12A. ADULTS WHO SMOKE INDICATOR – Upper Tier Local Authority
TABLE 1 – INDICATOR DESCRIPTION
| Information component | County Health Profiles: Pg 4 Health Summary – Indicator 12 |
| Subject category / domain(s) | The way we live |
| Indicator name (* Indicator title in health profile) | Prevalence of adult smoking (*Adults who smoke) |
| PHO with lead responsibility | SEPHO |
| Date of PHO dataset creation | 15/12/2006 |
| Indicator definition | Prevalence of smoking, percentage of resident population, adults, 2000-2002, persons |
| Geography | England, GOR, County. |
| Timeliness | Updated annually. |
| Rationale:What this indicator purports to measure | Estimate of smoking prevalence in adults |
| Rationale:Public Health Importance | Smoking is the most important cause of preventable ill health and premature mortality in the UK. It is linked to respiratory illness, cancer and coronary heart disease. Smoking not only affects the smoker; over 17,000 children under the age of five are admitted to hospital every year with illnesses resulting from passive smoking.A list of disease specific conditions attributable to smoking is published in The Smoking Epidemic in England, HDA, 2004 http://www.nice.org.uk/page.aspx?o=502811Smoking is a modifiable lifestyle risk factor; effective tobacco control measures can reduce the prevalence of smoking in the population. |
| Rationale: Purpose behind the inclusion of the indicator | To help reduce the prevalence of smoking.Smoking prevalence is a direct measure of health care need i.e. the ability to benefit from tobacco control interventions, including smoking cessation services. |
| Rationale:Policy relevance | Choosing Health: Making healthy choices easier.http://www.dh.gov.uk/en/Publicationsandstatistics/ Publications/PublicationsPolicyAndGuidance/DH_4094550Smoking Kills. A White Paper on Tobaccohttp://www.dh.gov.uk/en/Publicationsandstatistics/ Publications/PublicationsPolicyAndGuidance/DH_4006684. Tackling Health Inequalities: A Programme for Actionhttp://www.dh.gov.uk/en/Publicationsandstatistics/ Publications/PublicationsPolicyAndGuidance/DH_4008268 |
| Interpretation: What a high / low level of indicator value means | A high indicator value (red circle in health summary chart) represents a statistically significant higher level of adult smoking prevalence for that local authority when compared to the England average value.A low indicator value (amber circle in health summary chart) represents a statistically significant lower level of adult smoking prevalence for that local authority when compared to the England average value. However smoking at any prevalence level greater than 0 is undesirable, and therefore a low indicator value should not mean that PH action is not needed. |
| Interpretation: Potential for error due to type of measurement method | Each participant in the Health Survey for England was asked if they currently smoked cigarettes. Self-reported smoking status may be prone to respondent bias.There may also be a discrepancy between these estimates and the lower tier synthetic estimates (districts) which are based on modelled data. This has lead to inconsistencies between lower tier and county estimates for some areas as the datasets are derived using different methods. |
| Interpretation: Potential for error due to bias and confounding | The Health Survey for England under-samples younger people, people in employment, ethnic minorities, women, those who are healthier but exhibit less healthy behaviour.These data have not been age-standardised and, therefore, variation between area values may be a result of differences in population structure. |
| Confidence Intervals: Definition and purpose | A confidence interval is a range of values that is normally used to describe the uncertainty around a point estimate of a quantity, for example, a mortality rate. This uncertainty arises as factors influencing the indicator are subject to chance occurrences that are inherent in the world around us. These occurrences result in random fluctuations in the indicator value between different areas and time periods. In the case of indicators based on a sample of the population, uncertainty also arises from random differences between the sample and the population itself.The stated value should therefore be considered as only an estimate of the true or ‘underlying’ value. Confidence intervals quantify the uncertainty in this estimate and, generally speaking, describe how much different the point estimate could have been if the underlying conditions stayed the same, but chance had led to a different set of data. The wider is the confidence interval the greater is the uncertainty in the estimate.Confidence intervals are given with a stated probability level. In Health Profiles 2007 this is 95%, and so we say that there is a 95% probability that the interval covers the true value. The use of 95% is arbitrary but is conventional practice in medicine and public health. The confidence intervals have also been used to make comparisons against the national value. For this purpose the national value has been treated as an exact reference value rather than as an estimate and, under these conditions, the interval can be used to test whether the value is statistically significantly different to the national. If the interval includes the national value, the difference is not statistically significant and the value is shown on the health summary chart with a white symbol. If the interval does not include the national value, the difference is statistically significant and the value is shown on the health summary chart with a red or amber symbol depending on whether it is worse or better than the national value respectively. |
