Official statistics are the data collected by government departments in the course of their work (i.e. routine statistics) or collected specifically for statistical purposes. 'Unofficial' statistics are from independent organisations. Official statistics are often used as a data source for secondary statistical analysis, employing a quantitative approach. They are also used in health needs assessments, health status or profiles and health impact assessments. Statisticians who work in Official Statistics not only compile statistics but they also work at how to measure concepts and conditions. An example is how the ethnicity question in the census was refined between 1991 and 2001. They also look at how to improve the data collection of statistics and provide an information service to assist policy makers in decision-making and running government services efficiently. An interesting titbit is that a study using official statistics on New Zealand house prices showed that what were, in estate agent speak, 'up and coming' areas ten years ago were still 'up and coming' now and that areas which were expensive ten years ago remained desirable areas. Check out the Royal Statistical Society's Official Statistics Section for latest news and forthcoming meetings.
1. They are of a large-scale nature, offering a basis for generalizing findings, claiming representativeness and for investigating relationships between social variables that cannot be identified at a local level.
2. They are useful for placing smaller-scale (perhaps qualitative) data in a broader context.
3. Often published in the form of a statistical series which enables a more analytical perspective.
4. It is an unobtrusive measure. An unobtrusive measure is any method of observation that directly removes the observer from the set of interactions or events being studied. It removes researcher bias to an extent and 'reactivity' of the respondents. They don't know that they are participating so their behaviour is not influenced by their knowledge that they are being investigated.
1. Ecological fallacy - i.e. the error of assuming that inferences about individuals can be made from findings relating to aggregate data.
2. Problem of reliability of reporting, especially within an area like health.
3. Missing data! (Quite often, topics are added or dropped in accordance to a political agenda)
4. Think CART! There can be problems with Completeness, Accuracy, Relevance or Representiveness and Timeliness.
There is a whole load of useful data for health information purposes. First stop is always your friendly health intelligence team at your PCT. Sources of data include:
Data from Office of National Statistics (ONS) - e.g. neighbourhood statistics, census, population projections
Statistics published by WHO
Hospital Episode Statistics, Healthcare Resource Groups (HRG) data (i.e. hosptial episodes categorised by diagnosis or treatment given) and other healthcare provision data.
Disease Registers
Data held by public health observatories - e.g. community health profiles
Data held by ONS (Office for National Statistics) - includes neighbourhood statistics, small output areas, standardised mortality ratios (SMRs) etc.
Index of Multiple Deprivation (IMD)
Data held by Department of Health - including QOF (i.e. Quality and Outcomes Framework statistics, which records GP data), health inequalities, mortality statistics and immunisation statistics
Data held by National Centre for Health Outcomes Development - includes Clinical and Health Outcomes Knolwledge Base (which replaced the Public Health Common Data Set or Compendium of Clinical and Health Indicators)
Data held by NHS Information Centre - includes information on smoking, contraceptive services, maternity services and screening services
Data held by Health Protection Agency
Data held by Care Quality Commission (including patient and staff surveys)
Data held by Health and Safety Executive (HSE)- i.e. information on work related morbidity and mortality.
Health Survey for England (OPCS)
Health economic data
General datasets have questions on health
Bowling, A. Research Methods in Health. (Open University Press, 2002).
Neuman, W.L. Social Research Methods: Qualitative and Quantitative Approaches. (Allyn & Bacon, 1997).
Check out examples at ONS website.