + (21.1 x 0.018 x 1.96)

      = 21.1 + 0.7
      = 21.8%

Therefore, we can be 95% confident that the true crude smoking rate for 2001 is between 20.4% and 21.8%.


For the crude smoking rate for women in 1995...


lower 95% confidence limit = 22.0 - (22.0 x 0.011 x 1.96)

      = 22.0 - 0.5
      = 21.5%

The upper confidence limit = 22.0 + (22.0 x 0.011 x 1.96)

      = 22.0 + 0.5
      = 22.5

Therefore, we can be 95% confident that the true crude smoking rate of women for 1995 lies between 21.5% and 22.5%.


Now, by considering the two confidence intervals it can be seen that the intervals overlap. Therefore, we cannot be confident that there is a true difference between the two proportions and we cannot conclude that the true smoking rate in 2001 was higher than in 1995. Using this method, in order for there to be a difference between two estimates, the lower confidence limit of one proportion would need to be higher than the higher confidence limit of the other proportion. That is, the confidence intervals of the two proportions would not overlap.


Published estimates may also be used to calculate the difference between two survey estimates (numbers or percentages). Such an estimate is subject to sampling error. The sampling error of the difference between the two estimates depends on their SEs and the relationship (correlation) between them. An approximate SE of the difference between two estimates (p1-p2) may be calculated by the following formula:

      Equation: RSE of proportion

While this formula will only be exact for differences between separate and uncorrelated characteristics of sub-populations, it is expected to provide a reasonable approximation for all differences likely to be of interest.


The imprecision due to sampling variability, which is measured by the SE, should not be confused with inaccuracies that may occur because of imperfections in reporting by respondents, recording by interviewers, and errors made in coding and processing data. Inaccuracies of this kind are referred to as non-sampling error, and they may occur in any enumeration, whether it be a full count or a sample. Every effort is made to reduce non-sampling error to a minimum by careful design of questionnaires, intensive training and supervision of interviewers, and efficient operating procedures.

STANDARD ERRORS FOR PERSON ESTIMATES, NATIONAL HEALTH SURVEY 2001

STANDARD ERROR
AUSTRALIA
NSW
Vic.
Qld
SA
WA
Tas.
ACT
Standard error
Relative standard error
Size of estimate
no.
no.
no.
no.
no.
no.
no.
no.
%

500
520
488
499
404
438
342
268
468
93.7
1,000
848
782
777
647
686
526
397
750
75.0
1,500
1,113
1,019
997
839
880
666
492
978
65.2
2,000
1,342
1,222
1,184
1,002
1,046
780
570
1,174
58.7
2,500
1,548
1,403
1,350
1,145
1,190
880
635
1,350
54.0
3,000
1,734
1,566
1,500
1,272
1,320
969
693
1,512
50.4
3,500
1,904
1,718
1,638
1,390
1,439
1,047
742
1,659
47.4
4,000
2,064
1,860
1,764
1,496
1,548
1,120
788
1,800
45.0
4,500
2,219
1,989
1,881
1,598
1,652
1,184
832
1,930
42.9
5,000
2,360
2,115
1,995
1,690
1,745
1,245
870
2,055
41.1
6,000
2,622
2,346
2,202
1,866
1,920
1,362
942
2,286
38.1
8,000
3,088
2,752
2,568
2,160
2,232
1,552
1,056
2,696
33.7
10,000
3,500
3,100
2,880
2,420
2,490
1,710
1,160
3,060
30.6
20,000
5,040
4,440
2,060
3,340
3,460
2,260
1,480
4,440
22.2
30,000
6,180
5,400
4,920
3,960
4,140
2,610
1,680
5,490
18.3
40,000
7,080
6,160
5,600
4,440
4,680
2,880
1,840
6,320
15.8
50,000
7,850
6,800
6,200
4,850
5,100
3,100
1,950
7,050
14.1
100,000
10,600
9,100
8,300
6,200
6,600
3,800
2,300
9,700
9.7
200,000
13,800
12,000
10,800
7,600
8,400
4,400
2,600
13,200
6.6
300,000
16,200
13,800
12,600
8,400
9,600
4,800
3,000
15,600
5.2
400,000
17,600
15,200
14,000
8,800
10,400
5,200
2,800
17,600
4.4
500,000
19,000
16,500
15,000
9,500
11,000
. .
. .
19,000
3.8
1,000,000
23,000
20,000
19,000
11,000
13,000
. .
. .
24,000
2.4
2,000,000
28,000
24,000
22,000
. .
. .
. .
. .
30,000
1.5
5,000,000
35,000
. .
. .
. .
. .
. .
. .
40,000
0.8
10,000,000
. .
. .
. .
. .
. .
. .
. .
50,000
0.5
20,000,000
. .
. .
. .
. .
. .
. .
. .
60,000
0.3

. . not applicable

STANDARD ERRORS FOR PERSON ESTIMATES (USING CORE WEIGHTS), NATIONAL HEALTH SURVEY 1995(a)

STANDARD ERROR
AUSTRALIA
NSW
Vic.
Qld
SA
WA
Tas.
NT
ACT
Standard error
Relative standard error
Size of estimate
no.
no.
no.
no.
no.
no.
no.
no.
no.
%

150
. .
. .
. .
. .
. .
. .
. .
. .
. .
. .
200
. .
. .
. .
. .
. .
. .
100
. .
. .
. .
250
. .
. .
. .
. .
. .
. .
120
130
. .
. .
300
. .
. .
. .
. .
. .
. .
130
140
. .
. .
400
. .
. .
. .
. .
. .
. .
160
160
200
50.2
500
. .
. .
. .
. .
. .
. .
190
170
230
46.1
600
. .
. .
. .
. .
. .
. .
210
180
260
43.0
700
. .
. .
. .
. .
. .
380
230
190
280
40.5
800
. .
. .
. .
. .
. .
400
250
200
310
38.4
900
. .
. .
. .
460
. .
410
270
210
330
36.7
1 000
. .
. .
. .
470
. .
420
290
220
350
35.1
1 100
. .
. .
. .
490
. .
440
310
230
370
33.8
1 200
. .
. .
. .
500
. .
450
320
240
390
32.7
1 300
. .
. .
. .
520
. .
460
340
240
410
31.6
1 400
. .
. .
. .
530
730
470
350
250
430
30.7
1 500
. .
. .
. .
540
750
480
370
260
450
29.8
1 600
. .
. .
. .
550
760
490
380
260
460
29.1
1 700
. .
880
. .
560
780
500
400
270
480
28.3
1 800
. .
890
. .
570
800
510
410
270
500
27.7
1 900
. .
910
. .
580
810
510
420
280
510
27.1
2 000
. .
930
. .
590
830
520
440
280
530
26.5
2 100
. .
950
. .
600
840
530
450
290
550
26.0
2 200
. .
960
. .
610
850
540
460
290
560
25.5
2 300
. .
980
. .
620
870
550
470
300
570
25.0
2 400
. .
990
1,230
630
880
550
490
300
590
24.6
2 500
. .
1,010
1,250
640
890
560
500
310
600
24.1
3 000
. .
1,080
1,320
680
950
590
550
330
670
22.3
3 500
1,790
1,140
1,400
720
1,010
630
610
350
730
20.9
4 000
1,880
1,200
1,460
750
1,060
650
650
370
790
19.8
4 500
1,960
1,250
1,520
780
1,100
680
700
380
850
18.8
5 000
2,040
1,300
1,570
810
1,140
700
740
400
900
17.9
6 000
2,190
1,390
1,680
870
1,220
750
820
430
990
16.6
8 000
2,440
1,540
1,850
960
1,360
830
960
470
1,170
14.6
10 000
2,650
1,670
2,000
1,040
1,480
900
1,090
510
1,320
13.2
20 000
3,440
2,160
2,560
1,350
1,920
1,170
1,570
660
1,920
9.6
30 000
4,010
2,520
2,970
1,580
2,240
1,370
1,930
770
2,380
7.9
40 000
4,480
2,800
3,300
1,770
2,510
1,530
2,220
860
2,770
6.9
50 000
4,880
3,050
3,580
1,940
2,740
1,680
2,480
930
3,100
6.2
100 000
6,350
3,960
4,650
2,580
3,620
2,260
3,460
1,210
4,400
4.4
200 000
8,290
5,150
6,080
3,460
4,810
3,080
4,740
1,570
6,190
3.1
300 000
9,700
6,020
7,130
4,120
5,700
3,720
5,660
1,820
7,510
2.5
400 000
10,840
6,720
8,000
4,680
6,440
4,270
6,400
2,030
8,600
2.1
500 000
11,820
7,320
8,750
5,170
7,080
4,750
7,020
2,210
9,540
1.9
1 000 000
15,480
9,570
11,600
7,100
9,570
6,720
9,290
2,860
13,070
1.3
2 000 000
20,310
12,530
15,490
9,850
13,020
9,640
12,110
3,710
17,720
0.9
5 000 000
29,140
17,950
22,940
15,420
19,780
15,920
16,790
5,250
26,070
0.5
10 000 000
38,350
23,620
31,090
21,890
27,360
23,670
21,110
6,820
34,480
0.3
20 000 000
50,540
31,130
42,420
31,400
38,110
35,750
26,150
8,870
45,130
0.2

