Community Health Profiles

11. TEENAGE PREGNANCY INDICATOR

TABLE 1 – INDICATOR DESCRIPTION

Information component	Pg 4 Health Summary – Indicator No 11
Subject category / domain(s)	Giving children and young people a healthy start
*Indicator name ( Indicator title in health profile)**	Teenage conceptions (“Teenage pregnancy (under 18)” )
PHO with lead responsibility	EMPHO
Date of PHO dataset creation	August 2006
Indicator definition	Under-18 conception rate per 1,000 females (crude rate) 2002-2004.
Geography	England, GOR, Local Authority: Counties, County Districts, Metropolitan County Districts, Unitary Authorities, London Boroughs
Timeliness	Data published 14 months after period end, updated annually. (Raw data is available up to 11 months after the event)
Rationale:What this indicator purports to measure	This indicator measures the level of teenage conceptions in the area.
Rationale:Public Health Importance	Teenage pregnancy is a significant public health issue in England. Teenage parents are prone to poor antenatal health, lower birth weight babies and higher infant mortality rates. Teenage mothers are less likely to finish their education, less likely to find a good job, and more likely to end up as single parents or bringing up their children in poverty. Children born to teenage mothers run a much greater risk of poor health and have a much higher chance of becoming teenage mothers themselves. However, it is worth remembering that many young people are successful in adapting to the role of parenthood and have happy, healthy children.For further information see “Teenage Pregnancy: Accelerating the Strategy to 2010” (http://www.everychildmatters.gov.uk/_files/ 94C1FA2E9D4C9717E5D0AF1413A329A4.pdf) and Health Statistics Quarterly No. 33 (page 34) (http://www.statistics.gov.uk/downloads/theme_health/hsq33web.pdf)
Rationale: Purpose behind the inclusion of the indicator	The purpose of including this indicator is to highlight local authorities with high teenage pregnancy rates in order to assess need and enable targeted intervention. In order to assist local areas in reducing under-18 conception rates the following toolkit was produced by DfES. It provides local areas with detailed guidance on the key ingredients that need to be in place locally to reduce under-18 conception rates. www.everychildmatters.gov.uk/resources-and-practice/IG00198/
Rationale:Policy relevance	Teenage conceptions are an important public health target. There is a national PSA target to reduce teenage conception rates by 50% by 2010 with an intermediate target for a 15% reduction by 2004 (1998 baseline). Teenage conception targets feature in the performance ratings for PCTs and in the Priorities and Planning Framework 2003-2006 (seehttp://www.dh.gov.uk/en/Publicationsandstatistics/ Publications/PublicationsPolicyAndGuidance/DH_4008430). This indicator supports Choosing Health and Programme for Action.
Interpretation: What a high / low level of indicator value means	A high indicator value (red blob) represents a statistically significant higher rate of teenage conceptions for that local authority when compared to the national average.A low indicator value (yellow blob) represents a statistically significant lower rate of teenage conceptions for that local authority when compared to the national average.Rates that are lower than the England average may still represent a large number of teenage pregnancies and therefore a low indicator value should not be interpreted as meaning that public health action is not needed.
Interpretation: Potential for error due to type of measurement method	Miscarriages and illegal abortions are not included in the conception rates, resulting in rates that may be an under estimation. Data relating to legal abortions and births is collated through mandatory reporting processes and is of sound data quality. Whilst it is acknowledged that the non-inclusion of miscarriages reflects conceptions that are not included in these figures, comparable data in this area is not available. Conception cannot be inferred from the prescription of emergency contraception, and early loss of pregnancy may not be recognised or require medical attention. The omission of this data retains the quality of the indicator rather than limiting it.
Interpretation: Potential for error due to bias and confounding	Teenage pregnancy is often a cause and a consequence of social exclusion. The risk of teenage parenthood is greatest for young people who have grown up in poverty and disadvantage or those with poor educational attainment.
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	Estimates of conceptions (excluding pregnancies leading to spontaneous abortion before 24 weeks gestation), based on pregnancies which lead to a delivery at which one or more live or still births occurs and is registered in England and Wales, or termination of pregnancy by abortion under the 1967 Act in England and Wales.
Indicator definition: Statistic	Crude rate
Indicator definition: Gender	Females
Indicator definition: age group	Under 18
Indicator definition: period	2002-2004 pooled data
Indicator definition: scale	Per 1,000 population
Geography: geographies available for this indicator from other providers	ONS publish figures for England and Wales, England ONS area, SHA and PCO. Available to download fromhttp://www.everychildmatters.gov.uk/resources/IG00200/
Dimensions of inequality: subgroup analyses of this dataset available from other providers	Data is available broken down into under 16 years and under 18 years.Indicator cannot be broken down by ethnicity or socio-economic group.
Data extraction: Source	Produced by the Office for National Statistics and disseminated via the Teenage Pregnancy Unit in the Department for Education and Skills
Data extraction: source URL	Data received directly from Teenage Pregnancy Unit
Data extraction: date	Data received in August 2006
Numerator: definition	The number of conceptions estimated to have occurred to females aged under-18 during 2002-2004.Actual dates of conception are not directly available but have been estimated from a dataset of birth registrations and legal terminations of pregnancy recorded in the respective calendar years plus the following year (ie 2002-2005) as follows: a) For maternities resulting in one or more live births, the date of conception is assumed to be 38 weeks prior to the date of birth (no gestation is recorded at live birth registration); b) For maternities resulting in stillbirths, the date of conception is assumed to be the recorded gestation minus 2 weeks prior to the date of the stillbirth (recorded gestation is time since last menstrual period; conception is assumed to occur 2 weeks after);c) For abortions under the 1967 Act, the date of conception is assumed to be the recorded gestation minus 2 weeks prior to the date of the abortion (recorded gestation is time since last menstrual period; conception is assumed to occur 2 weeks after).The mother’s age at conception is then derived from the mother’s date of birth and the estimated date of conception.
Numerator: source	Produced by the Office for National Statistics and disseminated via the Teenage Pregnancy Unit in the Department for Education and Skills
Denominator: definition	Number of females aged 15-17.
Denominator: source	The resident population figures used are ONS revised mid year estimates 2002-2004, as derived from the 2001 census with allowance for subsequent births deaths, migration and ageing of the population.
Data quality: Accuracy and completeness	Data relating to legal abortions and births is collated through mandatory reporting processes and is of sound data quality.

