The feasibility of using ethnicity as a primary tool for antenatal selective screening for sickle cell disorders: pointers from the research evidence

The Department of Health has announced a linked antenatal and neonatal screening programme for haemoglobinopathies by 2004 in a comprehensive national plan for the National Health Service in Britain. In response the National Screening Committee has commenced development work on how such a programme can best be implemented, including investigation of the effectiveness of a question about ethnic origin as a basis for selection. In addition, two recent health technology assessment reports have assessed alternative options for antenatal and neonatal haemoglobinopathy screening programmes in the United Kingdom. Both reports and commentators have emphasised the importance of developing a standardised instrument for collecting ethnicity data and recommended early development of such work. An examination of the evidence base on the use of ethnicity as a primary screening tool reveals substantial variability in practice and in the quality of data collected, with risk group misclassification as high as 20% against a recommended target of under 5.5%. The literature on the conceptual basis and structure of ethnicity questions, method of assignment in data collection, and level of resolution on categorisation is reviewed to identify the most appropriate content and format of a screening question for the haemoglobinopathies. Question options are evaluated, including the use of an extended 2001 Census classification and a 'non-North European' identifier and a candidate question based on 'family origins' is offered for debate. Finally, issues relating to the testing of the efficiency of an ethnicity question and the operationalising of its use for antenatal sickle cell screening are discussed.