. . not applicable
(a) The full sample of respondents were sequenced through the 1995 smoking, exercise, and body mass index topics and the core weight is used when calculating the estimates. These standard errors should be used for these topics.
STANDARD ERRORS FOR PERSON ESTIMATES (USING NON-GENERAL HEALTH AND WELLBEING WEIGHTS), NATIONAL HEALTH SURVEY 1995(a)

STANDARD ERROR
AUSTRALIA


NSW
Vic.
Qld.
SA
WA
Tas.
NT
ACT
Standard error
Relative standard error
Size of Estimate
no.
no.
no.
no.
no.
no.
no.
no.
no.
%

100
1,970
550
1,310
400
560
390
60
160
80
80.0
200
2,040
660
1,350
460
640
420
100
200
140
70.0
300
2,100
740
1,400
500
690
450
130
220
190
63.3
500
2,210
860
1,480
560
780
490
200
260
280
56.0
700
2,310
950
1,550
610
860
520
250
290
350
50.0
1,000
2,430
1,060
1,640
670
940
570
320
320
450
45.0
1,500
2,600
1,210
1,760
750
1,060
630
410
370
590
39.3
2,000
2,740
1,330
1,860
820
1,160
680
500
420
710
35.5
2,500
2,850
1,450
1,950
900
1,250
750
550
450
800
32.0
3,000
3,000
1,500
2,050
950
1,350
800
650
500
900
30.0
3,500
3,100
1,600
2,100
1,000
1,400
800
700
500
1,000
28.6
4,000
3,200
1,700
2,150
1,050
1,450
850
750
550
1,100
27.5
5,000
3,350
1,800
2,300
1,100
1,600
900
850
600
1,250
25.0
7,000
3,650
2,050
2,500
1,250
1,800
1,050
1,050
700
1,550
22.1
10,000
4,000
2,350
2,800
1,450
2,050
1,200
1,250
800
1,900
19.0
15,000
4,550
2,700
3,150
1,700
2,400
1,450
1,600
950
2,400
16.0
20,000
4,950
3,050
3,450
1,900
2,750
1,650
1,850
1,100
2,850
14.3
30,000
5,650
3,550
4,000
2,250
3,250
2,000
2,250
1,350
3,550
11.8
40,000
6,250
3,950
4,450
2,600
3,700
2,300
2,550
1,550
4,150
10.4
50,000
6,800
4,350
4,850
2,850
4,100
2,550
2,850
1,700
4,650
9.3
100,000
8,900
5,800
6,450
4,000
5,750
3,750
3,800
2,450
6,600
6.6
150,000
10,550
6,900
7,750
4,950
7,050
4,750
4,500
3,050
8,000
5.3
200,000
12,000
7,800
8,850
5,750
8,200
5,700
5,000
3,600
9,200
4.6
300,000
14,450
9,300
10,800
7,150
10,250
7,350
5,750
4,550
11,050
3.7
500,000
18,500
11,750
14,000
9,600
13,650
10,400
6,850
6,100
13,850
2.8
1,000,000
26,500
16,250
20,450
14,500
20,550
17,050
8,400
9,350
18,450
1.8
2,000,000
38,950
22,650
30,750
22,500
31,700
29,000
10,050
14,600
24,100
1.2
5,000,000
67,500
35,850
54,950
41,650
58,100
61,750
12,250
27,000
33,400
0.7
10,000,000
105,600
51,400
88,100
68,250
94,300
113,750
13,750
44,050
41,750
0.4

(a) As only a sub-sample of respondents were sequenced through the 1995 alcohol topic, the non-General Health and Wellbeing weight is used when calculating the estimates. These standard errors should be used for the alcohol topic.

