Follow-up is conducted chiefly through linkages to routinely available national datasets. Data are already available on over 8,500 deaths, over 75,000 prevalent and incident cancers, and over 600,000 hospital admissions, while linkages are planned to a range of other datasets, including primary care, cancer screening data, and disease-specific registers. In addition, to reduce misclassification and increase biological specificity of health outcomes, UK Biobank is developing methods for accurate identification and detailed phenotyping of outcomes in a range of disease areas. Initial ascertainment of outcomes with electronic and semi-automated sources will be supplemented by more intensive methods (e.g., retrieval of case records, imaging data, or banked tissue samples) for validation and subclassification (Table 3).