TEENAGE PREGNANCY INDICATOR

Numerator: extraction	Received directly from the Teenage Pregnancy Unit
Numerator: aggregation /allocation	Not Applicable
Numerator data caveats	The conception figures exclude any pregnancies leading to spontaneous abortion before 24 weeks gestation and illegal abortions.
Denominator data caveats	In under-18s, a three year age group only (15-17) is used as the denominator, because the vast majority of conceptions to under-18 year olds occur in this age group (95%). To include younger populations would produce misleading results. The 15-17 group is effectively treated as the ”population at risk”. As the age at which conception can take place varies from child to child it is impossible to correctly define the population at risk (i.e. data identifying the female population aged 0-17 who are fertile is not available).
Methods used to calculate indicator value	The teenage conceptions indicator is presented as a crude rate. A crude rate is defined as the number of observed events divided by the population-years at risk. For presentation purposes rates are usually multiplied by a scaling factor, in this case 1,000. A rate, r, expressed per 1,000 population is given by: where:O is the number of observed events (i.e. estimated number of under-18 conceptions, 2002-2004);n is the population-years at risk (i.e. the sum of the mid-year female 15-17 years population estimate for each of the years in the period 20 02-2004).
Small Populations: How Isles of Scilly and City of London populations have been dealt with	Conception data supplied by the ONS does not include data for City of London and Isles of Scilly Local Authorities owing to the small number of events in these small populations. Instead conception figures are combined with those of Hackney LB and Penwith CD respectively.
Disclosure Control	Teenage conceptions data is subject to disclosure control and any LA with a conception count of fewer than five individuals needs to be suppressed. Because of the size of LA populations however it is only the City of London and Isles of Scilly Local Authorities due to their small population, which are affected. Their conception figures are combined with those of Hackney LB and Penwith CD respectively.
Confidence Intervals calculation method	The 95% confidence intervals for the crude rate per 1,000 was calculated using the likelihood-based method described by Aitken et al, which is a good approximation of the exact method.¹The lower and upper limits for a rate expressed per 1,000 are given by: Where and O is the number of observed events (i.e. estimated number of under-18 conceptions, 2002-2004);n is the population-years at risk (i.e. the sum of the mid-year female 15-17 years population estimate for each of the years in the period 20 02-2004). [1] Aitken M et al. Statistical Modelling in GLIM. Oxford: Oxford University Press, 1990.

Posted in: Indicators