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Title: Evaluation of strategies to improve case ascertainment and data quality in the National Congenital Anomaly System
Author: Botting, Beverley Jayne
ISNI:       0000 0001 3471 6734
Awarding Body: University of London
Current Institution: University College London (University of London)
Date of Award: 2003
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The thesis reports an evaluation of the National Congenital Anomaly System (NCAS) at a time of growing demands to use surveillance data for information on the effect of interventions (such as prenatal screening), for environmental exposures, and to provide information relevant to service provision for children with disability. In addition, recent developments in electronic data linkage have broadened the potential information that can be obtained through NCAS. The thesis describes the original purpose of NCAS for rapid surveillance of localised and national increases in notifications of major external anomalies. Limitations of NCAS are described, together with steps taken to quantify and reduce these problems. The thesis identifies two major problems for NCAS: ascertainment and data quality. It reports a study to determine the extent of underascertainment for a range of conditions notified to NCAS. This was possible through comparisons with data held by local or condition-specific registers. The thesis then reports a study to evaluate the effect on ascertainment of receiving notifications from local congenital anomaly registers rather than from health authorities. Effects on both overall and condition-specific notification rates are analysed. The impact of a step change in ascertainment on local surveillance and on national statistics is discussed. Notification to NCAS through four local registers resulted in substantial and significant changes in case ascertainment, which suggests that collaboration between NCAS and local and condition-specific registers should be extended. Another study evaluated the benefits of linking individual NCAS records with birth registration records. The study demonstrated that over 95 per cent linkage was achievable. Information collected at birth registration was more complete than the same data items collected by NCAS. Therefore, those data items could be derived from linkage with birth records instead of by NCAS. Using characteristics derived from birth records (e.g. country of birth of mother and survival), new analyses were possible. The concluding chapter discusses the impact on NCAS of these findings in the context of changing research and service demands. It looks at the strengths of NCAS, identifies priority areas for development, and presents my vision on shaping NCAS for the future.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available