STANDARD ERRORS FOR PERSON ESTIMATES, NATIONAL HEALTH SURVEY 1989-90

STANDARD ERROR
AUSTRALIA
NSW
Vic
Qld
SA
WA
Tas
NT
ACT
Standard error
Relative Standard Error
Size of estimate
no.
no.
no.
no.
no.
no.
no.
no.
no.
%

400
. .
. .
. .
. .
. .
210
. .
. .
. .
. .
500
. .
. .
. .
. .
. .
230
. .
. .
. .
. .
600
. .
. .
. .
. .
. .
260
. .
. .
. .
. .
700
. .
. .
. .
. .
. .
280
. .
360
. .
. .
800
. .
. .
. .
. .
. .
290
. .
390
. .
. .
900
. .
. .
. .
. .
. .
310
450
410
. .
. .
1000
. .
. .
. .
510
. .
330
480
430
. .
. .
1100
. .
. .
. .
530
. .
340
500
450
. .
. .
1200
. .
610
. .
550
620
360
520
460
610
50.9
1300
. .
630
. .
570
650
370
540
480
640
49.0
1400
. .
660
. .
590
670
380
550
490
660
47.4
1500
. .
680
760
610
690
390
570
510
690
45.9
1600
810
700
790
630
710
410
590
520
710
44.6
1700
840
720
810
650
740
420
610
540
740
43.4
1800
860
740
830
670
750
430
620
550
760
42.2
1900
880
760
850
690
770
440
640
560
780
41.2
2000
910
780
870
700
790
450
650
580
800
40.2
2100
930
800
900
720
810
460
670
590
830
39.3
2200
950
820
920
730
830
470
680
600
850
38.4
2300
970
840
940
750
850
480
690
610
870
37.7
2400
990
860
950
760
860
480
710
620
890
36.9
2500
1,000
870
970
780
880
490
720
640
910
36.2
3000
1,100
950
1,050
850
950
530
780
690
1,000
33.2
3500
1,200
1,050
1,150
910
1,000
570
840
730
1,100
30.8
4000
1,250
1,100
1,200
970
1,100
600
890
770
1,150
28.9
4500
1,350
1,150
1,300
1,000
1,150
630
940
810
1,250
27.3
5000
1,400
1,200
1,350
1,050
1,200
650
990
850
1,300
25.9
6000
1,500
1,300
1,450
1,150
1,300
700
1,100
920
1,400
23.7
8000
1,750
1,500
1,650
1,300
1,450
780
1,250
1,050
1,650
20.5
10000
1,900
1,650
1,850
1,450
1,600
850
1,350
1,150
1,850
18.4
20000
2,600
2,300
2,500
1,950
2,200
1,100
1,900
1,500
2,550
12.8
30000
3,100
2,700
2,950
2,300
2,600
1,250
2,250
1,750
3,100
10.4
40000
3,500
3,050
3,350
2,550
2,900
1,350
2,600
1,950
3,550
8.9
50000
3,850
3,350
3,700
2,800
3,150
1,450
2,900
2,100
3,950
7.9
100000
5,100
4,500
4,850
3,650
4,150
1,750
4,000
2,700
5,400
5.4
200000
6,700
5,900
6,400
4,750
5,400
2,050
5,600
3,450
7,200
3.6
300000
7,900
6,800
7,500
5,500
6,300
2,250
. .
3,950
8,500
2.8
400000
8,800
7,600
8,300
6,100
7,000
2,350
. .
. .
9,600
2.4
500000
9,500
8,300
9,000
6,600
7,600
. .
. .
. .
10,500
2.1
1000000
12,200
10,600
11,600
8,300
9,700
. .
. .
. .
13,700
1.4
2000000
15,500
13,300
14,700
10,400
12,300
. .
. .
. .
17,700
0.9
5000000
20,900
17,900
19,800
. .
. .
. .
. .
. .
24,500
0.5
10000000
25,900
22,000
. .
. .
. .
. .
. .
. .
30,800
0.3
20000000
. .
. .
. .
. .
. .
. .
. .
. .
38,300
0.2

. . not applicable