Addition of GP registered postcodes will create new SLS research opportunities
Susan Carsley, SLS-DSU
The Scottish Longitudinal Study (SLS) has recently received approval to include all SLS members’ GP registered postcodes since 2001 in the SLS database. The inclusion of this data will enable researchers to more accurately link to other environmental and geographical data in the intercensal period.
At present the SLS holds Census postcode data (current address and address one year ago, workplace/place of study), for all SLS members, also available are postcodes from registration data (births, deaths and marriages) and a postcode from the School Census data (where applicable). Although researchers do not have direct access to postcode data, they are essential in being able to identify different ecological factors associated with SLS members. Using postcode (thus grid references derived from them) researchers are able to link to any higher level geographies via lookup tables or to geographical and environmental indicators using GIS operations.
The main benefit of having this more frequent data will be the ability to start identifying any changes of address between censuses. This will be particularly useful for studies of mobility – for example how this interacts with labour market involvement. The data will also be very useful in studies of environmental exposure e.g. to pollution and having more frequent and accurate postcode data will become increasingly beneficial as we continue to add in more datasets to the SLS which provide annual data.
The addition of this data to the SLS will not only open doors to many new projects, it will also be beneficial to some projects currently being investigated. For example:
In this project postcodes of residence (mother’s address from birth registration) and workplace (from census) are used for linking to SIMD (datazone) and air pollution data (1km square). This allowed the researchers to explore whether levels of air pollution at residence and workplace are associated with low birth weight. More frequent postcode data could help improve the study by identifying whether a member moved to an area with different level of pollution. Thus helping more accurately identify how long a member stayed in a highly polluted area, as length of time exposure to pollution is highly relevant in study on its effect. Previously this project was only able to compare postcode from census and birth registration to see whether a member moved to an area with a different level of pollution and whether this has impact on low birth weight, this ignored the possibility of a member moving between the census time and vital registration. The addition of this more frequent data will reduce this problem.