How is the study managed?
To improve the accuracy and completeness of the data collected at the baseline survey (as well as at subsequent resurveys), and to facilitate quality control, monitoring, long-term follow-up and general management of the project, a range of computer systems have been developed. These include not only a computerised direct data-entry system for the baseline survey but also systems for blood sample aliquoting, tracking and storage. In addition, comprehensive systems are in place for reporting of quality control and monitoring; remote database management; consent form tracking and data entry; stock control and equipment calibration; and linkage for long-term follow-up of mortality and major morbidity.
How are the datasets managed?
All baseline data are now held securely at the study coordinating centres in Beijing and in Oxford. At present, there are seven broad categories of data relating to the main study: (i) questionnaire and physical measurements; (ii) blood handling, shipment and storage; (iii) personal identifiers and contact details; (iv) core operational data; (v) cause-specific mortality and morbidity information; (vi) biological assay data; and (vii) research management. This data system will be extended to incorporate new requirements as the study progresses.
Based on the main final database, subset databases for various analytical purposes will subsequently be generated for internal and external use. All of these subset databases will remain anonymised and will be stored and handled securely in accordance with relevant regulations and guidelines. Thorough documentation of the databases will allow potential collaborators to analyse the data with full knowledge of the source and definition of each variable.