Learning objectives: You will learn about health activity data, including primary/secondary care interactions, QMAS, General Practice Research Database, and Hospital Episode Statistics.
Please now read the resource text below.
Primary care interactions
In the UK, 90% of reported ill health is captured at GP practice level, and so primary care data is very important, especially when the iceberg effect is considered (see figure 1). There is the potential to offer a huge amount of information on health of population, but it has been historically very difficult to access. Most GP Practices are now computerised, and in some areas may allow public health staff direct access to the data. Changes in the NHS have resulted in improved primary care data collection.
In operation since 2004, the Quality Management and Analysis System (QMAS) supports a new GP contract which depends partly on quality of care as well as numbers of patients registered. Almost all practices are submitting data. Its primary function is financial, and awards payment under the Quality and Outcomes Framework (QOF). The database is replicated for other purposes, including public health. The replica is managed by the prescribing support unit, based at the information centre for health and social care.
Data are collected on a number of clinical domains, which vary over time. They currently include:
- mental health
QoF data enable local prevalence to be estimated for the conditions they cover. These data may be compared with other prevalence studies such as the Health Survey for England, as exemplified in the LHO report.
The new GP contract gives an incentive to GPs to improve completeness of data. It encourages the establishment of disease registers. There are incentives to identify more registered patients needing to be on disease registers and receive treatment.
Raw data are not available to PCT or public health departments. Instead, some ready analysed data are available. These are limited: there is no age/sex/ethnicity breakdown, comparable analyses may be inappropriate, there is no information on co-morbidity, and there is significant under-recording of some indicators.
General Practice Research Database (GPRD)
This is a proprietary product, only accessible to public health departments on a fee-paying basis. It is a longitudinal anonymised database, and claims to be the largest source of computerised information on morbidity and prescription activity in GP practices, holding data from 1987 to present. Participating practices agree guidelines on recording clinical data.
- quality continually assessed.
- available for research questions.
- standards for recording allow collation
- incomplete - only a small proportion of self selecting practices across the country (450 or so)
Secondary care interactions
In the NHS, data on patients' interactions with the secondary (i.e. hospital) care services are recorded on statutorily defined datasets. These are recorded by providers and exchanged with commissioners of care via electronic clearing houses. The data collected vary according to the type of interaction - outpatient attendance, admitted care, waiting for elective admission, A&E. In each case the data to be collected are set out in the NHS Data Dictionary.
The mechanism of exchange has varied from time to time, the former NHS Wide Clearing Service (NWCS) being replaced by the Secondary Uses Service (SUS), though at present the data flows remain similar.
Primary Care Trusts receive data on a monthly basis. Mostly this is a measure of activity, but data on admitted patients also include clinically coded diagnoses, operative procedures, and ethnicity, enabling the determination of met need and assisting in the analysis of health need and inequalities.
NWCS/SUS data can help to identify health needs of the local population. It can be used to determine patient flows for treatment and contribute to the analysis of health outcomes.
The most direct use of NWCS data is for monitoring contracts between primary care trusts and hospital providers. Under Payment by Results, hospitals are paid for the activity they undertake. Payment by Results is underpinned by Healthcare Resource Group (HRG) codes. HRGs are groupings of conditions and procedures that are clinically and resource-intensively similar. A national tariff is applied to each HRG code and updated each year.
NWCS/SUS data is cleaned and collated on a national basis to create HES data.
- Timely data: components of NWCS data are made available to PCTs by hospital trusts on a monthly basis. The system by which it is delivered allows questioning and challenging of the data before a certain date each month.
- clinical coding may be of variable quality. Recording of ethnicity is sometimes a problem.
- outpatient datasets do not contain diagnostic information.
- exchange of A&E data, although mandatory, often does not happen, as the define dataset is not considered particularly useful, so only a partial picture of A&E activity is available.