TABLE 2 – INDICATOR SPECIFICATION
| Indicator definition: Variable | Prevalence of smoking.Smoking is defined as self-reported current cigarette smoking. |
| Indicator definition: Statistic | Percentage of resident adult population aged 16 and over |
| Indicator definition: Gender | Persons |
| Indicator definition: age group | Adults (aged 16 and over) |
| Indicator definition: period | 2000-2002 |
| Indicator definition: scale | |
| Geography: geographies available for this indicator from other providers | Strategic Health Authority.http://www.dh.gov.uk/en/Publicationsandstatistics/ PublishedSurvey/HealthSurveyForEngland/index.htm |
| Dimensions of inequality: subgroup analyses of this dataset available from other providers | Age, gender, ethnicity, social classhttp://www.dh.gov.uk/en/Publicationsandstatistics/ PublishedSurvey/HealthSurveyForEngland/index.htm |
| Data extraction: Source | Health Surveys for England, National Centre for Social Research (NatCen). |
| Data extraction: source URL | Data received directly from NatCen. |
| Data extraction: date | February 2006 |
| Numerator: definition | The number of persons aged 16+ who are self-reported smokers in a sample survey of the health of the population of England. |
| Numerator: source | Health Survey for England (HSE), commissioned by the Department of Health and carried out by the Joint Health Survey Unit of Social and Community Planning Research and of the Department of Epidemiology and Public Health at University College, London. |
| Denominator: definition | Total number of respondents (with valid recorded smoking status) aged 16+ in the Health Survey for England 2000-2002. |
| Denominator: source | Health Survey for England (HSE), commissioned by the Department of Health and carried out by the Joint Health Survey Unit of Social and Community Planning Research and of the Department of Epidemiology and Public Health at University College, London. |
| Data quality: Accuracy and completeness | The Health Survey for England was designed to provide data at both national and regional level about the population living in private households in England. It uses a clustered, stratified multi-stage sample design. Each year, 720 postcode sectors were selected as the primary sampling units (PSUs). Before selection, postcode sectors are stratified in order to maximise the precision of the sample. Two stratification levels are used in the selection of PSUs. Postcode sectors are first sorted by Local/Unitary Authority, ensuring correct regional balance. Within each Local Authority, sectors are listed in order of the percentage of households with a head of household in a non-manual occupation. Those living in institutions were not covered. One of the effects of using this complex design is that standard errors for survey estimates are generally higher than the standard errors.The numerator and denominator counts used to estimate prevalence are based on a sample of the population in each area and, as such, are not true counts. For this reason the numerator and denominator data are not shown in the data sheet. |
TABLE 3 – INDICATOR TECHNICAL METHODS
| Numerator: extraction | Not Applicable |
| Numerator: aggregation /allocation | Residency by local authority of each respondent is allocated by postcode of residency. |
| Numerator data caveats | Questions about current cigarette smoking were asked by the interviewer. For those aged 16 and 17, the questions were asked through a self-completion questionnaire to allow for greater privacy.These data have not been age-standardised and, therefore, variation between area values may be a result of differences in population structure. |
| Denominator data caveats | The HSE is a series of annual surveys that began in 1991 with the aim of monitoring the health of the population. It was designed to be representative of the general, non-institutional population living in England. The current “full” sample size of the HSE comprises about 16,000 adults aged 16 and over. For each participant, the survey included an interview and a physical examination by a nurse, at which various physical measurements, tests, and samples of blood and saliva were collected. These measurements provided biomedical information about known risk factors associated with disease and objective validation for self-reported health behaviour. |
| Methods used to calculate indicator value | Estimates are based on pooling together three consecutive years of Health Survey for England data (2000-2002). The general population sample size in 2000 and 2002 was about half the sample size in 2001 owing to the sampling of specific population groups – namely, elderly living in institutions (2000) and children and young adults (2002). To ensure that each year’s sample was given an approximately equal weight in the calculation of the 2000-2002 estimates, respondents in 2000 and 2002 were weighted up by two. |
| Small Populations: How Isles of Scilly and City of London populations have been dealt with | Isles of Scilly are excluded from the dataset; City of London is included in the dataset. |
| Disclosure Control | Not applicable. |
| Confidence Intervals calculation method | The standard errors, and 95% confidence intervals, have been calculated using STATA’s survey module (the svy:mean commands), further details can be obtained from Shaun Scholes at NatCen (s.scholes@natcen.ac.uk).One of the effects of using a complex design is that standard errors for survey estimates are generally higher than the standard errors that would be derived from a simple random sample of the same size. |
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