24. FEELING IN POOR HEALTH INDICATOR

TABLE 1 – INDICATOR DESCRIPTION

Information component	Pg 4 Health Summary – Indicator No 24
Subject category / domain(s)	Health and ill health in our community
Indicator name (* Indicator title in health profile)	Self Assessed general Health: ‘Not Good’ (*Feeling in poor health)
PHO with lead responsibility	NWPHO
Date of PHO dataset creation	Dec. ‘06
Indicator definition	Self Assessed General Health: ‘Not Good’, directly age standardized percentage, All Ages, 2001, persons
Geography	England, GOR, Local Authority: Counties, County Districts, Metropolitan County Districts, Unitary Authorities, London Boroughs
Timeliness	Every 10 years, next update available in 2012.  Time trend analysis is appropriate.
Rationale:What this indicator purports to measure	Perception of General Health.
Rationale:Public Health Importance	The indicator was chosen as the best available measure of self assessed population health.  Self reported single item of health has a good correlation with mortality and health care utilisation.For further information see: Where Wealth means Health (www.nwpho.org.uk/inequlaities)
Rationale: Purpose behind the inclusion of the indicator	To help monitor likely health care burden.
Rationale:Policy relevance	No direct policy driver.
Interpretation: What a high / low level of indicator value means	A high indicator value (red blob in spine chart) represents a statistically significant higher level of estimated self assessed “not good” health for that local authority when compared to the national value.A low indicator value (yellow blob) represents a statistically significant lower level of estimated self assessed “not good” health for that local authority when compared to the national value.
Interpretation: Potential for error due to type of measurement method	Self reported health status can be subject to variation according to non causative effects (e.g. good weather).
Interpretation: Potential for error due to bias and confounding	The following groups may be under-sampled within the census: · Areas with high non-white population · Full-time students aged 18-74 (out of term time residents) · Prisoners · Men aged 20-39 · Residential homes, nursing homes, hospitals · Rough sleepers · Areas with high population density · Areas with high numbers of multi-occupancy households · Migrants: someone who spends 3 to 12 months in the country for certain purposes (excluding tourism), ?asylum seekers, ?migrant / seasonal workers, This can result in an underestimate or overestimate of self assessed ill-health in some areas.
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	Self Assessed General Health: ‘Not Good’
Indicator definition: Statistic	Directly age-standardised percentage
Indicator definition: Gender	Persons
Indicator definition: age group	All Ages
Indicator definition: period	2001
Indicator definition: scale	Per 100 European Standard population
Geography: geographies available for this indicator from other providers	Unique dataset not available elsewhere.
Dimensions of inequality: subgroup analyses of this dataset available from other providers	None.
Data extraction: Source	Source of data: Office for National Statistics
Data extraction: source URL	http://www.statistics.gov.uk/
Data extraction: date	Data extracted from source as at: Dec. ‘05
Numerator: definition	All people usually resident in the area at the time of the 2001 Census, who described their general health in the 12 months before Census day as ‘Not good’.
Numerator: source	Office for National Statistics (ONS).
Denominator: definition	All people counted as usually resident in the area at the time of the 2001 Census by 5 year age band.A usual resident was generally defined as someone who spent most of their time at a specific address. It included: people who usually lived at that address but were temporarily away (on holiday, visiting friends or relatives, or temporarily in a hospital or similar establishment); people who worked away from home for part of the time; students, if it was their term-time address; a baby born before 30 April 2001 even if it was still in hospital; and people present on Census Day, even if temporarily, who had no other usual address. However, it did not include anyone present on Census Day who had another usual address or anyone who had been living or intended to live in a special establishment, such as a residential home, nursing home or hospital, for six months or more.
Denominator: source	Office for National Statistics (ONS).
Data quality: Accuracy and completeness	The Census was followed by the Census Coverage Survey (CCS), an independent doorstep survey of a sample of a third of a million households, covering every local authority, which was used to adjust the Census counts for under-enumeration.Under-enumeration in the 2001 Census did not occur uniformly across all areas. Response rates were lowest for inner city areas where characteristics known to be related to non-response such as multi-occupancy and higher proportions of non-English speaking population, are most prevalent.This census data has been subject to edit and imputation procedures to correct for incorrect or missing data. There has been an extensive quality assurance process, including checks against administrative records and sources of information on particular groups such as students and the armed forces.

TABLE 3 – INDICATOR TECHNICAL METHODS

Numerator: extraction	Downloaded from ONS website.
Numerator: aggregation /allocation	Not applicable.
Numerator data caveats	Not applicable
Denominator data caveats	Not applicable
Methods used to calculate indicator value	Directly age standardised percentageMethod available from NWPHOwww.nwpho.org.uk
Small Populations: How Isles of Scilly and City of London populations have been dealt with	Isles of Scilly and City of London were excluded.
Disclosure Control	Not applicable
Confidence Intervals calculation method	95% Confidence intervals were calculated using a Normal approximation, modified to use the binomial variance for a proportion to estimate the variances of the crude age-specific rates Further details available from NWPHOwww.nwpho.org.uk

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