Hospital Episode Statistics (HES)
HES is a nation-wide dataset of all hospital admissions, recorded using computerised Patient Administration Systems. Each record is a subset of the record submitted by the provider to NWCS/SUS, and so defined in the NHS Data Dictionary. It is generally issued on an annual basis, though provisional data is now issued quarterly. Each record represents a period under the responsibility of a specific consultant, dubbed a 'finished consultant episode'. A patient could have several episodes within one spell in hospital. There are hundreds of fields, including data on maternities and augmented care for patients whose care involves the use of Intensive and High Dependency care facilities. Data include:
- NHS Number
- full postcode
- date of birth
- ethnicity (more complete with each year)
- diagnosis fields
- procedures fields
- registered GP
- PCT of residence
- date of admission
- date of discharge
- method of admission
- method of discharge
Public Health Observatories are considered 'HES safe havens' and get access to sensitive fields on a national basis. Strict protocols are in place for how data can be disseminated, including clear suppression rules to prevent disclosure. Various pre-analysed reports are available free online.
Dr Foster Intelligence has access to NWCS and HES data and provides data via web-based tools on hospital and PCT activity.
- at a national level, health service planning, monitoring activity, and assessing quality of care.
- at a local level (e.g. PCT), NCWS/SUS data are more timely, and HES are mostly used to enable national comparisons and benchmarking.
- comparisons can be made between areas, for example, by calculating standardised rates.
- monitoring inequalities across geographical areas, including ward level.
Examples of outputs can be found at the London Health Observatory.
- completeness of data increasing.
- standard codes (ICD10 and OPCS4) used for diagnoses and procedures.
- for serious morbidity, they can give prevalence of the condition across the country.
- recently becoming linked with ONS mortality data
HES and NWCS/SUS data only tell us about those who have a disease and then use health care facilities. They do not give full picture of morbidity. Specifically they do not tell us about those people who have a disease or disability but do not seek care - see iceberg effect and figure 1. Some fields are very incomplete - for example, whilst completeness of the ethnicity field has been increasing with each year, a significant proportion (10 - 15%) is filled with 'not stated'.
Outpatient data became available via HES in 2007 but comes with limitations. Diagnostic data are not completed. Other limitations can be found at the HES Online Questions about outpatient data. Timeliness - there used to be quite a delay between NWCS outputs and HES. This has improved because provisional data are made available on a quarterly basis, before ministerial sign-off.
Other examples of routine morbidity data
- notifications of communicable diseases
- notifications of foetal anomalies
- abortion statistics
- Korner data, or Central Returns, are available at aggregated level only and are the NHS's only source of community data. Significant datasets for Public health are:
- KC60 - GUM clinic activity
- KC50 - immunisation data
- KC53, 63 - adult screening, cervical and breast
- Mental health minimum dataset
The Mental Health Needs Index (MINI) provides an estimate of the need for inpatient mental health services for adults (ages 16-59) by ward and borough. It is calculated using a number of population variables likely to indicate need for access to services, such as deprivation, proportion of economically active adults unemployed, proportion of adults living in households not self contained, etc. The MINI provides both predicted admission rates and a ratio of need compared to the England average. The MINI was developed by the Centre for Public Mental Health which has produced an online tool for accessing information on a ward / borough level.
Ad hoc data
Local health surveys may be carried out by PCTs when national surveys do not give sufficient information at local level.
Communicable disease notifications in England and Wales
This is the responsibility of the attending doctor to notify the Proper Officer of the Local Authority. Food poisoning is a statutory notifiable disease. They tend to be reported to the Communicable Disease Surveillance Centre on a weekly basis.
About 1% of abortions are undertaken because of a risk that the child would be born handicapped. About 30% of abortions in England and Wales in 2007 were medical abortions. Abortion rates do not include women under the age of 15 in the denominator. The denominator is conventionally taken as women aged 15-44. Since 2002 self-reported ethnicity has been recorded.
The Total Fertility Rate in the UK was 1.90 children per woman in 2007. UK fertility has not been this high since 1980. In the UK the highest fertility is in the 30-34 age group. The General Fertility Rate is the total number of live births divided by the number of women aged 15-44. The Total Fertility Rate is the sum of age specific fertility rates. Fecundity is the ability to produce live offspring.
Child and infant death rates
Child mortality includes deaths up to five years after birth. Infant Mortality Rate is the number of infants deaths under one year divided by the total number of live births. Still births are intrauterine deaths occurring after 24 weeks gestation. Neonatal mortality only includes deaths in the first 28 days of life. In West and Central Africa more than 150 out of every 1000 children born will die before age five.
The Understanding Public Health Data pages at the Avon Public Health Network
Office of National Statistics
The UK Census
Two lectures on demography from the Global Supercourse resource at Pittsburgh University: